Question

Describe an upper body movement or injury by using anatomical terms to describe the movement and musculature involved. Must identify all movements that occur in the upper body and the plane of motion in which the movements occur. Must also identify five muscles involved in completing the movement and identify the primary action of each participating muscle.

Answer 1

Let's consider the shoulder joint movements as the shoulder joint is a part of our upper body - the shoulder joint is a type of ball and socket joint.

There are 6 types oglf shoulder movements - Abduction, Adduction, horizontal flexion and extension, Vertical flexion and extension.

Now, consider the vertical flexion and extension movement of the shoulder joint.

This movement occurs with respect to sagittal plane.

In vertical flexion, the arm moves backwards and literally and it occurs in a plane parallel to the surface of glenoid cavity.

The muscles which are responsible for extension of shoulder joint are posterior fibres of deltoid, latissimus dorsi and some accessory muscles like teres major and long head of biceps bracii.

Latissimus dorsi helps in holding the inferior angle of scapula in proper place and also helps in supporting various movements including extension, medial rotation and adduction of shoulder joint.

The posterior fibres of deltoid primary functions extensors but also helps in lateral rotation.

In Vertical flexion, the arm moves forwards and medially.

The muscles that are responsible for flexion off shoulder joint are clavicular head of pectoralis, major anterior fibres of deltoid, coracobrachialis, teres major.

The primary function of coracobrachialis is the flexion of shoulder joint.

The anterior fibres of deltoid flexes and medial rotators of the arm.

The movement of shoulder joint occurs mostly because all joints of shoulder complex like glenohumeral and sternoclavicular and acromioclavicular and scapulothoracic all work together.