THE RELATIONSHIP BETWEEN STANDING POSTURE, FUNCTIONAL HIP RANGE OF MOTION, AND POSTURAL CONTROL IN FEMALE COLLEGIATE VOLLEYBALL PLAYERS THESIS A THESIS Submitted to the Faculty of the School of Graduate Studies and Research of California University of Pennsylvania in partial fulfillment of the requirements for the degree of Master of Science BY CATHERINE L. DOUGHERTY Research Adviser, Dr. Rebecca A. Hess California, Pennsylvania 2005
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THE RELATIONSHIP BETWEEN STANDING POSTURE, FUNCTIONAL HIP RANGE OF MOTION, AND POSTURAL CONTROL IN FEMALE COLLEGIATE
VOLLEYBALL PLAYERS
THESIS
A THESIS Submitted to the Faculty of the School of Graduate Studies
and Research of California University of Pennsylvania in partial fulfillment of the requirements for the degree of
Master of Science
BY
CATHERINE L. DOUGHERTY
Research Adviser, Dr. Rebecca A. Hess
California, Pennsylvania
2005
ii
iii
Acknowledgements
Firstly, I want to thank God for waking me up this morning, for granting me the grace and perseverance with which I could accomplish this prestigious achievement. If it were not for the ability he has bestowed upon me, both mentally and physically, this feat may not have been possible.
Thanks to my parents, Bob and Judy Dougherty, for the many sacrifices they have made in order for me to obtain such a dignified education. Their constant encouragement, reassurance, and devotion have promoted the diligence necessary to complete this degree of success. Thank you, also, for instilling in me the firm, Catholic belief that God will provide for me and protect me on my journey through life. I will offer up all my accomplishments, tribulations, and defeats to gain his grace.
Thank you to my committee, Dr. Hess, Dr. Reuter, and Jeff Hatton, for the professional advice and the determination to make this endeavor a hopeful success. You have proven that nothing is merely handed to the undeserved; but with the proper amount of persistence (and loss of sleep), even the worst of researchers can develop a fundamental competence for the researching, and re-researching, process. I assure you that if I had commenced this program at the intended time, this would have been done two months ago. Instead it seems I have learned the necessary material after-the-fact.
Thanks to my fabulous boyfriend, Dave, who helped me maintain composure when this thesis-writing procedure had me at my whit’s end. If it were not for him, I would probably be bald in the loony-bin right now. Thank you to my classmates for the stress-relieving nights at Lagerhead’s and the many memories. Thank you to my Aunt JoAnne and Uncle Will for donating me a ’94 Acura Integra with 220,000 miles to get me to school daily. It still runs like a dream! And lastly, thanks to Lisa and Amber for allowing me to shack-up in their spare room on my air mattress to save me the excess mileage on my car and un-necessary sleep-deprivation.
selection, and preliminary research were done prior to data
collection. A graduate athletic training student’s
assistance was also sought, and he was informed of the
intent and correct procedures for the study. The
researcher then approached the Volleyball team as a group,
explained the requirements and benefits of participation in
the study, and asked for volunteers. Thereafter, the
19
subjects were asked to complete the consent form and were
assigned a subject number with which to preserve subject
confidentiality.
The subjects’ general demographic information was
requested from the subject and documented by the
researcher. The researcher then obtained the athletes’
weight on a scale. The subjects were then advised to warm-
up on the Life FitnessTM 9500 HR stationary bicycle for five
minutes (level 5, approximately 90 RPM, seat height set to
point at which extended knee has approximately 50 of
flexion) to promote tissue warming25 and to prepare for
flexibility testing, performance of the Overhead Squat, and
simulated jump recovery. Next, the subject was asked to
remove their shoes and instructed to lie supine on the
table to allow for their Q-angle to be measured and
recorded on the evaluation form. The goniometer axis was
placed in the center of the patella, with the stationary
arm aligned with the ASIS and movement arm aligned with the
tibial tuberosity.
Each participant’s hip AROM was then measured with a
goniometer and was recorded in degrees on the evaluation
form. The subject was positioned accordingly and asked to
actively move her leg into the desired range to be measured
while the researcher palpated the corresponding anterior
20
superior iliac spine (ASIS) to ensure that neutral pelvis
was sustained. A trial movement was permitted to determine
if the motion can occur pain-free. The second AROM was
measured and recorded when the subject could no longer move
within the desired proper position of neutral pelvis.
Hip flexion was measured with the subject lying supine with
measuring knee flexed, other leg flat on table, pelvis
neutral; and hip extension was measured with the subject
lying prone with both knees extended. The goniometer’s
stationary arm was in line with the trunk, axis at greater
trochanter, and movement arm in line with the longitudinal
axis of the femur for both the flexion and extension
measurements. Hip abduction and adduction was measured
with the subject lying supine with both knees extended.
The goniometer’s stationary arm was positioned horizontally
at ASIS level, axis at ipsilateral ASIS, and movement arm
in line with the longitudinal axis of the femur. Hip
internal- and external rotation was measured with the
subject seated with knees flexed at 900.17,21 The
goniometer’s stationary arm was positioned perpendicular to
the floor, axis at the patella, and movement arm in line
with the longitudinal axis of the tibia.17,21
The subjects’ standing posture was then evaluated for
static anomalies of tibial valgus and subtalar pronation
21
and documented on the evaluation forms. To efficiently
produce the subjects’ normal stance, they were asked to
walk forward four steps and stand comfortably while the
observed postures were recorded as tibial valgus and/or
subtalar pronation.
Next, the subjects were asked to perform the Overhead
Squat19 and simulated jump recovery to observe for dynamic
and/or functional compensations, respectively. For the
Overhead Squat, the researcher minimally instructed the
athlete by saying, “Perform your normal squat with arms
overhead,” and then recorded the postural deviations, if
any. A properly-executed squat is performed when all of
the following criteria are met: feet maintained in a
neutral position (no pronation or “toeing out”), knees
maintained in a neutral position (no valgus or varus
motion), weight distributed evenly throughout the motion,
core stabilization performed to prevent abdominal
protrusion and/or low back rounding/protrusion, scapulo-
thoracic stabilization to prevent scapular protraction, and
head maintained in a neutral position (not forward).19 The
athlete was permitted one trial squat and the second squat
was analyzed, recorded, and video-taped from the sagittal
view.
