Looking for the Best Exercises to Relieve Knee Pain and Improve Your Mobility Before ACL Reconstruction Surgery?
If you’re getting ready for ACL reconstruction surgery, doing the right pre-surgery exercises can make a big difference. Whether you’re counting down the days to your procedure or just starting to plan, focusing on movement now can help reduce knee pain, restore mobility, and improve your chances of a smoother, faster recovery after surgery.
This type of pre-surgery training—often called “prehab”—is backed by physical therapists and orthopedic specialists alike. By targeting the right muscles and gently improving range of motion, you’re not only preparing your body for surgery—you’re actively setting yourself up for better long-term outcomes.
In this guide, you’ll find:
- Stretching exercises to reduce stiffness and increase flexibility
- Strengthening exercises to support the knee joint and surrounding muscles
Best of all, everything can be done at home with little or no equipment.
If you’re also managing a meniscus tear, recovering from a meniscectomy, or looking for post-op meniscus repair exercises, be sure to check out our related guides for more targeted support.
Let’s get into the best exercises to do before ACL surgery—starting with stretches that help improve mobility and relieve pressure on your knee.
Disclaimers and Disclosures: All information in this article is for informational and educational purposes only and should not be taken as individual medical advice. Additionally, this article contains affiliate links, meaning when you make a purchase, we make a small commission at no additional cost to you. For more information, see our full Disclaimers and Disclosures.
Stretching Exercises Before ACL Reconstruction Surgery
Stretching plays a key role in improving knee joint mobility before ACL surgery. The best stretching exercises to perform before ACL reconstruction include the calf stretch on a slant board, hamstring stretch, heel prop, and heel slides. These movements help restore flexibility, regain range of motion (ROM), and optimize knee mechanics—all crucial for a smoother recovery after surgery.
To get the best results, aim to complete this routine twice per day, but avoid any movements that increase pain or symptoms. This program was designed by a Doctor of Physical Therapy and Orthopedic Clinical Specialist. As always, consult your healthcare provider before starting any new exercise regimen.
1. Calf stretch on a slant board
- Purpose: Targets the calf muscles, particularly the gastrocnemius, which crosses the knee joint and can limit knee extension.
- Benefits: Improves knee mobility and supports full knee extension.
- How to Do It:
- Place one or both feet flat on the slant board.
- Lean forward slowly until you feel a gentle stretch in the calf.
- Hold for 20 seconds and repeat 5 times.
- Pro Tip: A Slant Board provides a more effective angle for a deeper stretch.
2. Hamstring Stretch
- Purpose: Stretches the hamstrings, which can restrict knee movement when tight.
- Benefits: Reduces posterior knee tension and improves overall flexibility.
- How to Do It:
- Lie on your back, loop a strap around your foot, and keep your leg straight.
- Lift your leg until you feel a stretch in the back of your thigh.
- Hold for 20 seconds and repeat 5 times.
- Pro Tip: Use a Stretching Strap with loops for better control and positioning.
3. Heel Prop
- Purpose: Improves knee extension range of motion, which is often reduced after ACL injury.
- Benefits: Achieving full knee extension before surgery leads to better post-op outcomes.
- How to Do It:
- Prop your heel on a towel roll or foam roller.
- Place an ankle weight on your knee and allow the knee to relax and straighten.
- Set a timer for 5 minutes, work up to 10 minutes if restriction still exists.
- Pro Tip: Increase the Ankle Weight gradually to progress your stretch and extension gains.
4. Heel Slides
- Purpose: Improves knee flexion (bending), which is often limited before ACL surgery.
- Benefits: Regaining full knee flexion pirior to ACL reconstruction yields optimal results following surgery.
- How to Do It:
- Loop a strap around your foot.
- Slide your heel slowly toward your buttocks, keeping your foot on the surface.
- Hold for 10 seconds and repeat 10 times.
- Pro Tip: Use a Stretching Strap with loops for ease and for the best results.
Bonus: Ice Pack and TENS for Pre-Surgery Pain and Swelling
- Purpose: Controls inflammation and relieves pain in the knee before ACL reconstruction.
- Benefits: TENS (Transcutaneous Electrical Nerve Stimulation) helps interrupt pain signals, while ice reduces swelling and joint irritation.
- How to Use:
- Place TENS pads just over the painful area of the knee.
- Apply ice for 10–15 minutes post-exercise.
- Pro Tip: Combine ice therapy and TENS during flare-ups or after activity for faster recovery.
Strengthening Exercises before ACL Reconstruction Surgery
Targeted strengthening is essential when preparing for ACL reconstruction. The right exercises help improve knee stability, restore movement mechanics, and reduce joint irritation, all of which contribute to a smoother recovery post-surgery.
The most effective strengthening exercises before ACL surgery include the quad set, straight leg raise, short arc quad, long arc quad, and step downs. These movements are designed to activate and strengthen the quadriceps, which plays a vital role in stabilizing the knee.
