Date of Graduation
2001
Document Type
Thesis
Degree Type
MS
Committee Chair
Kenneth H. Means
Abstract
Skeletal muscle injury is a major concern in areas of occupational health and sports medicine. To date, the mechanisms responsible for muscle injury are not clearly understood. The objective of this research was to quantify the dynamic force parameters resulting from oscillatory contractions (stretch-shortening cycles), which are associated with skeletal muscle injury. An in vivo rodent experimental model was used to study the oscillatory contraction response of the dorsiflexor muscles in male Sprague-Dawley rats. In vivo testing of anesthetized animals was accomplished via a custom designed isokinetic rat dynamometer, which allowed for continuous monitoring of muscle force output. The rats were assigned to either an oscillatory injury group or an isometric control group. The oscillatory testing consisted of fifteen sets of ten oscillatory contractions for a total of 150 oscillatory contractions. The fifteen sets of oscillatory contractions were administered at one-minute intervals. Muscles in the isometric group were activated in the same manner as the oscillatory group to account for the metabolic impact of the oscillatory protocol. Isometric force tests were performed before, immediately after, and 48-hours after both group’s experimental sets to determine prolonged force decrements. The oscillatory and isometric groups were divided into two groups (N = 6). The experimental results indicated that oscillatory contractions were causing significant force decrements even after a prolonged recovery time while the isometric control group made a full recovery of force. The magnitude of force from the eccentric phase of the oscillatory contraction was the best indicator of force decrements from oscillatory contractions. The analytical method developed to compare forces from the oscillatory group and the isometric control group found a good relation between the minimum oscillatory forces and the isometric control forces over the experimental procedure. The analytical method also supported the experimental results in that the magnitude of force from the eccentric phase of the oscillatory contraction was the best indicator of force decrements from oscillatory contractions, and helped quantify how the magnitude of force from the eccentric phase of the oscillatory contraction was changing throughout the experimental protocol.
Recommended Citation
Geronilla, Kenneth Bradley, "The quantification of oscillatory force parameters that affect eccentric contraction-induced injury in an in vivo rodent." (2001). Graduate Theses, Dissertations, and Problem Reports. 10554.
https://researchrepository.wvu.edu/etd/10554