Frontiers in Sports and Active Living | 2026
Authors: Zöger M.; Nimmerichter A.; Baca A.; Wirth K.
DOI: 10.3389/fspor.2026.1836014
Journal: Frontiers in Sports and Active Living
Year: 2026
Publisher: Frontiers Media SA
Document Type: Article
Open Access: All Open Access; Gold Open Access; Green Open Access
Cited by: 0
Background – Interlimb strength asymmetry is widely used in sports medicine and performance diagnostics, yet the reliability of asymmetry measures in multi-joint dynamometry, their velocity specificity, and the consistency of limb dominance remain unclear. This study examined the test-retest reliability of interlimb strength asymmetry derived from unilateral multi-joint isometric and isokinetic dynamometry and investigated whether limb dominance remains consistent across different knee angles and contraction velocities in recreationally active adults. Methods – Twenty-five recreationally active adults, engaging in 150–300 min of moderate-to-vigorous physical activity per week and full-body resistance training without participation in elite-level sports, performed unilateral leg press assessments at two isometric knee angles (100° and 140°) and two isokinetic velocities (30 and 600 mm·s⁻¹) in two separate sessions. Interlimb strength asymmetry was calculated from peak force. Directional asymmetry was determined by assigning a positive or negative sign to represent right- or left-leg dominance, respectively. Systematic differences between sessions were evaluated using paired-sample t-test. Reliability was assessed using single-measure intraclass correlation coefficients (ICC), standard error of measurement (SEM), minimum detectable change (MDC), kappa coefficients, and Bland–Altman analysis. Results – No significant systematic differences between sessions were detected (p > 0.05), and mean asymmetry values were small (range −3.5% to 1.1%). Relative reliability ranged from moderate to good (ICC = 0.55–0.84), whereas absolute reliability indicated substantial variability (SEM = 2.9%–7.5%; MDC = 8.1–20.8%). Limb dominance showed fair to substantial inter-session agreement (kappa = 0.24–0.65), with 16% of participants demonstrating consistent dominance across all conditions and sessions. Conclusions – These findings suggest that interlimb strength asymmetry in multi-joint dynamometry is task-specific, exhibiting considerable individual variability and limited stability of dominance. As measurement error frequently approached or exceeded commonly cited clinical thresholds (e.g., 10%–15%), practitioners should interpret asymmetry values cautiously and avoid relying on universal cutoffs for return-to-sport or performance decision-making. © 2026 Zöger, Nimmerichter, Baca and Wirth.
isokinetic leg press; isometric leg press; limb dominance; lower-limb strength asymmetry; multi-Joint dynamometry; test-retest reliability