22
For the jump recovery, the athlete was instructed to
reach as high as possible while merely standing at the base
of the Vertec. The lowest vane was then positioned at this
maximum standing reach height. The athlete was instructed
to jump as high as possible, squatting as much as necessary
and without taking any step, to displace the vanes at their
maximum height reached with an extended arm, and land on
both legs simultaneously. The athlete was then permitted
one practice jump. Three actual jumps were then performed
at maximal effort, and the athlete was asked to displace
the vanes at the maximal height reached. Jump heights were
recorded in inches and later converted to centimeters.
Thirty seconds recovery time was permitted to the
participants between each jump. Resultant bilateral tibial
valgus and/or subtalar pronation, in addition to fully
extended knees during the landing phase of the assessment
were documented on the evaluation forms. Both the Overhead
Squat and the jump recovery were video-taped from a sitting
position, in the sagittal plane, approximately 10ft away
for later analysis.
23
Hypotheses
The following hypotheses were considered:
1) An increased Q-angle past the normal average value
will coincide and negatively correlate with tibial valgus
and subtalar pronation in static standing posture, and will
lead to the same observed dynamic and functional postural
discrepancies (tibial valgus and subtalar pronation, as
measured by the Overhead Squat and jump recovery).
2) Discrepancies in hip active range of motion,
specifically decreased hip abduction, extension, and/or
external rotation, and increased hip adduction, flexion,
and/or internal rotation past the normal values, will
result in tibial valgus and subtalar pronation, and will
lead to the same observed dynamic and functional postural
discrepancies (tibial valgus and subtalar pronation, as
measured by the Overhead Squat and jump recovery).
Data Analysis
Data from the evaluation form was descriptively
analyzed to determine the relationship between hip AROM,
and static, dynamic, and functional postural discrepancies
24
whereby trends in static standing posture should produce
similar results in dynamic and functional assessments, and
result in a potential profile for the jumping female
athlete. A Pearson Product Moment Correlation was also
used to determine the relationship between Q-angle (in
degrees), tibial valgus, and subtalar pronation (“present”
= 1, “not present” = 2). Statistical analysis using SPSS
version 12.0 (SPSS Inc., Chicago, IL) with an alpha level
set a priori at < 0.05 was used for the correlation.
25
RESULTS
The following section encompasses the information
obtained through the collection and analysis of the
demographic data, Q-angle and active hip range of motion
measurements, standing posture, and performance of the
Overhead Squat and jump recovery. The results have been
divided into the subsequent sections: (1) Demographic Data,
(2) Hypothesis Testing, and (3) Additional Findings.
Demographic Data
Ten female Collegiate Division II Volleyball players
completed the study. The average age of the sample was 20
years (SD = 0.88yrs), the average height was recorded at
174.24cm (SD = 5.61cm), and the average weight was recorded
at 74.57kg (SD = 11.07kg).
Hypothesis Testing
The following hypotheses were investigated for this
study:
Hypothesis 1: An increased Q-angle past the normal average
value will coincide and negatively correlate with tibial
26
valgus and subtalar pronation in static standing posture,
and will lead to the same observed dynamic and functional
postural discrepancies (tibial valgus and subtalar
pronation, as measured by the Overhead Squat and jump
recovery).
Conclusion: As illustrated in Table 1, one of the ten
athletes (10%), Subject 07, exhibited a Q-angle greater
than the normal value of 180. This athlete, furthermore,
was the only subject to exhibit the traits of tibial valgus
and subtalar pronation during all of the assessments of
standing posture, Overhead Squat, and jump recovery in
support of the hypothesis.
Subject 05 had a Q-angle of only 90 (half of the
average measurement), and still presented with tibial
valgus and subtalar pronation in all assessments with the
exception of standing posture. Subject 10, on the other
hand, with the smallest Q-angle of 50, presented tibial
valgus in her standing posture, as well as jump recovery,
but did not exhibit the characteristic in the Overhead
Squat. No other discrepancies were reported.
A Pearson correlation coefficient was calculated to
determine the relationship between standing posture and
performance of the Overhead Squat and jump recovery. A
27
perfect positive correlation was found when comparing the
presence of subtalar pronation during standing posture and
the Overhead Squat (r(9) = 1.00, P = 0.01), indicating a
perfect linear relationship between the two variables.
Subjects with subtalar pronation in standard standing
posture will exhibit subtalar pronation during the
performance of the Overhead Squat. No other correlations
were significant.
28
Table 1. Q-angle Compared to Standing Posture, Overhead Squat, and Jump Recovery
Posture OH Squat Jump Recov
Subj# Q-angle
Valgus Prona tion
Valgus Prona tion
Valgus Prona tion
1. X2. X01 -7
X X
3. X1. X X2. X X02 -6 X 3. X X1. X X2. 03 -11 3. X X1. X 2. X 04 -6 X 3. X 1. 2. X X05 -9 X X X 3. 1. X X2. X X06 -4 X 3. X X1. X X2. X X*07 +2 X X X X 3. X X1. X X2. X X08 -6 3. X X1. X X2. X X09 -5 X X 3. X X1. X X2. X X10 -13 X
3. ____________________________________________ An X indicates presence of the trait during the assessment. Q-angle measurements are noted as deviations from the average value of 180. *Subject 07 exhibited a Q-angle greater than this value, and tibial valgus and pronation was noted throughout all of her assessments.
29
Hypothesis 2: Discrepancies in hip active range of motion,
specifically decreased hip abduction, extension, and/or
external rotation, and increased hip adduction, flexion,
and/or internal rotation past the normal values, will
result in tibial valgus and subtalar pronation, and will
lead to the same observed dynamic and functional postural
discrepancies (tibial valgus and subtalar pronation, as
measured by the Overhead Squat and jump recovery).
Conclusion: As illustrated in Table 2, none of the subjects
exhibited all of the anticipated deviations in active hip
ROM simultaneously, namely decreased abduction, extension,
and external rotation, and increased adduction, flexion,
and internal rotation. Therefore, Hypothesis 2 was not
supported as the hip ROM measurements could not be
correlated with the subjects’ standing posture nor
performance of the Overhead Squat or jump recovery.