Aim to perform this routine twice per day, and avoid any movement that increases pain or swelling. This program was developed by a Doctor of Physical Therapy and Orthopedic Clinical Specialist. Always consult your healthcare provider before beginning any new exercise program.
1. Quad set
- Purpose: e-engages the quadriceps muscle on the front of your thigh, often inhibited after an ACL injury.
- Benefits: Early quad activation promotes better outcomes following ACL reconstruction.
- How to Do It:
- Lie on your back with a towel roll under your ankle.
- Tighten your thigh muscles to press the back of your knee down toward the floor.
- Hold for 2 seconds, perform 10 reps for 3 sets.
- Pro Tip: Use a thick Foam Mat for more comfort and support.
2. Straight Leg Raise
- Purpose: Strengthens the quadriceps muscle on the front of your thigh without stressing the knee.
- Benefits: Supports the knee by building quad strength and promoting joint stability.
- How to Do It:
- Lie on your back with one leg bent and the other straight.
- Tighten your thigh and lift the straight leg to the height of your bent knee, then lower slowly.
- Perform 10 reps for 2 sets.
- Pro Tip: A Thick Foam Mat helps reduce pressure on your hips and spine during floor exercises.
3. Short Arc Quad
- Purpose: Builds quad strength through a safe, limited range of motion.
- Benefits: Encourages active knee extension while minimizing stress on irritated tissues.
- How to Do It:
- Place a foam roll or bolster under your knee.
- Straighten your leg to lift your foot off the surface, pause breifly.
- Lower slowly and repeat 20 times for 2 sets.
- Pro Tip: Use Ankle Weights and a Foam Roll for proper support behind the knee.
4. Long Arc Quad
- Purpose: Strengthens the quads through their full range, promoting better knee control in everyday movements.
- Benefits: Enhances control and support for walking, stairs, and other daily tasks.
- How to Do It:
- Sit upright with your thigh supported.
- Slowly extend your leg fully, hold briefly, then lower.
- Do 20 reps for 2 sets.
- Pro Tip: Use Ankle Weights to increase resistance and muscular activation.
5. Step downs
- Purpose: Engages the quads, glutes, hamstrings, and hip stabilizers in a functional, weight-bearing position.
- Benefits: Prepares your body for post-surgical movements like stairs, walking, and balance tasks.
- How to Do It:
- Stand with the affected leg on the stair and gently hold on to your counter.
- Slowly bend your knee to lower your opposite heel to the floor, then return to the start.
- Repeat 10 times and complete 2 sets.
- Pro Tip: Use an Adjustable Stepper and slowly build the height as you re-gain strength.
Bonus: Helpful equipment for completing your exercises before ACL reconstruction; Thick Yoga Mat
- Purpose: Offers cushioned support for exercises done on the floor.
- Benefits: Reduces joint stress and discomfort, making it easier to stay consistent with your program.
- Why It’s Useful:
- Softens pressure points during strengthening and stretching exercises.
- Lightweight and portable for home or travel workouts.
- Pro Tip: Keep a Thick Yoga Mat in your car or travel bag so you can stretch and strengthen anywhere.
Best Exercises Before ACL Reconstruction Surgery: Final Thoughts
Preparing for ACL reconstruction can feel overwhelming—but having a plan makes all the difference. As a physical therapist, I’ve seen firsthand how structured prehab can dramatically improve outcomes, reduce recovery time, and set the stage for a stronger, more stable knee post-surgery.
That’s exactly why I developed the exercise program above. It’s the same ACL prehab routine I’ve used successfully with countless patients to help them reduce pain, restore mobility, and build quadriceps strength—all essential for a smoother recovery after ACL surgery.
The key to success? Consistency. Stick with this program daily, avoid movements that cause pain, and give your body time to adapt. Within just a few weeks, you may notice better flexibility, improved strength, and increased confidence in your knee—before you even step into the operating room.
Why trust Physical Therapy Simplified for Knee ACL Prehab Exercises?
At Physical Therapy Simplified, our mission is to provide an accessible, trustworthy source of physical therapy guidance that anyone can understand, follow, and benefit from. We want you to feel confident that you’re getting evidence-based advice and the best exercises for ACL prehab—all designed to reduce pain and restore your highest functional potential.
This article was written by Andrew Harkins, PT, DPT, OCS, a licensed physical therapist with over twelve years of clinical experience. He is certified by the American Board of Physical Therapy Specialties as an Orthopedic Clinical Specialist and has treated hundreds of patients undergoing ACL reconstruction.
Andrew has also served as a teaching assistant at the University of Pittsburgh’s Doctor of Physical Therapy Program, where he contributed to musculoskeletal coursework with a special focus on knee pain and surgical treatment recovery strategies. His knowledge and hands-on experience ensure that the information you’re reading is not only accurate but clinically proven to help.
