Question

*Please answer ALL parts...Thank you!!!

Analyze the baseball pitch. For each phase of the skill include:

• Range of motion needed to perform task at each joint.
• Movement and plane of motion at each joint.
• Muscles acting as agonists, antagonists, and stabilizers at each joint and type of muscle contraction.
• What may happen if any of the major muscles are weak or are not contracting correctly?

Answer 1

1) Range of motion needed to perform task at each joint:

pitching is described in six phases: wind up, stride, arm cocking, acceleration, deceleration.

Out of these, the arm-cocking, acceleration, and deceleration phases are the phases when high magnitudes of forces and moments are experienced at the shoulder and elbow joints.

During arm-cocking and acceleration phases, rapid sequential rotation of the pelvis, upper torso, and shoulder causes distal segments to lag behind the proximal segment .  The lag results in acute elongation of muscles that cross the segments, which allows the muscles to produce force effectively. This sequential segment rotation and distal segment lag places the joints in a vulnerable position for injuries.