DO MUSCLES WORK IN PAIRS

muscles actually work in pairs.a muscle can ony pull in one direction so it needs another muscle to pull in the opposite direction in order to return a bone to its original position.when you lift ur forearm,the biceps muscle shortens to lift the bone.when you straighten your arm,the triceps muscle pulls it back again and the biceps relaxes.the same action takes place in ur legs when you walk and run,and when you move ur fingers or toes