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Revalidatiewetenschappen en Kinesitherapie

Academiejaar 2015-2016

The effects of uniaxial and multiaxial balance training on the muscle activation in patients with

chronic ankle instability

Masterproef voorgelegd tot het behalen van de graad van

Master of Science in de Revalidatiewetenschappen en Kinesitherapie

De Paep Jan

Moens Stijn

Promotor: Prof. Dr. P. Roosen

Co-promotor: Dr. R. De Ridder

http://www.revaki.ugent.be/

Expression of gratitude

The authors would like to thank Prof Dr. P. Roosen (Promotor), Dr. R. De Ridder (Co-promotor) for

making this study possible. We also would like to express our gratitude to Buyse Francis and

Dedecker Nicolas who cooperated with us in order to accomplish the study setup and data collection.

Special thanks goes out to all the participants who donated their time and effort in the completion of

this study.

Table of Contents 1. Abstract (Dutch) .............................................................................................................................. 5

1. Abstract (English) ............................................................................................................................. 6

2. Introduction ..................................................................................................................................... 7

3. Methods .......................................................................................................................................... 8

3.1 Study design ..................................................................................................................................................... 8

3.2 Participants ...................................................................................................................................................... 8

3.3. Procedure and equipment ......................................................................................................................... 9

3.4. EMG...................................................................................................................................................................... 9

3.5. Questionnaires .............................................................................................................................................. 12

3.6. Intervention ................................................................................................................................................... 13

3.7. Data analysis .................................................................................................................................................. 15

3.7.1 MVC .......................................................................................................................................................... 15

3.7.2 Muscle reaction time......................................................................................................................... 16

3.7.3 Functional jumps ................................................................................................................................ 16

3.8 Statistical analysis ....................................................................................................................................... 16

4. Results ........................................................................................................................................... 17

4.1 Baseline ............................................................................................................................................................ 17

4.2 Intervention .............................................................................................................................................. 19

4.2.1 Pre-impact activation during the forward and side jump ................................................. 19

4.2.2 Post-impact activation in functional jumps ............................................................................ 20

4.2.3 MVC .......................................................................................................................................................... 22

4.2.4 Muscle reaction time on the trapdoor ....................................................................................... 22

4.2.5 Subjective parameters ..................................................................................................................... 22

4.3 Post intervention group comparison ................................................................................................... 25

5 Discussion ........................................................................................................................................... 27

5.1 Baseline ................................................................................................................................................................... 27

5.2 Pre- and post-impact activation ................................................................................................................... 27

5.3 Muscle reaction time ......................................................................................................................................... 28

5.4 Subjectives ............................................................................................................................................................. 29

5.5 Post-intervention group comparison ......................................................................................................... 30

5.6 Strengths and limitations ................................................................................................................................ 30

5.7 Practical applications and conclusion ........................................................................................................ 31

5.8 Acknowledgements ............................................................................................................................................ 31

6 References .......................................................................................................................................... 32

7. Abstract (lekentaal) ....................................................................................................................... 35

8. Ethical approval ............................................................................................................................. 36

9. Appendix:....................................................................................................................................... 42

List of tables and figures:

Picture 1: Normal trapdoor

Picture 2: Activated trapdoor

Picture 3: Forward jump

Picture 4: Side jump

Picture 5: Uniaxial wobble board

Picture 6: Multiaxial wobble board

Picture 7: Scheme statistical analysis

Table 1: Demographic variables

Table 2: Electrode placement

Table 3: 6-week exercise program

Table 4: Baseline comparison

Table 5: Changes pre-impact activation in MULTI group

Table 6: Post-hoc changes TA/PL ratio pre-impact in both groups

Table 7: Changes post-impact activation in MULTI group

Table 8: Post-hoc changes TA/PL ratio post-impact in both groups

Table 9: Changes in MVC in the MULTI group

Table 10: Changes of subjectives in both groups

Table 11: VAS UNI and MULTI

Table 12: GROC UNI and MULTI

Table 13: Post intervention group comparison

List of abbreviations:

CAI = Chronic Ankle Instability

CAIT = Cumberland Ankle Instability Tool

CI = Confidence Interval

FADI = Foot & Ankle Disability Scale

FJ = Forward Jump

GLAT = M. Gastrocnemius Lateralis

GMED = M. Gastrocnemius Medialis

GROC = Global Rating Of Change scale

MULTI = Multiaxial group

MVC = Maximal Voluntary Contraction

N = Amount of hits

PB = M. Peroneus Brevis

PL = M. Peroneus longus

sEMG = surface ElectroMyoGraphy

SJ = Side Jump

TA = M. Tibialis Anterior

TAMPA = Tampa scale of kinesiophobia

UNI = Uniaxial group

VAS = Visual Analog Scale

5

1. Abstract (Dutch)

Achtergrond: Balanstraining is een behandelvorm die frequent gehanteerd wordt in de behandeling

van chronische enkelinstabiliteit (CAI). Ondanks de sterke bewijskracht rond balanstraining blijft het

nog steeds onduidelijk welk soort oefeningen het best aansluit bij de revalidatiedoelen. Deze studie

oogt erop de spieractiviteit en reactietijden van de desbetreffende spieren te evalueren via het gebruik

van uni-axiale en multi-axiale kantelplanken.

Doel: Het doel van deze studie is het evalueren van de effecten van balanstraining op de spieractiviteit

binnen een populatie van CAI patiënten. Hiervoor werd gebruikt gemaakt van een 6 weken durend uni-

axiaal en multi-axiaal balanstraining programma.

Study design: Gerandomiseerd gecontroleerd onderzoek

Methode: 26 patiënten met chronische enkelinstabiliteit werden gerandomiseerd in een uni-axiale

groep (UNI, n=13) en een multi-axiale groep (MULTI, n=13). Oppervlakte electromyografie werd voor

en na het 6 weken durende balanstraining protocol uitgevoerd. Maximale vrijwillige contracties (MVC),

pre- en post-impact spieractiviteit tijdens een voorwaartse sprong (FJ) en zijwaartse sprong (SJ) werden

geregistreerd. Daarnaast werd ook de spierreactie tijd van de m. Tibialis Anterior (TA), m. Peroneus

Longus (PL) en Brevis (PB), m.Gastrocnemius Medialis (GMED) en Lateralis (GLAT) via een trapdoor

geregistreerd. Subjectieve parameters zoals VAS, FADI, CAIT en TAMPA werden ook afgenomen bij deze

populatie.

Resultaten: Binnen de MULTI-groep is er een effect voor pre-impact (p=0.007) en post-impact activatie

(p=0.001) gevonden. Verdere analyse toonde ook aan dat voor zowel de PB als GLAT de relatieve pre-

en post-impact spieractiviteit tijdens functionele sprongen significant daalden. Tijdens de voorwaartse

sprong was er ook bij de PL en GMED een daling in relatieve pre-impact spieractivatie zichtbaar. Echter,

de TA en PL vertoonde een significante daling in relatieve post-impact spieractiviteit, respectievelijk

tijdens de FJ en SJ. De UNI-groep vertoonde een niet significant effect. Niet voor de pre-impact activiteit

(p=0.053), noch voor de post-impact activiteit (p=0.141). De spierreactie tijd van beide groepen was

niet significant verandert (UNI: p=0.977, MULTI: p=0.479). Daarnaast onderging de FADI-sport een

stijging in resultaat en was er een daling van zowel de TAMPA als de VAS-schaal voor moeilijkheid en

instabiliteit.

Conclusie: Multi-axiale balanstraining zorgt voor een daling in relatieve spieractiviteit van de PB en

GLAT op vlak van pre- en post-impact. Daarnaast was er ook een daling in relatieve spieractiviteit van

de TA, PL en GMED zichtbaar. De uni-axiale groep vertoonde dezelfde trend, echter zijn deze resultaten

niet significant. Mogelijks is dit te verklaren door verschillende veranderingen in MVC tussen beide

groepen. Deze factoren maken het echter moeilijk om te concluderen dat multi-axiale balanstraining

mogelijks beter is dan uni-axiale balanstraining.

Kernwoorden: Chronische enkelinstabiliteit, balanstraining, uni-axiale kantelplank, multi-axiale

kantelplank, spieractiviteit

6

1. Abstract (English)

Background: Balance training is commonly used in the treatment of chronic ankle instability (CAI).

Although balance training has been proven effective, It still remains unclear which types of exercise

best serves the rehabilitation goals. This study intent to evaluate muscle activity levels and muscle

reaction time by using uniaxial and multiaxial wobble boards.

Objective: The aim of this study is to evaluate the effects of balance training on the muscle activity in

subjects with CAI by using a 6-week uniaxial and multiaxial balance training program.

Study design: Randomized controlled trial

Methods: Twenty-six patients with chronic ankle instability were randomized into a uniaxial (UNI,

n=13) and a multiaxial group (MULTI, n=13). Measurements were carried out with surface

electromyography before and after a 6 week multi- or uniaxial wobble board balance training protocol.

Maximum voluntary contractions (MVC), pre- and post-impact muscle activity during a forward jump

(FJ) and side jump (SJ) and muscle reaction time on a trapdoor of the m. Tibialis Anterior (TA), m.

Peroneus Longus (PL) and Brevis (PB) and m.Gastrocnemius Medialis (GMED) and Lateralis (GLAT) were

recorded. Furthermore, subjective outcome measures like the VAS, FADI, CAIT and TAMPA were

obtained.

Results: A main effect was found for pre-impact (p=0.007) and post-impact activation (p=0.001) in the

MULTI group. Further analysis revealed that the PB and GLAT significantly decreased in both the

relative pre- and post-impact muscle activation during functional jumps. Performing a forward jump,

the PL and GMED muscles also decreased in relative pre-impact muscle activation. Whereas, the TA

and PL muscle showed a significant decrease in relative post-impact muscle activation, respectively

during the FJ and SJ. The UNI group did not show a significant main effect for neither the pre- (p=0.053)

or post-impact (p=0.141) activation. Considering the muscle reaction time, either group did not show a

significant change (UNI: p=0.977, MULTI: p=0.479). Furthermore, the FADI-sport underwent an

increase in result. Next to that, a significant reduction was found in the TAMPA and the VAS-scales.

Conclusion: Multiaxial balance training decreases relative pre- and post-impact muscle activity of the

PB and GLAT during functional jumps. Furthermore, a reduction in relative muscle activity of the TA, PL

and GMED was observed. Although, there were no significant results, uniaxial balance training did

show the same tendency. Possible explanation might be found in the different changes in MVC between

of both groups. These facts make it difficult to declare whether multiaxial balance training is more

beneficial then uniaxial training.

