TempoLife › Features › Muscle and body-part reference › hip-joint
Hip joint
A deep, strong ball-and-socket joint built for carrying load over a lifetime of walking.
Latin name: Articulatio coxae. In plain English, the ball and socket where the leg meets the pelvis. It is filed here under joints, tendons and fascia.
Reference information, not a diagnosis. Where a symptom is described below, it is there so you can describe your own more precisely to a clinician — not so you can name what you have.
Where it is
Unlike the shoulder, the hip has a deep socket: the acetabulum encloses well over half the femoral head, and the labrum around its rim deepens it further and helps seal the joint. Three strong ligaments spiral around the capsule, tightening as the hip extends, which is part of why standing upright costs so little muscular effort.
The blood supply of the femoral head is the detail that matters most clinically. In adults it comes largely from retinacular branches of the medial circumflex femoral artery, which run up along the femoral neck. A fracture of the neck can interrupt them, and avascular necrosis of the head is the reason displaced femoral neck fractures in older adults are often treated by replacing the head rather than fixing it.
| Feature | Detail |
|---|---|
| Type | Synovial ball-and-socket joint |
| Bones | Head of the femur in the acetabulum of the pelvis, deepened by the acetabular labrum |
| Key ligaments | Iliofemoral, pubofemoral and ischiofemoral ligaments; the iliofemoral is the strongest ligament in the body and limits extension |
| Main movements | Flexion, extension, abduction, adduction, internal and external rotation |
What it does
The hip carries the weight of the upper body and transmits it into the legs, and the forces through it during walking exceed body weight substantially because of the muscle tension needed to keep the pelvis level. It also provides the range that lets you sit, squat, climb and run.
Two conditions dominate its clinical picture. Femoroacetabular impingement, where the shapes of the head and socket bring bone into contact at the extremes of movement, is associated with groin pain in active young adults. Osteoarthritis is the long-term one, and its hallmark is loss of internal rotation with groin pain that can refer to the knee — which is why a child or adult with knee pain always deserves a hip examination too.
Movements that load it
| Exercise | Category | Muscles the exercise library lists |
|---|---|---|
| Barbell back squat | Strength | Quads, glutes, core, back |
| Deadlift | Strength | Hamstrings, glutes, back, grip |
| Brisk walking (5.5 km/h) | Cardio | Legs, heart |
| Cycling (19-22 km/h) | Cardio | Quads, glutes, calves, heart |
| Stair climbing | Cardio | Quads, glutes, calves, heart |
The hip tolerates load extremely well when it is built gradually. Squatting, hinging, carrying and walking all load it in useful patterns; single-leg work loads the abductors that control it. In hip osteoarthritis, exercise therapy is first-line treatment in guidelines worldwide, and strength work does not accelerate joint damage.
Keeping its range
Range work in all directions is more useful than one favourite stretch: a half-kneeling lunge for extension, a figure-four for external rotation, a deep supported squat for flexion, and controlled rotations in a seated position. If a stretch produces a sharp pinch in the front of the groin rather than a broad pull, ease off — that pinch is often impingement rather than tightness.
When it goes wrong
| Problem | What it typically feels like | Usual setting |
|---|---|---|
| Hip osteoarthritis | Groin pain with stiffness, worse after rest and with activity, and early loss of internal rotation | Age, previous injury and joint shape; exercise and load management are first-line care |
| Femoroacetabular impingement | Groin pain with deep flexion and rotation, often in active young adults | Bone shape at the head or socket rim bringing them into contact at end range |
| Femoral neck fracture | Severe hip or groin pain after a fall, inability to bear weight, and a leg that may look short and turned outward | A fall in an older adult with reduced bone density; a medical emergency |
Hip pain after a fall with an inability to stand, or a leg that looks shortened and turned outward, is an emergency. Groin pain that persists in a runner should also be assessed, because femoral neck stress fractures present that way and are serious if missed.
Nothing on this page is a treatment plan. If a problem is limiting what you do, is not improving, or is getting worse, the right next step is an assessment by a doctor or a physiotherapist who can examine you.
Sources: descriptive anatomy from Gray's Anatomy of the Human Body, 20th US edition (1918), which is in the public domain; Latin names follow Terminologia Anatomica, published by the Federative International Programme for Anatomical Terminology. Nerve root levels are the conventional ranges taught from those sources and vary between individuals and between textbooks. Exercise cross-links use the TempoLife exercise library. Checked 2026-09-06.
Frequently asked questions
Why does hip arthritis cause knee pain?
The hip joint shares nerve supply with the front of the thigh and the knee, so pain from it is often referred there. A knee examination that finds nothing normal practice includes checking the hip.
Is the hip or the shoulder the more stable joint?
The hip, by a wide margin. Its socket is deep, its ligaments are strong, and it dislocates only under major force, whereas the shoulder trades that stability for range.
Does squatting deep damage the hips?
Not in a healthy hip. Some people reach a bony end range earlier than others because of the shape of their femur and socket, which is why comfortable squat depth and stance width vary so much between individuals.
Nearby in this reference
Shoulder joint
The ball and socket at the top of the arm
Knee joint
The hinge between thigh and shin
Lumbar spine
The five vertebrae of the lower back
Achilles tendon
The thick cord at the back of the ankle
Plantar fascia
The thick band along the sole of the foot
Deltoid
The cap of the shoulder
All 34 body parts · Exercise library · Body map
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