30
Table 2. Active Hip ROM Compared to Standing Posture, Overhead Squat, and JumpRecovery
Posture OH Squat Jump Recov
Sub# Flex Ext Abd Add IR ER Valg Pron Valg Pron Valg Pron1. X2. X*01 -3 -1 +4 +24 +3 -1 X X3. X1. X X2. X X02 -32 -8 0 +11 -4 -7 X3. X X1. X X2.*†03 -20 -1 -8 +9 +6 -13. X X1. X2. X04 -11 -5 -13 +4 -1 +21 X3. X1.2. X X*05 -10 -3 +1 +5 +2 +1 X X X3.1. X X2. X X†06 -7 -10 -12 +16 -1 -2 X3. X X1. X X2. X X07 -8 -10 -5 +5 -3 0 X X X X3. X X
31
Sub# Flex Ext Abd Add IR ER Valg Pron Valg Pron Valg Pron1. X X2. X X†08 -16 -13 -2 +6 -1 -53. X X1. X X2. X X*†09 -18 -12 -10 +13 +5 -6 X X3. X X1. X X2. X X10 -41 -17 +1 +8 -11 -16 X3.
_______________________________________________________________Flex indicates hip flexion supine with knee bent and neutral pelvis (Avg. 1220)Ext indicates hip extension prone with knee extended (Avg. 220)Abd indicates hip abduction supine (Avg. 440)Add indicates hip adduction supine (Avg. 100)IR indicates hip internal rotation seated with knee bent to 900 (Avg. 330)ER indicates hip external rotation seated with knee bent to 900 (Avg. 340)Valg indicates tibial valgusPron indicates subtalar pronation
None of the subjects exhibited the proposed patterns of hip range of motion: ↓ abd,ext, and ER, ↑ add, flex, and IR. Therefore, the hip ROM measurements cannot becorrelated with the subjects’ standing posture, performance of the Overhead Squat,or jump recovery. Hypothesis 2 was not supported.*Subjects 01, 03, 05, & 09, showed increased hip IR and add, while †Subjects 03, 06,08, & 09 showed decreased hip ER and abd.Subjects 03 and 09 exhibited all assumptions but increased hip flexion.
32
Additional Findings
Following the testing of the hypotheses, the data was
analyzed for any further findings. Upon analysis of Table
3, all ten of the subjects (100%) exhibited tibial valgus
and/or subtalar pronation during jump recovery. Only one
of the ten (10%), Subject 01, did not demonstrate tibial
valgus while pronating, and only one of the ten (10%),
Subject 04, did not demonstrate subtalar pronation while
allowing tibial valgus. The only occurrences when neither
of these characteristics was noted was when the subject
recovered with knees fully extended rather than allowing
the knees to flex to absorb the impact. However, only two
of the seven subjects (28.6%) who had anecdotally reported
previous injury recovered from jumping with this supposed
problematic position of knees fully extended. Subjects 03,
05, and 10 support this conclusion, since they present with
tibial valgus and subtalar pronation during one or two of
the trials, and with knees fully extended during the other
trial(s). Conversely, Subject 07’s third trial presents
tibial valgus, subtalar pronation, and knee extension
simultaneously.
Of the 10 subjects, seven women (70%) had anecdotally
reported previous history of knee injury. Two of these
33
seven (28.6%, Subjects 04 and 09), injured athletes had
sustained an ACL tear, four (57.1%, Subjects 02, 06, 08,
and 10), had patellar tendonitis, and one (14.3%, Subject
07), had a history of subluxing patella. One of the ACL-
injured women sustained trauma in 1999, and the other in
July of 2004. Three of the four (75%) athletes with
patellar tendonitis had reported a micro-trauma within the
past five months. The athlete with a history of subluxing
patella has not had an occurrence since 1996. None of the
subjects with tendonitis or subluxing patella required
surgery, however, both of the ACL victims necessitated
surgical repair.
All seven subjects (100%) who reported a history of
knee injuries produced tibial valgus, if not both traits,
during jump recovery. Subject 04, with a previous medical
history of the female athlete triad (ACL, MCL, and medial
meniscus), was the only subject to possess only tibial
valgus, not both characteristics. On the other hand,
Subjects 01, 03, and 05, have never sustained knee
pathology, but presented at least one of the traits during
jump recovery. Subject 05 demonstrated both
characteristics during the Overhead Squat.
34
Table 3. Knee Pathology Compared to Standing Posture, Overhead Squat, and Jump Recovery
Posture OH Squat Jump Recovery
Subj#
Knee Injury
Valg Pron ation
Valg Pron ation
Valg Pron ation
Knee Ext
1. X2. X01
X X
3. X1. X X2. X X†02 X X 3. X X1. X X2. *X 03 3. X X1. X 2. X †04 X X 3. X 1. *X 2. X X05 X X X 3. *X 1. X X2. X X†06 X X 3. X X1. X X2. X X†07 X X X X X 3. X X *X1. X X2. X X†08 X 3. X X1. X X2. X X†09 X X X 3. X X1. X X2. X X†10 X X
3. *X____________________________________________ Knee ext indicates that subject landed with knees fully extended. An X indicates presence of the trait. All subjects presented with one of the traits, if not both, during jump recovery. *The only occurrences when neither of these characteristics was noted was when the athlete recovered with knees fully extended. †All seven subjects who reported a history of knee injuries produced tibial valgus, if not both traits, during jump recovery.
35
With regards to menstruation, of the three women who
lacked a normal menstrual cycle, two (66.67%) had never
sustained a knee injury, and of the seven remaining women
who menstruate regularly, six (85.71%) have sustained a
knee injury. This leads to the conclusion that hormonal
changes may effect the physiological factors that affect
knee stability; however, more research would need to be
collected to correlate the menstrual cycle with the time of
injury.
As additional information, the following vertical jump
heights were also recorded in Table 4. No other measures
strongly nor significantly correlate with jump height.
36
Table 4. Vertical Jump Heights for 10 Division II Female Volleyball Athletes
____________________________________________ Additional information showing jump heights of all the participating athletes X = 42.80cm, SD = 5.82cm
37
DISCUSSION
To discuss the findings of this study, the following
sections are presented: (1) Discussion of Results, (2)
Conclusions, and (3) Recommendations.
Discussion of Results
The primary purpose of this study was to investigate
the relationship between standing posture, active hip range
of motion, and postural control in female collegiate
Volleyball athletes. With the increased prevalence of knee
injuries in female athletics, the athletic trainer is faced
with many concerns regarding his/her athletes’ safety and
well-being, especially those working with repetitive
jumping athletes.