Key-words: Chronic ankle instability, balance training, uniaxial board, multiaxial board, muscle activity

7

2. Introduction

The foot and ankle complex can be seen as the link between the human body and the ground. This

means it has a crucial role from fulfilling daily activities to performing sports. The ankle has to endure

extremely high loads.32 For that reason, the ankle is a very common injured joint of the human body

within which ankle sprains are rated up to 77%-85% of all ankle injuries.17,24 Many different definition

of chronic ankle instability (CAI) can be found in literature. CAI is most commonly defined as the

presence of recurrent ankle sprains and the subjective feeling of giving way for at least one year after

an initial sprain.7,9 Hertel’s paradigm explains that CAI may be contributed by both mechanical and

functional instability.14 In which mechanical instability can be defined as the range of motion beyond

the normal expected physiological range of motion of that particular joint.7 Functional instability on

the other hand, is referred to as ‘the feeling of joint instability and the subjective feeling of giving way’.7

Hertel also describes that impairments in the sensorimotor control may be the main cause of

functional instability and can lead to the development of CAI.14

Sensorimotor control contains a couple of concepts like the neuromuscular control, proprioception,

postural control and strength.17 This study mainly focuses on the neuromuscular control and can be

explained as the subconscious activation of dynamic restraints in preparation to and in response to

joint motion and loading for the purpose of maintaining and restoring functional joint stability.26

Impairments in neuromuscular control may be caused by alterations in the feedback and/or

feedforward mechanisms.17 Feedforward and/or feedback activation are the main factors in order to

assess the neuromuscular control.17 Extensive research has been done where muscle reaction time of

the peroneus longus has been used as an outcome measure of the feedback mechanism.3,15,18,20,21

Studies also suggest that damage to the mechanoreceptors, sustained during the ankle sprain, can

cause impairments in the feedforward mechanism, resulting in a decrease of neuromuscular control.27

In addition to these facts, subjects with CAI are also associated with residual arthrogenic muscle

inhibition, which leads to a decreased alpha motor pool excitability of the muscles surrounding the

affected ankle.12,29 Both impairments in feedforward and feedback mechanisms are believed to cause

episodes of giving way and recurrent ankle sprains that may lead to the development of CAI. Studies

also show that these alterations are also most apparent in the anterior tibialis muscle, soleus muscle,

gluteus maximus muscle, M. Tensor fascia Latae, Rectus femoris muscle and the vastus medialis

obliquus muscle.6,33,36

Since CAI can be associated with alterations in neuromuscular control, balance training is a commonly

used treatment modality in rehabilitation.19,34 Next to that, balance training might also be preventative

8

for sustaining an ankle sprain.19,34 Thus far, there is a predominant knowledge about the use of balance

equipment on muscle activity in healthy subjects.1,2,4,35 However less studies have been published

about the effects of balance surface type on the muscle activity in subjects with CAI. As the peroneus

longus is investigated in many other studies about CAI and it is expected to counteract the inversion

movement of the ankle. 5,15,18,20,21,23,31 De Ridder et. Al. (2014) described the muscle activity levels of

the ankle stabilisers during a single legged balance board protocol.5 He concluded that the highest

muscle activity of the peroneus longus was along the frontal axis while standing on a uniaxial wobble

board. As this static exercise was a snapshot, these results might be generalised into a balance training

protocol using specific exercises. Therefore, research of muscle activity levels during a uniaxial balance

training protocol in comparison with a multiaxial balance training protocol is necessary.

The main goal of this study is to evaluate the effects of balance training on the muscle activity in

subjects with CAI by using a 6-week uniaxial and multiaxial balance training program.

3. Methods

3.1 Study design

Randomised controlled trial.

3.2 Participants

Subject recruitment was undertaken by sending a questionnaire with the in- and exclusion criteria to

physiotherapy students of the University of Ghent. Appendix 2 Following inclusion criteria were set

according to the position statement for CAI research8: Having more than 1 ankle sprain (≥2 sprains) in

the past which led to pain and swelling and impossibility to perform ADL-activities for at least 1 day,

the feeling of giving way and the feeling of instability. If the participant fulfilled these criteria, a second

questionnaire, called the ‘Cumberland Ankle Instability Tool’ (CAIT), was sent to objectify the feeling

of instability.Appendix 3 Subjects with a CAIT ≤ 24, were asked to enter into the study. Participants who

underwent surgery on the lower extremities or were injured on the leg 3 months prior to the study

were excluded. Participants who scored ≥25 on the CAIT were excluded. Written informed consent

was obtained from all subjects and ethical approval was cleared by the ethics committee of the

University of Ghent.

Twenty-eight participants were enrolled in the study aged between 18 and 29. Two participants

dropped out after initial testing because of management issues which gives a total of 26 subjects who

9

completed the trial. All participants were randomized into 2 groups: the uniaxial (UNI) or multiaxial

(MULTI) group. Participant characteristics are given in table 1.

Table 1: Mean (SD) for demographic variables.

UNI

Mean (SD)

MULTI

Mean (SD)

N 13 13

Female/Male 12/1 9/4

Age (yrs) 20.69 (2.926) 21.15 (2.193)

Height (cm) 169.7 (5.62) 173.5 (9.52)

Weight (kg) 61.9 (4.54) 68.2 (13.08)

There was no significant baseline differences between the 2 groups for all demographic variables.

(p>0.05)

3.3. Procedure and equipment

All tests were carried out before and after the six-week balance protocol with standardized shoes. Two

clinical tests were implemented during the pre-testing: the varus click test and the anterior drawing

test. These test were done by 2 different researchers to diminish the variance.

3.4. EMG

Surface electromyography (sEMG) of 5 muscles were recorded: the anterior tibialis muscle, peroneals

(longus and brevis) and gastrocnemius medial and lateral head. Bipolar Ag/AgCl surface electrodes, 2

cm diameter, with conducting gel were placed with an inter-electrode distance of 2 cm center-to-

center and parallel to the muscle fibres according to surface ElectroMyoGraphy for Non-Invasive

Assessment of Muscles (SENIAM) guidelines (www.seniam.org). Table 2 shows the standardized

electrode placement. The lower leg was first shaved, scrubbed and cleaned with ether before

electrode application.

10

Table 2: Standardized electrode placement. (2 electrodes/muscle)

Muscle Electrode placement

M. Tibialis Anterior 1/3 th of the distance between the fibula head and the medial

malleolus (measured from proximal)

M. Peroneus Longus 1/4th of the distance between the fibula head and the lateral

malleolus (measured from proximal)

M. Peroneus Brevis 1/4th of the distance between the fibula head and the lateral

malleolus (measured from distal)

M. Gastrocnemicus Medialis On the most prominent bulge of the muscle

M. Gastrocnemicus Lateralis On the most prominent bulge of the muscle

Reference electrode Bony fibula head (Only 1 electrode)

All baseline signals of the EMG had to be below 10ms, otherwise the procedure (shaving, scrubbing

and cleaning) was repeated. All amplifiers were secured to the leg with patches. All wires were then

fixed with a circular gauze in order to reduce the possibility of motion artefacts. Afterwards, the lower

leg was wrapped with a bandage to make sure everything remains in place during the testing.

The Maximum voluntary contractions (MVC’s) of all 5 muscles were measured to get a baseline

measure for all the other EMG data. Afterwards, two tests were carried out: muscle reaction time on

the trapdoor and the functional jumps onto the force plate.

A. Maximum voluntary contraction (MVC’s)

First, the maximum voluntary contractions (MVC’s) of the 5 muscles were measured. All MVC’s were

measured in a standardized way. Each muscle was tested 3 times for at least 5 seconds. The subject

was asked to give a sign when the maximal contraction was reached. At that moment, the

measurement started. For the TA muscle, the subject was seated in long-sitting position on the

treatment table. Resistance was applied by the researcher on the dorsal side of the foot (distal of the

insertion of the TA) towards dorsal flexion. For the peroneal muscles (PL and PB), the starting position

was the same. The resistance given by the researcher was towards pronation. For the GMED and GLAT

muscle, the subject was lying in prone position. The tested foot was placed against the wall. The other

11

leg was flexed in the knee joint in order to have no wall contact. Next, the subject was asked to push

isometrically and as hard as possible against the wall.

B. Muscle reaction time (trapdoor)

A customized trapdoor was used to simulate a lateral ankle distortion. This trapdoor is displayed in

pictures 1 and 2. The starting position of the foot was 0 degree of plantar flexion, 0 degrees of

pronation/supination and 0 degree of abduction/adduction. When the trapdoor tilted by pulling a

cord, the foot moved to 30 degrees of supination. The subject stands on the trapdoor, equally dividing

their weight between the 2 feet. A command was given to stand as relaxed as possible. Feet were then

fixated onto the trapdoor. Two practice trials (1 with eyes open and 1 with eyes closed) were given to

the subjects to get used to the device. Next, the participants were blindfolded and wore headphones

to eliminate anticipation. An accelerometer was applied to the trapdoor in order to know the exact

starting point of the test. This way, the EMG signal and trapdoor activation were synchronized. The

subject did not know which side of the trapdoor would get pulled. This was randomized by taking a

paper (left or right foot) out of a closed box. The test was performed until 5 measurements were

recorded of the participants included foot.

Picture 1: normal Picture 2: activated

C. Functional jumps

Next test was a forward jump (FJ) and side jump (SJ) performed onto a force plate imbedded in a

walkway. For the SJ, if the left foot was included, the subject turned 90° to the right and vice versa if

the right foot was included. Participants had to jump over an obstacle with a height of 15 cm. Distance

between starting position and the landing position was measured as 40 percent of the participant’s

body length for the FJ and 33 percent of the body length for the SJ. Participants had to jump with both

12

feet and land on the included foot (unipodal) with both hands on the waist and looking straight

forward. They had to balance for at least 5 seconds. The subjects first got 5 practice trials before the

actual test trials on each jump. The order of the jumps was randomized by taking a paper (SJ or FJ) out

of a closed box. Each participant had to perform both protocols until they had 5 satisfying jumps in

both protocols. If the patient jumps on 1 leg, touches the ground with the other leg, does not hold

their arms on the pelvis and/or a calcaneal shift occurs, the jump was rejected. The amount of trials to

get 5 satisfying trials was written down after the test for each jump.

