ACL Injury Exercises: Rehabilitation and Prevention

An ACL tear is one of the most feared injuries in sports. The anterior cruciate ligament stabilizes your knee, and when it's damaged, the road back can be long. But with the right exercises—whether you're preparing for surgery, recovering after, or trying to prevent injury in the first place—you can rebuild a strong, stable knee.

Important: ACL rehabilitation should be supervised by a physical therapist or sports medicine professional. This guide provides general information, not personalized medical advice.

Understanding ACL Injuries

The ACL (anterior cruciate ligament) prevents the shin bone from sliding forward and provides rotational stability to the knee.

How ACL tears happen:

• Sudden stops or direction changes
• Landing from jumps incorrectly
• Pivoting with foot planted
• Direct contact to the knee
• Hyperextension

Treatment options:

• Conservative (non-surgical) management
• ACL reconstruction surgery

The choice depends on activity level, age, other injuries, and personal factors.

Phase 1: Pre-Surgery (Prehab)

If surgery is planned, strengthening the knee beforehand improves outcomes.

Goals

• Reduce swelling
• Restore range of motion
• Strengthen surrounding muscles
• Prepare for post-surgery rehab

Exercises

1. Quad Sets

Activate the quadriceps without movement.

How to do it:

1. Sit with leg extended
2. Tighten thigh muscle, pressing knee toward floor
3. Hold 5-10 seconds
4. Relax and repeat
5. 20+ reps, multiple times daily

2. Straight Leg Raises

Build quad strength without bending the knee.

How to do it:

1. Lie on back, one knee bent, other leg straight
2. Tighten thigh of straight leg
3. Lift leg 6-12 inches
4. Hold briefly, lower slowly
5. 3 x 15 each leg

3. Heel Slides

Restore range of motion.

How to do it:

1. Lie on back
2. Slide heel toward buttock, bending knee
3. Slide back out
4. 3 x 15

4. Ankle Pumps

Maintain circulation and prevent stiffness.

How to do it:

1. Point toes away, then pull toward shin
2. Repeat continuously
3. Throughout the day

5. Standing Hamstring Curls

How to do it:

1. Hold support for balance
2. Bend knee, bringing heel toward buttock
3. Lower slowly
4. 3 x 15

Phase 2: Early Post-Surgery (Weeks 1-2)

Focus on protecting the graft while preventing complications.

Goals

• Manage pain and swelling
• Protect the surgical site
• Begin gentle movement
• Activate muscles

Exercises

Continue From Prehab:

• Quad sets (critical)
• Ankle pumps
• Straight leg raises (when cleared)

Add:

6. Patellar Mobilizations

Prevent scar tissue from restricting kneecap.

How to do it:

1. Leg extended, relaxed
2. Gently push kneecap up, down, left, right
3. 1-2 minutes, several times daily

7. Passive Knee Extension

Regain full straightening.

How to do it:

1. Sit with heel propped on rolled towel
2. Let knee straighten with gravity
3. May add light weight on thigh
4. 10-15 minutes multiple times daily

Phase 3: Intermediate Rehab (Weeks 2-6)

Progress movement and begin weight-bearing as cleared.

Goals

• Achieve full extension (straightening)
• Progress flexion (bending) to 90+ degrees
• Begin weight-bearing exercises
• Restore normal walking

Exercises

8. Wall Slides

How to do it:

1. Lie on back, feet on wall
2. Slide feet down, bending knees
3. Go as far as comfortable
4. Slide back up
5. 3 x 15

9. Mini Squats

How to do it:

1. Stand with support nearby
2. Small squat (30-45 degrees)
3. Don't let knee go past toes initially
4. 3 x 15

10. Weight Shifts

How to do it:

1. Stand with feet hip-width apart
2. Shift weight to surgical leg
3. Hold 5-10 seconds
4. Return to center
5. 3 x 10

11. Standing Hip Abduction

How to do it:

1. Hold support
2. Lift surgical leg out to side
3. Keep body upright
4. 3 x 15

12. Calf Raises

How to do it:

1. Rise up on toes
2. Both legs initially, progress to single leg
3. 3 x 15

Phase 4: Advanced Strengthening (Weeks 6-12)

Build significant strength with progressive loading.

Goals

• Full range of motion
• Significant strength gains
• Improve balance and proprioception
• Prepare for functional activities

Exercises

13. Step-Ups

How to do it:

1. Start with low step (4-6 inches)
2. Step up with surgical leg
3. Control the movement
4. Progress step height gradually
5. 3 x 10-15

14. Step-Downs

Focus on eccentric control.