Lack of postural control, stemming from core and
lumbo-pelvic hip complex weaknesses, is a suggested cause
of knee injury.3,6 With improper muscle recruitment patterns
in the hip, and possibly even the entire lower extremity,
come muscular imbalances and compensatory movements.
Faulty posture has been noted as a factor in causing these
imbalances.3-5,19 Discrepancies in the hip lead to
discrepancies further down the kinetic chain, such as
38
increased Q-angle, tibial valgus, and subtalar pronation,
posing a lot of stress on the soft tissues of the
vulnerable knee.4,5,12,19
The Overhead Squat and the jump recovery assessments
can be useful tools when evaluating athletes’ functional
movement and neuromuscular control.19,23 The specialist who
is conducting the assessment can appropriately analyze the
athletes’ capabilities of creating force, stabilizing
against force, and reducing the impact of force, which can
be compared to their performance in actual sport. Again,
without a stable core, these impacts may be transferred to
weaker components of the body, like muscles and joints.
According to Lathinghouse and Trimble, Q-angle decreases
with an isometric quadriceps contraction, and the magnitude
of this decrease is dependent upon the magnitude of the Q-
angle at rest.28 An excessive Q-angle may predispose women
to greater lateral displacement of the patella during
rigorous activities and sports in which the quadriceps
muscle is stressed.28 In support of Guerra, an increased Q-
angle, according to this study, does tend to create more
valgus at the tibiofemoral joint; however, it is not the
only reason tibial valgus occurs.26 The only athlete to have
a Q-angle past the normal average was the only athlete to
also possess tibial valgus and subtalar pronation
39
throughout all of the assessments. However, many of the
athletes presented with tibial valgus in the assessments
even without a Q-angle greater than the average of 180.
This information suggests that the incorrect mechanics
likely happen due to improper education on jumping
correctly, compensatory motions possibly resultant from
injury, and lack of postural control of the hip and knee
musculature.7,10,12
Typically, when characteristics such as tibial valgus
and subtalar pronation are observed in standard posture,
one could assume they would be distinguished during
movement. If an athlete does not have the correct muscular
recruitment to stand in an ideal posture, then why would
they not display these patterns in a functional activity?
Chances are, if the characteristics noted during standing
posture are not also noted during functional activity,
these anomalies are structural more so than functional (ie,
an increased Q-angle).3,4,13 Conversely, only subtalar
pronation in standard posture correlated with subtalar
pronation during the Overhead Squat. This does not
specifically support nor refute Lephart’s reasoning that
postural discrepancies of standing posture will be
replicated while in motion.4,13 This could mean that athletes
are finding other ways to control for the unwanted tibial
40
valgus, for example, by limiting hip and knee flexion as
exhibited in the study. According to the data, when an
athlete landed with knees fully extended, and therefore
hips minimally flexed, they did not exhibit the tibial
valgus that may have been presented in the postural
assessment and Overhead Squat. No other correlations were
made between the static measures and the dynamic and
functional measures.
As with Q-angle, active hip range of motion is an
important variable when considering an athletes’ mechanics.
Suitable length-tension relationships are vital when
performing dynamic and functional movements.18,22 If one
muscle or muscle group is too tight, the body will
compensate and potentially cause injury. The same happens
when a muscle or muscle group does not produce the correct
amount of tension. Typically, certain patterns may be
witnessed; if one muscle group is shortened, other muscle
groups may shorten also, and opposing muscle groups may be
lengthened and become less-productive to adjust to this
tightness or over-productivity.18,19,22
In this case, probable characteristics for Volleyball
athletes’ active hip range of motion that may cause them to
present with tibial valgus and subtalar pronation were
considered. Specifically, the following deviations were
41
expected: weak gluteals and external rotators resulting in
decreased hip abduction, extension, and external rotation,
and tight adductors and hip flexors resulting in increased
adduction, flexion, and internal rotation. However, no
subjects followed this pattern precisely. On the other
hand, two of the subjects exhibited all of the desired AROM
relationships except for increased hip flexion. Perhaps
hip flexion is not a significant constituent of this
pattern. While jumping, some athletes may reduce the
amount of hip flexion, and thus knee flexion, to control
the amount of tibial valgus being permitted. This could
also possibly be due to the fact that neutral pelvis was
maintained for the flexion measurements, as well as the
rest of the measurements, but could not be accounted for
during the functional movements. Consequently, some
athletes may subconsciously attempt to correct the faulty
mechanics of the lower extremity by wrongly adjusting the
pelvis from a neutral position. However, the researcher
did not observe for nor document pelvic position during the
Overhead Squat or jump recovery. Roach and Miles did not
report that pelvic position was standardized when
performing their study on the effect of age on hip and knee
AROM.18 Neutral pelvis could be assumed in this case; but in
the event that it was not maintained, it may have skewed
42
the interpretation of the AROM data because additional
motion was permitted in the pelvis when Roach and Miles
performed their AROM assessments.
In support of Hass’s and Ashley’s findings, all ten of
the subjects exhibited one, if not both, of the traits
(tibial valgus and subtalar pronation) during the jump
recovery.10,23 One interesting finding was that the only time
that they did not have signs of the anomalies was when they
landed with knees fully extended. In addition, all seven
of the subjects who had reported a history of knee injury
coincidently demonstrated tibial valgus, if not both traits
during the jump recovery, indicating that this uncontrolled
motion may be a culprit for pathology.
In addition to improper mechanics posing additional
stress on stabilizing structures during functional
activity, hormonal changes have been found to have an
effect on the physiological factors that affect knee
stability, according to Wojtys.9 In support of her
conclusions, two of the three (66.7%) athletes with
amenorrhea had never sustained a knee injury, while six of
the seven (85.7%) regularly menstruating participants had.
These findings seem to support the belief that hormonal
productions present in menstruating women could potentially
weaken the static supports of certain articulations.