Picture 3: Forward jump

Picture 4: Side jump

3.5. Questionnaires

In order to objectify subjective parameters, a couple of questionnaires had to be filled in during the

pre and post testing. The CAIT as mentioned before is a way to objectify the feeling of instability.Appendix

3 Furthermore, the ‘foot and ankle disability index’ (FADI) was taken to measure the function of the

ankle and foot.Appendix 4 A ‘visual analog scale’ (VAS), where the subject had to indicate his score on a 10

cm long line, was filled in after the forward and after the side jumps to measure 4 parameters: pain,

fatigue, instability and difficulty during these jumps.Appendix 5 Also the TAMPA scale for kinesiophobia

was taken at the first intervention moment and at the last intervention moment to measure a change

of kinesiophobia during the 6-week stabilization program.Appendix 6 At the end of the intervention, the

13

subjects were asked about the subjective feeling of change in their ankle after the intervention with

the ‘global rating of change scale’ (GROC).Appendix 7

3.6. Intervention

Participants underwent a 6-week stabilization program using uniaxial and multiaxial, self-designed

wobble boards in respectively the UNI and MULTI group.Picture 5,6 The uniaxial wobble-board can only

rotate in 1 direction. The axis of rotation is from the calcaneus towards the toes, in the frontal plane.

The multiaxial wobble-board could rotate in every direction. Dimensions of the uniaxial wobble board

are 40 cm by 40 cm as top surface and the curvature was 21 cm in width by 6.8 cm in height, with a

diameter of 23 cm. The multiaxial wobble board has a diameter of 40 cm as top surface and the

curvature has a width of 21 cm by 6.8 cm in height and a diameter of 23 cm. As mentioned before,

participants were randomly assigned to the UNI or MULTI group. Each group underwent a 6-week

stabilization program, 3 times a week. Every intervention was supervised by at least one of the

researchers in order to maintain maximal quality of movement. Table 3 shows the exercises and

progress by week. Progression was made by increasing the time, doing the exercise with eyes open or

eyes closed and by increasing the difficulty of the exercise type. In between each trial, the participant

got 30 seconds rest. In between the exercises, a 2-minute break was given. All exercises were

performed in unipodal stance with the test foot on the wobble board. In the single leg stance exercise,

the subject stands on 1 foot for the duration of the targeted time. The single leg stance + reach is an

exercise where the subject had to reach with the not affected foot towards 4 cones that were placed

in front, at the back and at the 2 sides of the subject. The distance towards the cones is also mentioned

in table 3. This distance is measured from the middle of the wobble board to the middle of the cone.

One trial was done when the subject reached twice towards all 4 cones. The last exercise included is

the single leg stance squat where the subject performed a unipodal squat on the wobble board.

Picture 5: Uniaxial wobble board

14

Picture 6: Multiaxial wobble board

Table 3: 6-week exercise protocol

Exercise Modality Eyes Remarks

Week 1:

Single leg stance 3x20” Open Hands on the waist, looking forward


Week 2



Week 3


Single leg stance 3x30” Closed Hands are free

Single leg stance +

reach

3x2 times every

direction

Open Hands on the waist, reach = 30 cm

Week 4


Single leg stance 3x30” Closed Hands on the waist

Single leg stance +

reach

3x2 times every

direction


15

Week 5



Single leg stance +

reach

3x2 times every

direction


Single leg stance squat 3x20” Open Hands on the waist, looking forward

Week 6



Single leg stance +

reach

3x2 times every

direction


Single leg stance squat 3x20” Open Hands on the waist, looking forward

3.7. Data analysis

Noraxon was used for analysis of the EMG-data (Myosystem 1400A, Noraxon USA Inc, Scottsdale,

Arizona 85254, USA). All MVC-data and functional jump-data (pre- and post-testing) was analyzed by

1 researcher. All ‘muscle reaction time’-data (pre- and post-testing) was analyzed by another

researcher.

3.7.1 MVC

To determine the MVC’s of each muscle, rectification and smoothing (RMS 50ms) was applied to the

raw data. For all 3 trials of each muscle, an interval of 3 seconds after the marker was set for

measurement. The mean of these 3 trials was calculated and defined as the MVC of that muscle.

16

3.7.2 Muscle reaction time

The raw data was only rectified, not smoothed. The starting point was determined by the

accelerometer, applied to the trapdoor. Visual onset picking was applied for each muscle. Hodges’

guidelines were used when difficulties occurred.16 The mean of all 5 trials was calculated to determine

the muscle reaction time of all 5 muscles.

3.7.3 Functional jumps

All raw data was first rectified and smoothed (RMS 50ms). The force plate during this test was used to

determine the exact landing time. An interval of 0.2 seconds before and after this point was set. The

activity in these intervals were measured for all 5 muscles. This way, an analysis of the activity

immediately before and immediately after the landing could be done. In order to normalize the data,

the percentage on the MVC was calculated, which makes it possible to compare relative muscle activity

between subjects.

3.8 Statistical analysis

Statistical analysis was performed with SPSS 23 (SPSS Inc., Chicago, IL, USA). The purpose of this study

is to compare the UNI and MULTI group. Normality test was performed for all variables to check the

normality of the data sheet. In this study, the Shapiro-Wilk-test was used.appendix 1 Later, parametric

tests were performed on normal data and non-parametric tests on not-normal data. Baseline (1)

measurement (comparison between UNI and MULTI group before the intervention) was done by the

independent sample t-tests for the parametric variables and the Mann-Whitney U test for the non-

parametric variables. Afterwards, a main effect (2) was computed for 3 clusters of variables: pre-

impact activity, post-impact activity, muscle reaction time, by doing paired repeated measures. The

Bonferroni correction was applied. If a main effect was detected, further paired student’s t-tests and

Wilcoxon matched-pairs signed-ranks tests were performed for respectively the normal and not-

normal data. Group comparison post-intervention (3) was analyzed by independent sample t-tests and

Mann-Whitney U tests on the post-intervention data. Significance levels were set at p<0.05.

17

Picture 7: Scheme statistical analysis

4. Results

4.1 Baseline

There were no significant differences between the UNI and MULTI group, except for 3 variables:

relative pre-impact activation in the FJ for the TA muscle (p=0.034), relative post-impact activation in

the FJ for the TA muscle (p=0.034) and relative pre-impact activation in the SJ for the PL muscle

(p=0.034) where the MULTI group showed higher values than the UNI group, as shown in Table 4.

Considering the clinical tests, 12 (UNI/MULTI: 7/5) out of the 26 included subjects scored positive on

the varus click test. Regarding the anterior drawing test, 9 (UNI/MULTI: 4/5) out of the 26 subjects

scored positive.

Table 4: Baseline comparison

UNI

Mean (SD)

MULTI

Mean (SD)

Mean diff

[95% CI]

p-value

TA Muscle activity FJ PRE-IMPACT 0,29 (0,18) 0,41 (0,21) -0,122 0.034*

Muscle activity FJ POST-IMPACT 0,76 (0,20) 1,12 (0,48) -0,353 0.034*

Muscle activity SJ PRE-IMPACT 0,28 (0,09) 0,39 (0,21) -0,118 0.139

Muscle activity SJ POST-IMPACT 0.91 (0.18) 1.15 (0.49) -0.242 [-0.55, 0.06] 0.112

Timing 0.077 (0.0140) 0.082 (0.008) -0.0056 [-0.0150, 0. 0037] 0,222

18

PB Muscle activity FJ PRE-IMPACT 0.67 (0.24) 1.00 (0.63) -0.325 [- 0.71, 0,06] 0.095

Muscle activity FJ POST-IMPACT 0,90 (0,35) 1,48 (0,91) -0,579 0.072

Muscle activity SJ PRE-IMPACT 0.72 (0.30) 1.23 (0.99) -0.505 [-1.12, 0.11] 0.101

Muscle activity SJ POST-IMPACT 1,00 (0,55) 1,47 (0,88) -0,472 0.057

Timing 0.080 (0.014) 0.083 (0.012) -0.0027 [-0.0132, 0.0078] 0.602

PL Muscle activity FJ PRE-IMPACT 0,80 (0,50) 1,19 (0,73) -0,382 0.091

Muscle activity FJ POST-IMPACT 1,13 (0,59) 1,35 (0,64) -0,222 0.320

Muscle activity SJ PRE-IMPACT 0,77 (0,52) 1,20 (0,92) -0,436 0.034*

Muscle activity SJ POST-IMPACT 1,06 (0,38) 1,24 (0,59) -0,179 0.538

Timing 0.082 (0.011) 0.084 (0.008) -0.0018 [-0.0097, 0.0061] 0.647

GMED Muscle activity FJ PRE-IMPACT 1.07 (0.42) 1.37 (0.38) -0.300 [-0.63, 0,03] 0.074

Muscle activity FJ POST-IMPACT 0.79 (0.41) 0.89 (0.41) -0.104 [-0.44, 0.24] 0.533



Timing 0,114 (0,045) 0,097 (0,042) 0,0165 0.186

GLAT Muscle activity FJ PRE-IMPACT 1.25 (0.62) 1.27 (0.75) -0.028 [-0.59, 0.54] 0.919



Muscle activity SJ POST-IMPACT 1.09 (0.63) 0.99 (0.49) 0.100 [-0.37, 0.57] 0.663

Timing 0.088 (0.013) 0.076 (0.024) 0.0119 [-0.0037, 0.0275] 0.127

Ratio

TA/PL

FJ PRE-IMPACT 0.43 (0.34) 0.45 (0.30) -0.016 0.687

FJ POST-IMPACT 0.80 (0.37) 0.88 (0.58) -0.088 0.960

SJ PRE-IMPACT 0.42 (0.19) 0.46 (0.34) -0.045 [-0.27, 0.18] 0.684

SJ POST-IMPACT 0.91 (0.25) 0.96 (0.59) -0.050 [-0.43, 0.33] 0.782

Mean diff = mean difference; CI = confidence interval; * indicates significant differences between UNI

and MULTI before intervention (p<0,05), Timing (µsec)

19

4.2 Intervention

4.2.1 Pre-impact activation during the forward and side jump

A main effect of the pre-impact activation was computed for both the UNI- and MULTI group. Only for

the MULTI group, a main effect was observed (p=0.007). The UNI group did not show a significant main

effect (p=0.053).

Table 5 shows the change in pre-impact muscle activation for the MULTI group during the FJ and SJ.

For the FJ, a significant decrease in relative muscle activation was observed in the PL (p=0.028), PB

(p=0.006), GMED (p=0.040), GLAT (p=0.021). The TA did not display a significant change during the FJ

(p=0.064).

