SHOULDER ACTION DURING BOWLING

Abstract

Bowling to the casual observer appears to be a simple sport, having its object to tumble the highest number of pins with a rolling ball from a distance of 60 feet. The concealed complexity of the skill may be realized when an 1 degree deviation in the arm swing produces an error of 1 foot at the pins. The sport's complexity becomes more involved when considering the amount of pin and ball deflection produced as the ball collides with the pins. As a result of the growing popularity of bowling in the amateur and professional ranks and the need for qualified instruction, the National Bowling Council (1974) and American Bowling Congress (1975; Ritger,1976) found it necessary to develop a standardized teaching methodology. Their models for teaching the arm swing w~re that the arm should resemble a free swinging pendulum, where the ball must gripped firmly and the movement initiated by pushing the ball away from the body. Then as the elbow reached maximum extension and was locked in place, the shoulder muscles should be relaxed thereby permitting a free pendular swing (Sabol, 1962). This action would permit gravity to serve as the motivating force in the arm swing and as the arm was moving through its free swinging pendular action the shoulder joint (pivot joint) would be translated down the lane with the bowler taking evenly spaced steps. During the steps of the approach just prior to the slidestep, the vertical position of the shoulder joint should undergo only minor vertical displacements with a large drop in shoulder height occurring during the slidestep and ball release (Ritger, 1976). The teaching model also states that a bowler should use as heavy a ball as he/she can control, in order to increase the pin deflection and reduce the ball deflection. The purpose of this study was to examine the effects that different ball weights had on the kinetics and kinematics of the shoulder action during the bowling delivery of slow and high speed bowlers.