Recovery of shoulder muscle function characteristics and active range of motion in patients with frozen shoulder after manipulation under anesthesia

Abstract

The purpose of this study was to evaluate the changes in shoulder muscle isometric strength, endurance, and shoulder active range of motion in patients with frozen shoulder syndrome after manipulation under general anesthesia. Thirteen patients (eight women, five men, median age 53 years) with diagnosis of frozen shoulder syndrome participated in this study. Shoulder muscle isometric strength, active range of motion in flexion, extension, abduction, and shoulder muscle endurance were measured before manipulation under general anesthesia and at 1 and 6 months postoperatively. Patients were also screened by self-administered shoulder rating questionnaire. Six months after manipulation under general anesthesia, shoulder muscle isometric strength, active extension, and abduction for the involved extremity did not differ significantly compared with the uninvolved extremity. On the other hand, shoulder muscle isometric endurance time remained significantly shorter (p = 0.021) and active flexion remained significantly lower (p = 0.039) for the involved extremity (66.0 ± 42.9 s and 162.5 ± 16.2°, respectively) compared with the uninvolved extremity (98.0 ± 32.2 s and 171.5 ± 6.3°, respectively). Moreover, shoulder rating questionnaire scores significantly improved at the last follow-up (from 49.7 ± 8.7 to 80.1 points; p < 0.001). The recovery of shoulder muscle isometric endurance in patients with frozen shoulder syndrome after manipulation under general anesthesia was more delayed than recovery of isometric strength of these muscles or shoulder active range of motion. Shoulder muscle endurance training program should be recommended for patients after manipulation under general anesthesia.