Effects of Fatigue Due to Contraction of Evertor Muscles on the Ankle Joint Position Sense in Male Soccer Players

• Published in: The American journal of sports medicine 2010-04, Vol.38 (4), p.824-828
• Main Authors: Mohammadi, Farshid, Roozdar, Arash
• Format: Article
• Language: English
• Subjects: Adult; Ankle; Ankle Injuries - etiology; Ankle Joint - physiopathology; Biological and medical sciences; Diseases of the osteoarticular system; Fatigue; Humans; Male; Medical sciences; Muscle Contraction; Muscle Fatigue; Proprioception - physiology; Soccer; Soccer - injuries; Sports injuries; Sports medicine; Sprains and Strains - etiology; Young Adult
• ISSN: 0363-5465; 1552-3365
• DOI: 10.1177/0363546509354056

Background The high incidence of ankle sprains that occur later in matches suggests that fatigue may contribute to altered neuromuscular control of the ankle. Moreover, deficits in ankle joint position sense (JPS) were seen in patients with a history of recurrent ankle sprains. It has been hypothesized that ankle sprains may be related to altered ankle JPS as a consequence of fatigue. Purpose To evaluate if fatiguing contractions of evertor muscles alter the ankle JPS. Study Design Controlled laboratory study. Methods Thirty-six soccer players (age, 24.7 ± 1.3 years; height, 183.7 ± 8.2 cm; weight, 78.9 ± 7.9 kg) were recruited. Subjects were asked to recognize 2 positions (15° of inversion and maximal active inversion minus 5°) for 2 conditions: normal and fatigue. Muscular fatigue was induced in evertor muscles of the dominant leg by using isometric contractions. The average of the absolute and variable errors of 3 trials were recorded for both fatigue and nonfatigue conditions. A matched control group of 36 soccer players (age, 23.9 ± 0.9 years; height, 181.2 ± 6.9 cm; weight, 77.8 ± 6.5 kg) was asked to recognize the same positions, before a soccer match and after 45 minutes of playing, and their same scores were recorded. Finally, results of the 2 groups were compared. Results There was significant decrease in subjects’ ability to recognize passive and active repositioning of their ankle after a fatigue protocol (P < .001). Passive and active JPS were reduced after playing (P < .001). There was no significant difference between 2 groups in the results of JPS before and after the intervention (P > .1). Conclusion The acuity of the ankle JPS is reduced subsequent to a fatigue protocol and after a soccer match. Clinical Relevance Evaluation of athletes’ ankle JPS before returning to physical activity may prevent further injuries.