Development of an Automatic Functional Movement Screening System with Inertial Measurement Unit Sensors

• Main Authors: Wen-Lan Wu, Meng-Hua Lee, Hsiu-Tao Hsu, Wen-Hsien Ho, Jing-Min Liang
• Format: Article
• Language: English
• Published: MDPI AG 2021-12-01
• Series: Applied Sciences
• Subjects: FMS; IMU sensor; machine learning; ordinal logistic regression; confusion matrix; kappa
• Online Access: https://www.mdpi.com/2076-3417/11/1/96

Background: In this study, an automatic scoring system for the functional movement screen (FMS) was developed. Methods: Thirty healthy adults fitted with full-body inertial measurement unit sensors completed six FMS exercises. The system recorded kinematics data, and a professional athletic trainer graded each participant. To reduce the number of input variables for the predictive model, ordinal logistic regression was used for subset feature selection. The ensemble learning algorithm AdaBoost.M1 was used to construct classifiers. Accuracy and F score were used for classification model evaluation. The consistency between automatic and manual scoring was assessed using a weighted kappa statistic. Results: When all the features were used, the predict model presented moderate to high accuracy, with kappa values between fair to very good agreement. After feature selection, model accuracy decreased about 10%, with kappa values between poor to moderate agreement. Conclusions: The results indicate that higher prediction accuracy was achieved using the full feature set compared with using the reduced feature set.