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.
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.
Main Outcome Measures:
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.
Ko, Cynn, Lee, and Choi are with the Dept of Physical Therapy, Yonsei University, Wonju, South Korea. Yoon is with the Dept of Physical Therapy, Cheongju University, Cheongju, South Korea.