PROPULSION TECHNIQUE AND ANAEROBIC WORK CAPACITY IN ELITE WHEELCHAIR ATHLETES - CROSS-SECTIONAL ANALYSIS

Wheelchair sports and daily manual wheelchair propulsion are dominated by frequent short-term power demands. The purpose of the current cros s-sectional study was to determine the variation in propulsion techniq ue in association with sprint power production among elite wheelchair athletes. Therefore, 67 wheelchair athletes (different impairments; 17 female and 50 male athletes; age, 29.1 +/- 7 yr; body weight, 60.7 +/ - 11.8 kg; training hours, 12.9 +/- 6.4 h.wk(-1); VO2 peak, 1.7 +/- 0. 7 liter.min(-1); aerobic power output, 72.2 +/- 36.7 W) were studied d uring the World Championships and Games for the Disabled in Assen (199 0) on propulsion technique and anaerobic work capacity in a 30-s sprin t test on a computer controlled wheelchair ergometer. Mean power outpu t (P30) (97 +/- 45.8 W; range, 8.3-195.3 W) and heart rate (158.6 +/- 23.6 b.min(-1)) were highly variable and seemed associated with impair ment level: track athletes, classified in four different functional cl asses, showed a class-related P30 of 23, 68, 100, and 138 W for the ma le athletes (n = 38). Sprint power relative to body weight varied betw een 0.36 W.kg BW-1 +/- 0.04 and 1.85 W.kg BW-1 +/- 0.43 for the differ ent subject groups. Propulsion technique in terms of forces applied to the rim and timing showed significant differences between subject gro ups for the majority of parameters studied. Apart from the mediolatera l force and the negative dip at the start of the push phase, the techn ique parameters were significantly related to power production. Fracti on effective force, the ratio between the total force vector and the e ffective force applied to the hand rim, appeared low on average (espec ially for subjects with cerebral palsy and those with a high spinal le sion) but showed a significant correlation with power output (r = 0.5) . In general, propulsion technique parameters were related to both per formance and functionality. The number of training hours showed a smal l but significant relation with peak power (r = 0.31), peak torque (r = 0.4), the amount of work per push (r = 0.41) and the total force vec tor (r = 0.31), stressing the role of training status, next to disabil ity, as important mediating factor in both propulsion technique as wel l as performance capacity. No association between training hours and f raction effective force was seen. It can be concluded that propulsion technique and performance parameters are highly variable among wheelch air athletes. Also, propulsion technique is strongly associated with f unctionality and training hours and does clearly relate to performance . The current results on technique and performance and their possible causal relationship, but also with impairment and sports discipline, m ust be further substantiated in a longitudinal study design.