Comparison of Soft Tissue Biased Manual Therapy and Conventional Physical Therapy on Shoulder Kinematics, Muscle Performance, Functional Impairment & Pain in Patients With Frozen Shoulder

Adhesive capsulitis, also known as frozen shoulder (FS), is a condition characterized by a functional restriction of both active and passive shoulder motion with unremarkable glenohumeral joint radiographs findings. Frozen shoulder is divided into primary and secondary type. The mechanism of primary FS is still unknown and the secondary FS may accompany with shoulder injuries. The incidence of primary FS is 2 to 5.8% and the risk factors are diabetes and thyroid disease.

The course of FS is divided into four consecutive stages which are inflammation, painful, frozen and thawing phase. Shoulder pain almost exists during the whole course of frozen shoulder. The pain and discomfort of FS patients are frequently localized to the deltoid insertion and coracoid process. Pain induces muscle spasm and causes pain-spasm-pain cycle resulting in limited range of motion, changed muscle recruitment pattern and finally influences neuromuscular control.

Commonly used conservative interventions for FS patients include joint mobilization, corticosteroid injection, exercise, modality and soft tissue mobilization. Despite joint mobilization is the most commonly used manual therapy in patients with FS, the evidence level is weak and the efficacy is not superior to other conservative treatment s. Soft tissue mobilization is widely used in lots of musculoskeletal conditions. The effects of soft tissue mobilization include breaking the adhesion tissue and improving range of motion, muscle strength and motor control. However, few studies have investigated the effect of soft tissue mobilization in patients with frozen shoulder. Only one study used one-time muscle release to FS patients and investigate improvement in shoulder biomechanics, muscle strength and ROM. Therefore, the purpose of this study is to investigate and compare the effect of soft tissue biased manual therapy and conventional physical therapy for six weeks in patients with primary FS.

The study design is a pretest-posttest control group design. The investigators plan to recruit 70 patients with primary frozen shoulder and divide them into a soft tissue biased manual therapy group and a conventional physical therapy group. The sample size is determined by the previous study. It is based on a significance level of 0.05, and a power of 0.80. The outcome measures in this study include scapula kinematics, scapula position, the range of motion, muscle tone, muscle strength, pain and functional impairment.

LIBERTY™ electromagnetic tracking system (Polhemus, Colchester, VT, USA) was used to collect three-dimensional kinematic (3D) data during scaption, hand to neck and hand to back tasks at a sampling rate of 120 Hz, and the software Motion Monitor® (Innovative Sport Training, Inc., Chicago. IL. USA) was used to analyze the data. The main measurements of shoulder kinematics include scapular upward/downward rotation, internal/external rotation, and anterior/posterior tilt. A stylus was used to digitize the bony landmarks for defining the anatomical coordinate system. The methods for this measure have been described previously.