International Society of Biomechanics in Sports (ISBS)
Abstract
INTRODUCTIONT he purpose of this investigation was to compare an adult novice (NOV) with an experienced (EXP) adult performing a badminton deep serve, a racquetball forehand, and a racquetball drive serve. Movements were videotaped by 4cameras at 120 Hz and the 3-D data were analyzed using the PEAK5 motion measurement system. Range of motion (ROM), sequence of motion, and temporal values were assessed on the following angular movements: absolute pelvic (P) and upper torso (UT) rotation, and relative humeral (H), elbow (E), and wist (W) rotation. RESULTS For each skill and performer, the segmental sequence and ROM are presented. This information is followed by the range of lag times (LT) between segments within the sequence and the total time (TT) (backswing to contact)over which the skill occurred. Badminton Serve EXP P(37.4"),UT(69.6"), H(76.3"), W(59.7"), E(16.0°).LT(.02-.I 8s). TT(.23s).NOV UT(30.4"), P(l 3.0°), H(67.0°),W(10.2"), E(34.2").LT(.OI -.14~)T. T(.2Os).Racquetball Forehand EXP H(68.8"),P(57.g0),U T(71. I") , W(ll .go), E(12.8").LT(.02-.1 0s). TT(. II S).NOV P(34.8"), UT(69.2"), W(59.4"),E(8.7"), H(10.7").LT(.03-. 1 3s). TT(.20s).Racquetball Serve U(P P(92.4"),UT(122.0°), H(154.0°), E(75.3"),W(41.8"). LT(.00-. 10s). TT(. 1 8s).NOV P(64.3"), UT(77.g0), W(81 .OO),H(87.0°), E (0.8").LT(.OI -. 14s). TT(. 194.CONCLUSIONS1) Results for the badminton serve indicated the EXP exhibited greater ROM than the NOV for all angles except E. The NOV constrained the W to possibly allow for the greater E movement.2) In the forehand and in the racquetball serve, the NOV constrained the elbow more than the EXP which was consistent with Southard's (1 987) results; however, the great W ROM was inconsistent and appeared to be a last resort to generatevelocity.3) The EXP was more compact performing the forehand than the racquetball serve. During the serve, the lack of initial ball velocity required greater ROM to achieve the goal.4) In all 3 tasks, the EXP displayed essentially the same sequence of propulsive segmental initiation (proximal to distal). The patterns exhibited by the NOV were more simultaneous and the sequences varied for each task. REFERENCES Bird, M., Hills, L., & Hudson, J. L.(1 991 ). Intersegmental coordination: an exploration of context. In C. Tant, P.Patterson, & S. York (Eds.),Biomechanics in Sworts IX: Proceedings of the 9th International Symposium on Biomechanics in Sports (pp. 233-237).Ames, IA: Iowa State University.Southard, D. & Higgins,T,. (1 987).Changing movement patterns: effects of demonstration and practice. Research Quarterlv for Exercise and Sport, 58(1),77-80