THE EFFECTS OF GRIP WIDTH ON THE KINEMATICS AND KINETICS OF MAXIMAL LIITS IN THE BENCH PRESS

Abstract

The purpose of this study was to examine the effects of various grip widths on the kinematic and kinetic aspects of maximal bench press performance. Six college aged males who had at least two years of bench pressing experience volunteered for this study. Standard two-dimensional high-speed cinematographic procedures were utilized to obtain film data of the bar path in both the descending and ascending phases of the bench press. Each subject bench pressed utilizing three grips which corresponded to 95.165 and 270 percent of biacromial breadth. Randomization of grips was performed and at least 48 hours separated each testing session. During each testing session. each subject was allowed to warm up by performing a set of eight repetitions utilizing a low weight. Testing began utilizing a load which corresponded to 75 percent of the subject's perceived maximum. The load was increased by 10 percent until a maximum lift was achieved. All trials were filmed. Only the maximum lifts were analyzed for this study. Analysis of variance (ANOVA) procedures with repeated measures were utilized to examine differences in accelerations and forces e x don the bar at the greatest positive vertical acceleration during descent (MXAL), first maximum positive vertical acceleration during ascent (MXAR) and first minimum of vertical acceleration during ascent (MNAR). No significant differences @>.05) in accelerations or forces were detected. In addition. ANOVA with repeated measures were utilized to detect differences in horizontal and vertical position of the bar relative to the shoulder at the points of minimum and maximum acceleration in the ascending phase. Significant differences (px.05) between the grips were determined for the horizontal position at MXAR and MNAR and the vertical bar position at MNAR. The results of this study have training implications for understanding the effects of grip width on strength development in the bench press.