VERTICAL HAND FORCE AND FOREARM EMG DURING A HIGH-STEP ROCK-ON CLIMBING MOVE WITH ' AND WITHOUT ADDED MASS

Eight experienced climbers completed four trials of a climbing movement known to climbers as a high-step rock-on on a vertical ind.oor wall. Climbers performed 2 trials of each condition of body mass (BM) and body mass plus 4.5 kg of added mass (AM). Two force platforms (FP) were imbedded into the wall flush with the climbing surface and modified to accept artificial climbing holds. During the movement sequence, a point was attained when all. weight was supported by the right foot and right hand on the two FP. Vertical ground reaction force (Fv) and forearm EMG were recorded at 500 Hz throughout the movement. Peak Fv was significantly higher for AM vs BM. Also peak Fv was higher than Fv at peak IEMG. There were no differences in IEMG. Added weight increases the support maintained by the hand, but, is not related to in IEMG at the point of peak force. KEY WORDS: rock climbing, electromyography, contact force INTRODUCTION: The nature of rock climbing requires the individual, to transport body mass vertically, with varying degrees of support, through a series of complex movements and bod