Hyperextension of the Thumb: Prevalence and its Impact on Grip Strength in Manual Therapy Practitioners

Background: Manual therapists, such as physiotherapists are frequently engaging in repetitive hand motions that necessitate significant grip strength and stability of the thumb. Thumb hyperextension beyond its usual range of motion, can result in decreased hand grip strength and potentially hinder the therapist’s ability to carry out their responsibilities proficiently. The study hypothesizes that manual therapists with thumb hyperextension will demonstrate significantly lower grip strength compared to those without hyperextension. The objective of this study is to evaluate the frequency of thumb hyperextension and its correlation with decreased hand grip strength in manual therapists. Methods: A cross-sectional study involved 309 physiotherapists with at least 1 year of manual therapy experience. Assessments included thumb extension range of motion using a goniometer and hand grip strength with a digital dynamometer. Spearman’s correlation test was employed to determine the relation between thumb hyperextension and demographic variables with grip strength. Results: Prevalence of thumb hyperextension was 41% among the participants. The mean grip strength and the work experience of the participants were 32.25±2.92 and 5.29±3.98 respectively. However, there is no significant relationship exist between thumb hyperextension and demographic with grip strength. Conclusion: The study demonstrates a significant occurrence of thumb hyperextension among physiotherapists, with 41% of participants being affected. However, there was no significant association observed between thumb hyperextension and grip strength, as well as between demographic characteristics and grip strength. This study indicates that thumb hyperextension is frequently observed among manual therapists, but it does not have a direct effect on their grip strength and is not impacted by demographic characteristics. Major Findings: Thumb hyperextension affects 41% of manual therapists, but no significant association exists with grip strength or demographic factors, suggesting it doesn’t directly impact this population.