The leg is the entire lower limb of the human body, including the foot, thigh or sometimes even the hip or buttock region. The major bones of the leg are the femur, tibia, and adjacent fibula. The thigh is between the hip and knee, while the calf (rear) and shin (front) are between the knee and foot.
In humans and other primates, the knee joins the thigh with the leg and consists of two joints: one between the femur and tibia, and one between the femur and patella. It is the largest joint in the human body. The knee is a modified hinge joint, which permits flexion and extension as well as slight internal and external rotation. The knee is vulnerable to injury and to the development of osteoarthritis.
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 ankle, the talocrural region or the jumping bone (informal) is the area where the foot and the leg meet. The ankle includes three joints: the ankle joint proper or talocrural joint, the subtalar joint, and the inferior tibiofibular joint. The movements produced at this joint are dorsiflexion and plantarflexion of the foot. In common usage, the term ankle refers exclusively to the ankle region. In medical terminology, "ankle" can refer broadly to the region or specifically to the talocrural joint.
The gluteus minimus, or glutæus minimus, the smallest of the three gluteal muscles, is situated immediately beneath the gluteus medius.
The sacroiliac joint or SI joint (SIJ) is the joint between the sacrum and the ilium bones of the pelvis, which are connected by strong ligaments. In humans, the sacrum supports the spine and is supported in turn by an ilium on each side. The joint is strong, supporting the entire weight of the upper body. It is a synovial plane joint with irregular elevations and depressions that produce interlocking of the two bones. The human body has two sacroiliac joints, one on the left and one on the right, that often match each other but are highly variable from person to person.
In vertebrate anatomy, the hip, or coxa(pl.: coxae) in medical terminology, refers to either an anatomical region or a joint on the outer (lateral) side of the pelvis.
The psoas major is a long fusiform muscle located in the lateral lumbar region between the vertebral column and the brim of the lesser pelvis. It joins the iliacus muscle to form the iliopsoas. In animals, this muscle is equivalent to the tenderloin.
The biceps femoris is a muscle of the thigh located to the posterior, or back. As its name implies, it consists of two heads; the long head is considered part of the hamstring muscle group, while the short head is sometimes excluded from this characterization, as it only causes knee flexion and is activated by a separate nerve.
The shoulder joint is structurally classified as a synovial ball-and-socket joint and functionally as a diarthrosis and multiaxial joint. It involves an articulation between the glenoid fossa of the scapula and the head of the humerus. Due to the very loose joint capsule that gives a limited interface of the humerus and scapula, it is the most mobile joint of the human body.
A hip dislocation is when the thighbone (femur) separates from the hip bone (pelvis). Specifically it is when the ball–shaped head of the femur separates from its cup–shaped socket in the hip bone, known as the acetabulum. The joint of the femur and pelvis is very stable, secured by both bony and soft-tissue constraints. With that, dislocation would require significant force which typically results from significant trauma such as from a motor vehicle collision or from a fall from elevation. Hip dislocations can also occur following a hip replacement or from a developmental abnormality known as hip dysplasia.
The sacrotuberous ligament is situated at the lower and back part of the pelvis. It is flat, and triangular in form; narrower in the middle than at the ends.
The iliofemoral ligament is a thick and very tough triangular capsular ligament of the hip joint situated anterior to this joint. It attaches superiorly at the inferior portion of the anterior inferior iliac spine and adjacent portion of the margin of the acetabulum; it attaches inferiorly at the intertrochanteric line.
The ligament of the head of the femur is a weak ligament located in the hip joint. It is triangular in shape and somewhat flattened. The ligament is implanted by its apex into the anterosuperior part of the fovea capitis femoris and its base is attached by two bands, one into either side of the acetabular notch, and between these bony attachments it blends with the transverse ligament.
The zona orbicularis or annular ligament is a ligament on the neck of the femur formed by the circular fibers of the articular capsule of the hip joint. It is also known as the orbicular zone, ring ligament, and zonular band.
The acetabular labrum is a fibrocartilaginous ring which surrounds the circumference of the acetabulum of the hip, deepening the acetabulum. The labrum is attached onto the bony rim and transverse acetabular ligament. It is triangular in cross-section.
The capsule of hip joint, articular capsule, or capsular ligament is strong and dense attachment of the hip joint.
The elbow is the region between the upper arm and the forearm that surrounds the elbow joint. The elbow includes prominent landmarks such as the olecranon, the cubital fossa, and the lateral and the medial epicondyles of the humerus. The elbow joint is a hinge joint between the arm and the forearm; more specifically between the humerus in the upper arm and the radius and ulna in the forearm which allows the forearm and hand to be moved towards and away from the body. The term elbow is specifically used for humans and other primates, and in other vertebrates forelimb plus joint is used.
Posterolateral corner injuries of the knee are injuries to a complex area formed by the interaction of multiple structures. Injuries to the posterolateral corner can be debilitating to the person and require recognition and treatment to avoid long term consequences. Injuries to the PLC often occur in combination with other ligamentous injuries to the knee; most commonly the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL). As with any injury, an understanding of the anatomy and functional interactions of the posterolateral corner is important to diagnosing and treating the injury.
The pelvis is the lower part of the trunk, between the abdomen and the thighs, together with its embedded skeleton.
