The human leg, in the general word sense, is the entire lower limb of the human body, including the foot, thigh or sometimes even the hip or gluteal region. However, the definition in human anatomy refers only to the section of the lower limb extending from the knee to the ankle, also known as the crus or, especially in non-technical use, the shank. Legs are used for standing, and all forms of locomotion including recreational such as dancing, and constitute a significant portion of a person's mass. Female legs generally have greater hip anteversion and tibiofemoral angles, but shorter femur and tibial lengths than those in males.
The femur, or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with the tibia (shinbone) and patella (kneecap), forming the knee joint. By most measures the two femurs are the strongest bones of the body, and in humans, the largest and thickest.
The humerus is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius and ulna, and consists of three sections. The humeral upper extremity consists of a rounded head, a narrow neck, and two short processes. The body is cylindrical in its upper portion, and more prismatic below. The lower extremity consists of 2 epicondyles, 2 processes, and 3 fossae. As well as its true anatomical neck, the constriction below the greater and lesser tubercles of the humerus is referred to as its surgical neck due to its tendency to fracture, thus often becoming the focus of surgeons.
The tibia, also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two bones in the leg below the knee in vertebrates ; it connects the knee with the ankle. The tibia is found on the medial side of the leg next to the fibula and closer to the median plane. The tibia is connected to the fibula by the interosseous membrane of leg, forming a type of fibrous joint called a syndesmosis with very little movement. The tibia is named for the flute tibia. It is the second largest bone in the human body, after the femur. The leg bones are the strongest long bones as they support the rest of the body.
The gluteus maximus is the main extensor muscle of the hip. It is the largest and outermost of the three gluteal muscles and makes up a large part of the shape and appearance of each side of the hips. It is the single largest muscle in the human body. Its thick fleshy mass, in a quadrilateral shape, forms the prominence of the buttocks. The other gluteal muscles are the medius and minimus, and sometimes informally these are collectively referred to as the glutes.
The pectineus muscle is a flat, quadrangular muscle, situated at the anterior (front) part of the upper and medial (inner) aspect of the thigh. The pectineus muscle is the most anterior adductor of the hip. The muscle does adduct and internally rotate the thigh but its primary function is hip flexion.
The biceps femoris is a muscle of the thigh located to the posterior, or back. As its name implies, it has two parts, one of which forms part of the hamstrings muscle group.
The adductor brevis is a muscle in the thigh situated immediately deep to the pectineus and adductor longus. It belongs to the adductor muscle group. The main function of the adductor brevis is to pull the thigh medially. The adductor brevis and the rest of the adductor muscle group is also used to stabilize left to right movements of the trunk, when standing on both feet, or to balance when standing on a moving surface. The adductor muscle group is used pressing the thighs together to ride a horse, and kicking with the inside of the foot in soccer or swimming. Last, they contribute to flexion of the thigh when running or against resistance.
The adductor magnus is a large triangular muscle, situated on the medial side of the thigh.
The semimembranosus muscle is the most medial of the three hamstring muscles in the thigh. It is so named because it has a flat tendon of origin. It lies posteromedially in the thigh, deep to the semitendinosus muscle. It extends the hip joint and flexes the knee joint.
In human anatomy, the muscles of the hip joint are those muscles that cause movement in the hip. Most modern anatomists define 17 of these muscles, although some additional muscles may sometimes be considered. These are often divided into four groups according to their orientation around the hip joint: the gluteal group; the lateral rotator group; the adductor group; and the iliopsoas group.
The gluteal tuberosity is the lateral ridge above the linea aspera of the femur. It is the site of insertion of the gluteus maximus muscle.
In vertebrates, the pubic region is the most forward-facing of the three main regions making up the coxal bone. The left and right pubic regions are each made up of three sections, a superior ramus, inferior ramus, and a body.
The fascia lata is the deep fascia of the thigh. It encloses the thigh muscles and forms the outer limit of the fascial compartments of thigh, which are internally separated by the medial intermuscular septum and the lateral intermuscular septum. The fascia lata is thickened at its lateral side where it forms the iliotibial tract, a structure that runs to the tibia and serves as a site of muscle attachment.
The body of femur is the almost cylindrical, long part of the femur. It is a little broader above than in the center, broadest and somewhat flattened from before backward below. It is slightly arched, so as to be convex in front, and concave behind, where it is strengthened by a prominent longitudinal ridge, the linea aspera.
The perforating arteries, usually three in number, are so named because they perforate the tendon of the Adductor magnus to reach the back of the thigh.
The medial intermuscular septum of thigh is a fold of deep fascia in the thigh.
In human anatomy, the adductor minimus is a small and flat skeletal muscle in the thigh which constitutes the upper, lateral part of the adductor magnus muscle. It adducts and laterally rotates the femur.
The vastus muscles are three of the four muscles that make up the quadriceps femoris muscle of the thigh. The three muscles are the vastus intermedius, the vastus lateralis, and the vastus medialis located in the middle, on the outside, and inside of the thigh, respectively. The fourth muscle is the rectus femoris muscle a large fleshy muscle which covers the front and sides of the femur.
