ATTENUATION OF GROUND REACTION FORCES IN SALTO DISMOUNTS FROM THE BALANCE BEAM

Abstract

INTRODUCTION • Epidemiological studies have documented the incidence of injuries in female gymnasts. In comparison to other sports, the incidence of injury in gymnastics is high. One epidemiological study prompted the author to state that "...women's gymnastics should be recognized as a hazardous sport." To understand the etiology of injury, researchers have identified these by sites on he body, types of injuries, and/or events (f1oor, uneven bars, vault, and balance beam) in which they occurred. Dismounts, considered an element of all events, have drawn attention as an injury mechanism. Studies have shown the dismount, especially when gymnasts attempt to "stick" their landing, to be a major component of the incidence of injury. This study investigated ground reaction forces (medial-lateral, anterior-posterior, and vertical) in salto dismounts from the balance beam under two styles (stick and roll-out) of landing. The subjects ware 6 female gymnasts ranging in age from 131 to 184 months and in skill level from 7 to 10. RESULTS -Ground reaction forces were recorded for both styles of dismount for 4 subjects in the back salto, 2 subjects in the front salto, and 2 subjects in the cartwheel back salto. Table 1 contains a summary of the ground reaction forces normalized in units of body weight. The results indicate that, by rolling out of the landing, vertical ground reaction forces are substantially reduced for all types of salto dismounts investigated. CONCLUSION -Attenuation of relatively high impact forces through modification of landing may be used, at minimum, in practices 10 reduce the exposure of gymnasts to this physical contraindication.