43
Conclusions
Q-angle was directly correlated with the presence of
tibial valgus and subtalar pronation during standing
posture, dynamic activity, and functional activity. As
well, subtalar pronation in standing posture was directly
correlated with pronation while squatting. However,
patterns among hip AROM were not as conclusive. Perhaps
this could indicate that a functionally sound performance
of the Overhead Squat and jump recovery is not dependant
upon the subjects’ hip AROM measurements. Otherwise,
subjects’ may subconsciously adjust pelvic position to
compensate for abnormal length-tension relationships
occurring at the hip. Furthermore, all ten of the subjects
exhibited tibial valgus and/or subtalar pronation during
jump recovery, suggesting that females have either not
received proper instruction on correct landing biomechanics
or that they are not neuromuscularly efficient enough to
prevent these faulty biomechanics from occurring.
Additionally, females who menstruate regularly may be more
susceptible to injury due to the physiological effect of
hormones on soft tissues’ stability.
44
Recommendations
The researcher makes the subsequent recommendations
for further study related to this topic. Collection of
data from volleyball athletes of other divisions/schools
should be done to limit bias. The results discussed here
are only applicable to athletes of the California
University of Pennsylvania’s Division II Female Volleyball
team, and are intended to represent comparable athletes.
Q-angle should be also measured in standing, in addition
to supine to see if there is any difference noted. Q-angle
in this position takes into account contraction of the
quadriceps to maintain the standing posture.27,28 According
to Lathinghouse and Trimble, Q-angle decreases with an
isometric quadriceps contraction, and the magnitude of this
decrease is dependent upon the magnitude of the Q-angle at
rest.28 An excessive Q-angle may predispose women to greater
lateral displacement of the patella during rigorous
activities and sports in which the quadriceps muscle is
stressed.28
Pelvic position during squatting and landing should be
analyzed to observe for anterior- or posterior-tiling of
the pelvis to compensate for abnormal length-tension
relationships occurring at the hip. This may further
45
explain why the hip AROM measurements did not have any
significant correlations with the Overhead Squat or jump
recovery assessments.
The menstrual cycle should be compared with time of
injury and time of testing. Hormonal changes have been
linked to ligamentous laxity, and furthermore, to the
incidence of knee injury.14,15 It would be interesting to
personally discover precisely when in the menstrual cycle
women are most vulnerable.
46
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4. Tiberio D. Pathomechanics of structural foot deformities.
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J Sports Med. 2003;37(3):279-280.
7. Pollard CD, Davis IM, Hamill J. Influence of gender on hip and knee mechanics during a randomly cued cutting
maneuver. Clin Biomech. 2004;19(10):1022-31. 8. Starkey C, Ryan J. Evaluation of Orthopedic and Athletic Injuries. 2nd ed. Philadelphia, PA: F.A. Davis Company, 2002, 71-79, 120-121, 205-207, 244- 268, 285-293, 303-318. 9. Wojtys EM, Huston LJ, Lindenfeld TN, Hewett TE, Greenfield ML. Association between the menstrual cycle and anterior cruciate ligament injuries in female athletes. Am J of Sports Med. 1998;26:614. 10. Hass CJ, Schick EA, Tillman MD, Chow JW, Brunt D, Cauraugh JH. Knee biomechanics during landings: comparison of pre- and post-pubescent females. Med. Sci. Sports Exerc. 2005;37(1):100-107. 11. Harmon KG, Ireland ML. Gender differences in non- contact anterior cruciate ligament injuries. Clin. Sports Med. 2000;19:287-302.
47
12. Huston LJ, Greenfield ML, Wojtys EM. Anterior cruciate ligament injuries in the female athlete: potential risk factors. Clin. Orthop. 2000;50-63. 13. Lephart SM, Ferris CM, Riemann BL, Myers JB, Fu FH. Gender differences in strength and lower extremity kinematics during landing. Clin. Orthop. 2002;162-169.
14. Heitz NA, Eisenman PA. Hormonal changes throughout the menstrual cycle and increased anterior cruciate ligament laxity in females. J Athletic Training.
1999;34:144.
15. Cheah SH, Ng KH, Johgalingam VT, Ragavan M. The effects of oestradiol and relaxin on extensibility and collagen organization of the pregnant rat cervix. J Endocrinol.
1995;146:331–337. 16. McLean SG, Lipfert SW, Van Den Bogert AJ. Effect of
gender and defensive opponent on the biomechanics of sidestep cutting. Med Sci Sports Exerc. 2004;36(6): 1008-1016. 17. Norkin CC, White DJ. Measurement of Joint Motion: A
Guide to Goniometry. 3rd ed. Philadelphia,PA: F.A. Davis Co,2003, 176-186.
18. Roach KE, Miles TP. Normal hip and knee active range of motion: the relationship to age. Phys Ther. 1991;71:656 19. Clark MA, Russell AM. NASM OPT: Optimum Performance
Training for the Performance Enhancement Specialist. 1st ed. Calabasas, CA: National Academy of Sports Medicine,
2001, 93-114, 187-241. 20. Kendall FP, McCreary EK, Provance PG. Muscles: Testing and Function. 4th ed. Philadelphia, PA: Lippincott Williams & Wilkins, 1993, 32. 21. Berryman-Reese N, Bandy WD. Joint Range of Motion and Muscle Length Testing. Philadelphia, PA: W.B. Saunders Co., 2002, 49-50. 22. Simoneau GG, Hoenig KJ, Lepley JE, Papanek PE. Influence of hip position and gender on active hip internal and external rotation. J Orthop Sports Phys Ther. 2001;28:158-164.
48
23. Ashley CD, Weiss LW. Vertical jump performance and
selected physiological characteristics of women. Journal of Strength and Conditioning Research. 1994;8:5-11. 24. MF Athletic Company. 2004. Available at
25. Power K, Behm D, Cahill F, Carroll M, Young W. An acute bout of static stretching: effects on force and jumping performance. Med Sci Sports Exerc. 2004;36: 1389-1396. 26. Guerra JP, Arnold MJ, Gajdosik RL. Q-angle: effects of isometric quadriceps contraction and body position. J
Orthop Sports Phys Ther. 2002;19:200. 27. Di Brezzo R, Fort LI, Hall K. Q angle: the relationship with selected dynamic performance variables in women. Clinical Kinesiology. 1996;50(3):66-70. 28. Lathinghouse LH, Trimble MH. Effects of isometric quadriceps activation on the Q-angle in women before and after quadriceps exercise. J Orthop Sports Phys Ther. 2000;30(4):211-216.
