Assessing Muscle-Strength Asymmetry via a Unilateral-Stance Isometric Midthigh Pull

• DOI: 10.1123/ijspp.2016-0179
• Publication Date: 2016-09-06T17:33:32Z
• Authors: Thomas Dos’Santos; Christopher Thomas; Paul A. Jones; Paul Comfort
• Keywords: Adult; Male; imbalance; reliability; peak force; 1106 Human Movement and Sports Sciences; Football; Reproducibility of Results; impulse; Young Adult; 03 medical and health sciences; 0302 clinical medicine; 1701 Psychology; Athletes; 1116 Medical Physiology; Isometric Contraction; Exercise Test; Humans; Muscle Strength; Muscle, Skeletal; Sport Sciences

Purpose:To investigate the within-session reliability of bilateral- and unilateral-stance isometric midthigh-pull (IMTP) force–time characteristics including peak force (PF), relative PF, and impulse at time bands (0–100, 0–200, 0–250, and 0–300 milliseconds) and to compare isometric force–time characteristics between right and left and dominant (D) and nondominant (ND) limbs.Methods:Professional male rugby league and multisport male college athletes (N = 54; age, 23.4 ± 4.2 y; height, 1.80 ± 0.05 m; mass, 88.9 ± 12.9 kg) performed 3 bilateral IMTP trials and 6 unilateral-stance IMTP trials (3 per leg) on a force plate sampling at 600 Hz.Results:Intraclass correlation coefficients (ICCs) and coefficients of variation (CVs) demonstrated high within-session reliability for bilateral and unilateral IMTP PF (ICC = .94, CV = 4.7–5.5%). Lower reliability measures and greater variability were observed for bilateral and unilateral IMTP impulse at time bands (ICC = .81–.88, CV = 7.7–11.8%). Paired-sample t tests and Cohen d effect sizes revealed no significant differences for all isometric force–time characteristics between right and left limbs in male college athletes (P >.05, d ≤ 0.32) and professional rugby league players (P > .05, d ≤ 0.11); however, significant differences were found between D and ND limbs in male college athletes (P < .001, d = 0.43–0.91) and professional rugby league players (P < .001, d = 0.27–0.46).Conclusion:This study demonstrated high within-session reliability for unilateral-stance IMTP PF, revealing significant differences in isometric force–time characteristics between D and ND limbs in male athletes.