For the SJ, the decrease was found in the PB (p=0.044) and GLAT (p=0.010). The other 3 muscles did

not show a significant change (TA: p=0.133, PL: p=0.055, GMED: p=0.344).

Post hoc, the TA/PL ratios were computed for both jumps (Table 6). Only in the UNI group, a significant

increase was found during the SJ (p=0.005). The FJ did not change significantly in the UNI group

(p=0.382). The MULTI group did not show a significant change for both jumps (FJ: p=0.879, SJ: p=0.244)

Table 5: Changes pre-impact activation in MULTI group

Pre

intervention

Mean (SD)

Post

intervention

Mean (SD)

Mean diff

[95% CI]

p-value

TA Muscle activity FJ 0.41 (0.21) 0.30 (0.14) 0.105 0.064

Muscle activity SJ 0.39 (0.21) 0.30 (0.14) 0.090 0.133

PB Muscle activity FJ 1.00 (0.63) 0.69 (0.47) 0.310 [0.11, 0.51] 0.006*

Muscle activity SJ 1.23 (0.99) 0.75 (0.44) 0.481 [0.01, 0.95] 0.044*

PL Muscle activity FJ 1.19 (0.73) 0.76 (0.27) 0.424 [0.05, 0.79] 0.028*

Muscle activity SJ 1.20 (0.92) 0.86 (0.40) 0.347 [-0.01, 0.70] 0.055

GMED Muscle activity FJ 1.37 (0.38) 1.09 (0.56) 0.274 [0.02, 0.53] 0.040*


GLAT Muscle activity FJ 1.27 (0.75) 0.87 (0.48) 0.399 [0.07, 0.73] 0.021*


20

Mean diff = mean difference; CI = confidence interval; * indicates significant change after intervention

(p<0,05)

Table 6: Post-hoc changes TA/PL ratio pre-impact in both groups

Pre intervention

Mean (SD)

Post intervention

Mean (SD)

Mean diff

[95% CI]

p-value

UNI FJ 0.43 (0.34) 0.40 (0.14) 0.033 0.382

SJ 0.42 (0.19) 0.56 (0.21) -0.141 [-0.23, -0.05] 0.005*

MULTI FJ 0.45 (0.30) 0.43 (0.20) 0.016 [-0.21, 0.24] 0.879

SJ 0.46 (0.34) 0.37 (0.13) 0.095 [-0.07, 0.26] 0.244


(p<0,05)

4.2.2 Post-impact activation in functional jumps

As in comparison with the pre-impact activation, there was a significant main effect for the post-impact

activation in the MULTI group (p=0.001) and not in the UNI group (p=0.141).

The changes in the post-impact activation of the MULTI group are shown in Table 7. For the FJ, a

significant decrease in relative post-impact muscle activation was found in the TA (p=0.005), PB

(p=0.003) and GLAT (p=0.010). The PL (p=0.084) and GMED (p=0.262) did not show a significant

change.

Whereas for the SJ, there was also a significant decrease found in the PB (p=0.005) and GLAT (p=0.003).

Also the PL (p=0.019) reduced significantly. The other 2 muscles (TA and GMED) did not change

significantly (respectively p=0.932 and p=0.123).

In comparison to the pre-impact activation, TA/PL ratios were computed post hoc for the post-impact

activation (Table 8). Similar changes can be found. There was no significant change during the FJ for

both groups (UNI: p=0.150, MULTI: p=0.650). During the SJ however, a significant increase can be

found in the UNI group only (UNI: p=0.036, MULTI: p=0.196).

21

Table 7: Changes post-impact activation in MULTI group

Pre

intervention

Mean (SD)

Post

intervention

Mean (SD)

Mean diff

[95% CI]

p-value

TA Muscle activity FJ 1.12 (0.48) 0.90 (0.51) 0.221 0.005*

Muscle activity SJ 1.15 (0.49) 1.16 (0.64) -0.011 [-0.29, 0.26] 0.932

PB Muscle activity FJ 1.48 (0.91) 0.87 (0.41) 0.603 0.003*


PL Muscle activity FJ 1.35 (0.64) 1.24 (0.78) 0.107 0.084

Muscle activity SJ 1.24 (0.59) 1.03 (0.49) 0.203 0.019*

GMED Muscle activity FJ 0.89 (0.41) 0.77 (0.58) 0.125 [-0.11, 0.36] 0.262





(p<0,05)

Table 8: Post-hoc changes TA/PL ratio post-impact in both groups

Pre intervention

Mean (SD)

Post intervention

Mean (SD)

Mean diff

[95% CI]

p-value

UNI FJ 0.80 (0.37) 0.94 (0.32) -0.140 [-0.34, 0.06] 0.150

SJ 0.91 (0.25) 1.21 (0.36) -0.299 [-0.57, -0.02] 0.036*

MULTI FJ 0.88 (0.58) 0.76 (0.30) 0.127 0.650

SJ 0.96 (0.59) 1.12 (0.32) -0.156 0.196


(p<0,05)

22

4.2.3 MVC

The MVC-analysis showed a significant increase in main effect in the MULTI group (p=0.027) only. The

UNI group did not show a significant main effect (p=0.489). Paired tests for the MULTI group (table 9)

show an increase in MVC for all muscles, except the GMED. Only the PB (p=0.008) increased

significantly. The other 4 muscles did not show a significant change in MVC after the intervention (TA:

p=0.144, PL: p= 0.221, GMED: p=0.972 and GLAT: p= 0.073).

Table 9: Changes in MVC in the MULTI group

Pre intervention

Mean (SD)

Post intervention

Mean (SD)

Mean diff

[95% CI]

p-value

TA 365.82 (151.12) 403.05 (139.43) -37.231 [-89.09, 14.62] 0.144

PB 243.31 (143.44) 359.29 (142.03) -115.985 [-195.95, -36.02] 0.008*

PL 253.12 (136.23) 285.07 (129.97) -31.957 0.221

GMED 249.19 (173.19) 227.21 (120.88) 21.985 0.972

GLAT 226.76 (149.22) 314.17 (247.70) -87.41 [-184.42, 9.60] 0.073


(p<0,05), MVC (mV)

4.2.4 Muscle reaction time on the trapdoor

There was no significant main effect found for both the UNI- (p=0.977) and MULTI group (p=0.479). No

further analysis was done.

4.2.5 Subjective parameters

A. CAIT, TAMPA, FADI sport and FADI activities

Looking at the means, all subjective variables improve in both the UNI and MULTI group. However, this

improvement was not significant in the MULTI group. Only in the UNI group (table 10), the TAMPA

(p=0.040) and FADI-s (p=0.021) showed a significant improvement. These results do suggest slight

improvements on kinesiophobia, disability in activities and sport and the subjective feeling of

instability. Only two of these parameters (kinesiophobia and disability during sport) are significant and

this only in the UNI group.

23

Table 10: Changes of subjectives in both groups

Pre intervention

Mean (SD)

Post intervention

Mean (SD)

Mean diff

[95% CI]

p-value

UNI CAIT 15.54 (3.97) 16.38 (6.55) -0.846 [-5.07, 3.38] 0.670

FADI activity 90.56 (5.69) 91.79 (7.21) -1.231 0.284

FADI sport 75.67 (11.24) 81.51 (12.46) -5.839 [-10.60, -1.08] 0.021*

TAMPA 34.00 (4.51) 31.15 (5.01) 2.846 [0.15, 5.55] 0.040*

MULTI CAIT 15.69 (5.41) 16.62 (5.80) -0.923 [-4.83, 2.98] 0.616

FADI activity 89.77 (8.94) 92.89 (6.09) -3.122 0.197

FADI sport 76.44 (12.54) 78.13 (16.34) -1.683 [-11.54, 8.18] 0.716

TAMPA 34.23 (6.91) 31.77 (6.67) 2.462 [-1.42, 6.34] 0.192


(p<0,05)

B. VAS during the functional jumps

Table 11 displays the VAS-scales of both groups during the 2 functional jumps. In the UNI group, the

VAS difficulty (FJ: p=0.033 and SJ: p=0.007) and VAS-instability (FJ: p=0,012 and SJ: p=0,008) decreased

significantly during both the SJ and FJ. Considering the VAS-pain (FJ: p=0.088, SJ: p=0.092) and VAS-

fatigue (FJ: p=0.838, SJ: p=0.075), a decrease was noticed. However this was not statistical significant

in the UNI group.

In the MULTI group, considering the VAS difficulty and VAS-instability, all VAS-scales were significantly

lower (VAS-difficulty SJ: p=0.030, VAS-instability FJ: p=0.004 and VAS-instability SJ: p=0.027), except

for the VAS-difficulty during the FJ (p=0.084). The VAS-fatigue also showed a significant decrease

during both jumps (FJ: p=0.021, SJ: p=0.019). The VAS-pain on the other hand, did not change

significantly for both jumps. (FJ: p=0.933, SJ: 0.672).

24

Table 11: VAS UNI and MULTI

Pre intervention

Mean (SD)

Post intervention

Mean (SD)

Mean diff

[95% CI]

p-value

UNI VAS pain FJ 0.73 (1.07) 0.39 (0.77) 0.339 0.088

VAS pain SJ 0.82 (1.06) 0.36 (0.83) 0.454 0.092

VAS fatigue FJ 1.20 (1.99) 1.05 (1.37) 0.146 0.838

VAS fatigue SJ 1.68 (2.51) 0.83 (1.25) 0.854 0.075

VAS difficulty FJ 2.71 (1.94) 2.00 (1.96) 0.708 0.033*

VAS difficulty SJ 4.78 (1.97) 2.85 (1.77) 1.923 [0.63,

3.21]

0.007*

VAS instability FJ 2.98 (1.84) 1.85 (1.84) 1.138 0.012*

VAS instability SJ 4.39 (2.54) 2.32 (1.74) 2.077 [0.66,

3.50]

0.008*

MULTI VAS pain FJ 0.62 (0.85) 0.72 (1.61) -0.100 0.933

VAS pain SJ 0.96 (1.63) 0.54 (1.10) 0.423 0.672

VAS fatigue FJ 2.79 (2.24) 1.27 (2.55) 1.523 0.021*

VAS fatigue SJ 3.74 (2.72) 1.38 (2.33) 2.362 0.019*

VAS difficulty FJ 2.97 (1.87) 1.66 (1.84) 1.308 [-0.20,

2.82]

0.084

VAS difficulty SJ 3.72 (2.00) 2.31 (1.65) 1.415 0.030*

VAS instability FJ 3.97 (2.48) 1.81 (1.68) 2.161 [0.82,

3.50]

0.004*

VAS instability SJ 4.35 (2.43) 2.70 (2.01) 1.646 [0.23,

3.06]

0.027*


(p<0,05)

25

C. GROC

As mentioned before, at the end of the intervention, every participant except 1 filled out the GROC to

measure the subjective feeling of change after the intervention. All subjects indicate an improvement

(>1) except for one who felt no change after the intervention (score = 0). Overall, an improvement of

3.7 (mean) ± 1.59 (SD) was measured. Comparing the 2 groups (Table 12), a slightly bigger change was

seen in the UNI group (mean: 4.2 ± SD: 1.34) than in the MULTI group (mean: 3.3 ± SD: 1.76), but this

was not significant between the 2 groups (p=0.161).