49
APPENDIX A
Review of the Literature
50
Introduction
The prevalence of knee injuries is a serious problem
for athletic trainers, particularly those working with
female athletes. Knee injuries have been traced back to
defects such as: lack of core strength, lower-crossed
syndrome, increased Q-angle, genu valgum, pes
planus/pronation, as well as imbalances in flexibility and
functional range of motion.1,2 While core stability and
postural control is a necessary component to every
athlete’s training regimen, its beneficial effects on power
and function have often been ignored.2
The kinetic chain works synergistically to produce
force concentrically, reduce force eccentrically, and
dynamically stabilize isometrically against abnormal
forces. When functionally efficient, each component of
the core disperses weight, absorbs force, and transfers
ground reaction forces.2 Core strength is also mandatory,
specifically in lower extremity dominant sports, to
provide proximal stability while in competition.2,3 If the
distal musculature is strong but the core is weak, there
will not be enough force created to produce or control
efficient movements. A weak core is a typical cause of
inefficient movements that could lead to injury.2,3
51
Neuromuscular efficiency is promoted by the
appropriate combination of postural alignment (static and
dynamic) and stability, which allows the body to absorb
momentum at the correct joint, in the correct plane, and at
the correct time.2 As this efficiency decreases, so does the
body’s ability to react accordingly to abnormal forces.
This could potentially lead to compensation and
substitution patterns, as well as poor posture during
functional activities.4 Pathology of structures within the
neuromusculoskeletal system can result from skeletal
malalignment, which has been defined as either abnormal
joint alignment or deformity within a bone. Pathology can
also result from correlated or compensatory motions or
postures, which may accompany skeletal malalignment.5,6
Consequently, mechanical stress is placed on the static
(ligaments and bones) and dynamic (muscles and tendons)
tissues causing repetitive microtrauma, incorrect
mechanics, and injury.4 Sometimes this overloading of joints
and small muscles is due to the core not sufficiently
contributing to the effort.2 Therefore, stability and
movement are critically dependent on the coordination of
all the muscles surrounding the lumbo-pelvic hip complex.5
It is imperative to link common lower limb skeletal
52
malalignments to their correlated and compensatory motions
and postures.5,6
If more athletic trainers and coaches were aware of
their role in optimal performance, core stability, postural
control, and functional flexibility might be incorporated
more readily into every athlete’s conditioning program.
However, do we as athletic trainers know enough about these
matters to correct improper mechanics and potentially
prevent episodes like these from occurring?
This paper will review: (1) The Importance of Core
Stability, (2) Postural Deviations, (3) Functional Range of
Motion of the Lower Extremity, and (4) Knee Injuries Often
Sustained by Female Jumping Athletes.
Core Stability
Composition of the Core
The core is sometimes referred to as the lumbo-pelvic-
hip complex and is where the human body’s center of gravity
resides. All motion stems from this “core”, comprised of
29 muscles.2,7 To better comprehend what goes into core
training, it is imperative to have a good understanding of
these muscles that supply the entire kinetic chain with
neuromuscular control and efficiency. The core can be
53
thought of as a box with the abdominals in the front, the
paraspinals and gluteals in the back, the diaphragm as the
roof, and the hip musculature as the bottom. Combined,
these muscle groups create stabilization and force-couple
relationships that normal function is dependent upon.2,7
The lumbar muscles that contribute to core
stabilization are the transversospinalis group, erector
spinae, quadratus lumborum, and latissimus dorsi. The
abdominals consist of the rectus abdominis, external
oblique, internal oblique, and transversus abdominis.8 The
transversus abdominis is the most important abdominal
muscle because it is active during all trunk movements and
contracts before any other abdominal prior to the
initiation of any limb motion. The back and abdominal
muscles combined provide sagittal, frontal, and transverse
plane stabilization by controlling forces that are applied
to the body. The core-stabilizing hip muscles are
comprised of the iliacus, psoas, gluteus medius, gluteus
maximus, and hamstrings. Any disruption of these force-
couples can place the body in incorrect alignment and
predispose an athlete to postural imbalances, unnecessary
body aches, and potential injury.8
54
Importance of Core Strengthening
When normal length-tension relationships are
established, the body is provided with an environment to
allow optimal arthrokinematics during functional kinetic
chain movements. The kinetic chain works synergistically
to produce force concentrically, reduce force
eccentrically, and dynamically stabilize isometrically
against abnormal forces.2 When functionally efficient, each
component of the core disperses weight, absorbs force, and
transfers ground reaction forces. Core strength is also
mandatory, specifically in lower extremity sports, to
provide proximal stability while in competition. If the
extremity muscles are strong but the core is weak, there
will not be enough force created to produce efficient
movements. Again, a weak core is a typical cause of
inefficient movements that lead to injury.3
All athletes should incorporate core stability into
their conditioning to gain neuromuscular control, strength,
power, and muscular endurance of the lumbo-pelvic hip
complex. Neuromuscular efficiency is promoted by the
appropriate combination of postural alignment (static and
dynamic) and stability strength, which allows the body to
absorb momentum at the correct joint, in the correct plane,
and at the correct time. As this efficiency decreases, so
55
does the body’s ability to react accordingly to abnormal
forces. This could potentially lead to compensation and
substitution patterns, as well as poor posture during
functional activities.8 Consequently, mechanical stress is
placed on the static (ligaments and bones) and dynamic
(muscles and tendons) tissues causing repetitive
microtrauma, incorrect mechanics, and injury. Therefore,
stability and movement are critically dependent on the
coordination of all the muscles surrounding the lumbo-
pelvic hip complex.
Athletes with poor posture, asymmetries in stance and
gait, chronic or repetitive injuries, overuse or non-
traumatic injuries such as tendonitis, patellofemoral
dysfunction, or non-contact ACL injuries are good
candidates for application of core stabilization.
Sometimes this overloading of joints and small muscles is
due to the core not doing its share of the work.2 However,
before any implementation of strengthening can occur, an
assessment should be performed to provide a basis of the
athlete’s capabilities of core stability.
