Post-ACL Surgery Exercises: Complete Rehabilitation Guide

ACL reconstruction is just the beginning—the real work is rehabilitation. Full recovery takes 9-12 months of dedicated exercise to rebuild strength, restore stability, and return to sport safely. This guide walks you through each phase, from day one to return to play.

Understanding ACL Rehabilitation

The ACL (anterior cruciate ligament) prevents forward translation of the tibia and rotational instability. After reconstruction, the new graft needs time to heal and "ligamentize"—a process taking 6-12 months.

Graft types:

• Patellar tendon autograft
• Hamstring autograft
• Quadriceps tendon autograft
• Allograft (donor tissue)

Rehabilitation principles are similar regardless of graft, though some specifics vary.

Goals of rehabilitation:

1. Protect the healing graft
2. Restore full range of motion
3. Rebuild quadriceps and hamstring strength
4. Restore proprioception and neuromuscular control
5. Progress through functional activities
6. Return to sport safely

Phase 1: Protection (Weeks 0-2)

Goals

• Control pain and swelling
• Protect the graft
• Achieve full extension (crucial!)
• Begin quad activation

Immediately Post-Op

RICE protocol:

• Rest with leg elevated
• Ice 20 minutes, several times daily
• Compression with ace wrap
• Elevation above heart

Range of Motion

Extension is priority #1:

Prone hangs:

1. Lie face down, knee at edge of bed
2. Let lower leg hang
3. Gravity assists extension
4. Hold 10-15 minutes, 3-4 times daily

Heel props:

1. Place heel on rolled towel
2. Let knee straighten with gravity
3. Add light weight on top of knee if needed
4. 10-15 minutes, multiple times daily

Goal: 0 degrees extension (fully straight) by week 2

Flexion:

• Gentle heel slides: 90 degrees by week 1-2
• Don't force—protect the graft

Quad Activation

Quad sets:

1. Sit with leg straight
2. Tighten quad, pushing knee down
3. Hold 5-10 seconds
4. 10-20 repetitions, every hour while awake
5. Critical for preventing quad shutdown

Straight leg raises (SLR):

1. Lie on back
2. Lock knee straight (quad set first)
3. Lift leg 12 inches
4. Hold 3 seconds, lower slowly
5. 3 sets of 10
6. Must be able to lock knee first

Mobility

• Ankle pumps: Prevent blood clots
• Walking with crutches and brace (as prescribed)
• Weight-bearing per surgeon protocol

Phase 2: Early Rehabilitation (Weeks 2-6)

Goals

• Achieve full extension (mandatory)
• Progress flexion to 120+ degrees
• Normalize gait
• Strengthen quads and hamstrings

Range of Motion

Continue extension work:

• Full extension (0 degrees) is non-negotiable
• If lacking, prioritize until achieved

Flexion progression:

• Heel slides: progress to 120+ degrees
• Wall slides: feet on wall, let knees bend
• Seated flexion: use good leg to push further

Strengthening

Quad exercises:

Terminal knee extension:

1. Loop band around something sturdy at knee height
2. Step into band, behind knee
3. Bend knee against band, then straighten
4. Focus on last 30 degrees of extension
5. 3 sets of 15

Leg press (light):

1. Limited range (0-60 degrees)
2. Light weight
3. 3 sets of 10-15

Step-ups (low):

1. 4-6 inch step
2. Step up with surgical leg
3. Control descent
4. 3 sets of 10

Hamstring exercises:

Hamstring curls:

1. Prone or standing
2. Light resistance
3. 3 sets of 15

Glute bridges:

1. Lie on back, knees bent
2. Lift hips
3. Progress to single-leg
4. 3 sets of 15

Gait Training

• Wean off crutches (per surgeon)
• Focus on normal heel-toe pattern
• No limping—if you can't walk normally, use crutches
• May take 2-4 weeks to normalize

Cardio

• Stationary bike: when flexion allows
• Pool walking: when incision healed
• Upper body ergometer

Phase 3: Intermediate Rehabilitation (Weeks 6-12)

Goals

• Full ROM maintained
• Significant strength gains
• Begin proprioception training
• Normal walking and daily activities

Strengthening Progression

Quad-focused:

Squats:

1. Start with wall squats
2. Progress to bodyweight squats
3. Progress to goblet squats
4. Keep form perfect—knee over toes
5. 3 sets of 10-15

Lunges:

1. Start with stationary split squats
2. Progress to forward lunges
3. Keep knee stable—no wobbling
4. 3 sets of 10 each leg

Step-ups:

1. Increase step height (8-12 inches)
2. Add weight gradually
3. 3 sets of 10 each leg

Leg press:

