Figure-8 Strap Application: Immediate Alteration of Pectoralis Minor Length and Scapular Alignment During Arm-Lifting Exercise in Participants With Forward Shoulder Posture

• Published in: Journal of sport rehabilitation 2016-08, Vol.25 (3), p.273-279
• Main Authors: Ko, Chang-Hee, Cynn, Heon-Seock, Lee, Ji-Hyun, Yoon, Tae-Lim, Choi, Sil-Ah
• Format: Article
• Language: English
• Subjects: Arm - physiology; Braces; Cross-Sectional Studies; Electromyography; Exercise - physiology; Humans; Lifting; Male; Muscle function; Muscle Strength - physiology; Pectoralis Muscles - anatomy & histology; Pectoralis Muscles - physiology; Posture; Posture - physiology; Scapula - physiology; Shoulder - physiology; Young Adult
• ISSN: 1056-6716; 1543-3072
• DOI: 10.1123/jsr.2015-0002

Scapular bracing can correct scapular kinematics and restore normal scapular-muscle activity. However, there is little evidence to support the beneficial effects of a figure-8 strap, a type of scapular bracing, on muscle length, scapular alignment, and muscle activity during arm-lifting exercise. To investigate the immediate effect of a figure-8 strap on pectoralis minor length, scapular alignment, and scapular upward-rotator-muscle activity. Cross-sectional study. Research laboratory. Fifteen male participants (age 22.1 ± 1.9 y, weight 68.2 ± 5.7 kg, height 176.2 ± 3.3 cm) with forward shoulder posture (FSP) were examined for pectoralis minor length and scapular alignment with and without the application of a figure-8 strap. Pectoralis minor length was measured using the Pectoralis Minor Index (PMI), scapular alignment was measured with FSP, and upper trapezius, lower trapezius, and serratus anterior muscle activity were measured using surface electromyography while participants performed an arm-lifting exercise. Data collected with and without applying a figure-8 strap were compared using a paired t-test. Applying a figure-8 strap significantly decreased the PMI (P = .005) and scapular anterior tilting (P = .000). There were no differences in the muscle activity of the upper trapezius (P = .784), lower trapezius (P = .241), and serratus anterior muscles (P = .639). A figure-8 strap resulted in positive changes in pectoralis minor length and scapular alignment. The results support its use as a treatment aid in managing pectoralis minor length and scapular alignment during arm-lifting exercises.