What criteria must be met for ACL return-to-sport clearance?

Standard ACL return-to-sport criteria include: quadriceps strength LSI above 90%, hamstring strength LSI above 90%, full range of motion, passing all four hop tests with LSI above 90%, ACL-RSI psychological readiness score above 65, and surgeon clearance. Most guidelines recommend waiting at least 9 months post-surgery.

How long after ACL surgery can you return to sport?

Most current evidence recommends waiting at least 9 months after ACL surgery before returning to sport. Each additional month of waiting up to 9 months reduces reinjury risk by 51%. However, time alone is not sufficient — meeting all objective clearance criteria is essential.

What is limb symmetry index (LSI) and why is it important?

Limb symmetry index (LSI) measures how closely your injured leg performs compared to your uninjured leg, expressed as a percentage. An LSI of 90% or greater on strength and hop tests is typically required for return-to-sport clearance, indicating the injured leg is within 10% of the healthy leg.

Return-to-Sport Checklist | ACL Clearance Criteria & Benchmarks

Important Disclaimer

This checklist is for educational purposes only and should not replace professional medical evaluation. Final clearance for return to sport must come from your surgeon or physical therapist who can perform objective testing. Many of these tests require professional administration.

0 of 24 criteria met

Track your progress as you work toward return-to-sport clearance

⏱️

Time-Based Criteria

0/2 ▼

Minimum 9 months post-surgery

Research shows graft maturation and remodeling takes at least 9 months. Earlier return significantly increases reinjury risk.

Benchmark: ≥9 months from surgery date

Completed progressive return-to-sport program

Structured progression through running, agility, plyometrics, and sport-specific training over several months.

Benchmark: 8-12 weeks of sport-specific training

Note: Time alone is not sufficient for clearance. All functional and strength criteria must also be met. Some research suggests waiting 12+ months reduces reinjury risk further.

📐

Range of Motion

0/2 ▼

Full knee extension (0°)

Surgical leg matches non-surgical leg for full straightening. Any extension deficit increases stress on the graft.

Benchmark: 0° extension, matching opposite leg

Full knee flexion

Surgical leg matches non-surgical leg for full bending. Should be within 5° of opposite side.

Benchmark: Within 5° of non-surgical leg (typically 135-145°)

💪

Strength Testing (Limb Symmetry Index)

0/4 ▼

Quadriceps strength LSI ≥90%

Isokinetic or isometric quad strength on surgical leg is at least 90% of non-surgical leg.

Benchmark: LSI ≥90% (some advocate for ≥95%)

Hamstring strength LSI ≥90%

Isokinetic or isometric hamstring strength on surgical leg is at least 90% of non-surgical leg.

Benchmark: LSI ≥90%

Hip abductor strength LSI ≥90%

Hip abductor strength is critical for knee stability during cutting and pivoting movements.

Benchmark: LSI ≥90%

Single-leg squat quality

Can perform single-leg squat to 60° with good form (no knee valgus, trunk stable).

Benchmark: Good quality movement without compensation

Testing Note: Isokinetic dynamometry is the gold standard for strength testing. Manual muscle testing is less reliable. Ask your PT about objective strength testing.

🦘

Functional Hop Testing

0/6 ▼

Single-leg hop for distance LSI ≥90%

Maximum single-leg hop distance. Surgical leg achieves at least 90% of non-surgical leg distance.

Benchmark: LSI ≥90%

Triple hop for distance LSI ≥90%

Three consecutive hops for maximum distance. Tests power endurance.

Benchmark: LSI ≥90%

Crossover hop for distance LSI ≥90%

Three hops crossing back and forth over a line. Tests frontal plane control.

Benchmark: LSI ≥90%

6-meter timed hop LSI ≥90%

Time to hop 6 meters on one leg. Surgical leg time within 10% of non-surgical leg.

Benchmark: LSI ≥90% (lower time = better)

Y-Balance Test (anterior reach) LSI ≥90%

Single-leg balance with reach in anterior direction. Tests dynamic balance and stability.

Benchmark: LSI ≥90%

Side hop test (30 seconds) LSI ≥90%

Number of side-to-side hops over a line in 30 seconds. Tests reactive stability.

Benchmark: LSI ≥90%

Important: Hop tests should be performed under professional supervision with proper warm-up. Quality of movement matters as much as symmetry—watch for compensation patterns.

🧠

Psychological Readiness

0/4 ▼

ACL-RSI score ≥65

ACL-Return to Sport after Injury scale score of 65 or higher correlates with successful return.

Benchmark: Score ≥65 (take assessment here)

Low fear of reinjury during sport activities

Can participate in sport-specific drills without significant fear or hesitation.

Benchmark: Minimal avoidance behavior during training

Confidence in knee during cutting/pivoting

Feel confident in your knee's ability to handle the demands of your sport.

Benchmark: High confidence on self-report

No significant depression or anxiety symptoms

Mental health is stable and not interfering with recovery or sport participation.

Benchmark: PHQ-9 <10, GAD-7 <10

Remember: 76% of athletes who don't return to sport cite fear as the primary barrier—not physical limitations. Addressing psychological readiness is essential.

⚕️

Clinical Criteria

0/6 ▼

No knee effusion (swelling)

Knee is not swollen at rest or after activity. Persistent swelling indicates ongoing issues.

Benchmark: Trace or no effusion on clinical exam

Stable knee on clinical examination

Negative Lachman test and pivot shift. Graft is intact and functioning.

Benchmark: Stable on ligament testing

No pain during sport-specific activities

Can perform running, cutting, jumping without pain in the knee.

Benchmark: Pain-free during all activities

Surgeon clearance obtained

Your surgeon has evaluated you and given clearance for return to sport.

Benchmark: Written or verbal clearance from surgeon

Physical therapist clearance obtained

Your PT has performed functional testing and recommends return to sport.

Benchmark: PT discharge or clearance for sport

Completed graduated return-to-sport protocol

Successfully completed progressive return through practice to game situations.

Benchmark: Full participation in practice for 2+ weeks

Ready to Discuss Clearance?

Print or save this checklist to bring to your next appointment with your surgeon or physical therapist.