Knee flexor
Encyclopedia
The knee flexors are a group of muscles which cross the posterior of the knee
joint whose contraction induces flexion
of the joint. They include, but are not limited to:
Knee
The knee joint joins the thigh with the leg and consists of two articulations: one between the fibula and tibia, and one between the femur and patella. It is the largest joint in the human body and is very complicated. The knee is a mobile trocho-ginglymus , which permits flexion and extension as...
joint whose contraction induces flexion
Flexion
In anatomy, flexion is a position that is made possible by the joint angle decreasing. The skeletal and muscular systems work together to move the joint into a "flexed" position. For example the elbow is flexed when the hand is brought closer to the shoulder...
of the joint. They include, but are not limited to:
- The hamstringHamstringIn human anatomy, the hamstring refers to any one of the three posterior thigh muscles, or to the tendons that make up the borders of the space behind the knee. In modern anatomical contexts, however, they usually refer to the posterior thigh muscles, or the tendons of the semitendinosus, the...
s (also hip extensors):- biceps femoris (short head does not extend hip)
- semimembranosus
- semitendinosus
- The gastrocnemius (also plantar flexor as a calf muscle)
- The gracilis muscleGracilis muscleThe gracilis is the most superficial muscle on the medial side of the thigh. It is thin and flattened, broad above, narrow and tapering below.-Origin and insertion:...
(also hip flexor/adductor) - The sartorius muscleSartorius muscleThe Sartorius muscle – the longest muscle in the human body – is a long thin muscle that runs down the length of the thigh. Its upper portion forms the lateral border of the femoral triangle.-Origin and insertion:...
(also hip flexor/abductor/lateral rotator)