Quadriceps-hamstrings intermuscular coherence during single-leg squatting 3-12 years following a youth sport-related knee injury

Maurice Mohr; Vinzenz von Tscharner; Jackie L Whittaker; Carolyn A Emery; Benno M Nigg

doi:10.1016/j.humov.2019.04.012

Quadriceps-hamstrings intermuscular coherence during single-leg squatting 3-12 years following a youth sport-related knee injury

Hum Mov Sci. 2019 Aug:66:273-284. doi: 10.1016/j.humov.2019.04.012. Epub 2019 May 9.

Authors

Maurice Mohr¹, Vinzenz von Tscharner², Jackie L Whittaker³, Carolyn A Emery⁴, Benno M Nigg²

Affiliations

¹ Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Alberta, Canada; Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Alberta, Canada. Electronic address: mmaurice@ucalgary.ca.
² Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Alberta, Canada.
³ Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Alberta, Canada; The Department of Physical Therapy, Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Canada.
⁴ Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Alberta, Canada; Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Alberta, Canada; The Alberta Children's Hospital Research Institute and McCaig Institute for Bone and Joint Health, Cumming School of Medicine, University of Calgary, Alberta, Canada.

PMID: 31078946
DOI: 10.1016/j.humov.2019.04.012

Abstract

The purpose of this study was to determine the degree of co-contraction as per electromyographic gamma-band intermuscular coherence of the quadricep (Q) and hamstring (H) muscles during single-leg squatting (SLS), and to assess the influence of sex and self-reported knee complaints on the association between knee injury history and medial and lateral Q-H intermuscular coherence. Participants included 34 individuals who suffered a youth sport-related intra-articular knee injury 3-12 years previously, and 37 individuals with no knee injury history. Surface electromyographic signals were recorded from medial and lateral thigh muscles bilaterally to determine the gamma-band (30-60 Hz) intermuscular coherence between medial and lateral Q-H muscle pairs during SLS. Multivariable linear regression (α = 0.05) was performed to investigate the relationship between knee injury history (main exposure) and medial and lateral Q-H coherence (outcome) while accounting for the influence of sex and self-reported knee pain and symptoms (covariates). The median age of participants was 25 (range 18-30) and 67% were female. Q-H gamma-band coherence was present for 60-90% of legs. Medial and lateral Q-H coherence was higher in females compared to males. There was no evidence for an association between medial Q-H coherence, knee injury history, knee pain, or symptoms. There was evidence for an association between knee injury history and lateral Q-H coherence, which was modified by sex such that previously injured males demonstrated reduced Q-H coherence compared to uninjured males. These finding suggest that females demonstrate a more pronounced Q-H co-contraction strategy during a SLS than males regardless of knee injury history. Further, that male who suffered a youth sport-related knee injury 3-12 years previously demonstrate less Q-H co-contraction during a SLS than uninjured males. The mechanisms behind differences in neuromuscular control between males and females as well as previously injured and uninjured males require further investigation.

Keywords: Alberta Youth Prevention of Early Osteoarthritis (PrE-OA) cohort; Anterior Cruciate Ligament (ACL); Biomechanics; Co-activation; Co-contraction; Motor unit synchronization.