The primary aim of this dissertation was to examine the role of short-term immobilization on muscle function recovery, excitability of the muscle, evoked contractile properties of the muscle, and muscle proteins in the blood after contraction-induced muscle injury. In Studies I and II, the effects of four days of immobilization on recovery of muscle function and serum creatine kinase (CK) activity after eccentric exercise was examined in 26 males, who were placed into one of three groups: immobilization, control, or light exercise. When the damaged elbow flexor muscles were immobilized or exercised for four consecutive days, force recovery over eight days was significantly enhanced compared to a control. In Study II, during the four-day treatment period after eccentric exercise, immobilization resulted in a significant blunting of the CK response compared to the light exercise or control groups. However, increasing activity with light exercise did not have any effect on the CK response compared to control. The data from Study II suggested that reduced lymphatic transport with decreased muscular activity may have contributed to the lower CK response in the immobilized muscle. In Study III, mechanisms to explain the observations in Studies I and II with immobilization were undertaken. Muscle excitability and evoked contractile properties of the muscle were examined to determine whether immobilization altered the mechanical properties of the muscle to favor an enhanced force response. After eccentric exercise, there were immediate and prolonged reductions in the evoked contractile properties of the muscle. Immobilization, however, had no effect on these measures. CK and myoglobin were assessed during the four-day treatment period as well as during the five-day recovery period. There was a significant difference in the CK response between groups, with the immobilization demonstrating significant blunting of the CK response during the treatment period. Upon remobilization of the arm, CK activity increased but not as high as was anticipated. The myoglobin response, however, was not different between groups. Because their routes of entry into the blood differ, taken together, the myoglobin and CK response suggest that lymph transport likely contributed to the blunting of the CK response observed with immobilization.
| Identifer | oai:union.ndltd.org:UMASS/oai:scholarworks.umass.edu:dissertations-3584 |
| Date | 01 January 2001 |
| Creators | Sayers, Stephen P |
| Publisher | ScholarWorks@UMass Amherst |
| Source Sets | University of Massachusetts, Amherst |
| Language | English |
| Detected Language | English |
| Type | text |
| Source | Doctoral Dissertations Available from Proquest |
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