Handgrip Strength Asymmetry in Female Basketball Players: The Critical Role of Arm Position and the Challenge of Statistical Power.

Background: Handgrip strength asymmetry is a critical yet underexplored basketball component. While the digit ratio (2D:4D) is linked to strength, its interplay with age, body composition, and biomechanics is unclear. This study aimed to quantify these independent and interactive effects on asymmetry in female basketball players. Methods: Maximum handgrip strength was measured bilaterally in three arm postures in 26 adolescent and adult players. Linear Mixed Model with a random intercept tested the effects. Results: Omnibus tests revealed no statistically significant main effects or interactions for age group, lean body mass (LBM), or 2D:4D ratio. However, a planned contrast showed that asymmetry was significantly lower in an overhead arm posture compared to an extended arm posture (p = 0.035). A simulation-based power analysis determined the study was significantly underpowered (11.5%) to detect small-to-medium interaction effects. Conclusions: While biomechanical position subtly modulates strength asymmetry, the influence of age, lean mass, and digit ratio may be negligible or require substantially larger samples to detect. Individual differences, which accounted for 57% of the variance, appear to be the dominant drivers of handgrip asymmetry in this athletic cohort, highlighting the complexity of strength imbalances and the critical need for adequately powered research in this domain.