Table 12: GROC UNI and MULTI

UNI

Mean (SD)

MULTI

Mean (SD)

Mean diff

[95% CI]

p-value

GROC 4.2 (1.34) 3.3 (1.76) 0.904 [-0.39, 2.20] 0.161

Mean diff = mean difference; CI = confidence interval

4.3 Post intervention group comparison

Group comparison after the intervention was carried out. Five variables had a significant bigger muscle

activity in the MULTI group than the UNI group: relative pre-impact TA activation during the FJ

(p=0.044), relative post-impact PL activation during the FJ (p=0.012), relative post-impact PL activation

during the SJ (p=0.034), relative pre-impact PL activation during the FJ (p=0.030) and relative pre-

impact PL activation during the SJ (p=0.007) as shown in table 13. The pre-impact TA/PL ratio during

the SJ was also significantly bigger in the UNI group compared to the MULTI group (p=0.010).

Table 13: Post intervention group comparison

UNI

(n=13)

MULTI

(n=13)

Mean diff

[95% CI]

p-value

TA Muscle activity FJ PRE-IMPACT 0.22 (0.08) 0.30 (0.14) -0.087 0.044*




Timing 0.082 (0.009) 0.084 (0.006) -0.0016 [-0.0077, 0.0046] 0.602

26

PB Muscle activity FJ PRE-IMPACT 0.67 (0.24) 0.68 (0.45) -0.009 [-0.30, 0.28] 0.949

Muscle activity FJ POST-IMPACT 0.99 (0.35) 0.87 (0.41) 0.118 0.223



Timing 0.086 (0.008) 0.088 (0.007) -0.0013 [-0.0077, 0.0050] 0.672

PL Muscle activity FJ PRE-IMPACT 0.56 (0.13) 0.76 (0.27) -0.198 [-0.37, -0.02] 0.030*

Muscle activity FJ POST-IMPACT 0.85 (0.31) 1.24 (0.78) -0.395 0.012*

Muscle activity SJ PRE-IMPACT 0.52 (0.14) 0.86 (0.40) -0.342 [-0.58, -0.10] 0.007*

Muscle activity SJ POST-IMPACT 0.77 (0.26) 1.03 (0.49) -0.267 0.034*

Timing 0.085 (0.008) 0.085 (0.008) 0,0000 [-0.0068, 0.00067] 0.990

GMED Muscle activity FJ PRE-IMPACT 1.17 (0.40) 1.09 (0.56) 0.079 [-0.32, 0.48] 0.688

Muscle activity FJ POST-IMPACT 0.86 (0.50) 0.93 (0.81) -0.072 0.880



Timing 0.101 (0.032) 0.094 (0.020) 0.0069 0.390

GLAT Muscle activity FJ PRE-IMPACT 0.73 (0.20) 0.87 (0.48) -0.147 [-0.47, 0.17] 0.342

Muscle activity FJ POST-IMPACT 0.73 (0.37) 0.65 (0.41) 0.074 [-0.26, 0.40] 0.648



Timing 0.085 (0.010) 0.085 (0.008) 0.0005 [-0.0068, 0.0078] 0.894

Ratio

TA/PL

FJ PRE-IMPACT 0.40 (0.14) 0.43 (0.20) -0.034 0.840

FJ POST-IMPACT 0.93 (0.32) 0.76 (0.30) 0.179 [-0.07, 0.43] 0.150

SJ PRE-IMPACT 0.56 (0.21) 0.37 (0.13) 0.192 [0.05, 0.33] 0.010*

SJ POST-IMPACT 1.21 (0.36) 1.12 (0.32) 0.092 0.579

Mean diff = mean difference; CI = confidence interval; * indicates significant differences between UNI

and MULTI after intervention (p<0,05), Timing (µsec)

27

5 Discussion

The main purpose of this study was to evaluate the effects of a 6-week uniaxial and multiaxial balance

training program on the muscle activity in subjects with CAI. In particular, the pre- and post-impact

activation and muscle reaction time were analyzed. Furthermore, subjective variables were included.

5.1 Baseline

Baseline comparison between the groups was carried out to evaluate the homogeneity of both groups.

This is important to compare the effect of the intervention between both groups. Most variables were

equal, except for the pre-impact muscle activation of the TA and PL during the FJ and SJ respectively

and the post-impact activation of the TA during the FJ. For all three variables, the MULTI groups

showed significant higher values than the UNI group.

5.2 Pre- and post-impact activation

Previous research described that ankle muscle activity of the ankle stabilizers and more specific the PL

is the highest among the frontal axis while standing on a uniaxial wobble board.5 This study wanted to

investigate the effects of a 6-week uniaxial balance training protocol on the activity levels of the 5

lower leg muscles. Also a multiaxial balance program was included in order to compare the effect of 2

different types of wobble boards on this matter. The hypothesis was an increase of the relative PL

activity in the UNI group. The multaxial balance program on the other hand, might give a more

generalized effect on all ankle stabilizing muscles. An increased muscle activity of the peroneals should

lead to better counteraction against the inversion movements during an ankle sprain. 5,15,18,20,21,23,31

The results of the functional jumps showed that both the pre-impact and post-impact activation

decreased significantly, only in the MULTI group. Considering both the pre- and post-impact activation,

the PB and GLAT decreased significantly in both the SJ and FJ. Furthermore, an effect on the pre-impact

activation was also seen in the PL and GMED during the FJ. Whereas post-impact, the TA decreased

during the FJ and the PL during the SJ. These results are not fully as hypothesized. Possible explanations

might be found in the MVC’s. A significant increase in MVC can only be found in the PB. This only

explains the significant decrease in relative muscle activity of the PB in the MULTI group. Considering

the means of the other 4 muscles, an incremental tendency can be seen in all muscles except for the

GMED. Although this was not significant, this might be an explanation for the decrease in relative

muscle activity for these muscles. Looking at the baseline comparison, the MULTI group started with

higher post-impact TA muscle activity levels during FJ. This has to be taken into account when looking

28

at the post-intervention results. Furthermore, the TA/PL ratio did not change significantly in the MULTI

group for neither jumps.

Although results did not provide any significant main effect in the UNI group, post hoc analysis

(appendix 8) showed a significant decrease in relative muscle activation of the PL and GLAT during the

pre-impact phase for the UNI group as well. Also in the post-impact phase, a significant decrease can

be found in these two muscles but only during the SJ. The TA/PL ratio increased significantly during

the SJ in the UNI group. This is due to less PL activity during this jump.

The decrease in relative PL and GLAT activity in the UNI group can be explained by an increase in MVC

of these muscles, although this increase was only significant in the PL. Remarkable is the fact that the

TA, PB and GMED decreased in MVC in the UNI group, which might be an explanation for the non-

significant results in the UNI group. Post hoc analysis of the muscle activity during the jumps showed

a tendency to decrease significantly. This might be a factor in the explanation of the non-significant

results.

Foot orientation is also a main factor in the declaration of these results. Research showed most PL

muscle activity along the frontal axis using a uniaxial wobble board, which is also used in this balance

training protocol.5 Articles also suggest that most GLAT activity can be found along the diagonal axis

and secondly the frontal axis, which declares these positive results for both these muscles.5 On the

other hand, multiaxial balance training does not have one specific axis, but combines all axes together.5

This means that all axes will be trained and all muscles might decrease in relative muscle activity, which

can also declare significant findings for the PB in the multiaxial balance training group.5

Another explanation can be the amount of effort. The researchers observed both groups and stated

that the UNI group needed a less amount of effort to perform the program in contrary to the MULTI

group who needed a great amount of effort to complete the exercise program. In this study, both the

uni- and multiaxial wobble boards had the same curvature. This was done to be able to compare both

groups. Future research should take this into account and might consider to adapt the uniaxial wobble

boards to make them more provocative.

5.3 Muscle reaction time

Previous studies suggested that there is a deficit in muscle reaction time within CAI patients.21 Other

studies suggest that balance training might improve the onset and peak latency of the ankle stabilizing

muscles, especially the PL.3,15,18,20,21 A decrease of muscle reaction time after the intervention was

expected in this study.

29

However, this study showed that there is no effect on the muscle reaction time within CAI patients by

doing a balance training program. Clark et al. however showed in their article that a 4-week wobble

board training program improves the onset and peak latency of the TA and PL muscles.3 When looking

at both balance training protocols, different exercises were performed.3 This might explain the results

found in this study.

During the testing, some subjects suggested that, however they could not see nor hear anything during

the trapdoor test, they sometimes felt which side would be pulled. This was due to the use of manual

activation of the trapdoor. This could have affected the data negatively. Future studies might consider

a trapdoor with an automated trapdoor like used in the article of Clark et al. (2005).3,25

Visual onset picking was applied on the data. This was done by 1 researcher only, to diminish the

variance. However, Hodges’ guidelines for visual onset picking was applied, it was difficult to pick the

right onset time on a lot of trials.16 This might also be an explanation of the non-significant results.

5.4 Subjectives

Subjective parameters like disability, kinesiophobia, etc. are important in the rehabilitation of a patient

with CAI. A reliability and sensitivity study by Hale and Hertel showed that the FADI-act and FADI-s

questionnaires are reliable in establishing functional limitations in subjects with CAI and are responsive

to improvements in function after rehabilitation.13 Based on other articles, our hypothesis was an

increase in the CAIT, FADI-act and FADI-s.12,25,32 However, all 4 subjective questionnaires (CAIT, TAMPA,

FADI-s and FADI-act) improve in both the UNI and MULTI group, only in the UNI group, the TAMPA

(p=0.040) and FADI-s (p=0.021) showed a significant improvement. These results do suggest slight

enhancements on kinesiophobia, disability in activities and sport and the subjective feeling of

instability. Only two of these parameters (kinesiophobia and disability during sport) are significant and

this only in the UNI group. These improvements are also found in the MULTI group. Nevertheless, these

were not significant. Sefton et al. (2011) also analyzed the FADI-activities and FADI-sport after a 6-

week balance training on a maze balance board.30 An increase in the FADI-activities and FADI-sport was

also found.30 This suggests that balance training has a positive influence on the disability levels within

CAI.

