Effects of 4-week self-cross body stretching with scapular stabilization on shoulder motions and horizontal adductor strength in subjects with limited shoulder horizontal adduction: cross body stretching with stabilization

Prediction model of subacromial pain syndrome in assembly workers using shoulder range of motion and muscle strength based on support vector machine

Subacromial pain syndrome (SAPS) is the most common upper-extremity musculoskeletal problem among workers. In this study, a machine learning model was built to predict and classify the presence or absence of SAPS in assembly workers with shoulder joint range of motion (ROM) and muscle strength data using support vector machine (SVM). Permutation importance was used to determine important variables for predicting workers with or without SAPS. The accuracy of the support vector classifier (SVC) polynomial model for classifying workers with SAPS was 82.4%. The important variables in model construction were internal rotation and abduction of shoulder ROM and internal rotation of shoulder muscle strength. It is possible to accurately perform SAPS classification of workers with relatively easy-to-obtain shoulder ROM and muscle strength data using this model. In addition, preventing SAPS in workers is possible by adjusting the factors affecting model building using exercise or rehabilitation programs.Practitioner summary: This study aimed to create a machine learning model that can predict and classify SAPS using shoulder ROM and muscle strength and identify the variables that are of high importance in model construction. This model could be used to predict or classify workers' SAPS and manage or prevent SAPS.

Comparison of shoulder functions between assembly workers with and without subacromial pain syndrome

BACKGROUND: The occurrence of subacromial pain syndrome (SPS) is associated with the frequent handling and lifting of heavy loads and excessive repetitive work. Thus, assembly workers have a high prevalence of SPS. OBJECTIVE: The purpose of this study was to investigate differences in shoulder ROM, muscle strength, asymmetry ratio, function, productivity, and depression between workers with and without SPS. METHODS: Sixty-seven male workers (35 workers with SPS and 32 workers without SPS) participated in this study. Shoulder internal rotation (SIR), shoulder external rotation (SER), shoulder abduction (SAB), shoulder horizontal adduction ROM and SIR, SER, elbow flexion (EF), scapular depression and adduction, scapular protraction strength were measured. The asymmetry ratio was calculated using the asymmetry ratio formula; shoulder functions were measured using the shoulder pain and disability index (SPADI), disabilities of the arm, shoulder, and hand (DASH), and visual analogue scale (VAS); and Endicott work productivity scale (EWPS). RESULTS: The SPADI (p = 0.001), DASH (p = 0.001), and VAS (p = 0.001) values of workers with SPS were higher than those of workers without SPS. Also, workers with SPS had lower SIR (p = 0.001) and SAB (p = 0.002) ROM compared to workers without SPS. In addition, workers with SPS exhibited lower SIR (p = 0.012) strength than workers without SPS. Workers with SPS had higher asymmetry ratio in SIR (p = 0.015), SER (p = 0.005), and EF (p = 0.008) strength than workers without SPS. CONCLUSIONS: The SIR, SAB ROM, SIR strength, and the asymmetry ratio of SIR, SER, EF strengths could provide an important baseline comparison for the workers with SPS.