ผลของ active scapular retraction ในท่างอข้อไหล่ 60 องศาต่อความยาวกล้ามเนื้อ pectoralis minor และ forward shoulder angle

Abstract

Posture control in fault position such as forward shoulder angle results in pectoralis minor de-creasing in length. Appropriate muscle stretching technique could increase muscle length and posture may be realign into a good position by reduction in forward shoulder angle (FSA). Fifty eight healthy par-ticipants with averaged age of 20.9 years and right arm dominant were included. After pectoralis minor stretching, pectoralis minor length was measured by digital vernier caliper and forward shoulder angle was measured from side view photograph in upright sitting by Kinovea program. The stretching was performed 2 rounds by active retraction at shoulder flexion 60°. Each round includes 3 consecutive sets of 20-second hold and 10-second rest. Mean differences of pectoralis minor length and forward shoulder angle before and after stretching were statistically significant (p < 0.001). Pectoralis minor length was increased 1.99 mm. (95%CI 1.27, 2.72), but forward shoulder angle was decreased 3.6° (95%CI 5.2, 2.0). In addition, pectoralis minor length was correlated with forward shoulder angle (p < 0.01). Active scapular retractionfollowing this study caused an immediate effect on increased pectoralis minor length and reducedforward shoulder angle using two dimensional measurement.