The thigh muscle primarily consists of four main groups: the quadriceps, hamstrings, adductors, and sartorius. The quadriceps, located at the front of the thigh, are responsible for extending the knee. The hamstrings, found at the back, help in bending the knee and extending the hip. The adductors are situated on the inner thigh and assist in bringing the legs together, while the sartorius runs diagonally across the thigh, aiding in hip and knee flexion. Together, these muscles play a crucial role in various activities such as walking, running, and jumping, contributing to overall mobility and stability.