Question

The pectoralis major and latissimus dorsi muscles can be both synergists and antagonists to each other. Explain.

Answer 1

Yes , pectrolis major and lattismus dorsi both acts as synergists and antagonist.

Synergists which gives similar action whereas antagonists which give opposite action.

Pectrolis major muscle has following actions.

1. Whole muscle - Adduction , medial rotation of shoulder.

2. Clavicular part - flexion of arm.

3. Sternocoastal part - climbing.

Lattismus dorsi has following actions -

1. Adduction .

2. Medial rotation of shoulder.

3. Climbing.

4. Extension .

so synergistic actions are Adduction , medial rotation of shoulder and climbing.

Antagonistic actions are extension in lattismus dorsi and flexion in pectrolis major.