title: Cervical flexion-relaxation response to neck muscle fatigue in males and females.
abstract: In this study the effect of muscle fatigue on the cervical spine flexion-relaxation response was studied. Twenty healthy participants (10 males and 10 females) were recruited for data collection. The Sorenson protocol was utilized to induce neck muscle fatigue. Surface electromyography and optical motion capture systems were used to measure neck muscle activation and head-neck posture, respectively. A post-fatigue reduction in the Flexion-Relaxation Ratio (FRR) and higher FRR for females compared to males were observed. A post-fatigue decrease was also observed in the onset and offset angles resulting in an expansion of the myoelectric silence period. Gender had no effect on the onset and offset angles of the silence period. Post-fatigue shift in the onset and offset angles and the expansion of the silence period indicate an increased contribution by the passive viscoelastic tissues in stabilizing the cervical spine under fatigued condition.
authors.affiliation: Industrial and Management Systems Engineering, West Virginia University, PO Box 6070, Morgantown, WV 26506-6107, United States. Electronic address: Ashish.Nimbarte@mail.wvu.edu.
authors.forename: Ashish D
authors.initials: AD
authors.lastname: Nimbarte
authors.affiliation: Safety Sciences Department, Indiana University of Pennsylvania, 1011 South Drive, Indiana, PA 15705, United States.
authors.forename: Majed M
authors.initials: MM
authors.lastname: Zreiqat
authors.affiliation: Industrial and Management Systems Engineering, West Virginia University, PO Box 6070, Morgantown, WV 26506-6107, United States.
authors.forename: Suman Kanti
authors.initials: SK
authors.lastname: Chowdhury
mesh_terms: D000328:Adult; D002574:Cervical Vertebrae / Q000502:physiology*; D004576:Electromyography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D018763:Muscle Fatigue / Q000502:physiology*; D009126:Muscle Relaxation / Q000502:physiology*; D009334:Neck Muscles / Q000502:physiology*; D011187:Posture / Q000502:physiology; D016059:Range of Motion, Articular / Q000502:physiology; D012737:Sex Factors; D055815:Young Adult
keywords: Cervical spine; Fatigue; Flexion–relaxation phenomenon; Gender