Explain how major muscles in the upper body work together to perform an overhead throw. (5 marks)
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Sample Answer
- During the wind-up phase, latissimus dorsi and posterior deltoids contract to pull the arm backward into extension. This action stretches the anterior muscles (pectorals, anterior deltoid), creating stored elastic energy. Meanwhile, the external rotators position the shoulder in external rotation. As a result, the throwing arm is optimally positioned for force generation.
- Core muscles initiate the forward phase through trunk rotation. Obliques and rectus abdominis contract to rotate the trunk toward the target. This rotation generates the initial force that will transfer up the kinetic chain.
- Subsequently, pectoralis major and anterior deltoid contract powerfully. These muscles accelerate the arm forward through horizontal adduction and flexion. At the same time, rotator cuff muscles (supraspinatus, infraspinatus) stabilise the shoulder joint, preventing injury during rapid movement.
- Finally, the triceps contracts explosively to extend the elbow at release. This final extension adds velocity to the ball. Therefore, coordinated muscle activation from core to fingertips enables powerful, accurate throwing.
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Sample Answer
- During the wind-up phase, latissimus dorsi and posterior deltoids contract to pull the arm backward into extension. This action stretches the anterior muscles (pectorals, anterior deltoid), creating stored elastic energy. Meanwhile, the external rotators position the shoulder in external rotation. As a result, the throwing arm is optimally positioned for force generation.
- Core muscles initiate the forward phase through trunk rotation. Obliques and rectus abdominis contract to rotate the trunk toward the target. This rotation generates the initial force that will transfer up the kinetic chain.
- Subsequently, pectoralis major and anterior deltoid contract powerfully. These muscles accelerate the arm forward through horizontal adduction and flexion. At the same time, rotator cuff muscles (supraspinatus, infraspinatus) stabilise the shoulder joint, preventing injury during rapid movement.
- Finally, the triceps contracts explosively to extend the elbow at release. This final extension adds velocity to the ball. Therefore, coordinated muscle activation from core to fingertips enables powerful, accurate throwing.