How to do it:

1. Stand on step
2. Lower opposite foot to ground slowly
3. Tap and return
4. Control is key—no dropping
5. 3 x 10-15

15. Leg Press

How to do it:

1. Start with both legs, light weight
2. Progress weight gradually
3. Eventually single-leg
4. 3 x 10-15

16. Romanian Deadlifts

Build hamstring strength.

How to do it:

1. Light dumbbells
2. Hip hinge with flat back
3. Feel hamstring stretch
4. 3 x 10-12

17. Single-Leg Balance

How to do it:

1. Stand on surgical leg
2. Hold 30 seconds
3. Progress to eyes closed, unstable surface
4. Multiple sets daily

18. Lateral Band Walks

How to do it:

1. Band around ankles or above knees
2. Quarter squat position
3. Step sideways
4. 2-3 x 15 steps each direction

Phase 5: Return to Sport Preparation (3-6+ Months)

Prepare for high-level activities.

Goals

• Near-normal strength (>85% of other leg)
• Plyometric ability
• Sport-specific movements
• Confidence in the knee

Exercises

19. Single-Leg Squats

How to do it:

1. Stand on surgical leg
2. Squat as deep as controlled
3. Keep knee tracking over toes
4. 3 x 8-12

20. Box Jumps (Landing Focus)

How to do it:

1. Start with step-downs from box
2. Progress to small jumps onto box
3. Focus on soft, controlled landings
4. Land with good knee alignment

21. Lateral Hops

How to do it:

1. Single-leg hops side to side
2. Stick each landing
3. Progress distance gradually

22. Deceleration Drills

How to do it:

1. Jog forward
2. Quick stop on surgical leg
3. Focus on good mechanics
4. Progress speed gradually

23. Cutting Drills

How to do it:

1. Start with slow, controlled direction changes
2. Progress speed as confidence builds
3. Good knee position throughout

ACL Injury Prevention Exercises

Whether you've had an ACL injury or want to prevent one, these exercises reduce risk.

24. Neuromuscular Training

Exercises that train proper landing and cutting mechanics.

Jump-Landing Drills:

• Focus on soft landings
• Knees track over toes (not caving in)
• Land with knee flexion, not straight-legged

25. Hamstring Strengthening

Strong hamstrings protect the ACL.

Key exercises:

• Nordic curls
• Romanian deadlifts
• Leg curls
• Glute-ham raises

26. Hip Strengthening

Strong hips control knee position.

Key exercises:

• Clamshells
• Hip bridges
• Lateral band walks
• Side-lying hip abduction

27. Core Stability

A stable core improves body control.

Key exercises:

• Planks
• Dead bugs
• Bird dogs
• Pallof press

28. Plyometric Training

Controlled jumping and landing.

Progress gradually:

• Two-foot jumps → single-leg hops
• Vertical → horizontal → lateral
• Always emphasize landing quality

Prevention Program Sample

3x per week, 15-20 minutes:

1. Lateral band walks: 2 x 15 each direction
2. Single-leg balance: 2 x 30 seconds each leg
3. Nordic curl (assisted): 2 x 6
4. Single-leg Romanian deadlift: 2 x 10 each leg
5. Jump-landing drill: 2 x 10 (focus on landing)
6. Lateral hops: 2 x 10 each direction

Timeline Expectations

General milestones (vary by individual):

• Week 1-2: Manage swelling, gentle ROM
• Week 2-6: Restore ROM, begin weight-bearing
• Week 6-12: Progressive strengthening
• Month 3-6: Advanced strengthening, begin running
• Month 6-9: Sport-specific training
• Month 9-12: Return to sport consideration

Return to sport criteria typically includes:

• Quadriceps strength >90% of other leg
• Hop tests >90% of other leg
• Full range of motion
• No swelling or pain
• Psychological readiness

Important Considerations

Don't Rush

The graft needs time to heal and mature. Pushing too fast increases re-injury risk.

Trust Your PT

Your physical therapist can progress exercises based on your specific situation.

Both Legs Matter

Strengthening the non-surgical leg maintains overall fitness and provides a comparison.

Mental Recovery

Fear of re-injury is normal. Address it with gradual progression and confidence-building exercises.

Long-Term Maintenance

Even after returning to sport, continue prevention exercises regularly.

The Bottom Line

ACL recovery is a marathon, not a sprint. The exercises progress from gentle activation to advanced sport-specific training over many months. Each phase builds on the last.

Work with your medical team. Progress when appropriate. Don't skip steps. And remember that the goal isn't just returning—it's returning stronger and more resilient than before.

Rebuild your knee. Rebuild your confidence. Return to what you love.