The effect of muscle-biased manual therapy on shoulder kinematics, muscle performance, functional impairment, and pain in patients with frozen shoulder

Background

Frozen shoulder (FS) is characterized by restricted active and passive shoulder mobility and pain.

Purpose

Compare the effect of muscle-biased manual therapy (MM) and regular physical therapy (RPT) in patients with FS.

Study Design

Pretest–post-test control group study design.

Methods

We recruited 34 patients with FS and compared the effect of 12-session MM and RPT. The outcome measures were scapular kinematics and muscle activation, scapular alignment, shoulder range of motion, and pain intensity. Two-way analysis of variance was used to examine the intervention effect with α = 0.05.

Results

Both programs resulted in similar improvements in pain and shoulder function. Compared to the RPT, MM resulted in increased posterior tilt (MM: 7.04°-16.09°, RPT: −2.50° to −4.37°; p = 0.002; ES = 0.261) and lower trapezius activation (MM: 260.61%-470.90%, RPT: 322.64%-313.33%; p = 0.033; ES = 0.134) during scaption, and increased posterior tilt (MM: 0.70°-15.16°, RPT: −9.66° to −6.44°; p = 0.007; ES = 0.205) during the hand-to-neck task. The MM group also showed increased GH backward elevation (MM: 37.18°-42.79°, RPT: 43.64°-40.83°; p = 0.004, ES = 0.237) and scapular downward rotation (MM: −2.48° to 6.80°, RPT: 1.93°-1.44°; p < 0.001; ES = 0.404) during the thumb-to-waist task, enhanced shoulder abduction (MM: 84.6°-102.3°, RPT: 85.1°-92.9°; p = 0.02; ES = 0.153), and improved scapular alignment (MM: 10.4-9.65 cm, RPT: 9.41-9.56 cm; p = 0.02; ES = 0.114).

Conclusions

MM was superior to the RPT regarding scapular neuromuscular performance. Clinicians should consider adding muscle-biased treatment when treating FS.