How Muscles and Bones Work Together to Flex the Knee

How Muscles and Bones Work together to Flex the Knee
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How Muscles and Bones Work together to Flex the Knee
Knee joints sustain the whole body's weight, connecting the thighbone(femur) and shinbone (tibia) with quadriceps muscles bounding them. These muscles pull the joints, which allow individuals to move. Bones are essential in supporting the body and assist in forming people's shapes. Even though bones are incredibly light, they are adequately powerful in supporting the whole body's weight. Markolf et al. (2019) state that the knee links the upper and lower leg bones. Generally, people need their knees to move and perform activities such as swimming, biking and running.
Knees have complex structures that help individuals to bend and straighten the body. Nielsen et al. (2018) assert that strong knees can move from 0 to more than140 degrees, and an individual can turn a bent knee inward and outward. The knees have several bones, muscles, and ligaments. Muhammad and Anup (n.d.) posit that when front thigh muscles contract, the leg straightens and bends at the knee when back thigh muscles contract. These two muscles are functional rivals, and people require them for physical performance. When individuals straighten their legs, front thigh muscles pull on tendons, which pull kneecaps (patella), making the knees extend. When an individual bends their knees, hamstring muscles contract, pulling the shinbone backward, hence making the knees flex. How far the knees move depends on muscle stiffness and soft-tissue restraints, among other factors. Therefore, the quadriceps and hamstrings permit knee joints to balance, move, and become stable.
When fully extended, the tibia and femur lock into position, allowing the legs to be stable and improve their capacity to bear loads. According to Zabrzynski et al. (2021), popliteus muscles behind the legs unlock knees by rotating thighbones on shinbones, permitting knee joints to flex. The muscles around the femur, such as vastus intermedius and rectus femoris, cross the knees through the kneecaps, allowing the legs' extension. On the other hand, the muscles around the hamstring, such as the biceps femoris and semitendinosus, flex the knees and extend the hips (Zabrzynski et al., 2021). The femoral muscles and those around the hamstring flex the knees and extend the hips.
Knee joints are two, which comprise the...