Hip impingement syndrome

Other names for hip impingement syndrome

• Femoroacetabular Impingement
• FAI (Femoroacetabular Impingement)
• Hip impingement syndrome

What is hip impingement syndrome?

Hip impingement syndrome occurs when there is abnormal contact between the head of the femur (thigh bone) and the acetabulum (the socket in the pelvis that forms the hip joint). This repeated friction irritates the joint structures, causing pain, stiffness, and limited movement.

The hip joint functions like a ball-and-socket joint: the head of the femur (the "ball") fits into the acetabulum (the "socket") of the pelvis. Normally, these surfaces glide smoothly over each other. When impingement occurs, the bones make abnormal contact during certain movements.

There are three types of hip impingement syndrome:

• Cam Type: The head of the femur is not perfectly round. This irregular shape creates friction against the rim of the acetabulum during bending and rotating movements.

• Pincer Type: The rim of the acetabulum is too prominent and "pinches" the femoral head during movements.

• Mixed Type: A combination of both forms. This accounts for approximately 86% of diagnoses.

If the syndrome is not addressed, repeated friction can damage the labrum (a ring of cartilage that stabilizes the joint) and the articular cartilage.

What causes hip impingement syndrome?

Hip impingement syndrome is caused by a combination of anatomical and functional factors. Repetitive hip bending movements, especially in sports, contribute to the irritation of the joint structures.

The main causes include:

• Abnormalities in the shape of the femoral head (cam) or acetabulum (pincer)
• These abnormalities can be present from birth or develop during growth.

• Muscle imbalance between hip flexors and extensors
• Lack of hip flexibility
• Overloading in sports without proper progression
• Weakness of stabilizing muscles (glutes, rotators)

• Sudden increase in training volume
• Resuming sports activity after a period of inactivity
• Sports that involve repeated hip bending movements
• Intense training before bones are fully mature (adolescents)

What are the risk factors for developing hip impingement syndrome?

Active young adults aged 20 to 40 are most affected, especially those who participate in sports involving repeated hip bending movements.

• Hockey and skating
• Dance and gymnastics
• Running
• Martial arts
• Soccer and basketball
• Volleyball

• History of hip or back pain
• Period of inactivity followed by an intense return to sports
• Weakness in the muscles that stabilize the hip
• Previous hip injury

What are the symptoms of hip impingement syndrome?

The main symptom is groin pain that appears during hip bending movements. You may also feel clicking or cracking, joint stiffness, and difficulty sitting for long periods.

• Primarily in the groin crease (in front of the hip)
• Can radiate towards the buttock, outer thigh, or even the knee
• Sometimes described as a "C" shape around the hip

• Increased by hip bending movements
• Worse with prolonged sitting
• Aggravated by weight-bearing activities

• Clicking, popping, or cracking sensations in the hip
• Joint stiffness, especially in the morning
• Decreased range of motion
• Occasional feeling of hip catching or locking

• Running or walking with long strides
• Climbing stairs or hiking in the mountains
• Deep squats
• Getting up from a chair or out of a car
• Prolonged sitting (at a desk, in a car, on a plane)

How is hip impingement syndrome diagnosed?

Diagnosis is based on your symptom history and a physical exam, which includes specific tests. X-rays can confirm bone abnormalities, but imaging isn't always necessary.

Your physiotherapist or doctor will ask questions about:

• The exact location of your pain
• Movements and activities that worsen the pain
• How long you have had symptoms
• Your sports or work activities

The FADIR test (Flexion, Adduction, Internal Rotation) is the most commonly used. Your professional will move your hip into flexion, then adduction and internal rotation. If this reproduces your pain, it suggests hip impingement syndrome.

• X-rays: used to measure bone abnormalities (alpha angle, center-edge angle)
• MRI: used in complex cases to assess the condition of the labrum and cartilage

It's important to note that radiological abnormalities can be present in people without any symptoms. Therefore, diagnosis is not based solely on imaging.

When should you see a physiotherapist for hip impingement syndrome?

Consult a physiotherapist if you experience groin pain during hip movements, especially if it lasts more than two weeks. You don't need to see a doctor before consulting.

• Groin pain that has lasted for more than 2 weeks
• Pain that limits your daily activities
• Clicking or catching in the hip
• Difficulty participating in your sports or hobbies
• Significant morning stiffness in the hip

You do not need a medical referral to consult a physiotherapist. If your condition requires a medical evaluation or imaging, your physiotherapist will be able to refer you.

Early consultation generally leads to better results. The sooner symptoms are treated, the easier the recovery.

What are the physiotherapy treatments for hip impingement syndrome?

Conservative treatment is the first line of approach for mild to moderate hip impingement syndrome. Your physiotherapist will create a personalized program including gluteal strengthening, core stabilization, education on activity pacing, and joint mobilization.

Your physiotherapist will assess:

• Your joint mobility
• The strength of your muscles (glutes, stabilizers, rotators)
• The quality of your movements
• Your Walking Pattern
• Your physical activity and sports habits

• Glute muscles (gluteus medius and maximus)
• External hip rotators
• Pelvic and core stabilizing muscles

• Techniques to improve range of motion
• Mobilizations in directions that do not worsen impingement

• Identifying problematic positions and movements
• Strategies to modify activities without stopping them completely
• Gradual progression for returning to activities

• Correcting inefficient movement patterns
• Improving neuromuscular control

Studies show that a well-structured physiotherapy program leads to significant improvement in 82% of individuals, especially when treatment is started early.

What to do at home for hip impingement syndrome?

Temporarily modify activities that cause pain and regularly strengthen your glutes. Avoid prolonged hip flexion positions and movements with forced internal rotation.

• Swimming
• Stationary bike with a properly adjusted seat
• Moderate walking on flat ground
• Exercises in water

• Sitting with crossed legs
• Deep squats (only go to a maximum of 90 degrees)
• Aggressive hip flexion stretches
• Sitting for long periods without breaks (stand up every 30-45 minutes)

• Take regular breaks if you sit for long periods at work
• To get out of the car, pivot both legs together instead of stepping out one at a time
• If you sleep on your side, place a pillow between your thighs
• Avoid standing with all your weight on one hip

• Glute bridges: 3 sets of 10-15 repetitions
• Clamshells: 3 sets of 15 repetitions on each side
• Core activation (transverse abdominis): 3 sets of 10 seconds

If you don't see any improvement after 10 to 14 days of making changes, consult a physiotherapist.

What is the recovery time for hip impingement syndrome?

With appropriate conservative treatment, most people experience significant improvement within 6 to 12 weeks. Recovery time varies depending on the severity and adherence to recommendations.

• Symptom reduction: 4-8 weeks
• Significant functional improvement: 8-12 weeks
• Return to sport (depending on level): 3-4 months

• Duration of symptoms before starting treatment (shorter duration = better prognosis)
• Severity of joint involvement
• Adherence to exercises and recommendations
• Appropriate activity modifications

The vast majority of hip impingement syndrome cases respond well to conservative treatment. Surgery (hip arthroscopy) is rarely needed when treatment starts early and is followed consistently.

If you don't see improvement after 3 months of consistent physiotherapy treatment, a re-evaluation and possibly imaging may be recommended to explore other options.

Sources

• Pun S, Kumar D, Lane NE. Femoroacetabular impingement. Arthritis & Rheumatology. 2015;67(1):17-27.
• Griffin DR, Dickenson EJ, O'Donnell J, et al. The Warwick Agreement on femoroacetabular impingement syndrome (FAI syndrome). Br J Sports Med. 2016;50(19):1169-1176.