Group XIII. Function: Extension of hip and flexion of knee; outward and inward rotation of flexed knee; acting with rectus femoris and sartorius synchronizing simultaneous flexion of hip and knee and extension of hip and knee by belt-over-pulley action at knee joint. Posterior thigh group, Hamstring complex of 2-joint muscles: Biceps femoris; semimembranosus; semitendinosus (DC 5313)

Rating levels

• 40% — The hamstring muscles in the back of your thigh (biceps femoris, semimembranosus, and semitendinosus) are severely damaged, causing major problems with bending your knee, straightening your hip, and rotating your leg. You have significant difficulty with basic movements like walking, climbing stairs, or getting up from a chair because these muscles can't properly coordinate the movement between your hip and knee joints.
• 30% — The hamstring muscles in the back of your thigh (biceps femoris, semimembranosus, and semitendinosus) are moderately severely damaged, significantly affecting your ability to bend your knee, straighten your hip, and rotate your leg. These muscles work together to help you walk, run, and move your leg properly, and when they're this damaged, you'll have noticeable difficulty with basic leg movements like stepping up stairs, getting up from chairs, or walking normally. Your leg function is clearly impaired but you can still perform most daily activities with some limitation and discomfort.
• 10% — You have moderate injury to your hamstring muscles - the three muscles in the back of your thigh (biceps femoris, semimembranosus, and semitendinosus) that help you bend your knee and extend your hip backward. This causes noticeable difficulty with activities like walking, running, or getting up from a sitting position, but you can still perform these movements with some limitation. The injury affects how well these muscles work together to coordinate bending and straightening your hip and knee at the same time.
• 0% — A "slight" hamstring injury means you have minor damage to the muscles in the back of your thigh (the biceps femoris, semimembranosus, and semitendinosus muscles) that help you bend your knee and extend your hip backward. You may experience mild pain, stiffness, or weakness when walking, running, or bending your knee, but these symptoms don't significantly interfere with your daily activities or work duties. The injury causes only minimal limitation in your ability to move your leg normally.