Femoroacetabular Impingement (FAI)

Femoroacetabular impingement (FAI) occurs when there is abnormal contact between the ball (femoral head) and socket (acetabulum) of the hip joint during movement. This typically causes pain in the groin or deep in the hip, particularly with flexion-based activities — squatting, running, sitting for long periods or movements that bring the thigh toward the chest.

FAI is increasingly recognised as a common source of hip and groin pain in young and middle-aged athletes.

Types of FAI

• Cam impingement: An abnormal bony bump on the femoral head that jams against the socket rim during hip flexion — more common in young male athletes
• Pincer impingement: Excess bone on the acetabular rim that causes over-coverage of the femoral head — more common in active women
• Mixed: Both cam and pincer features (most common)

Who Gets It?

• Young athletes involved in football, hockey, dance, gymnastics, cycling or martial arts
• People with anatomical variation in hip bone shape (often identified on X-ray)
• Active adults with groin pain that hasn’t responded to other treatment

Symptoms

• Deep groin pain or “C-sign” (hand cupped around the lateral hip and groin)
• Pain with hip flexion — squatting, sitting, getting in and out of a car
• Catching, clicking or a feeling of restriction in the hip
• Pain after prolonged activity that eases with rest
• Limited internal rotation (turning the leg inward)
• Positive impingement test — pain with hip flexion and internal rotation

Conservative Physiotherapy

Many people with FAI anatomy live without symptoms — the shape of the hip alone doesn’t determine treatment. Conservative management aims to reduce pain and optimise function:

• Activity modification to avoid end-range hip flexion provocations
• Hip strengthening (external rotators, abductors, deep hip stabilisers)
• Core and lumbopelvic control
• Movement pattern retraining to reduce impingement during sport
• Manual therapy to surrounding muscles and joint mobilisation within pain-free range

Surgical Management

Hip arthroscopy to reshape the bone and repair any associated labral damage is considered when symptoms are significant, the anatomy is clearly impinging, and conservative management has been adequately trialled. Post-operative physiotherapy is essential and spans 6–9 months.