Workplace-related shoulder protraction: effects of home-based axioscapular muscles-targeted stretching frequency in office workers – a randomized controlled trial

This study aimed to compare the effects of different training frequencies in a home-based stretching program targeting axioscapular muscles (Homeaxiostretch) among office workers with shoulder protraction. Participants who had more than 7 cm of shoulder protraction were randomly assigned to either a high-frequency (HFS) or low-frequency (LFS) Homeaxiostretch program for 6 weeks. Shoulder and cervical – thoracic alignment, periscapular muscle strength, and neck- and upper-extremity – related disabilities were evaluated. Forty-eight participants completed the study. Significant within-group improvements were found in right-side shoulder protraction, craniovertebral angle, and neck disability and shoulder function in both groups. However, the HFS group showed significant improvements in left-side shoulder protraction, thoracic kyphosis, lower trapezius (both sides), and left-side middle trapezius strength. Despite these findings, the changes showed only small effect sizes or did not exceed minimal clinically important thresholds. Between-group comparisons favored the HFS group only for left-side trapezius strength, which reached clinical significance. We have concluded that both Homeaxiostretch frequencies led to improvements in posture, neck disability, and upper-extremity function; however, these effects were small and not clinically meaningful. In contrast, the HFS program demonstrated reached clinical significance by providing greater enhancements in trapezius strength compared with the LFS program.Registration number NCT05596916, 18 March 2023