Pushing economy and wheelchair propulsion technique were examined for 8 wheelchair racers on a motorized treadmill at 6.0, 6.5, and 7.0 m/s. Kinematic data for the sagittal view were collected by a video camera for two-dimensional analysis. Adaptations to speed changes occurred, initially by a decrease in cycle time and an increase in cycle rate, and later by an increase in the flexion of the elbow. At each speed there were large variations in pushing economy between individuals. The relationship between pushing economy and selected kinematic variables revealed that at 6.0, 6.5, and 7.0 m/s, economy was associated with (a) the lighter athletes (r = .89, .86, .83), (b) a greater range of elbow movement (r = -.85, -.65, -.63), and (c) a lower push rate (r = .73, .81, .63), respectively. Effects of lesion level and wheelchair design may be more important in explaining differences in pushing economy than differences in propulsion technique.
Victoria L. Goosey and Ian G. Campbell
Victoria L. Goosey, Neil E. Fowler and Ian G. Campbell
The aim of the study was to examine and compare the propulsion techniques of senior male, senior female, and junior male athletes and to determine the relationship between the kinematic variables and performance. A two-dimensional video analysis was performed on the 800 m finals (n = 23) at the 1994 British Wheelchair National Track Championships. From this, the angle of lean, elbow angle, and the cycle dynamics were determined. The senior male athletes achieved a faster maximum velocity (7.3 ± 0.3 m.s-1) than that achieved by the senior female (5.9 ± 1.0 m.s1) and junior male athletes (6.0 ± 1.0 m.s-1), resulting in a greater distance covered during each push cycle. The kinematic analysis showed that the junior athletes adopted a 5° more upright position and spent less time in contact with the hand-rim (25%) than the senior athletes. A moderate correlation was found between cycle distance and performance time (r = -0.68; p < 0.01). In conclusion, this study suggests that there are kinematic differences between senior male, senior female, and junior male wheelchair athletes.
Victoria L. Goosey, Ian G. Campbell and Neil E. Fowler
Three-dimensional kinematic and physiological data were obtained from 18 wheelchair racers, to allow the relationship between pushing economy and kinematic variables at 4.70 m · s−1 (n = 18) and 6.58 m · s−1 (n = 12) to be examined. Large inter individual differences in wheelchair propulsion styles were present, which made it difficult to identify variables that were associated with pushing economy and indeed to distinguish key variables that were characteristic of an economical wheelchair racer. Furthermore, those variables associated with economy proved inconsistent across the two speeds. However, at both speeds a higher mechanical efficiency and lower push rate were associated with better economy (p < .05). It was also found that the timing parameters were important. In this respect most athletes tended to push through a similar push angle; however, push rate differed between individuals, suggesting that the magnitude and direction of the hand-rim forces may be important for determining economy of propulsion.
Thomas J. O’Connor, Rick N. Robertson and Rory A. Cooper
Three-dimensional kinematic variables and their relationship to the physiology of racing wheelchair propulsion were studied. Six male wheelchair athletes performed two trials (medium and maximum speed) of 3 min each. VO2, VO2/kg, VE, and HR were measured. Results showed that at medium speed, wrist velocity on hand contact was significantly correlated with VO2/kg. At maximum speed, elbow velocity during preparatory phase was significantly correlated with VO2. Stepwise regression showed wrist trajectory angle and elbow velocity during preparatory phase were significantly correlated with VO2/kg. Results indicate that kinematic variables recorded prior to and on hand contact with the pushrim are significant variables in developing a more efficient racing wheelchair propulsion technique. Results of this study indicate a need to educate coaches of wheelchair track athletes concerning the best racing wheelchair propulsion technique.
Luc H.V. van der Woude, Dirk-Jan E.J. Veeger and Rients H. Rozendal
A review of wheelchair research within the scope of the wheelchair as a means of daily ambulation is presented. The relevance of a combined biomechanical and physiological research approach is advocated for enhancing the body of knowledge of wheelchair ergonomics, that is, the wheelchair/user interaction in relation to aspects of vehicle mechanics and the user’s physical condition. Results of experiments regarding variations in the wheelchair/user interface stress the possibilities of optimization in terms of wheelchair dimensions and user characteristics. Analysis of propulsion technique is aimed at the within-cycle characteristics and the time-dependent organization of technique.
Josje van Houwelingen, Sander Schreven, Jeroen B.J. Smeets, Herman J.H. Clercx and Peter J. Beek
In this paper, a literature review is presented regarding the hydrodynamic effects of different hand and arm movements during swimming with the aim to identify lacunae in current methods and knowledge, and to distil practical guidelines for coaches and swimmers seeking to increase swimming speed. Experimental and numerical studies are discussed, examining the effects of hand orientation, thumb position, finger spread, sculling movements, and hand accelerations during swimming, as well as unsteady properties of vortices due to changes in hand orientation. Collectively, the findings indicate that swimming speed may be increased by avoiding excessive sculling movements and by spreading the fingers slightly. In addition, it appears that accelerating the hands rather than moving them at constant speed may be beneficial, and that (in front crawl swimming) the thumb should be abducted during entry, catch, and upsweep, and adducted during the pull phase. Further experimental and numerical research is required to confirm these suggestions and to elucidate their hydrodynamic underpinnings and identify optimal propulsion techniques. To this end, it is necessary that the dynamical motion and resulting unsteady effects are accounted for, and that flow visualization techniques, force measurements, and simulations are combined in studying those effects.
Ron Davis, Gale Gehlsen and Jerry D. Wilkerson
This study quantitatively analyzed the backward propulsion technique used by elite Class II CP wheelchair athletes. Six subjects, 3 males and 3 females, were selected from the 1984 International Games for the Disabled. The subjects were filmed in a staged setting during a sprint start for the first three complete cycles. A digitizer interfaced to an Apple II+ computer was employed to digitize the film data. A computer program served to reduce the data into linear and angular kinematic components. For the purposes of analysis, the foot propulsive movement cycles or thrust cycles were divided into the two movement phases of push and recovery. The results of the study indicated that the initial three movement cycles appeared to be characterized by longer push than recovery time, and wheelchair velocity appeared to be associated with recovery phase displacement.
Amy R. Lewis, William S.P. Robertson, Elissa J. Phillips, Paul N. Grimshaw and Marc Portus
Optimization of propulsion technique for both performance and injury risk can be achieved using musculoskeletal modeling approaches, which can take into account athlete-specific physical attributes. The limiting factor of this approach, however, is the inherent reliance on the quality of input parameters
Rand Wilcox, Travis J. Peterson and Jill L. McNitt-Gray
, McNitt-Gray JL . Modifications in wheelchair propulsion technique with speed . Front Bioeng Biotechnol . 2015 ; 3 : 171 . doi:10.3389/fbioe.2015.00171 10.3389/fbioe.2015.00171 26579513 35. Peterson T , Wilcox R , McNitt-Gray J . Angular impulse and balance regulation during the golf swing
Travis J. Peterson and Jill L. McNitt-Gray
.1016/0021-9290(91)90167-L 1744147 10.1016/0021-9290(91)90167-L 20. Russell IM , Raina S , Requejo PS , Wilcox RR , Mulroy S , McNitt-Gray JL . Modifications in wheelchair propulsion technique with speed . Front Bioeng Biotechnol . 2015 ; 3 : 171 . PubMed ID: 26579513 doi:10.3389/fbioe.2015.00171 10