title: Relationship Between Muscle Fiber Type and Reactive Balance: A Preliminary Study.
abstract: The authors' objective was to quantify the relationship between type II muscle fiber composition and recovery latency from controlled perturbations. Thirty healthy adults performed a Thorstensson test to indirectly determine muscle fiber composition of the knee extensors. On a subsequent day, reactive balance was measured by assessing latency time required to accommodate three controlled perturbations via computerized dynamic posturography. The proportion of type II fibers had a negative correlation with latency caused by a large backward perturbation (r = -.62, p = .001). These data may indicate a higher percentage of type II fibers in the knee extensors are associated with better reactive balance. Further investigation is warranted, in particular as it pertains to populations at risk for balance impairment.
authors: a Arizona State University, School of Nutrition and Health Promotion, Healthy Lifestyles Research Center, Exercise and Wellness , Phoenix.
authors: Andrew I
authors: AI
authors: Miller
authors: Edward M
authors: EM
authors: Heath
authors: Jared M
authors: JM
authors: Dickinson
authors: Eadric
authors: E
authors: Bressel
mesh_terms: D000328:Adult; D001827:Body Height; D001835:Body Weight; D002452:Cell Count; D005260:Female; D006801:Humans; D007717:Knee / Q000502:physiology; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D018656:Muscle Fibers, Fast-Twitch / Q000502:physiology*; D018485:Muscle Fibers, Skeletal / Q000502:physiology; D018482:Muscle, Skeletal / Q000166:cytology; D004856:Postural Balance / Q000502:physiology*; D011434:Proprioception / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D055815:Young Adult
keywords: balance; dynamic balance; fast twitch fibers; motor control test; type II fibers