Includes bibliographical references / The studies described in this thesis were the first to investigate in - depth body composition, exercise performance and neuromuscular characteristics of elite Paralympic athletes with cerebral palsy (CP). In the first study, in - depth whole body and site specific body composition was investigated in six athletes with CP using dual - energy x - ray absorptiometry. There were no differences between non - affected and affected sides with respect to bone mineral density and fat mass. Fat free soft tissue mass was lower on the affected side in bot h upper and lower limbs of the athletes. The novel findings of this study provided the first insight into anthropometric and bone physiology of elite Paralympic athletes with CP, and the possible residual effect of CP in these individuals. In the second study, five athletes with CP and 16 able - bodied (AB) age and performance matched controls performed a 30 second Wingate sprint cycle test. Power output was significantly higher in the AB group, although fatigue indices were statistically similar between groups. Muscle activity changed similarly in all muscle groups tested, in both affected and non - affected sides, in both CP and AB groups. However, certain neuromuscular irregularities were identified in the CP group. The similarity in fatigue profile was a novel finding. It was proposed that this similarity in fatigue was the result of long term high level athletic training required for Paralympic competition. Study three tested the similarity in fatigue between CP and AB athletes (that was described in the second study), using an externally paced fatiguing running trial. Six athletes with CP and 12 AB athletes performed one 40 m sprint test and vertical jump tests off both legs, the affected leg individually and the non - affected leg individually, before and after an adapted multistage shuttle run test to exhaustion. The 40 m sprint test, vertical jump off both legs and vertical jump off the affected leg were significantly compromised in the CP group, while vertical jump off the non - affected leg was similar between groups. Both groups fatigued similarly with regard to performance and muscle activity. The third study's finding s generally supported those of the second study. However, it was shown that although athletes with CP may represent a group of individuals who have achieved maximal physiological adaptation toward AB levels, the activity generated by both legs was performed towards the capacity of the affected leg. Study four attempted to elucidate explanations for the novel findings in studies 2 and 3 through investigation of pacing strategies employed by these athletes. Six athletes with CP and 13 AB athletes performed two trials of eight sets of ten shuttles (totalling 1600 m). One trial was distance deceived and the other was non distance deceived. The CP group ran slower than the AB group in both trials, and differences in pacing were observed in the deceived trial in the CP group. This novel study provided evidence for a possible pacing strategy underlying the exercise performance and fatigue profiles observed in the athletes with CP documented in the previous studies. The work described in this thesis lends novel insights and understanding to the physiology and physiological adaptations of highly functioning ambulant athletes with CP. The findings might have important implications with respect to the understanding of rehabilitation, coaching and clinical management of individuals with CP.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:uct/oai:localhost:11427/20269 |
| Date | January 2015 |
| Creators | Runciman, Phoebe Anne |
| Contributors | Derman, Wayne, Tucker, Ross, Ferreira, Suzanne, Albertus-Kajee, Yumna |
| Publisher | University of Cape Town, Faculty of Health Sciences, MRC/UCT RU for Exercise and Sport Medicine |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Doctoral Thesis, Doctoral, PhD |
| Format | application/pdf |
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