A Comparison Of Load Characteristics Associated With Pogo Stick Bowlding And Jumping Rope

Abstract

The purpose of this study was to compare the loading characteristics associated with two similar activities: jumping rope (JR) and pogo stick bounding (PS). Twenty-one male volunteers (weight =778 +70 N, height = 180.6 +7.3 cm) continously rebounded on a pogo stick and jumped with a jump rope on top of a force plate while being videotaped (fields per second = 60) from a lateral view. The following variables were compared: (a) peak vertical reaction forces (AVEZ), (b) onset of peak vertical reaction forces, (c) load frequency, and (d) the moments at the ankle and knee (ANKMOM and KNEEMOM) during impact. Also, the following related movement parameters of the two activities were evaluated: (a) head and trunk inclination; (b) center of mass displacement (CGDIS); and (c) ankle, knee, hip, and upper limb range of motion. The results of this investigation indicated that there were significant differences between the two tasks for both the kinetic and kinematic measurements. Center of mass displacement was greater for pogo stick bounding. Mean vertical impact force, ankle range of motion, knee range of motion, shoulder range of motion, elbow range of motion, moment at the ankle, and moment at the knee were all greater for the jump rope task . Significant (p < .05 and greater) correlations between variables were found for both the PS and JR groups. For the PS .group the kinematic CGDIS correlated negatively to the load characteristic KNEEMOM. Positive correlations for this group also included several other kinematic to load matches (CGDIS and ANKMOM, CGDIS and AVEZ, and knee range of movement and ANKMOM). The regression analysis for the PS group indicated three variables (CGDIS, ankle range, and elbow range) as significant predictors of knee moment, and CGDIS as a significant predictor of peak vertical impact force. For the JR group the variable elbow range was found to be a significant predictor of both knee moment and peak vertical impact force.