MODELING JOINT FORCES IN HIGH BAR RELEASE MOVES

Authors

  • M. Nichols-Ketchum

Abstract

In competitive gymnastics, release-regrasp moves on the mens' high bar and womens' uneven parallel bars have become more prevalent and more difficult as "courage, originality and virtuosity" requirements encourage gymnasts and coaches to develop new and more difficult skills. The learning process for a "basic" release skill, such as Tkatchev (a reverse hecht over the bar) may take 6 - 18 months. During this process. "errors of performance may bring about ... injuries due to abnormal loading of tissue structures" (Sands, 1981). If potentially damaging habits are learned with skill, chronic damage may occur. The purpose of the proposed study is to develop a model of the Tkatchev which will predict joint forces during the performance and determine which aspects of the performance are critical to minimizing the risk of injury. Two or three subjects will be used to develop the model. The subjects will be male gymnasts who have recently begun learning the Tkatchev. Each subject will be filmed at four stages of their learning process: (1) Subject can sporadically complete the move independently, but still is required to use spotting belt for safety reasons. (2) Subject can consistently completed the move independently with spotting belt in place. (3) Subject has just begun to work the move independent of spotting assistance. (4) Subject is ready to include the move in competitive routines. The gymnast's coach will determine when the subject has reached each level. The film for each performance will be digitized and kinematic and kinetic analyses will be done to determine joint forces and reaction forces. The high bar will be instrumented with strain gages to provide additional data on reaction forces at the bar. Correlations will be done to determine the relationship between joint forces and anthropometric and performance characteristics. Existing data on the material and mechanical properties of soft tissues will be used to determine the probability of damage due to the calculated forces. It is hoped that the outcome of this study will provide biomechanical data to aid coaches, gymnasts and trainers in optimizing release skills and minimizing the risks of i injury. ! REFERENCES Sands, B. (1981). Kinematic analysis of the reverse hecht on the women's uneven ; parallel bars (unpublished paper). United States Gymnastics Federation.