Assessment of Core Strength and Stability
Prior to the commencement of a core stabilization
program, a baseline assessment should be administered to
56
determine the athlete’s muscle imbalances, arthrokinematic
genuvalgum, pes planus/pronation, as well as imbalances in
flexibility and functional range of motion.1,2 While core
stability and postural control is a necessary component to
every athlete’s training regimen, its beneficial effects on
power and function have often been ignored.2 If more
athletic trainers and coaches were aware of their role in
optimal performance, core stability and postural control
might be incorporated more readily into every athlete’s
conditioning program. However, do we as athletic trainers
know enough about core stability and postural control to
correct these improper mechanics and potentially prevent
episodes like these from occurring? This thesis will
attempt to correlate standing posture, hip range of motion,
and postural control in female athletes to possibly promote
incorporation of these vital concepts into rehabilitation
for the purposes of prevention of initial injury, as well
as recurrence of injury.
86
APPENDIX C
Additional Methods
87
APPENDIX C1
Informed Consent
88
Informed Consent Form
1. “Catie Dougherty, ATC, who is a Graduate Athletic Training Student, has requested my participation in a research study at this institution. The title of the research is The Relationship between Standing Posture, Functional Hip Range of Motion, and Postural Control in Female Collegiate Volleyball Players.”
2. "I have been informed that the purpose of the research is to correlate postural defects and functional hip range of motion with measures of postural control in the female Division II volleyball athletes." 3. "My participation will involve evaluation of my posture, hip range of motion, and performance of two (2) functional tests (Overhead Squat and vertical jump). It will require one session of approximately 30-40 minutes of my time and will be video-taped for optimal analysis." 4. "Delayed onset muscle soreness (DOMS) is the only foreseeable risk with the performance of this study, however, I will perform the warm-up as advised. This risk is no different than what is possible in a normal volleyball practice session.” 5. "There are no feasible alternative procedures available for this study." 6. “I am aware that performance of the tests will be video- taped for later analysis by only the researcher and the research advisor.” 7. "I understand that the possible benefits of my participation in the research are to contribute to existing research, enhance injury prevention and understand mechanisms of injury, and/or to enhance the rehabilitative process of my withstanding injury.” 8. "I understand that the results of the research study may
be published but that my name or identity will not be revealed. In order to maintain confidentiality of my records, Catie will maintain all documents in a secure location in which only the student researcher and research advisor can access."
89
9. "I have been informed that I will not be compensated for my participation."
10. “I have been informed that any questions I have concerning the study or my participation in it, before or after my consent, will be answered by Catie Dougherty, ATC, [email protected], (412)480-6486, and/or Rebecca A. Hess, Ph.D., [email protected], (724)938-4359.
11. “I understand that written responses may be used in quotations for publication but my identity will remain anonymous.” 12. "I have read the above information. The nature, demands, risks, and benefits of the project have been explained to me. I knowingly assume the risks involved, and understand that I may withdraw my consent and discontinue participation at any time without penalty or loss of benefit to myself. In signing this consent form, I am not waiving any legal claims, rights, or remedies. A copy of this consent form will be given to me upon request."
Subject's signature________________________________________ Date _______________
13. "I certify that I have explained to the above individual the nature and purpose, the potential benefits, and possible risks associated with participation in this research study, have answered any questions that have been raised, and have witnessed the above signature." 14. "I have provided the subject/participant a copy of this signed consent document if requested."
Ref. Roach and Miles33(p32) *Adduction value obtained from Kendall, McCreary, and
Provance34(p32)
102
APPENDIX C6
Overhead Squat Assessment
103
TOTAL BODY PROFILE Overhead Squat Objective: To observe for total body neuromuscular efficiency, integrated functional strength and functional flexibility Foot and Ankle
Feet flatten (pronate): Y / N � Externally rotate (turn out): Y / N Knees
Knees buckle inward: Y / N � Knees bow outward: Lumbo-Pelvic-Hip Complex
Asymmetrical weight shifting: Y / N � Low back arches: Y / N � Low back rounds: Y / N � Abdomen protrudes: Y / N Shoulder Complex
Shoulder protraction/abduction: Y / N � Shoulder elevation: Y / N � Scapular winging: Y / N Head
Forward Head: Y / N
104
REFERENCES
1. Prentice WE. Rehabilitation Techniques for Sports Medicine and Athletic Training. 4th ed. New York, NY: McGraw-Hill Companies Inc., 2004, Ch 10:201-223. 2. Akuthota V, Nadler SF. Core strengthening. Arch Phys Med Rehabil. 2004;85(3 Suppl 1):S86-92.
3. Mitchell B, Colson E. Lumbopelvic mechanics. British J Sports Med. 2003;37(3):279-280.
4. Krivickas LS. Anatomical factors associated with overuse sports injuries. Sports Med. 1997;24:132. 5. Massie DL, Haddox A. Influence of lower extremity biomechanics and muscle imbalances on the lumbar spine.
J Orthop Sports Phys Ther. 1999;4:46. 6. Tiberio D. Pathomechanics of structural foot deformities. Phys Ther. 1998;68:1840. 7. Clark MA, Russell AM. NASM OPT: Optimum Performance
Training for the Performance Enhancement Specialist. 1st ed. Calabasas, CA: National Academy of Sports Medicine,
2001, 93-114, 187-241. 8. Bagnall D, Gray G. Functional rehabilitation for low back pain: functional restoration and the lower extremity functional profile. North American Spine Society. 2001. Available at: http://www.spine.org/articles/rehab_lowbackpain.cfm.
9. Wallmann H, Mirabito J. Low back pain:is it really all behind you? An excellent 7-step abdominal strengthening program. ACSM’s Health and Fitness J.
1998;2(5):30-35. 10. Drysdale CL, Earl JE, Hertel J. Surface electromyographic activity of the abdominal muscles during pelvic-tilt and abdominal-hollowing exercises. J Athl Train. 2004;39(1):32-36. 11. Hildenbrand K, Noble L. Abdominal muscle activity while performing trunk-flexion exercises using the Ab Roller, ABslide, FitBall, and conventionally performed trunk
105
curls. J Athl Train. 2004;39(1):37-43. 12. Konrad P, Schmitz K, Denner A. Neuromuscular evaluation of trunk-training exercises. J Athl Train.
2001;36(2):109-118.
13. Sternlicht E, Rugg S. Electromyographic analysis of abdominal activity using portable abdominal exercise devices and a traditional crunch. J Strength Cond Res. 2003;17(3):463-468.
14. Willett GM, Hyde JE, Uhrlaub MB, Wendel CL, Karst GM. Relative activity of abdominal muscles during commonly prescribed strengthening exercises. J
Strength Cond Res. 2001;15(4):480-485.
