Postural risk factors for work-related musculoskeletal disorders during manual versus device-assisted lower-limb stretching

Abstract

Work-related musculoskeletal disorders (WMSDs) are prevalent among physiotherapists and occupational therapists due to the physically demanding and repetitive nature of manual therapy techniques. Stretching requires therapists to exert substantial force while holding static postures for extended periods. Assistive devices may mitigate these ergonomic risks. This crossover study evaluated postural risk factors for WMSDs during lower-limb muscle stretching (targeting the hamstrings, calves, iliopsoas, quadriceps, hip adductors, hip abductors, and gluteal muscles) and compared manual with device-assisted techniques among 32 healthy practitioners (highly trained students and licensed therapists). Postural risk was evaluated using the Rapid Entire Body Assessment (REBA), and perceived comfort via a five-point Likert scale. Data were analyzed using mixed-effects regression models. Device-assisted stretching significantly improved therapists’ posture (mean REBA score: 11.35 units lower, P < 0.001) and increased the odds of belonging to a lower WMSDs risk category by 69.17-fold. Furthermore, device-assisted stretching significantly enhanced participants’ comfort for nearly all muscle groups ( P < 0.010), with no period or carryover effects. These findings indicate that the assistive device can substantially reduce postural risk factors for WMSDs and improve comfort during lower-limb stretching. However, prospective clinical studies are needed to determine whether these postural improvements reduce the incidence of WMSDs.