title: Finger flexors fatigue in trained rock climbers and untrained sedentary subjects.
abstract: The present series of experiments were conducted to access the surface EMG frequency parameters during repeated fingertip isometric contractions to determine if they can be used as a fatigue index under specific grip used in rock climbing. Electromyograms of the finger flexors and extensors were characterised in ten elite climbers and ten non-climbers. The exercise consisted in reaching 80 % of maximal isometric finger force as quickly as possible intermittently with a 5-s contraction followed by 5-s of rest until exhaustion (i. e. when the subject was unable to maintain 80 - 70 % MVC force range for the 5 s). The results clearly indicate that expert climbers performed significantly greater fingertip force than sedentary subjects (420 +/- 46 N vs. 342 +/- 56 N). This force was maintained during twelve repetitions (12.88 +/- 4.96) in sedentary subjects, whereas the climbers maintained the force during nineteen repetitions (19.33 +/- 4.84). The median frequency of both the flexor and extensor EMG power spectra decreased during fatiguing isometric contractions, but at different rates in climbers and non-climbers. In non-climbers, the results replicated previous findings, whereas in climbers the results were novel.
authors.affiliation: Université Joseph Fourier, Grenoble, France. franck.quaine@ujf-grenoble.fr
authors.forename: F
authors.initials: F
authors.lastname: Quaine
authors.forename: L
authors.initials: L
authors.lastname: Vigouroux
authors.forename: L
authors.initials: L
authors.lastname: Martin
mesh_terms: D000328:Adult; D004576:Electromyography; D015444:Exercise; D005385:Fingers; D006801:Humans; D008297:Male; D018763:Muscle Fatigue; D013177:Sports