Facilitating Trunk Endurance Assessment by means of Mobile Health Technologies Oresti Banos, Jaehun Bang, Donguk Kang, Choong Seon Hong, Sungyoung Lee Ubiquitous Computing Lab, Department of Computer Engineering, Kyung Hee University, Korea [email protected] Trunk endurance tests are widely used in physical medicine to assess the muscle status of people affected by low back pain. Nevertheless, traditional evaluation procedures suffer from practical limitations, which can lead to potential misdiagnoses. This work presents mDurance, a novel mobile health system aimed at supporting specialists in the functional assessment of trunk endurance by using wearable and mobile devices. The system makes use of a wearable inertial sensor to track the patient trunk posture, while portable electromyography sensors are employed to seamlessly measure the electrical activity produced by the trunk muscles. The information registered by the sensors is processed and managed by a mobile application that facilitates the expert normal routine, while reducing the impact of human errors and expediting the analysis of the test results. The reliability and usability of mDurance is proved through a case study, thus demonstrating its potential interest for regular physical therapy routines. Keywords : Mobile Health ; Physical Therapy ; Trunk Endurance ; Inertial Sensors ; EMG Sensors Abstract Trunk Endurance Assessment - TEA The system consists of a wearable inertial sensor to estimate the trunk position and an attachable electromyography sensor to measure the activity of the skeletal muscles of the trunk. The sensor data is transmitted to a mobile application for the data processing and analysis. The app automatically estimates the duration of the test, presents the physiological responses of the patient and generates reports summarizing the patient status and evolution. mDurance: a Novel Mobile Health System for TEA This work was supported by the Industrial Core Technology Development Program (10049079, Development of mining core technology exploiting personal big data) funded by the Korean Ministry of Trade, Industry and Energy. This work was also supported by the Junta de Andalucia Project P12- TIC-2082 and FPU Spanish Grant AP2012-1789. Jose Antonio Moral Munoz, Ignacio Diaz Reyes, Manuel Arroyo Morales, Miguel Damas, Hector Pomares, Ignacio Rojas, Claudia Villalonga Research Centre for Information and Communications Technology, University of Granada, Spain mDurance App mDurance Sensors mDurance Core Technology ACC, GYR, MAG, EMG Ten volunteers (8 males and 2 females, 21-37 years old) were recruited to be evaluated by three external physical therapists using both mDurance and traditional procedures: • In the traditional approach experts had to visually determine the start and end of each test and time it using a stopwatch ΔT traditional • When using mDurance these processes were automated ΔT mDurance Evaluation Inter-rater reliability • Measures the agreement between both methods (ΔT traditional – ΔT mDurance ) • All the differences fall within the limits of agreement, thus confirming that both methods can be used interchangeably Usability • Experts appreciate the practicality of the automatic angle measurement to determine the user start position and to estimate the end-of-test • They also value the EMG online representation to observe the muscle contraction during the test • System Usability Scale (SUS) scores indicated high levels of acceptability, ease of use and confidence when utilizing mDurance Acknowledgements TEA consists in the measurement of the time a person can hold a specific posture involving the trunk muscles : • The Sorensen test is the most common medical procedure for TEA • The subject has to hold a horizontal unsupported posture while extending the upper body beyond the edge of a bench • The timing begins when the posture is horizontal and unsupported, and the test ends when a) the position is held 240s or b) the trunk position drops >10° High Subjectivity Limitations of traditional TEA : • The human expert has to estimate the start and end visually • The expert has to supervise various aspects simultaneously, such as time, position, and possible abnormalities during the test • Specialists elaborate their diagnosis on the recorded time, and that is the only information to compare with in future tests