How Antagonistic Pairs Help Muscles Move
When one muscle contracts, another relaxes.
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Transcript
Every day you rely on your muscles to help you move. From simple tasks to feats of athletic performance, we are using our muscles all the time.
The muscles around many movable joints form antagonistic pairs. The two muscles in an antagonistic pair are arranged so that when one muscle contracts, or grows shorter, the other muscle in the pair relaxes, or lengthens. The muscles work in opposition, causing the joint to move.
When you bend your arm at the elbow, one muscle, your biceps, is contracting, while another muscle, your triceps, relaxes. When you straighten your arm, your triceps is contracting while your biceps is relaxing. Together, the biceps and triceps form an antagonistic pair.
The muscles above the knee joint form another antagonistic pair. Contraction of the quadriceps femoris, or quads for short, causes your leg to extend at the knee. When the hamstrings contract, the quads relax, causing the leg to flex, or bend, at the knee.
Another antagonistic pair is found in the lower leg. These muscles go to work when you flex your foot up toward the front of your leg. When you do this, the tibialis muscle works in conjunction with the calf muscles in the back of the lower leg.
As you flex your foot upward, you can feel your calf muscles relax while the tibialis muscle contracts.
The muscles around many movable joints form antagonistic pairs. The two muscles in an antagonistic pair are arranged so that when one muscle contracts, or grows shorter, the other muscle in the pair relaxes, or lengthens. The muscles work in opposition, causing the joint to move.
When you bend your arm at the elbow, one muscle, your biceps, is contracting, while another muscle, your triceps, relaxes. When you straighten your arm, your triceps is contracting while your biceps is relaxing. Together, the biceps and triceps form an antagonistic pair.
The muscles above the knee joint form another antagonistic pair. Contraction of the quadriceps femoris, or quads for short, causes your leg to extend at the knee. When the hamstrings contract, the quads relax, causing the leg to flex, or bend, at the knee.
Another antagonistic pair is found in the lower leg. These muscles go to work when you flex your foot up toward the front of your leg. When you do this, the tibialis muscle works in conjunction with the calf muscles in the back of the lower leg.
As you flex your foot upward, you can feel your calf muscles relax while the tibialis muscle contracts.
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