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

ABSTRACT

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.