J Korean Orthop Assoc.  2021 Feb;56(1):68-75. 10.4055/jkoa.2021.56.1.68.

Investigation for Shoulder Kinematics Using Depth Sensor-Based Motion Analysis System

• Lee I
• Park JH
• Son DW
• Cho Y
• Ha SH
• Kim E

• KMID: 2512898
• DOI: http://doi.org/10.4055/jkoa.2021.56.1.68

Abstract

Purpose
The purpose of this study was to analyze the motion of the shoulder joint dynamically through a depth sensor-based motion analysis system for the normal group and patients group with shoulder disease and to report the results along with a review of the relevant literature.
Materials and Methods
Seventy subjects participated in the study and were categorized as follows: 30 subjects in the normal group and 40 subjects in the group of patients with shoulder disease. The patients with shoulder disease were subdivided into the following four disease groups: adhesive capsulitis, impingement syndrome, rotator cuff tear, and cuff tear arthropathy. Repeating abduction and adduction three times, the angle over time was measured using a depth sensor-based motion analysis system. The maximum abduction angle (θ_max ), the maximum abduction angular velocity (ω_max ), the maximum adduction angular velocity (ω_min ) , and the abduction/adduction time ratio (t_abd / t_add ) were calculated. The above parameters in the 30 subjects in the normal group and 40 subjects in the patients group were compared. In addition, the 30 subjects in the normal group and each subgroup (10 patients each) according to the four disease groups, giving a total of five groups, were compared.
Results
Compared to the normal group, the maximum abduction angle (θ_max ), the maximum abduction angular velocity (ω_max ), and the maximum adduction angular velocity (ω_min ) were lower, and abduction/adduction time ratio (t_abd /t_add ) was higher in the patients with shoulder disease. A comparison of the subdivided disease groups revealed a lower maximum abduction angle (θ_max ) and the maximum abduction angular velocity (ω_max ) in the adhesive capsulitis and cuff tear arthropathy groups than the normal group. In addition, the abduction/adduction time ratio (t_abd /t_add ) was higher in the adhesive capsulitis group, rotator cuff tear group, and cuff tear arthropathy group than in the normal group.
Conclusion
Through an evaluation of the shoulder joint using the depth sensor-based motion analysis system, it was possible to measure the range of motion, and the dynamic motion parameter, such as angular velocity. These results show that accurate evaluations of the function of the shoulder joint and an in-depth understanding of shoulder diseases are possible.

Keyword

shoulder; range of motion; kinect; dynamic; angular velocity