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


CONCLUSIONS
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.
Thomas
T
Dos'Santos
Christopher
C
Thomas
Paul A
PA
Jones
Paul
P
Comfort
D000328:Adult; D056352:Athletes; D005080:Exercise Test; D005538:Football; D006801:Humans; D007537:Isometric Contraction; D008297:Male; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000502:physiology*; D015203:Reproducibility of Results; D055815:Young Adult
imbalance; impulse; peak force; reliability