Wheelchair racquetball players in the A and B divisions of the 1989 Canadian Racquetball Championships were videotaped and their performances were analyzed. The results indicated that the athletes had an exercise-to-pause ratio of 1:1.5 at the A level and 1:2.3 at the B level. Rallies were slightly longer at the higher level, with substantially longer pause periods at the B level. There was a higher percentage of longer rallies at the A level, although both divisions of play had comparable percentages of forehand and backhand shots. A-level players demonstrated greater distances covered per rally, greater wheelchair speed, and a higher degree of wheelchair maneuverability measured by the number and magnitude of directional changes. In particular, A-level players showed a greater tendency to use small directional corrections, particularly turns to the right of less than 45 °. It is suggested that this action allowed a less restricted backswing for powerful forehand shots.
A computer model was developed of the aerodynamic drag forces acting to slow down a wheelchair. The model calculated drag forces over a range of wheeling speeds between 2 and 20 m/sec, and for wind conditions over the same range of speeds with wind direction varied between 0° (headwind) and 180° (tailwind). The computer model suggests that the large lateral area of a wheelchair adds considerably to the retarding drag forces at relative wind angles between 0 and 90°. It further suggests that three-wheeled wheelchairs have a considerable aerodynamic advantage over four-wheeled wheelchairs for a wide range of wind speeds and directions. In straight line races, the four-wheeled wheelchair has a slight aerodynamic advantage when the relative wind angle exceeds 90°, but under other speed and wind conditions in this study the three-wheeled wheelchair was more efficient.
Yeshayahu Hutzler, Colin Higgs and David Legg
Colin Higgs, Pamela Babstock, Joan Buck and Christine Parsons
A total of 4,698 performances by 904 athletes from 46 countries were analyzed to answer the following questions: (a) Were there significant differences in performance between athletes in each of the International Stoke Mandeville Games Federation (ISMGF) medical classifications? (b) To what extent did the classification system yield consistent results across events? (c) To what extent did performance discriminate between athletes in the various classes? (d) What classification systems would the performance data support? The analysis indicated that not all classes differed significantly from all other classes in performance and that there were different patterns of interclass performance between the track events and the throws. Individual athletic performance was shown not to be a good discriminator of medical classification, particularly for paraplegics. The data supported a reduction in the number of classifications from 7 to 3 in track and from 8 to 4 classes in the throws.