How the hip works
The hip is a ball-and-socket joint where the head of the thigh bone (femur) sits in the socket of the pelvis (acetabulum). This design allows movement in all directions: bending (flexion), straightening (extension), moving out to the side (abduction), moving inward (adduction) and rotation. The muscles that cross the hip produce these movements and, just as importantly, control the pelvis during walking, running and climbing stairs. The hip and lower back work together, so problems in one often affect the other.
Hip flexors (front of the hip)
- Iliopsoas: the psoas major (from the lower spine) and iliacus (from the inside of the pelvis) join to form the strongest hip flexor.
- Rectus femoris: part of the quadriceps that crosses both hip and knee.
- Sartorius: the longest muscle in the body, running diagonally across the thigh.
- Tensor fasciae latae (TFL): on the outer front of the hip, feeding into the IT band.
- Hip flexors can become tight with long sitting and are often strained in sprinting and kicking sports; see hip flexor strain.
Gluteal muscles (back and side of the hip)
- Gluteus maximus: the largest muscle of the body; it extends the hip for climbing, running and standing up from a chair.
- Gluteus medius: on the side of the pelvis; it moves the leg outward and keeps the pelvis level when you stand on one leg.
- Gluteus minimus: beneath the medius, with a similar stabilising role.
- Weak gluteus medius is linked with a dropping pelvis when walking, knee pain and pain on the outside of the hip.
Adductors (inner thigh)
The adductor group, including adductor longus, brevis and magnus, gracilis and pectineus, brings the legs together and helps stabilise the pelvis. They work hard in changing direction, kicking and skating, which is why they are commonly strained in football, ice hockey and tennis. Pain in the groin with these sports is often adductor-related; see our guide to groin strain.
Deep rotators
Six small muscles deep in the buttock, including the piriformis, gemelli, obturators and quadratus femoris, rotate the thigh outward and hold the ball of the femur in its socket. The sciatic nerve passes close to the piriformis, which is why irritation of this muscle can cause buttock pain that mimics sciatica; see piriformis syndrome.
Hip and back: how they connect
The psoas attaches directly to the lumbar spine, and the glutes, hamstrings and deep abdominal muscles all influence the position of the pelvis. Tight hip flexors can tilt the pelvis forward and increase the arch of the lower back, while weak glutes can shift load onto the lower back during lifting and walking. This is why exercise programmes for lower back pain often include hip strengthening and mobility, and why hip problems can be felt in the buttock or lower back.
Common hip muscle problems
- Muscle strains of the hip flexors, adductors or hamstrings.
- Gluteal tendinopathy: pain on the outside of the hip, often in women over 40.
- Hip bursitis, overlapping with gluteal tendinopathy.
- Tight hip flexors from long sitting.
- Piriformis syndrome.
- Snapping hip, when a tendon flicks over bone.
- Muscle weakness after injury, surgery or inactivity.
Exercises for strong, mobile hips
- Glute bridge: lying on your back, knees bent, lift the hips; progress to one leg. 3 × 10–12.
- Clamshell: side-lying, knees bent, lift the top knee. 3 × 15.
- Side-lying leg raise: top leg straight and slightly back. 3 × 12.
- Squat or sit-to-stand: from a chair, with knees in line with toes. 3 × 10.
- Step-ups: onto a low step, controlling the knee. 3 × 10 each leg.
- Side plank: from knees or feet, 20–40 seconds.
- Kneeling hip flexor stretch and figure-four glute stretch, 30 seconds each.
- Start with low effort and increase gradually; mild muscle soreness is normal, sharp joint pain is not.
Three common situations
- Desk worker with tight hips and low back ache: regular breaks, hip flexor stretches and glute bridges often help both.
- Runner with knee pain and a dropping pelvis: gluteus medius strengthening is a key part of rehab.
- Woman over 50 with pain on the outside of the hip when lying on that side: gluteal tendinopathy is likely; avoid crossing legs and see a physical therapist for a loading programme.
Key points to remember
- The hip muscles fall into flexors, glutes, adductors and deep rotators.
- The glutes, especially gluteus medius, are key for stability.
- Hip strength and mobility affect the knees and lower back.
- A balanced programme of strengthening and stretching keeps hips healthy.
Questions about hip muscles
These answers are general information and do not replace an examination or individual medical advice.
What is the strongest hip muscle?
The gluteus maximus is the largest and most powerful hip muscle, while the iliopsoas is the strongest hip flexor.
Which hip muscles cause lower back pain?
Tight hip flexors and weak glutes can both increase strain on the lower back, although back pain usually has several contributing factors.
How do I know if my hip pain is muscular?
Muscle pain tends to be felt in a muscle area, worsens with stretching or using that muscle, and is often linked to an activity. Groin pain with stiffness may come from the joint itself and should be assessed.
How often should I do hip strengthening exercises?
Two to three times a week is enough for most people to build strength, with mobility work more often if helpful.
Can weak hips cause knee pain?
Yes. Weak hip abductors and rotators can let the knee drift inward during activity, which is linked with kneecap pain and IT band problems.
Sources
- NHS · Hip pain in adults
- AAOS OrthoInfo · Hip strains
- Presswood L, et al. Gluteus medius: applied anatomy, dysfunction, assessment, and progressive strengthening. Strength Cond J. 2008
This guide is for general information and does not replace medical advice. How a problem is diagnosed and treated depends on your examination and medical history. If you think you have an emergency, contact your local emergency services.