Hip Anatomy: Understanding Your Hip's Structure
The hip is a remarkable joint that supports your body weight while allowing for a wide range of movement. Understanding its anatomy helps you better grasp why certain pains occur and how physiotherapy can help you regain your mobility.
What are the main structures of the hip?
The Hip Bones
The hip joint, also known as the coxofemoral joint, connects the head of the femur (thigh bone) to the pelvis. The spherical head of the femur fits into the acetabulum (or hip socket), a cup-shaped cavity located in the pelvic bone1.
The acetabulum is formed by the fusion of three distinct bones: the ilium, ischium, and pubis. This bowl-shaped structure encloses about two-thirds of the femoral head, creating a joint that is both very stable and highly mobile2.
Cartilage and the Labrum
The joint surfaces of the femur and acetabulum are covered with articular cartilage, a smooth, strong tissue that allows the bones to glide without friction. Cartilage acts like a cushion, absorbing shock and distributing forces during your movements.
The acetabular labrum is a ring of fibrous cartilage that lines the acetabulum. It deepens the joint socket and stabilizes the femoral head, much like a seal. A labral tear can cause significant pain and limit your movements.
The Stabilizing Ligaments
Three main capsular ligaments strengthen the hip joint:
The iliofemoral ligament (or Bigelow's ligament) is the strongest in the human body. Its inverted Y-shape limits excessive hip extension and external rotation1.
The pubofemoral ligament is located at the front and limits excessive abduction (moving the leg too far out to the side).
The ischiofemoral ligament is located at the back and controls internal rotation and extension.
These three ligaments work together to keep the femoral head well-centered in the acetabulum while allowing a wide range of motion.
The Hip Muscles
The gluteal muscles (gluteus maximus, medius, and minimus) are essential for hip stability and power. The gluteus maximus allows for extension (when you stand up from a chair), while the gluteus medius stabilizes the pelvis when you walk on one leg.
The iliopsoas is the main hip flexor. It allows you to lift your thigh forward, a crucial movement for walking and climbing stairs.
The rotator muscles (piriformis, obturators, gemelli) control the fine rotations of the hip and contribute to the deep stability of the joint.
The Bursae
Bursae are small, fluid-filled sacs that reduce friction between tendons, muscles, and bones. The trochanteric bursa is located on the side of the hip, at the greater trochanter (the bony bump you can feel on your side). Inflammation of this bursa causes trochanteric bursitis, a common source of lateral hip pain.
How Does the Hip Work?
A Highly Mobile Ball-and-Socket Joint
The hip is a ball-and-socket joint (or enarthrosis), meaning it allows movement in all three planes. This configuration gives it exceptional mobility while maintaining excellent stability2.
Possible Movements
Flexion and Extension: You flex your hip when you lift your knee towards your chest (up to about 120 degrees). Extension brings your leg behind you (about 10 to 15 degrees).
Abduction and Adduction: Abduction moves your leg out to the side (about 45 degrees), while adduction brings it back towards the midline of your body and can even cross it slightly.
Internal and External Rotation: These movements turn your leg inward or outward. They are essential for changing direction when you walk or run.
Load Transmission
Your hip supports 3 to 5 times your body weight when walking, and even more when running or jumping. The spherical shape of the joint distributes these forces over a large surface, which protects the cartilage and surrounding structures.
Stability Mechanisms
Hip stability relies on three elements: the depth of the acetabulum, which cups the femoral head; the strength of the capsular ligaments that hold the joint together; and the power of the muscles that control movement. When one of these elements weakens, pain can develop.
What are common hip injuries?
Gluteal Tendinopathy
The gluteal tendinopathy affects the tendons of the gluteal muscles, especially the gluteus medius. This condition causes pain on the side of the hip, often worsened when climbing stairs or standing on one leg for extended periods.
Trochanteric Bursitis
The trochanteric bursitis results from inflammation of the bursa located on the side of the hip. Symptoms include sharp pain to the touch and tenderness when lying on the affected side. This condition generally responds well to physiotherapy with exercises to strengthen the gluteal muscles3.