Considering the VAS-scales during the functional jumps, both the UNI and MULTI group showed a great

improvement. In the UNI group, the VAS-difficulty and VAS-instability improved significantly for both

jumps. The VAS-pain and VAS-fatigue did not show any significant decrease. Also in the MULTI group,

a strong improvement is found, except for the VAS-difficulty (p=0.084) during the FJ and VAS-pain for

30

both jumps (FJ: p=0.933, SJ: p=0.672) where the improvement was not significant. Comparing the

means between the FJ and SJ, greater VAS-scores are noticed in the SJ for both groups.

These findings show that a 6-week balance protocol does improve the subjective feeling of instability

and difficulty during functional jumps. Training could also have an effect on the fatigue, however this

is only proven in the MULTI-group. Based on our results, the pain does not reduce during functional

jumps after a 6-week balance training.

Regarding the GROC, overall the participants improved and called it ‘somewhat better’ to ‘moderately

better’. The UNI group indicates a bigger subjective feeling of change than the MULTI group. However,

there is no significant difference between the 2 groups.

5.5 Post-intervention group comparison

Comparison of the groups after the intervention shows that the higher TA and PL pre-impact activity

levels in the MULTI group as found at baseline, are still significant higher in the MULTI group post-

intervention. Furthermore, mainly the PL activity levels are significant higher in the MULTI group, both

pre- and post-impact. The pre-impact TA/PL ratio during the SJ was significant higher in UNI group

which was expected due to the significant changes after the intervention in the UNI group.

5.6 Strengths and limitations

Inclusion criteria were based on the position statement, released by the Ankle Consortium8. The

criteria suggest that CAI can be defined as: (1) a history of at least one significant ankle sprain, (2) a

history of the previously injured ankle joint giving way, and/or recurrent sprain and/or ‘feelings of

instability’, and (3) a general self-reported foot and ankle function questionnaire. However, in this

study the inclusion criteria were more strict. The subjects had their ankle sprained at least twice. Also

the ankle joint showed giving way AND a feeling of instability objectified with the CAIT. This led to a

more specified population.

When looking at the intervention type, a lot of studies give the participants home exercises, which has

an effect on the compliance and proper execution of the exercise. Another strength in this study was

the supervision of the therapists during the balance training, which led to 100 percent proper

execution of the exercises. Furthermore, the wobble boards were custom made, which led to the same

curvature on both the uniaxial and multiaxial wobble boards. This way, a good comparison between

the two groups can be made.

31

As mentioned before, the strict inclusion criteria led to a specified population. On the other side, these

severe criteria led to a small population size in this study. For future research, the use of bigger

population groups is recommended.

All aspects of the study took place in a laboratory setting. Subjects may be more focused on the task

at hand during the testing. Whereby subjects with CAI do not experience episodes of giving way

continuously, so the execution of these controlled tasks might be less applicable. The use of a

controlled environment also led to two participants leaving the study due to practical issues, which

could maybe be solved by doing a home-exercise protocol.

While testing the MVC’s, two different therapists gave resistance during the test. This was done due

to practical considerations. Only one therapist performing this test would be better to limit the amount

of variation.

Although extensive research has already been done on this subject, the lack of a control group might

be a limitation to this study. As research investigated results based on a CAI group in comparison with

a healthy control group, it can be interesting to include a CAI control group to compare the effects of

intervention. This way, conclusions can be made if the balance training protocol is effective compared

to no intervention.

5.7 Practical applications and conclusion

Considering the results of this study, multiaxial balance training might be useful in the rehabilitation

of CAI. As multiaxial training gives significant improvements for both the GLAT and PB muscle, by

decreasing the relative muscle activity. The uniaxial group, on the other hand, did show the same

tendency as the multiaxial group, however these results were not significant. The use of both uniaxial

and multiaxial balance training might also interesting to be further investigated as there might be a

positive result on PL and GLAT when using a uniaxial balance protocol.

5.8 Acknowledgements

The authors would like to thank Prof Dr. P. Roosen (Promotor), Dr. R. De Ridder (Co-promotor) and all

the participants who donated their time and effort in order to complete this study.

32

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35

7. Abstract (lekentaal)

Achtergrond: Balanstraining is een behandelvorm die frequent gehanteerd wordt in de behandeling

van chronische enkelinstabiliteit (CAI). Ondanks de sterke bewijskracht rond balanstraining blijft het

nog steeds onduidelijk welk soort oefeningen het best aansluit bij de revalidatiedoelen. Deze studie

oogt erop de spieractiviteit en reactietijden van de spieren te evalueren via het gebruik van 2

verschillende kantelplanken: een die enkel naar links en rechts (uni-axiaal) kan kantelen en een die naar

verschillende richtingen (multi-axiaal) kan kantelen.

Doel: Het doel van deze studie is het evalueren van de effecten van een 6-weken durende balans

training met 2 verschillende kantelplanken op de spieractiviteit bij mensen met chronische

enkelinstabiliteit.

Methode: 26 patiënten met chronische enkelinstabiliteit deden mee aan de studie. Dertien van hen

voerden een 6 weken durende balanstraining uit op een uni-axiale kantelplank en 13 anderen op een

multi-axiale kantelplank. De spieractiviteit van 5 onderbeenspieren werd gemeten via elektroden

tijdens voorwaartse en zijwaartse sprongen. De spierreactie tijd van dezelfde spieren werd gemeten

door hen geblinddoekt op een zelfgemaakte trapdoor te plaatsen waarbij hun voet wordt gekanteld

om zo een enkelverstuiking te simuleren.

Resultaten: Deze studie toonde aan dat de patiënten die een kantelplank gebruikten die naar alle

richtingen kan kantelen, minder spieractiviteit gebruiken na de interventie. Dit is niet het geval voor de

kantelplank die enkel naar links en rechts kan kantelen. Verder zagen we in beide groepen geen snellere

reactietijd van de 5 spieren op een gesimuleerde enkeldistortie.

36

8. Ethical approval

37

38

39

40

41

42

9. Appendix:

Appendix 1: Table Shapiro-Wilk

Multiaxial or uniaxial

Shapiro-Wilk Distribution

Statistic df Sig.

Normal (N)/Not normal

(NN)

