Generalized Joint Hypermobility, Handgrip Strength, Countermovement Jump, and Ankle Mobility in Physically Active Young Adults: An Exploratory Cross-Sectional Study

Purpose: This exploratory cross-sectional study examined associations between generalized joint hypermobility (GJH), physical performance, and ankle mobility in physically active young adults. Methods: Forty university students (28 males and 12 females) from Korea National University of Transportation were recruited by convenience sampling. GJH was assessed using the Beighton Scoring System (BSS), and outcomes included handgrip strength (HGS), countermovement jump (CMJ), and passive ankle range of motion (ROM). Pearson correlations, GJH–NGJH group comparisons, and exploratory sex-stratified analyses were performed. All p values were unadjusted and interpreted as nominal. Results: BSS score showed a positive association with left ankle dorsiflexion ROM at the unadjusted significance level (r = 0.322, 95% CI [0.012, 0.576], unadjusted p = 0.043); this association did not meet the Bonferroni-adjusted threshold for seven principal correlations, whereas no significant associations were observed with HGS, CMJ, or other ankle-ROM outcomes. No significant differences were found between GJH and NGJH groups. Males showed higher absolute HGS and CMJ, whereas females showed greater left ankle dorsiflexion ROM (p = 0.045). Sex-stratified correlations were not statistically significant, and no significant sex difference in correlation coefficients was detected. Conclusions: No statistically significant associations were detected between BSS scores and HGS or CMJ performance. The nominal association with left ankle dorsiflexion should be interpreted cautiously and considered hypothesis-generating.