Femoroacetabular Impingement
The femoroacetabular impingement (FAI) occurs when the femoral head or the rim of the acetabulum have abnormal shapes. These bone irregularities cause abnormal friction that can damage the labrum and cartilage, leading to pain and stiffness.
Hip Osteoarthritis
The hip osteoarthritis is a progressive wearing down of the joint cartilage. Symptoms include deep groin pain, morning stiffness, and a gradual decrease in range of motion. Physiotherapy can slow its progression and help maintain your function for as long as possible.
Labral Tear
The acetabular labrum can tear due to trauma or repetitive movements. Typical symptoms include a sensation of locking or catching in the hip, accompanied by deep groin pain. Treatment depends on the severity of the tear and can range from conservative physiotherapy to surgery.
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How Does Physiotherapy Help Hip Problems?
The complete assessment
Your physiotherapist begins with a detailed assessment of your hip. This assessment includes:
- Analysis of your gait and functional movements
- Range of motion tests to identify limitations
- Assessment of muscle strength for different muscle groups
- Specific tests to identify the problematic structure
- Analysis of your posture and whole-body biomechanics
This assessment accurately identifies the source of your pain and helps create a treatment plan tailored to your condition.
Treatment Approaches
Physiotherapy for hip pain uses several complementary approaches:
Strengthening exercises target weakened muscles, especially the glutes and deep rotators. Adequate strengthening reduces abnormal stress on the joint.
Mobility exercises restore normal hip range of motion. Your physiotherapist will teach you specific stretches and mobilization techniques.
Manual therapy includes joint mobilizations and myofascial release techniques to reduce pain and improve movement.
Gait retraining corrects movement patterns that contribute to your problems. Learning to walk and move correctly helps prevent recurrence.
Education and pain management give you the tools to understand your condition and manage your symptoms daily.
Expected results
Most hip conditions respond well to physiotherapy, especially when treatment starts early. Your commitment to home exercises directly influences your results. With appropriate treatment and active participation, you can expect:
- Significant pain reduction within the first few weeks
- Progressive improvement in your mobility and strength
- A gradual return to your daily and sports activities
- Strategies to prevent long-term recurrence
FAQ about Hip Anatomy
Why does my hip hurt when I sleep on my side?
This nocturnal side pain often suggests trochanteric bursitis or gluteal tendinopathy. Direct pressure on the inflamed structures causes discomfort. A physiotherapist can help you with strengthening exercises and positioning advice.
Are my hips connected to my lower back pain?
Absolutely. The hip and lower back work together to create movement. When the hip loses mobility or strength, the lower back has to compensate, which can cause pain. Treating both regions together often yields better results.
At what age does hip osteoarthritis begin?
Hip osteoarthritis can appear at any age, but it becomes more common after 50. Factors such as joint shape abnormalities, previous injuries, or being overweight can accelerate its development. Physiotherapy can help you even in the early stages.
Can I continue to play sports with hip pain?
It depends on the cause and severity of your symptoms. Some activities can be continued with modifications, while others require temporary rest. Your physiotherapist can guide you on safe activities during your rehabilitation.
How long does it take to heal a hip problem?
Healing time varies depending on the condition. Mild bursitis or tendinopathy can improve in a few weeks with appropriate treatment. More complex conditions like femoroacetabular impingement may require several months of rehabilitation. The important thing is to start treatment quickly.
How can I prevent hip injuries?
Prevention relies on several elements: maintaining good strength in the gluteal and rotator muscles, preserving adequate hip mobility, avoiding sudden increases in physical activity, and correcting biomechanical imbalances. Your physiotherapist can assess your risk factors and create a personalized preventive program.
References:
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Hip and knee surgery. Hip anatomy: bones, muscles, ligaments, nerves, vascularization.
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Institut Harmonie Tours. Hip Bursitis Exercises: Effective Strengthening [2025].
