Muscles and bones are connected to each other by tendons. Hence the movement of any organ depends on the rhythmic activity of the musculoskeletal system. Bone and muscle coordination in the knee joint is described below.
1. Flexor Muscles: Hamstring muscles and gastrocnemius muscles are required to bend the knee joint backwards. The hamstring muscle consists of three muscles. Biceps femoris, semimembranosus and semitendinosus. These muscles arise from the ischium of the pelvis and attach to the tibia. Their contraction brings the femur and tibia closer together and creates a fold in the knee joint.
2. Extensor muscle: The gastrocnemius muscle is the main muscle of the ball of the foot or ankle. It arises from the condyle of the femur and is attached to the calcaneus or ankle bone by the Achilles tendon. Their contraction brings the femur and tibia closer together and the knee joint bends backwards.
Intermittent contraction of muscle in normal or resting state is called muscle tension. Muscles are attached to bones by tendons. Each organ requires two types of muscles to move. These two muscles together are called antagonistic muscles. During limb movement, one muscle contracts and the other muscle stretches. That is, when one muscle is shortened, the opposite muscle is lengthened. Two types of muscles are attached to the humerus of the arm. Biceps muscle and triceps muscle. When raising the arm, the biceps muscle contracts and the triceps muscle stretches. At this time, no shock is felt in the muscles. Again, the biceps muscle expands and the triceps muscle contracts when the arm is lowered. Even at this time, the muscles do not need any push. Only the muscles are tense.
Muscle contains actin and myosin proteins. These proteins extend from one end of the muscle to the other and can stretch the muscle. This means that the muscles are only stretched, but not pushed.