Electrically Evoked Torque at Rest Is Strongly Related to Quadriceps Muscle Size in Individuals with Anterior Cruciate Ligament Reconstruction

ABSTRACT

Electrically evoked torque at rest (i.e., the torque produced from supramaximal stimuli applied to a resting muscle) has been shown to be related to muscle size in healthy adults, but this relationship has not been evaluated in pathological populations where atrophy is present. This study aims to evaluate the relationship between the electrically evoked torque at rest and vastus lateralis cross-sectional area (CSA) in individuals with anterior cruciate ligament (ACL) reconstruction. Eighteen individuals with ACL reconstruction participated. Quadriceps electrically evoked torque at rest was elicited bilaterally via sex-specific, standardized supramaximal triplet stimulations. Vastus lateralis CSA was measured at 50% of thigh length using ultrasound. Pearson’s r and partial correlations were used to evaluate associations between outcomes. Evoked torque at rest was positively associated with vastus lateralis CSA in the ACL reconstructed limb (r = 0.865, partial r = 0.816, P < .01), non-reconstructed limb (r = 0.628, partial r = 0.575, P < .05), and side-to-side ratios (r = 0.670, partial r = 0.659, P < .01). These results indicate that electrically evoked torque at rest may indirectly assess side-to-side differences in quadriceps muscle size after ACL reconstruction.

KEYWORDS:

• Twitch
• Resting Torque
• Cross-sectional Area
• Morphology

Funding

This work was supported by National Institute of Child Health and Human Development (NICHD) under award number [R21 HD092614]. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.