Effect of fatigue on neuromuscular function at the ankle.
BACKGROUND
Lateral ankle sprains occur more frequently than any other orthopedic injury. Athletes often report sustaining more injuries late in competition when fatigue is present.


OBJECTIVE
To evaluate neuromuscular function of the ankle musculature after fatigue.


METHODS
Experimental, pretest-posttest.


METHODS
Research laboratory.


METHODS
Ten female and 9 male college-aged subjects.


METHODS
Fatigue was induced via continuous concentric and eccentric muscle actions of the ankle: inversion (INV), eversion (EV), plantar flexion (PF), and dorsiflexion (DF).


METHODS
Peak torque (PT), peak EMG, and median frequency (MF) were calculated prefatigue and postfatigue in the tibialis anterior (TA), peroneus longus (PER), and lateral gastrocnemius (GAS) muscles.


RESULTS
Main effects were noted for test (P < 0.0125) in all statistical tests performed indicating changes in PT, peak EMG, and MF after fatigue.


CONCLUSIONS
A significant decrease in MF of the PER muscle after PF fatigue and corresponding with a decreased firing rate, may be of importance, especially with regard to the role in countering the violent moment seen with inversion ankle sprains.
Gutierrez
Gregory M
GM
Department of Health, Nutrition, & Exercise Sciences, University of Delaware, Newark, USA. gregmg@udel.edu
Jackson
Nicole D
ND
Dorr
Kristin A
KA
Margiotta
Sarah E
SE
Kaminski
Thomas W
TW
D000328:Adult; D016512:Ankle Injuries / Q000150:complications / Q000209:etiology* / Q000503:physiopathology; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D018763:Muscle Fatigue / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology / Q000503:physiopathology; D009469:Neuromuscular Junction / Q000502:physiology; D010807:Physical Endurance; D012737:Sex Factors; D013180:Sprains and Strains / Q000209:etiology* / Q000503:physiopathology; D019415:Torque