What it is

Femoroacetabular impingement is a shape mismatch between the ball and socket of the hip that increases contact during movement.

Cam shape on the femur or pincer shape on the socket can irritate the labrum and joint cartilage, especially with deep flexion and rotation.

People feel groin pain with squats, sitting low, turning, and change of direction. Some get lateral hip or buttock pain.

Many people with cam or pincer shapes have no pain. Symptoms arise when load, movement, and shape combine to stress the joint.

What happens when it occurs

Repeated contact under load irritates the labrum and cartilage. Managing depth and rotation while improving strength and control reduces symptoms.

Common causes and risk factors

  • Cam morphology, pincer morphology, or combination
  • Repetitive deep flexion and rotation in training
  • Weakness and poor trunk control

Who is most affected

Young and middle-aged active adults, especially field and court athletes and lifters who train deep squats.

Typical symptoms

  • Groin pain with squats, sitting low, or turning
  • Clicking or catching at end range
  • Reduced hip flexion or internal rotation

When to seek care

Seek assessment if pain persists beyond two weeks, if catching or locking occurs, or if night pain develops.

How we diagnose

Examination with flexion-adduction-internal rotation testing and range measures. X-rays define bony shape; MRI assesses labrum and cartilage when surgery is considered.

Management

  • Modify depth and stance for squats and lunges
  • Strengthen rotators, abductors, and trunk control
  • Gradual exposure back to depth and rotation as tolerated
  • Arthroscopy considered when mechanical symptoms persist despite rehabilitation

Rehabilitation milestones

Phase 1 weeks 0 to 4: pain control, range in neutral arcs, isometrics.

Phase 2 weeks 4 to 8: heavy slow resistance, technique changes for squats and lunges.

Phase 3 weeks 8 to 16: graded run and direction change, deeper range under control.

Phase 4 months 4 to 6: full training with performance drills.

Readiness to progress

  • Pain-free squats to training depth with good technique
  • Rotation strength within 90 percent of the other side
  • Run and cut without pain during and the next morning

Prevention

  • Technique coaching for deeper lifts
  • Balanced hip and trunk strength
  • Careful volume progressions for sports that use deep hip flexion

Australia snapshot

  • Cam morphology is more common in male field-sport athletes
  • Pincer patterns and hypermobility are more frequent in females
  • Active young adults form the core caseload

Latest insights

Not all cam or pincer shapes cause pain. Focus on controllable factors such as technique and strength.

Activity modification combined with strength work is effective for many.

Frequently Asked Questions

Expect 8 to 16 weeks of focused rehabilitation. Surgical timelines vary and depend on labral and cartilage involvement.

Yes. Adjust depth, stance width, and tempo to avoid end-range pinch. Build strength in ranges that are comfortable, then progress depth.

X-rays define bone shape. MRI is used when labral or cartilage injury is suspected or when surgery is considered.

No. Many people manage well with technique change and strength. Surgery is considered when mechanical symptoms persist.

When you can squat to your training depth pain-free with good control, run and cut without pain, and pass hop or agility tests.

Raise seat height, avoid low crouch positions, and vary posture with standing breaks.

Drive and work as tolerated, using posture changes and breaks to limit deep flexion.