What would happen if muscle did not work in pairs? please!!! help!!!?

Question

umm. i need alot of detail

Answer 1

Lets say you had triceps and no biceps, you would not be able to do curls.  Triceps extend your arm and biceps bend your arm.  On your forearm you have muscles to twist your arm inward and another to twist it outward.  Without pairs of muscles we would rely only on gravity to bring our limbs back from a flexed position.  Without the reversing pull of the paired muscle the single muscle would tend to stay bunched up.  The pulling of the second muscle helps to stretch out the contracted muscle.  This stretching out also helps to remove the lactic acid that builds up in our muscles as we use them.  The lactic acid is what causes your muscles to ache when you exercise them.  How would you like to have that in your arms and not able to get it out?  Imagine the way you would walk if you had to wait for your leg to swing back on its own and forget about running.  How would fish swim without paired muscles?

Answer 2

Skeletal muscles only pull in one direction. For this reason they always come in pairs. When one muscle in a pair contracts, to bend a joint for example, its counterpart then contracts and pulls in the opposite direction to straighten the joint out again. Without this arrangement you wouldn't be able to straighten your legs when you walk or bend your fingers to grip something.