15. Guerra JP, Arnold MJ, Gajdosik RL. Q-angle: effects of isometric quadriceps contraction and body position. J
GD. The relationship between clinical measurements of lower extremity posture and tibial translation. Clinical Biomechanics. 2002;17(4):286-290. 17. Norkin CC, White DJ. Measurement of Joint Motion: A
Guide to Goniometry. 3rd ed. Philadelphia, PA: F.A. Davis Co, 2003, 176-186.
18. Starkey C, Ryan J. Evaluation of Orthopedic and Athletic Injuries. 2nd ed. Philadelphia, PA: F.A. Davis Company, 2002, 71-79, 120-121, 205-207, 244- 268, 285-293, 303-318. 19. Powers CM, Chen P, Reischl SF, Perry J. Comparison of foot pronation and lower extremity rotation in persons with and without patellofemoral pain. Foot and Ankle International. 2002;23(7):634-640. 20. Svenningsen S, Terjesen T, Auflem M, Berg V. Hip motion related to age and sex. Acta Orthop Scand. 1999;60:97- 100. 21. Simoneau GG, Hoenig KJ, Lepley JE, Papanek PE. Influence of hip position and gender on active hip internal and external rotation. J Orthop Sports Phys Ther. 2001;28:158-164.
106
22. Pollard CD, Davis IM, Hamill J. Influence of gender on hip and knee mechanics during a randomly cued cutting
maneuver. Clin Biomech. 2004;19(10):1022-31. 23. McLean SG, Lipfert SW, Van Den Bogert AJ. Effect of gender and defensive opponent on the biomechanics of sidestep cutting. Med Sci Sports Exerc. 2004;36(6): 1008-1016. 24. Wojtys EM, Huston LJ, Lindenfeld TN, Hewett TE, Greenfield ML. Association between the menstrual cycle and anterior cruciate ligament injuries in female athletes. Am J of Sports Med. 1998;26:614. 25. Hass CJ, Schick EA, Tillman MD, Chow JW, Brunt D, Cauraugh JH. Knee biomechanics during landings: comparison of pre- and post-pubescent females. Med. Sci. Sports Exerc. 2005;37(1):100-107. 26. Harmon KG, Ireland ML. Gender differences in non- contact anterior cruciate ligament injuries. Clin. Sports Med. 2000;19:287-302. 27. Huston LJ, Greenfield ML, Wojtys EM. Anterior cruciate ligament injuries in the female athlete: potential risk factors. Clin. Orthop. 2000;50-63 28. Lephart SM, Ferris CM, Riemann BL, Myers JB, Fu FH. Gender differences in strength and lower extremity kinematics during landing. Clin. Orthop. 2002;162-169.
29. Heitz NA, Eisenman PA. Hormonal changes throughout the menstrual cycle and increased anterior cruciate ligament laxity in females. J Athletic Training.
1999;34:144.
30. Cheah SH, Ng KH, Johgalingam VT, Ragavan M. The effects of oestradiol and relaxin on extensibility and collagen organization of the pregnant rat cervix. J Endocrinol.
1995;146:331–337.
31. Lin F, Wang G, Koh JL, Hendrix RW, Zhang L. In vivo and noninvasive three-dimensional patellar tracking induced by individual heads of the quadriceps. Med Sci Sports Exerc. 2004;36(1):93-101.
107
32. Smith LK, Weiss EL, Lehmkuhl LD. Brunnstrom’s Clinical Kinesiology. 5th ed. Philadelphia, PA: F.A. Davis Co.,1996. 33. Roach KE, Miles TP. Normal hip and knee active range of motion: the relationship to age. Phys Ther. 1991;71:29- 38. 34. Kendall FP, McCreary EK, Provance PG. Muscles: Testing and Function. 4th ed. Philadelphia, PA: Lippincott Williams & Wilkins, 1993, 32.
108
ABSTRACT
Title: The Relationship between Standing Posture, Functional Hip Range of Motion, and Postural Control in Female Collegiate Volleyball Players
Researcher: Catherine L. Dougherty Adviser: Dr. Rebecca Hess Purpose: The purpose of this study was to portray any
correlation between standing posture, active hip range of motion, and postural control in female collegiate volleyball players. The results were used to outline a potential profile for injury prevention in this susceptible population.
Methods: Ten members of the California University of
Pennsylvania’s Female Volleyball team participated in the study. The subjects’ Q-angle, active hip range of motion, standing posture, and performance of the Overhead Squat and jump recovery were analyzed for characteristics that would generate a female volleyball players’ profile and could potentially lead to injury. Frequency tables and Pearson Correlations were used to analyze the data.
Findings: The amount of Q-angle can be correlated with
the performance of the assessments. The sole athlete who possessed a Q-angle greater than the average exhibited tibial valgus and subtalar pronation throughout all of the assessments. Subtalar pronation in standing posture can be correlated with pronation while squatting. However, no direct correlation between active hip range of motion, standing posture, and performance of the assessments were reported. Additionally, all ten subjects displayed at least one of the supposed traits during jump recovery. The only incidence when neither trait was exhibited was when the athlete recovered with knees fully extended. All
109
seven subjects who reported a history of knee injuries produced tibial valgus, if not both traits, during jump recovery. With regards to menstruation, of the three women who lacked a normal menstrual cycle, two had never sustained a knee injury, and of the seven remaining women who menstruate regularly, six have sustained a knee injury.
Conclusions: Q-angle is directly correlated with the presence of tibial valgus and subtalar pronation during standing posture, dynamic activity, and functional activity.
Subtalar pronation in standing posture can be correlated with pronation while
squatting. However, patterns among active hip range of motion were not as conclusive.
Perhaps this could indicate that a functionally sound performance of the Overhead Squat and jump recovery is not dependant upon the subjects’ active hip range of motion measurements. Otherwise, subjects’ may subconsciously adjust pelvic position to compensate for abnormal length- tension relationships occurring at the hip. Furthermore, all ten of the subjects exhibited tibial valgus and/or subtalar pronation during jump recovery, suggesting that females have either not received proper instruction on correct landing biomechanics or that they are not neuromuscularly efficient enough to prevent these faulty biomechanics from occurring. Additionally, females who menstruate regularly may be more susceptible to injury due to the physiological effect of hormones on soft tissues’ stability.