Junior Class 1 Answered

Hi,

• Antagonistic muscles often occur in pairs. When one contracts the other relaxes.
• Let us consider the movement of the forearm. The upper arm has two muscles—the biceps and triceps.
• When the biceps contract, the forearm is drawn near the body However, a relaxation of biceps cannot push the forearm back to its original position. When triceps contract the forearm is brought back to its original position.