Mechanical power in well trained swimmers with a physical impairment

The aims of this thesis were to: 1) develop and validate tests of propulsive force and mechanical power that can be used to monitor British Disability swimmers; and 2) contribute to the development of an objective, evidence-based international classification system for swimmers with a physical impairment. The propulsive force produced by unilateral arm amputee and able-bodied swimmers was assessed during a 30 s fully tethered swim (Chapter 3). It was concluded that as a consequence of their physical impairment, arm amputee swimmers produced significantly lower tether forces than able-bodied swimmers. Due to the limitation of the fully tethered method, an Isokinetic Tethered Swimming (ITS) Ergometer was developed (Chapter 4). To establish the setting in which peak power occurs on the device, external power was calculated at a range of tether speeds (Chapter 5). The results demonstrated that peak power occurred at a tether speed of 50 or 60% of the swimmer’s maximal swimming speed, and peak power was significantly related to the level of the swimmer’s physical impairment (IPC Class). Using the peak power setting, the decline in external power was quantified during a 30 s maximal effort swim (Chapter 6). All swimmers exhibited a decline in external power during the swim; however this decline was not related to the swimmer’s IPC Class. The validity of the movement on the ITS Ergometer was established using electromyography (EMG). The data revealed that muscle activation and recruitment patterns were similar to that of free swimming (Chapter 7). Using EMG the effect of neuromuscular fatigue on the contractile properties of the muscles during a 30 s maximal effort swim was examined (Chapter 8). Of the muscles tested, the muscle which appeared to fatigue the most was different for each swimmer