Which muscle's function does NOT include shoulder flexion and abduction?

The function of the brachialis muscle does not include shoulder flexion or abduction; rather, it primarily acts as a flexor of the elbow joint. This muscle is located beneath the biceps brachii and is responsible for flexing the forearm at the elbow, regardless of the position of the shoulder.

In contrast, the other muscles listed – the biceps brachii, coracobrachialis, and deltoid – are involved in shoulder flexion and/or abduction. The biceps brachii assists in shoulder flexion in addition to its role in elbow flexion. The coracobrachialis primarily acts to flex and adduct the shoulder. The deltoid is a key muscle for shoulder abduction and also contributes to shoulder flexion.

Understanding the actions of these muscles is crucial for assessing shoulder movements and the mechanics involved in upper limb activities.