Hip and thigh muscles are among the largest in the body and carry body weight in standing and walking. They are grouped by the movement they make and the nerve that supplies them.
Gluteals
The gluteus maximus extends the hip, as in climbing stairs or rising from a chair. The gluteus medius and minimus abduct the hip and keep the pelvis level when standing on one leg.
Quadriceps
Four muscles on the front of the thigh join in the patellar tendon to straighten the knee. The rectus femoris also flexes the hip, and all four are supplied by the femoral nerve.
Hamstrings and adductors
The hamstrings on the back of the thigh bend the knee and extend the hip (sciatic nerve). The adductors on the inner thigh pull the leg toward the midline (obturator nerve).
Hip flexors
The iliopsoas runs from the lumbar spine and pelvis to the femur and is the strongest hip flexor. Pain when it is stretched or flexed against resistance (psoas sign) can point to appendicitis or an abscess behind it.
| Group | Main action | Nerve |
|---|---|---|
| Gluteus maximus | Hip extension | Inferior gluteal |
| Gluteus medius and minimus | Hip abduction | Superior gluteal |
| Quadriceps | Knee extension | Femoral |
| Hamstrings | Knee flexion, hip extension | Sciatic |
| Adductors | Hip adduction | Obturator |
At the bedside
If the pelvis drops on the opposite side when the patient stands on one leg (positive Trendelenburg sign), the gluteus medius is weak. The ventrogluteal site over the gluteus medius and the vastus lateralis are preferred sites for intramuscular injections.
Related guides
Written by Making Synapses. Topic reference: OpenStax, Anatomy and Physiology 2e (no text adapted).