D Theisen

Wheelchair propulsion biomechanics: implications for wheelchair sports

AbstractThe aim of this article is to provide the reader with a state-of-the-art review on biomechanics in hand rim wheelchair propulsion, with special attention to sport-specific implications. Biomechanical studies in wheelchair sports mainly aim at optimising sport performance or preventing sport injuries. The sports performance optimisation question has been approached from an ergonomic, as well as a skill proficiency perspective. Sports medical issues have been addressed in wheelchair sports mainly because of the extremely high prevalence of repetitive strain injuries such as shoulder impingement and carpal tunnel syndrome. Sports performance as well as sports medical reflections are made throughout the review.Insight in the underlying musculoskeletal mechanisms of hand rim wheelchair propulsion has been achieved through a combination of experimental data collection under realistic conditions, with a more fundamental mathematical modelling approach. Through a synchronised analysis of the movement pattern, force generation pattern and muscular activity pattern, insight has been gained in the hand rim wheelchair propulsion dynamics of people with a disability, varying in level of physical activity and functional potential. The limiting environment of a laboratory, however, has hampered the drawing of sound conclusions. Through mathematical modelling, simulation and optimisation (minimising injury and maximising performance), insight in the underlying musculoskeletal mechanisms during wheelchair propulsion is sought. The surplus value of inverse and forward dynamic simulation of hand rim stroke dynamics is addressed.Implications for hand rim wheelchair sports are discussed. Wheelchair racing, basketball and rugby were chosen because of the significance and differences in sport-specific movement dynamics. Conclusions can easily be transferred to other wheelchair sports where movement dynamics are fundamental.n

Determinants of shuttle run performance in the prediction of peak VO2 in wheelchair users

Purpose. The purpose of this study was to determine the impact of ergonomic and environmental variations on indoor shuttle run (SR) performance in wheelchair sportsmen. Methods. Eleven experienced male wheelchair sportsmen performed three 25-m SRs in random order with varying turning capacity (TC) and mechanical resistance (MR): condition NN where participants used their sports wheelchair on a tartan surface, condition RN with increased MR, and condition RD with limited TC. Metabolic data were continuously recorded using a portable K4b2 system. Results. Friedman ANOVA with Wilcoxon a posteriori testing indicated similar VO2peak values in all three tests. SR performance, however, was significantly different across the three test conditions (NN: 536.18 ± 119.09 s; RN: 488.82 ± 119.84 s; RD: 404.91 ± 88.41 s). SR performance contributed for 28% of the explained variance of the measured VO2peak. The addition of TC or MR or both increased the explained variance to 32, 38 and 41%, respectively. Conclusions. These findings demonstrate a significant impact of variations in floor surface and wheelchair-user interface on SR performance. The findings also suggest that strong reservations have to be made regarding the validity of a SR test, as predictor of VO2peak in a wheelchair user population.