1. Increase weight
2. Full range now OK
3. 3 sets of 10-12

Hamstring-focused:

Romanian deadlifts:

1. Start with bodyweight
2. Progress to dumbbells
3. 3 sets of 10-12

Nordic hamstring curls (assisted):

1. Partner-assisted or using support
2. Eccentric focus
3. 3 sets of 5-8

Balance and Proprioception

Single-leg balance:

1. Stand on surgical leg
2. Hold 30 seconds
3. Progress: eyes closed, unstable surface

Single-leg squat touches:

1. Stand on surgical leg
2. Squat and touch floor in front
3. Stand back up
4. 3 sets of 10

Bosu ball exercises:

1. Standing balance
2. Squats
3. Progress to eyes closed

Cardio Progression

• Swimming: when cleared
• Elliptical: progressing intensity
• Stationary bike: increasing resistance
• Walking: longer distances

Phase 4: Advanced Strengthening (Weeks 12-20)

Goals

• Near-normal strength
• Begin running preparation
• Sport-specific foundation

Strength Training

Heavy strengthening:

• Barbell squats
• Deadlifts
• Heavy leg press
• Bulgarian split squats
• Weighted step-ups

Target: 80% strength compared to other leg by week 16-20

Power Development

Plyometric preparation:

Box step-ups (quick):

1. Quick step-ups on low box
2. Focus on speed
3. 3 sets of 10

Mini hops:

1. Small two-leg hops in place
2. Progress to forward hops
3. Focus on soft landings
4. 3 sets of 10

Running Preparation

Criteria to start running (typically week 12-16):

• Full ROM
• No swelling
• Quad strength 70-80% of other side
• Normal walking and stairs
• Passed single-leg hop tests

Running progression:

1. Walk-jog intervals (walk 2 min, jog 1 min × 8-10)
2. Progress intervals (jog 2 min, walk 1 min)
3. Continuous jogging (10-15 minutes)
4. Gradual increase (10% per week)

Phase 5: Return to Sport (Months 6-12)

Goals

• Sport-specific training
• Pass return-to-sport tests
• Safe return to competition

Advanced Plyometrics

Jumping:

• Box jumps
• Broad jumps
• Vertical jumps
• Single-leg hops

Agility:

• Lateral shuffles
• Carioca
• Cutting drills (progress angles)
• Deceleration drills

Sport-Specific Training

Running progression:

• Straight-line sprints
• Curved running
• Figure-8s
• Shuttle runs
• Sport-specific patterns

Cutting progression:

• Planned cuts at 45 degrees
• Progress to 90 degrees
• Progress to reactive cuts

Return-to-Sport Testing

Criteria (typically 9-12 months):

• Quad and hamstring strength ≥90% of other side
• Single-leg hop tests ≥90% of other side
• No pain, swelling, or instability
• Passed sport-specific agility tests
• Psychological readiness

Common tests:

• Single-leg hop for distance
• Triple hop
• Crossover hop
• 6-meter timed hop
• Y-balance test

Sample Weekly Routines

Phase 1-2 (Week 1-6)

Daily:

• Extension work: 3-4 × 15 minutes
• Quad sets: Every hour, 10-20 reps
• ROM exercises: 3 times daily
• Ice: 20 minutes, multiple times

3x/week:

• SLR: 3 × 10
• Hip exercises: 2-3 sets each
• Bike (when able): 10-15 minutes

Phase 3 (Week 6-12)

3-4x/week strength:

• Squats: 3 × 12
• Leg press: 3 × 12
• Lunges: 3 × 10 each
• Hamstring curls: 3 × 12
• Glute bridges: 3 × 15
• Single-leg balance: 3 × 30 seconds

Daily:

• ROM maintenance
• Walking/bike: 20-30 minutes
• Balance exercises

Phase 4-5 (Week 12+)

4x/week:

• Heavy strength: 2 days
• Power/plyometrics: 2 days
• Running: 3 days (when cleared)
• Sport-specific: As appropriate

Common Mistakes

1. Neglecting extension - This is the #1 predictor of poor outcome
2. Progressing too fast - Graft healing takes time
3. Skipping phases - Each builds on the last
4. Returning to sport too early - High re-tear risk under 9 months
5. Ignoring the other leg - Maintain fitness in uninjured limb

The Bottom Line

ACL rehabilitation is a marathon:

1. Extension first - Full extension is non-negotiable
2. Quad strength - The foundation of recovery
3. Progress by phase - Don't skip steps
4. Test before returning - Meet objective criteria
5. Be patient - 9-12 months is standard

Re-tear rates are 15-25% in young athletes returning to cutting sports. Following a structured rehab program and passing return-to-sport testing significantly reduces this risk. Put in the work, trust the process, and return stronger than before.