Development and evaluation of a novel flex sensor-based glenohumeral subluxation degree assessment for wearable shoulder sling

Glenohumeral subluxation (GHS) is reported in as many as 81% of patients with stroke. To ensure that the glenohumeral joint head is in the socket, an orthosis is required to automatically adjust the degree of orthosis according to the degree of GHS. However, there is currently no wearable method for assessing the degree of GHS. This study aims to develop a GHS assessment method for patients with stroke that has the potential to be integrated into a wearable shoulder sling. To that end, we developed a GHS assessment method for patients with stroke based on a flex sensor. Seventeen patients with stroke in a diverse degree of GHS were recruited for the study. The GHS degree of patients was assessed by the flex sensor and gold-standard radiographic assessment. The GHS degree measurement by flex sensor (AGHS) and radiographic assessment (AGTD) has strongly correlated (r=0.92,p<0.01). The relationship of AGTD and AGHS is linear according to an interpolating curve with an equation: AGTD=1.091AGHS−0.702 (R2=0.84, RMSE=1.92mm). The method has excellent reliability with R=0.87, CI=95% for assessment of GHS degrees. The proposed method demonstrates good performance, is wearable, easy to use, and allows automatic measurements, so as to be a valuable method to assessment of GHS.