Determination of shoulder range of motion

Abstract

The shoulder joint is undoubtedly one of the most important joints in the human body as it is needed to independently carry out essential daily activities such as drinking and combing. It allows for high degrees of mobility and a myriad of complex motions. However, due to the high degrees of mobility, the shoulder is susceptible to injuries and disorders. Also, the shoulder joint condition differs between people due to factors such as age and gender. Therefore, it is important to be able to measure and quantify the range of motion to accurately assess one’s shoulder condition to provide the necessary treatments. This study investigates the shoulder range of motion (ROM) using a globe model and inertial measurement unit (IMU). In recent years, the globe model was introduced to analyse the kinematics and humerus motion at any location. The globe model, unlike the orthogonal planes system, can quantify all motions unambiguously, which will be helpful in describing the activities of daily living (ADLs) motions which occur in more than just one plane. This study makes use of an open-loop globe model to fully quantify the ROM of the shoulder to allow a quick and easy visualisation of each individual’s ROM. In this study, 21 subjects aged 24 to 26 years old, with no history of shoulder injuries were recruited. The subjects had to perform 8 ADLs, 6 standard ROMs and a global ROM (GROM), and these motions were captured with the optical motion capture system. Additionally, 4 of the ROMs were captured simultaneously with IMUs to validate the accuracy of the MATLAB programme. This study showed a significant difference (p < 0.05) in ROM when compared to a similar group of subjects recruited for FYP 19/20 for almost all 15 captured motions. However, there were generally no significant differences (p > 0.05) when comparing IMU results to those of the MATLAB programme.