Análisis mecánico de la práctica del boliche

A Biomechanical Analysis Of Bowling's 5-Step Approach
This is an initial biomechanical review of the sport of bowling. The objective of the sport is to approach and roll a ball behind a foul line, down a lane, and into a set of ten pins attempting to knock as many down as po ssible. A second chance is given if the bowler is unsuccessful knocking down all ten pins on the first ball. The game isscored according to how many pins are knocked down each frame with frames accumulating a total score. Bonus scoring is awarding during those frames in which all the pins are tumbled. Knocking down all ten pins on the first ball is constituted as a strike (X). Knocking down all ten pins on the second ball is termed a spare (/). Once a game is completed, the registered score will range from 0 to 300,300 being twelve strikes in succession. The biomechanical analysis is an anatomical study of the stance, approach, and delivery of a right-handed 5-step bowler. Three phases will be analyzed (preparation, movement, and follow through). The preparation phase occurs when the bowler assumes the stance position. The movement phase begins with the initiation of the first step of the approach and endswith the release (delivery) of the ball. The follow through phase begins immediately after the release of the ball. All musculoskeletal joints w ill be analyzed during each phase.

Preparation Phase
The preparation phase begins when a person steps onto the approach, grasps a ball off the ball return, aligns the body to the target (including eyes), places the hand in the ball, and assumes thestarting position. The bowler is now ready t o initiate the approach to the foul line and delivery of the ball (Berglund, 1983; Kouros, 1976). • • • • • • • • Right Hip Joint - slightly extended to provide a 4"- 6" recession of the right foot. Right/Left Knee Joints - flexed 15 degrees. Trunk - 10 - 15 degree trunk flexion. Right Shoulder Joint - isometric elevation due to ball's weight depressingjoint. Right Shoulder Girdle - slight isometric upward rotation. Right Elbow Joint - isometric flexion at 90 degrees. Right Wrist Joint - isometric flexion due to ball weight. Right Hand Finger Joints - flexion (slight).

In the stance, the left arm is used to support the weight of the ball. The left hand s placed under or aside the ball to provide about 30% support (Burglund, 1983). Otherbowling instructor's philosophies vary on the amount of weight the support arm should carry..Left Shoulder Joint - horizontal flexion. • • • Left Elbow Joint - medially rotated and isometrically flexed. Left Shoulder Girdle - abducted. Left Wrist and Finger Joints - isometrically flexed to hold the ball's weight.

Movement Phase
The movement phase begins with the initiation of the first stepcontinuing through the release of the ball. Since we are diagraming the 5-step approach, each step will be analyzed during the movement phase.

First Step
The first step of the 5-step approach is a small shuffle or half step taken with the left foot to get the momentum of the bowler started (Borden, 1986). The transfer of weight forward eases the ability to start the remaining movements. • • • • • LeftHip Joint - flexion. Left Knee Joint - extension. Right Hip Joint - extension. Right Knee Joint - extension. Right Ankle Joint - plantar flexion.

Second Step
The second step is taken with the right foot. Simultaneously, as the step begins to move, the bowler initiates the ball into the armswing. This action, commonly termed as "the pushaway" is accomplished by extending the right arm forward allowing it to drop into the armswing (Kouros, 1976). The left arm and hand equally support the weight of the ball and assist with extension, or the bowling pushaway with the right arm..Right Hip Joint - flexion. • • • • • • • • • • • • Right Knee Joint - extension. Left Hip Joint - extension. Left Knee Joint - flexion. Left Ankle Joint - plantar flexion. Right Shoulder Joint - flexion. Right...