Muscle act. pre-

intervention FJ TA PRE-

IMPACT

UNI ,725 11 ,001 NN

MULTI ,815 9 ,030 NN

Muscle act. pre-

intervention FJ PL PRE-

IMPACT

UNI ,540 11 ,000 NN

MULTI ,963 9 ,825 N

Muscle act. pre-

intervention FJ PB PRE-

IMPACT

UNI ,896 11 ,165 N

MULTI ,889 9 ,193 N

Muscle act. pre-

intervention FJ GMED

PRE-IMPACT

UNI ,945 11 ,585 N

MULTI ,945 9 ,636 N

Muscle act. pre-

intervention FJ GLAT

PRE-IMPACT

UNI ,986 11 ,990 N

MULTI ,913 9 ,339 N

Muscle act. pre-

intervention FJ TA POST-

IMPACT

UNI ,937 11 ,491 N

MULTI ,821 9 ,035 NN

Muscle act. pre-

intervention FJ PL POST-

IMPACT

UNI ,730 11 ,001 NN

MULTI ,925 9 ,433 N

Muscle act. pre-

intervention FJ PB POST-

IMPACT

UNI ,911 11 ,254 N

MULTI ,825 9 ,039 NN

Muscle act. pre-


POST-IMPACT

UNI ,900 11 ,186 N

MULTI ,897 9 ,235 N

Muscle act. pre- UNI ,861 11 ,060 N

43


POST-IMPACT

MULTI ,952 9 ,708

N

Muscle act. pre-

intervention SJ TA PRE-

IMPACT

UNI ,964 11 ,822 N

MULTI ,801 9 ,021 NN

Muscle act. pre-

intervention SJ PL PRE-

IMPACT

UNI ,609 11 ,000 NN

MULTI ,951 9 ,705 N

Muscle act. pre-

intervention SJ PB PRE-

IMPACT

UNI ,933 11 ,443 N

MULTI ,963 9 ,832 N

Muscle act. pre-

intervention SJ GMED

PRE-IMPACT

UNI ,931 11 ,421 N

MULTI ,877 9 ,145 N

Muscle act. pre-

intervention SJ GLAT

PRE-IMPACT

UNI ,961 11 ,788 N

MULTI ,904 9 ,274 N

Muscle act. pre-

intervention SJ TA POST-

IMPACT

UNI ,941 11 ,538 N

MULTI ,950 9 ,687 N

Muscle act. pre-

intervention SJ PL POST-

IMPACT

UNI ,701 11 ,000 NN

MULTI ,800 9 ,021 NN

Muscle act. pre-

intervention SJ PB POST-

IMPACT

UNI ,800 11 ,009 NN

MULTI ,939 9 ,573 N

Muscle act. pre-


POST-IMPACT

UNI ,890 11 ,138 N

MULTI ,870 9 ,123 N

Muscle act. pre-


POST-IMPACT

UNI ,904 11 ,206 N

MULTI ,930 9 ,480 N

Muscle act. post-

intervention FJ TA PRE-

IMPACT

UNI ,801 11 ,010 NN

MULTI ,936 9 ,541 N

44

Muscle act. post-

intervention FJ PL PRE-

IMPACT

UNI ,918 11 ,301 N

MULTI ,921 9 ,398 N

Muscle act. post-

intervention FJ PB PRE-

IMPACT

UNI ,943 11 ,554 N

MULTI ,974 9 ,925 N

Muscle act. post-


PRE-IMPACT

UNI ,954 11 ,695 N

MULTI ,894 9 ,219 N

Muscle act. post-


PRE-IMPACT

UNI ,895 11 ,159 N

MULTI ,953 9 ,718 N

Muscle act. post-

intervention FJ TA POST-

IMPACT

UNI ,912 11 ,259 N

MULTI ,945 9 ,631 N

Muscle act. post-

intervention FJ PL POST-

IMPACT

UNI ,834 11 ,026 NN

MULTI ,809 9 ,026 NN

Muscle act. post-

intervention FJ PB POST-

IMPACT

UNI ,827 11 ,021 NN

MULTI ,944 9 ,622 N

Muscle act. post-


POST-IMPACT

UNI ,843 11 ,035 NN

MULTI ,895 9 ,225 N

Muscle act. post-


POST-IMPACT

UNI ,935 11 ,467 N

MULTI ,945 9 ,637 N

Muscle act. post-

intervention SJ TA PRE-

IMPACT

UNI ,901 11 ,190 N

MULTI ,935 9 ,529 N

Muscle act. post-

intervention SJ PL PRE-

IMPACT

UNI ,970 11 ,887 N

MULTI ,935 9 ,533 N

Muscle act. post-

intervention SJ PB PRE-

IMPACT

UNI ,959 11 ,760 N

MULTI ,950 9 ,693 N

45

Muscle act. post-


PRE-IMPACT

UNI ,953 11 ,684 N

MULTI ,907 9 ,293 N

Muscle act. post-


PRE-IMPACT

UNI ,977 11 ,951 N

MULTI ,934 9 ,516 N

Muscle act. post-

intervention SJ TA POST-

IMPACT

UNI ,910 11 ,247 N

MULTI ,963 9 ,833 N

Muscle act. post-

intervention SJ PL POST-

IMPACT

UNI ,827 11 ,021 NN

MULTI ,946 9 ,650 N

Muscle act. post-

intervention SJ PB POST-

IMPACT

UNI ,879 11 ,100 N

MULTI ,959 9 ,793 N

Muscle act. post-


POST-IMPACT

UNI ,936 11 ,478 N

MULTI ,929 9 ,471 N

Muscle act. post-


POST-IMPACT

UNI ,939 11 ,513 N

MULTI ,962 9 ,820 N

CAIT pre-intervention UNI ,979 11 ,962 N

MULTI ,890 9 ,200 N

CAIT post-intervention UNI ,885 11 ,119 N

MULTI ,939 9 ,568 N

FADI ACT Pre-intervention UNI ,946 11 ,588 N

MULTI ,761 9 ,007 NN

FADI ACT post-

intervention

UNI ,821 11 ,018 NN

MULTI ,882 9 ,164 N

FADI SPORT Pre-

intervention

UNI ,931 11 ,425 N

MULTI ,982 9 ,976 N

FADI SPORT Post- UNI ,875 11 ,089 N

46

intervention MULTI ,947 9 ,656 N

TAMPA pre-intervention UNI ,968 11 ,865 N

MULTI ,961 9 ,813 N

TAMPA post-intervention UNI ,940 11 ,525 N

MULTI ,938 9 ,566 N

GROC_post-intervention UNI ,903 11 ,201 N

MULTI ,937 9 ,553 N

VAS difficulty FJ pre-

intervention

UNI ,806 11 ,011 NN

MULTI ,981 9 ,971 N

VAS Instability FJ pre-

intervention

UNI ,841 11 ,033 NN

MULTI ,872 9 ,129 N

VAS difficulty SJ pre-

intervention

UNI ,952 11 ,667 N

MULTI ,979 9 ,958 N

VAS Instability SJ pre-

intervention

UNI ,857 11 ,052 N

MULTI ,909 9 ,310 N

VAS difficulty FJ post-

intervention

UNI ,866 11 ,068 N

MULTI ,837 9 ,054 N

VAS Instability FJ post-

intervention

UNI ,856 11 ,051 N

MULTI ,880 9 ,157 N

VAS difficulty SJ post-

intervention

UNI ,939 11 ,506 N

MULTI ,818 9 ,033 NN

VAS Instability SJ post-

intervention

UNI ,931 11 ,416 N

MULTI ,936 9 ,536 N

Pre-intervention Timing TA UNI ,902 11 ,193 N

MULTI ,985 9 ,984 N

Pre-intervention Timing PL UNI ,894 11 ,157 N

MULTI ,985 9 ,985 N

47

Pre-intervention Timing

PB

UNI ,863 11 ,063 N

MULTI ,930 9 ,477 N


GMED

UNI ,872 11 ,082 N

MULTI ,776 9 ,011 NN


GLAT

UNI ,959 11 ,756 N

MULTI ,896 9 ,227 N

Post-intervention Timing

TA

UNI ,911 11 ,253 N

MULTI ,924 9 ,424 N


PL

UNI ,957 11 ,739 N

MULTI ,921 9 ,403 N


PB

UNI ,955 11 ,714 N

MULTI ,898 9 ,241 N


GMED

UNI ,688 11 ,000 NN

MULTI ,750 9 ,005 NN


GLAT

UNI ,961 11 ,779 N

MULTI ,849 9 ,073 N

MVC TA pre-intervention UNI ,022 ,841 13 NN

MULTI ,057 ,873 13 N

MVC PL pre-intervention UNI ,602 ,950 13 N

MULTI ,149 ,903 13 NN

MVC PB pre-intervention UNI ,232 ,918 13 N

MULTI ,131 ,899 13 N

MVC GMED pre-

intervention UNI ,108 ,893 13 N

MULTI ,016 ,831 13 NN

MVC GLAT pre-intervention UNI ,113 ,895 13 N

MULTI ,323 ,928 13 N

MVC TA post-intervention UNI ,519 ,945 13 N

48

MULTI ,470 ,941 13 N

MVC PL post-intervention UNI ,038 ,859 13 NN

MULTI ,010 ,813 13 NN

MVC PB post-intervention UNI ,007 ,800 13 NN

MULTI ,287 ,924 13 N

MVC GMED post-


MULTI ,619 ,951 13 N

MVC GLAT post-


MULTI ,092 ,888 13 N

Ratio TA/PL pré FA before Uni ,737 13 ,001 NG

Multi ,869 13 ,050 G

Ratio TA/PL pré FA after Uni ,922 13 ,265 G

Multi ,812 13 ,009 NG

Ratio TA/PL pré FZ before Uni ,889 13 ,094 G

Multi ,901 13 ,139 G

Ratio TA/PL pré FZ after Uni ,946 13 ,542 G

Multi ,875 13 ,060 G

Ratio TA/PL post FA before Uni ,862 13 ,041 NG

Multi ,885 13 ,084 G

Ratio TA/PL post FA after Uni ,967 13 ,860 G

Multi ,934 13 ,388 G

Ratio TA/PL post FZ before Uni ,932 13 ,366 G

Multi ,909 13 ,177 G

Ratio TA/PL post FZ after Uni ,975 13 ,945 G

Multi ,782 13 ,004 NG

49

Appendix 2: Initial Questionnaire

1) Naam (ter contact voor evt. deelname) …

2) Geboortedatum …

3) Lengte (cm) …

4) Gewicht (kg) …

5) Studierichting en jaar …

6) E-mailadres …

7) Hebt u ooit al eens uw enkel naar binnen omgeslagen, met pijn en zwelling tot gevolg en

waardoor u minstens 1 dag u dagdagelijkse activiteiten niet meer kon uitvoeren?

1. Nee (de vragenlijst dient niet verder ingevuld te worden)

2. Ja, links

3. Ja, recht

4. Ja, beide

8) Wanneer was de eerste keer dat u uw enkel verstuikt hebt? (cf vragenlijst, klachten

minimum een jaar aanwezig)

1. Links: ... jaar ... maanden ... weken geleden

2. Rechts: .... jaar ... maanden ... weken geleden

9) Heeft u sindsdien deze enkel meerdere malen omgeslagen?

1. Nee

2. Ja, links: ... keer

3. Ja, rechts: ... keer

10) Is het enkelletsel vastgesteld door een arts of door uzelf?

1. Arts

2. Mezelf

50

11) Bent u geïmmobiliseerd geweest? (niet mogen steunen, plaaster, ...)

1. Ja, hoelang …

2. Nee

12) Heeft u sindsdien gevoel van ‘giving way’ of periodes van onverwachte en ongecontroleerde

bewegingen van uw voet of enkel al dan niet met of zonder pijn?

1. Nee

2. Ja, links

3. Ja, rechts

13) Hoeveel keer in de laatste 6 maanden heeft u dit ‘giving way’-gevoel gevoeld?

1. Links: … keer

2. Rechts: … keer

14) Heeft u een onstabiel gevoel aan de enkel?

1. Nee

2. Ja, links

3. Ja, rechts

15) Hoeveel keer in de laatste 6 maanden heeft u dit onstabiel gevoel gevoeld?

1. Links: … keer

2. Rechts: … keer

16) Heeft u reeds een chirurgische ingreep aan de enkel ondergaan?

1. Nee

2. Ja, links

3. Ja, rechts

17) Zo ja, welke chirurgische ingreep was dat?

1. Nee

2. Ja, …

51

18) Heeft u ooit een beenbreuk gehad?

1. Nee

2. Ja

19) Heeft u nog andere letsels gehad aan uw been/benen in de laatste 3 maanden?

1. Nee

2. Ja

20) Doet u momenteel aan sport? Zo ja, welke sport en hoeveel uur per week beoefent u deze

sport?

1. Nee

2. Ja, …

52

Appendix 3: CAIT

Naam:

Gelieve bij ELKE vraag ÉÉN stelling aan te duiden die het BEST uw enkels beschrijft.

LINKS RECHTS

1. Ik heb pijn aan mijn enkel

Nooit □ □

Bij het sporten □ □

Bij het lopen op oneffen ondergrond □ □

Bij het lopen op effen ondergrond □ □

Bij het stappen op oneffen ondergrond □ □

Bij het stappen op effen ondergrond □ □

2. Mijn enkel voelt ONSTABIEL aan

Nooit □ □

Soms bij het sporten (niet altijd) □ □

Vaak bij het sporten (elke keer) □ □

Soms bij dagelijkse activiteiten □ □

Vaak bij dagelijkse activiteiten □ □

3. Als ik SCHERPE bochten maak, voelt mijn enkel ONSTABIEL aan

Nooit □ □

Soms bij het lopen □ □

Vaak bij het lopen □ □

Bij het stappen □ □

53

LINKS RECHTS

4. Als ik trappen afdaal, voelt mijn enkel ONSTABIEL aan

Nooit □ □

Als ik snel stap □ □

Af en toe □ □

Altijd □ □

5. Mijn enkel voelt onstabiel aan als ik op ÉÉN been sta

Nooit □ □

Op de bal van mijn voet (tenenstand) □ □

Met mijn voet plat op de grond □ □

6. Mijn enkel voelt ONSTABIEL aan als

Nooit □ □

Ik van de ene kant naar de andere kant huppel □ □

Ik ter plaatse huppel □ □

Als ik spring □ □

7. Mijn enkel voelt ONSTABIEL aan als

Nooit □ □

Ik op oneffen ondergrond loop □ □

Ik jog op oneffen ondergrond □ □

Ik op oneffen ondergrond stap □ □

Ik op een vlakke ondergrond stap □ □

54

LINKS RECHTS

8. NORMAAL GEZIEN, als ik mijn enkel begin te verstuiken, kan ik dit ... stoppen

Meteen □ □

Vaak □ □

Soms □ □

Nooit □ □

Ik heb nog nooit mijn enkel verstuikt □ □

9. Na een TYPISCH voorval van het verstuiken van mijn enkel, wordt mijn enkel weer

‘normaal’

Bijna meteen □ □

In minder dan één dag □ □

1–2 dagen □ □

Meer dan 2 dagen □ □

Ik heb nog nooit mijn enkel verstuikt □ □

55

Appendix 4: FADI

Naam:

Gelieve elke vraag te beantwoorden met één antwoord dat het best aansluit bij hoe u zich

de afgelopen week hebt gevoeld. Als de activiteit in kwestie beperkt wordt door iets anders

dan uw voet of enkel, duid dan N/T*aan.

