Search results
Results from the WOW.Com Content Network
The lateral rotator group is a group of six small muscles of the hip which all externally (laterally) rotate the femur in the hip joint.It consists of the following muscles: piriformis, gemellus superior, obturator internus, gemellus inferior, quadratus femoris and the obturator externus.
of thigh/femur at hip [2] Gluteus maximus; Lateral rotator group. piriformis; gemellus superior; obturator internus; pectineus ; gemellus inferior; obturator externus; quadratus femoris; Sartorius; of leg at knee [3] Biceps femoris; of eyeball (motion is also called "extorsion" or excyclotorsion) [4] Inferior rectus muscle; Inferior oblique muscle
When the legs open, such as in the lotus posture of yoga, this is called "lateral rotation", with the opposite movement called "medial rotation". Hip abduction occurs when the femur moves outward to the side, as in taking the thighs apart. Hip adduction occurs when the femur moves back to the midline. Many muscles contribute to these movements:
This causes the femur to rotate and point the knee laterally. The lateral rotators also oppose medial rotation by the gluteus medius and gluteus minimus. When the hip is flexed to 90 degrees, piriformis abducts the femur at the hip and reverses primary function, internally rotating the hip when the hip is flexed at 90 degrees or more. [7]
Piriformis syndrome is tightness or inflammation of the piriformis (a buttock muscle that supports hip rotation), irritating the sciatic nerve. Pain is usually burning, shooting, or aching down ...
The gluteus maximus is a tensor of the fascia lata, and by its connection with the iliotibial band steadies the femur on the articular surfaces of the tibia during standing, when the extensor muscles are relaxed. Therefore, the muscle carries out an extension, a valgisation and an external rotation of the knee. [5]
Located on the posterior side of the hip joint, it is a strong external rotator and adductor of the thigh, [2] but also acts to stabilize the femoral head in the acetabulum. The quadratus femoris is used in Meyer's muscle pedicle grafting to prevent avascular necrosis of femur head.
However, its function changes in different positions of the femur. For example: If the leg is flexed, the whole muscle will flex. [5] The posterior fibres of gluteus medius contract to produce hip extension, lateral rotation and abduction. During gait, the posterior fibres help to decelerate internal rotation of the femur at the end of swing phase.