How do the fexor and extensor work together?

Answer 1

Flexor and extensor muscles basically do opposite jobs: flexors contract to "close" a joint whereas extensors lengthen to "open" a joint.

Sets of flexors and extensors are attached to the same joints, which means that there is a relationship between how they work. In smooth, efficient movement activity in the flexors will also cause inhibition in the extensors (and vice versa). If this weren't the case, the muscles would be working against each other which would not provide efficient movement, and can actually cause damage to the body.

Due to faulty movement learning, many people unfortunately have less than perfect cooperation between their flexors and extensors, and it is a common cause of chronic pain and inflammation.

Answer 2

These muscles are antagonistic to each other and move a move able bone in opposite direction to bend or straighten a joint .