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Updated: Jun 11, 2026
Muscle Imbalances: Testing and Training Functional Eccentric Hamstring Strength in Athletic Populations
Published on: May 1, 2018
Interlimb strength asymmetry is task-specific: moderate reliability but inconsistent limb dominance in multi-joint
Manfred Zöger1,2,3, Alfred Nimmerichter1,2, Arnold Baca2
1Training and Sports Sciences, University of Applied Sciences Wiener Neustadt, Wiener Neustadt, Austria.
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.
