The purpose of this study was to identify factors affecting efficiency of wheelchair propulsion by male subjects in the 800-m racing event. High-speed films were taken of finalists (n=31) at the 1986 National Wheelchair Track and Field Championships. Kinematic data were calculated on the head, trunk, upper arm, elbow, and thigh in addition to cycle velocity (wheelchair velocity), cycle duration, cycle rate, cycle distance, and percentage of propulsion and recovery. In general, fastest cycle velocities, rates, and greatest distances occurred in the higher classes. During propulsion, head movement was greatest in Classes II/III (13.9°) and trunk movement was greatest in Classes IV/V (7.8°). Additionally, the higher classes exhibited greater movement at the shoulder and elbow than did Classes IA/IB. The thighs were closest to the trunk in Classes IA/IB and were farthest from the trunk in Classes IV/V. Movement of the trunk and head, as well as positioning of the thighs during wheelchair racing, may help in propulsion and with aerodynamics.
The results suggested that the PALM method of measuring leg length differences may have clinical utility in differentiating between patients who are likely to sustain patello-femoral pain syndrome and those who will not.
The purpose of this study was to provide quantitative data about changes in coordination after practicing a racquetball forehand drive serve. Novice women (N = 10) were videotaped before and after 10 min. of practicing a racquetball forehand drive serve on Day 1, and after 10-min. practice sessions on consecutive Days 2 through 5. The PEAK5 Motion Measurement System was used to evaluate the following dependent variables: (a) range of motion of the wrist, elbow, upper torso, and pelvis from backswing to ball contact: (b) racket head velocity at ball contact; and (c) coordination. Coordination was evaluated based on analysis of the angular velocity graphs of each performance to assess sequencing and timing of the segmental contributions. Shared positive contribution was assessed between adjacent 2-segment combinations: pelvis-torso and elbow-wrist. A repeated-measures analysis of variance indicated racket velocity, pelvic rotation, and upper torso rotation significantly increased over the 5 days of practice. Although participants increased their pelvic and torso ranges of motion and racket velocity, improvement in coordination was not documented.
This paper describes the sprint running of selected Class 6, 7, and 8 international-level athletes with cerebral palsy (CP), contrasts their biomechanical characteristics with those reported for nondisabled runners, and delineates discriminating biomechanical parameters among classes. Subjects included 17 male and female Class 6, 7, and 8 athletes with CP who competed in international competition and were finalists or semifinalists in sprint events. High speed films were taken, and data reduction was performed. It was concluded that (a) elite Class 6, 7, and 8 athletes with CP descriptively differ from findings reported in the nondisabled literature on variables of stride length, velocity, ratio of support to nonsupport time, time of forward swing, trunk angle, hip angle, angle of touchdown, and stride time (females only); (b) athletes with CP differ (right-side values only) between classes for hip range of motion, hip velocity, knee and elbow range of motion, and trunk angle average; and (c) distinguishing biomechanical characteristics exist between the more involved and noninvolved or less involved sides for hip velocity, angle of touchdown, and hip, knee, ankle, and shoulder range of motion.
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