The hamstrings refer to a collection of muscles and tendons located in the back of the thigh. Specifically, these muscles include the biceps femoris, the semimembranosus, and the semitendinosus. Additionally, some anatomists may also identify a section of the adductor magnus as part of the hamstrings. These muscles serve several important purposes, including the flexion of the knee and aiding in movements of the hip. Given their significant involvement in leg motion, the hamstrings are susceptible to injuries.
Anatomy
The hamstrings are a group of muscles that attach to the ischial tuberosity of the hip, also known as the sit bones. When we sit, a significant portion of our body’s weight is placed on the ischial tuberosity. These muscles also connect to a rough area on the back of the femur called the linea aspera. Among the hamstrings, the biceps femoris has two parts: the long head and the short head. However, only the long head is considered part of the hamstrings from a technical standpoint. The semimembranosus, on the other hand, is a long muscle with a lengthy tendon of insertion, making it the central muscle of the hamstrings.
Purpose and Functions of the Hamstrings
The hamstrings serve two primary functions: knee flexion and hip joint extension. Flexion and extension are terms used to describe the movement that alters the angle between different body parts. Specifically, knee flexion refers to the bending that decreases the angle between the calf and the thigh, while hip joint extension involves moving the entire leg backward. These essential movements performed by the hamstrings are vital for numerous everyday activities, including walking and running.