Geen

enkel

probleem

Niet zo

moeilijk Moeilijk

Enorm

moeilijk Onmogelijk

1. Staan

2. Op effen grond

wandelen

3. Blootsvoets op effen

ondergrond wandelen

4. Helling opwandelen

5. Helling afwandelen

6. Trap opgaan

7. Trap afgaan

8. Op oneffen grond

wandelen

9. Stoeprand open afgaan

10. Hurken

11. Slapen

12. Op de tenen gaan staan

13. Beginnen te wandelen

56

14. 5 minuten of minder

wandelen

15. Ongeveer 10 minuten

wandelen

16. 15 minuten of langer

wandelen

17. Huishoudelijke taken

18. Dagelijkse activiteiten

19. Persoonlijke verzorging

20. Licht tot gematigd werk

(staan, stappen)

21.

Zwaar werk

(duwen/trekken,

klimmen, dragen)

22. Recreatieve activiteiten

GEEN

PIJN

MILDE

PIJN

GEMATIGDE

PIJN

HEVIGE

PIJN

ONDRAAGLIJKE

PIJN

23. Gemiddeld pijnniveau

24. Pijn in rust

25. Pijn bij normale

activiteiten

26. Pijn bij het begin van de

dag

57

Sportmodule

Geen

enkel

probleem

Niet zo

moeilijk Moeilijk

Enorm

moeilijk Onmogelijk

1. Lopen

2. Springen

3. Neerkomen

4. Hurken en plots stoppen

5.

Plotseling van richting

veranderen, zijwaartse

bewegingen

6. Weinig belastende activiteiten

7. Mogelijkheid om activiteit uit te

voeren met uw normale techniek

8. Mogelijkheid om aan uw favoriete

sport deel te nemen zolang u wil

Heel erg bedankt om alle vragen te beantwoorden van deze vragenlijst.

58

Appendix 5: VAS

Sprongprotocol

Naam: Code:

1. Forward Jump aantal pogingen:

Hebt u pijn tijdens het uitvoeren van de oefening?

Geen pijn _________________________________________________ ondraaglijke pijn

Vindt u deze oefening moeilijk?

Niet moeilijk _________________________________________________ enorm moeilijk

Ervaart u een instabiel gevoel tijdens deze oefening?

Neen _________________________________________________ enorm instabiel

Heb u een vermoeid gevoel tijdens deze oefening?

Neen _________________________________________________ enorm vermoeid

2. Side Jump aantal pogingen:

Hebt u pijn tijdens het uitvoeren van de oefening?

Geen pijn _________________________________________________ ondraaglijke pijn

Vindt u deze oefening moeilijk?

Niet moeilijk _________________________________________________ enorm moeilijk

Ervaart u een instabiel gevoel tijdens deze oefening?

Neen _________________________________________________ enorm instabiel

Heb u een vermoeid gevoel tijdens deze oefening?

Neen _________________________________________________ enorm vermoeid

59

Appendix 6: TAMPA

TAMPA-SCHAAL VOOR KINESIOFOBIE

Miller, RP., Kori, SH & Todd, DD.(1991)

Geautoriseerde Nederlandse Vertaling

Vlaeyen J.W.S., Kole-Snijders A.M.J., Crombez, G. Boeren R.G.B. & Rotteveel, A.M.(1995)

INSTRUCTIE:

Met deze lijst willen wij onderzoeken op welke wijze u tegen uw pijn aankijkt en hoe u deze ervaart.

Het is de bedoeling dat u met behulp van de cijfers 1 t/m 4 aangeeft in welke mate u het eens of

oneens bent met elke bewering. Het is van essentieel belang dat u bij de beoordeling uitgaat van uw

eigen gevoelens; wat anderen denken is hierbij niet relevant.

Het is ook niet de bedoeling uw medische kennis te testen. Waar het om gaat is dat u aangeeft hoe u

uw pijn ervaart.

Geef van onderstaande beweringen door middel van een cijfer tussen 1 en 4 aan in welke mate u het

eens of oneens bent met deze bewering. De betekenis van de cijfers is als volgt:

1 = in hoge mate mee oneens

2 = enigszins mee oneens

3 = enigszins mee eens

4 = in hoge mate mee eens

1. Ik ben bang om bij het doen van lichaamsoefeningen letsel 1 2 3 4

op te lopen.

2. Als ik me over de pijn heen zou zetten, dan zou hij erger 1 2 3 4

worden.

3. Mijn lichaam zegt me dat er iets gevaarlijks mis mee is. 1 2 3 4

4. Mijn pijn zou waarschijnlijk minder worden als ik lichaams- 1 2 3 4

oefeningen zou doen.

5. Mijn gezondheidstoestand wordt door anderen niet serieus 1 2 3 4

genoeg genomen.

6. Door mijn pijnproblemen loopt mijn lichaam de rest van 1 2 3 4

mijn leven gevaar.

60

7. Mijn pijn betekent dat er sprake is van letsel. 1 2 3 4

8. Als mijn pijn erger wordt door iets, betekent dat nog niet 1 2 3 4

dat dat gevaarlijk is.

9. Ik ben bang om per ongeluk letsel op te lopen. 1 2 3 4

10. De veiligste manier om te voorkomen dat mijn pijn erger 1 2 3 4

wordt is gewoon oppassen dat ik geen onnodige bewegingen maak.

11. Ik had wellicht minder pijn als er niet iets gevaarlijks aan de 1 2 3 4

hand zou zijn met mijn lichaam.

12. Hoewel ik pijn heb, zou ik er beter aan toe zijn als ik 1 2 3 4

lichamelijk actief zou zijn.

13. Mijn pijn zegt me wanneer ik moet stoppen met lichaams- 1 2 3 4

oefeningen doen om geen letsel op te lopen.

14. Voor iemand in mijn toestand is het echt af te raden om 1 2 3 4

lichamelijk actief te zijn.

15. Ik kan niet alles doen wat gewone mensen doen, omdat 1 2 3 4

ik te gemakkelijk letsel oploop.

16. Zelfs als ik ergens veel pijn door krijg, geloof ik niet dat 1 2 3 4

dat gevaarlijk is

17. Ik zou geen lichaamsoefeningen hoeven doen wanneer ik 1 2 3 4

pijn heb.

61

Appendix 7: GROC

Life Connections Health Center

Nurturing health through the human connection Services delivered by North First Street Medical Group

GLOBAL RATING OF CHANGE SCALE (GROC)

Thank you for the opportunity to assist in your rehabilitation. The following rating scale allows us

to review the overall outcome of your condition with physical therapy intervention. It allows us

to review your physical therapy outcome, which helps guide our treatment to better serve our

patients in the future. The Global Rating of Change (GROC) has been well documented and

extensively used in research as an outcome measure as well as to compare outcome measures.

Please rate the overall condition of your injured body part or region FROM THE TIME THAT YOU

BEGAN TREATMENT UNTIL NOW (Check only one):

A very great deal worse (-7) About the same (0) A very great deal better (7)

A great deal worse (-6) A great deal better (6)

Quite a bit worse (-5) Quite a bit better (5)

Moderately worse (-4) Moderately better (4)

Somewhat worse (-3) Somewhat better (3)

A little bit worse (-2) A little bit better (2)

A tiny bit worse (-1) A tiny bit better (1)

From: Jaeschke R, Singer J, Guyatt GH. Measurement of health status. Ascertaining the minimal clinically

important difference. Control Clin Trials 1989: 407-15.

∙ 3571 North First Street, Suite 200 ∙ San Jose, CA 95134 ∙

∙ Phone: 424.2000 ∙ Fax: 408.321.8710 ∙

www.ciscolifeconnections.com

http://www.ciscolifeconnections.com/

62

Appendix 8: Tables pre- and post-impact activation in UNI-group

Table A: Changes pre-impact activation in UNI group

Pre

intervention

Mean (SD)

Post

intervention

Mean (SD)

Mean diff

[95% CI]

p-value

TA Muscle activity FJ 0.29 (0.18) 0.22 (0.08) 0.070 0.087


PB Muscle activity FJ 0.67 (0.24) 0.67 (0.24) 0.009 [-0.20, 0.22] 0.928


PL Muscle activity FJ 0.80 (0.50) 0.56 (0.13) 0.240 0.016*


GMED Muscle activity FJ 1.07 (0.42) 1.17 (0.40) -0.104 [-0.39, 0.18] 0.442





(p<0,05)

Table B: Changes post-impact activation in UNI group

Pre

intervention

Mean (SD)

Post

intervention

Mean (SD)

Mean diff

[95% CI]

p-value

TA Muscle activity FJ 0.76 (0.20) 0.75 (0.26) 0.016 [-0.16, 0.19] 0.848


PB Muscle activity FJ 0.90 (0.35) 0.99 (0.35) -0.094 0.382

Muscle activity SJ 1.00 (0.55) 0.97 (0.27) 0.028 0.861

PL Muscle activity FJ 1.13 (0.60) 0.85 (0.31) 0.280 0.064


GMED Muscle activity FJ 0.79 (0.41) 0.86 (0.50) -0.068 0.507


63

GLAT Muscle activity FJ 0.94 (0.55) 0.73 (0.37) 0.217 [-0.07, 0.51] 0.127



(p<0,05)

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