Teres major redirects here. For the beef cut, see shoulder tender. The teres major muscle (Latin teres meaning 'rounded') is a muscle of the upper limb and one of seven scapulohumeral muscles.It is a thick but somewhat flattened muscle, innervated by the lower subscapular nerve (C 5 and C 6).eres major redirects here. For the beef cut, see shoulder tender. The teres major muscle (Latin teres meaning 'rounded') is a muscle of the upper limb and one of seven scapulohumeral muscles.