Effect of seated thoracic manipulation on changes in scapular kinematics and scapulohumeral rhythm in young asymptomatic participants: a randomized study.

Objective: The purpose of this study was to evaluate the immediate effects of seated thoracic manipulation on scapulothoracic kinematics and scapulohumeral rhythm during arm flexion in young asymptomatic participants.

Methods: A convenience sample of 42 young asymptomatic participants was randomly divided in 2 groups: manipulation and sham group. Measurements were taken before and after the intervention. All participants completed the Disabilities of the Arm, Shoulder, and Hand questionnaire to assess pain and physical function. The manipulation group received the manipulation (high velocity, low amplitude), which was performed by a physical therapist with the patient in the seated position and with the arms crossed over the chest and hands passed over the shoulders. For the sham group, the same procedure was performed, with the exception that the high-velocity thrust was not applied. Three-dimensional (3D) kinematic data were collected with the participants in a relaxed standing position using a 3D electromagnetic tracking system. All participants performed 3 repetitions of arm flexion before and after manipulation.

Results: There were no differences (P = .79) in Disabilities of the Arm, Shoulder, and Hand scores when the manipulation (3.37 ± 3.72) was compared with the sham group (3.68 ± 4.27). The 3-way analysis of variance showed no significant interaction among group, angle, and time differences for the outcomes (scapulothoracic internal/external rotation [F = 0.43; P = .82], upward/downward rotation [F = 0.08; P = .99], tilt [F = 0.23; P = .94], and scapulohumeral rhythm [F = 4; P = .86]). The intragroup effect was small for the outcomes measured in both groups.

Conclusions: Thoracic manipulation in the seated position did not affect scapulohumeral rhythm and 3D scapular kinematics during arm flexion in young asymptomatic participants.