Guest Post by Dr. Ethan Lennox, ACL Rehabilitation Specialist at Cohen Health and Performance (CHP)
One of the toughest challenges athletes face after ACL surgery is knowing whether they are truly ready to return to play. Getting this wrong can have serious consequences, not only a higher risk of re-tearing the repaired ACL, but also the possibility of injuring the other knee or sustaining a completely new lower body injury.
If you’re an athlete, parent, or coach navigating the ACL recovery process, this guide will walk you through the objective criteria that determine readiness for a safe return.
Why Time Alone Isn’t Enough
A safe return to sport after ACL surgery isn’t about simply waiting 6, 9, or 12 months. At CHP, our ACL physical therapy program goes beyond the calendar. We use specific benchmarks for strength, movement quality, knee health, and confidence.
For athletes in cutting or pivoting sports, we typically recommend at least 9–12 months before full competition, as research shows that early return carries a much higher risk of re-injury. Our goal is not just to “clear” an athlete, but to build a durable return that lasts.
What Really Determines Readiness?
1. Strength
Strength is the foundation of ACL physical therapy. But it’s not just about moving heavy weight in the gym. The question is:
- Can the athlete produce strength quickly in the chaos of sport?
- Can they tolerate the workload of practices and games?
We focus heavily on restoring quadriceps strength to sport-specific demands, not just symmetry between legs. A common benchmark is ≥ 3.0 Nm/kg of knee-extension torque relative to body weight. Symmetry matters, but hitting an absolute strength threshold is what keeps knees safe during high-speed stops and cuts.
2. Force-Plate Testing
Traditional field tests often miss hidden deficits. At CHP, our ACL physical therapy program uses force-plate technology to analyze how each leg produces and absorbs force during jumps, landings, and change-of-direction tasks. To learn more about our forceplates, check out this link.
We track asymmetry (aiming for ≤10%) and test both when athletes are fresh and fatigued. This helps us individualize rehab, catch weaknesses before they become injuries, and make safer clearance decisions.
3. Movement Quality
Numbers matter, but how an athlete moves under fatigue is just as critical. During ACL rehab, we look for:
- Controlled deceleration
- Proper knee and hip alignment
- Strong trunk stability
- Quiet, efficient landings at game speed
By combining movement analysis with force-plate data, we ensure athletes are not just strong on paper—but resilient in real game conditions.
4. Knee Health
A successful ACL recovery also depends on the joint’s response to load. Non-negotiables include:
- Full, pain-free range of motion
- No swelling or irritation after training
- Zero “giving way” episodes
If the knee flares up as we increase intensity, we scale back. Just because the calendar says “9 months” doesn’t mean the knee is ready.
5. Confidence
Physical readiness means little without mental readiness. At CHP, our ACL physical therapy program uses validated questionnaires like the ACL-RSI (Return to Sport after Injury) to track confidence. Scores in the mid-60s or higher, paired with strong physical metrics, usually indicate safe readiness.
We also coach mindset—helping athletes rebuild trust in their body is just as important as rebuilding strength.
Clearance Does Not Mean Full Game Readiness
“Cleared” to return to sport means an athlete can begin practicing. It does not mean they’re ready for full minutes or their pre-injury role. Building back to game-day fitness requires another 6–12+ weeks of gradual progression:
- Non-contact practice and controlled drills
- Controlled contact with planned rest
- Increased intensity and practice density, monitoring workload
- Gradual introduction of limited game minutes
This measured progression is how we prevent setbacks and ensure long-term success.
How CHP Puts It All Together
At Cohen Health and Performance, our clearance testing includes:
- Strength testing with precise benchmarks
- Force-plate assessments for braking and propulsion
- Movement quality reviews under fatigue
- Knee health evaluation for calm, stable joints
- Confidence tracking for mental readiness
From there, we design a stepwise return-to-play plan that gradually increases training load and game minutes while monitoring next-day knee response.
Our philosophy is simple: earn the right to do more, then prove you can repeat it.
If you or your athlete is recovering from ACL surgery, don’t settle for a clearance based only on time or basic hop tests. A true ACL physical therapy program should integrate strength, force-plate data, movement analysis, joint health, and confidence.
At CHP, our ACL specialists are committed to helping athletes not only return safely, but come back stronger than before.
If your athlete is working toward a safe, confident return to sport, our ACL rehabilitation team would love to guide the process. Contact us here.
