Let's face it: knee surgery is brutal. ACL rehab exercises can be monotonous, and to recover properly, you might even have to drive across town to meet with your physical therapists.

It'd be great to be able to rehabilitate your ACL at home after your knee injury, right?

This was a most surprising recent customer story.  We came across a competitive runner who used the ARENA platform to nurse their ACL injury back to health.

While we were remorseful to hear of the injury itself, we admittedly found the use case endlessly interesting too.

The result?

Please enjoy the below ultimate guide to this all-too important knee ligament, and a number of excellent ACL rehab exercises you can use for reconditioning and recovery!

Table of Contents

• What is an ACL and what does it do?
• Help prevent knee injuries through strength training
• ACL rehab exercises you can do at home
• Best practice tips to optimize your ACL recovery speed
• Recovery is a marathon, not a sprint

What is an ACL and what does it do?

An ACL injury is a tear to the anterior cruciate ligament, one of the four major ligaments in your knee.

It can occur when you make a sudden change in direction, land from a jump awkwardly, or collide with another player, and can be incredibly debilitating! We're talking intense pain, swelling, and difficulty walking.

A common way that ACL injuries occur is from wear and tear over a long period of time. Ligaments can wear down from repetitive stress, like the kind experienced by our runner referenced above.

When your ACL is weakened, perhaps by a prior knee injury, it becomes up to 5 times more susceptible to tearing. Most ACL injuries are treated by surgery, followed by a lengthy rehabilitation process.

However, there are things that you can do to minimize your chances of sustaining an ACL injury. And, if you do sustain one, there are exercises that you can do to speed up your recovery too!

Help prevent knee injuries through strength training

One of the best ways to prevent an ACL injury is through strength training, of course!

By strengthening the muscles around your knee, you will be better able to stabilize your joint and avoid ACL injuries. Compound exercises involving movement at multiple joints are especially beneficial.

Examples of compound exercises include squats, lunges, and deadlifts!

If you use weightlifting machines that have a set path, it can hurt your joints and make your knees weaker. This happens because the fixed track on the machine makes you move in a way that is not natural for your body.

Thus, your knee joints experience repetitive shear stresses as they are pulled along a forced trajectory. Over the long term, some muscles groups may develop in an unbalanced manner, causing joints to be pulled or stretched in unhealthy ways that increase their chance of injury day-to-day.

While these machines have their place in strength training as a discipline, you should avoid using machines like knee extensions, hamstring curls, and leg presses if you are worried about your knee health!

ACL rehab exercises you can do at home

If you unfortunately do injure your ACL, there are certain exercises that can help you recover more quickly. Strength training is again key here, as it will help you rebuild the muscles around your knee and improve joint stability.

Lying cable hamstring curls, squats, and weighted step-ups are some of our favorite targeted movements for strengthening the muscles around your knee, and for improving joint stability!

You can use any cable-based resistance system like those found in your local gym or an ARENA platform to hit these movements.

Lying hamstring curl

This exercise strengthens the hamstrings, which are muscles that attach to the back of your knee and are key to stabilizing it.

It also takes the load off of needing to balance, allowing you to focus on activation around the injured area and establishing deep mind-muscle connection!

To do this exercise, first lie on your stomach in front of a cable-based resistance machine with an ankle strap on one of your legs.

Next, slowly bend your knee, pulling your ankle towards your butt. Hold for a breath and then lower it back to the starting position.

Remember to keep the reps nice and slow, focusing on good form and controlling the leg movement rather than allowing it “fall”.

Repeat this for 12-15 reps before switching to the other leg.

Squats

Squats develop virtually all muscles involved with healthy knee function in a balanced, even, and functional manner. This is amongst the most popular reason athletes love squat training!

Hold your body weight in front of you, and focus your weight on your heels.

Stand with your feet shoulder-width apart and your toes pointed slightly outwards.

Next, bend your knees and lower your body until your thighs are parallel to the ground.

Rise back to the starting position and repeat!

Wall Squats

If you can't do weighted squats comfortably, try wall squats instead!

Position yourself about two feet away from a wall and lean against it with your palms flat on the wall.

Bend your knees and lower your body until your thighs are parallel to the ground. Hold for 10-30 seconds and repeat.

Avoid rushing through these, as strengthening your entire range of motion here is the goal!

Once you're ready (but not a moment before you've received clearance from your physical therapist), you can consider adding light weights into your ACL rehab regimen.

Remember, lifting too heavily too soon can put unnecessary stress on your ACL and increase your risk of (re)injury. This would of course slow down your recovery process.

Focus on lifting a weight that you can control and that allows you to maintain proper form to ensure you're healing correctly.

If you lack upper body strength or have spinal injuries, consider doing belt squats as an alternative.

Front Squats

Front squats are great for rebuilding your lower body strength!

They are straightforward to perform, and only require that you perform a normal squat while holding the bar just above your chest region.

This exercise shifts your center of gravity slightly forward. 

Keep your balance as you slowly lower yourself into the nadir of your front squat rep. This is critical to working out your ACL joints thoroughly!

Goblet Squats

If you've mastered the front squat, then the goblet squat will be a breeze!

A goblet squat is a variation of the front squat, but it is performed while holding a free weight, or in this case, a tricep rope attached to an ARENA home gym, in front of you.

Please remember to control your descent speed into your squat.

Exercising the full range of those ligaments is crucial!

Zercher Squats

The next ACL rehabilitation exercise is the Zercher Squat. This squat variation combines the ligament extension and contraction demonstrated above, but maintains the workout bar in the crux of the elbow.

This is a front-loaded leg exercise, and thus emphasizes your upper back, quads and core (in order to prevent being pulled forward).

Remember to set your feet, and to make sure your elbows fall inside your legs during your descent into the squat!

Belt Squats

Belt squats are a variation of the prototypical squat form. 

In this squat exercise, you just attach a squat belt to the ARENA platform as you lower yourself into each rep.

If you don't have an ARENA home gym–not to worry.

You can achieve this same exercise by securing a squat belt around your waist to a different type of free weight too!

Step-ups 

Weighted step-ups are a great exercise for ACL injury prevention and recovery because they work many of the muscles around your knee while working on balance. This is important because people who have ACL injuries often have poor proprioception (sense of position and movement), which can lead to further injury.

To do a weighted step-up, hold a weight in your hand and stand in front of or onto a sturdy bench or box.

Like with squats, good form and cadence are crucial to seeing the benefits!

Place your left foot on the bench or box and press your body weight up with your left leg until your right leg is fully extended. Hold for a second and then slowly lower yourself back to the starting position.

Then, repeat the same–just on your right side this time.

You can combine this exercise with other balancing exercises, such as standing on one leg or walking on a beam, to help improve your proprioception!

Suitcase Step-Ups

Suitcase step-ups work out the muscles surrounding your knees after an ACL injury, while also helping you to regain your sense of balance.

To perform a suitcase step-up, one needs to grab a weight in on hand, and then to use that same leg to step onto the higher surface.

You should feel the effect of the workout in your quads on the way up, and in your hamstrings on the wayback down.

Goblet Step-Ups

Goblet step-ups are just like the suitcase variation, but also mix in the goblet grip performed in the squat exercise demonstrated above.

You will begin to notice you are regaining your balance and muscle tone around your ACL joint in no time!

Contralateral Step-Ups

Contralateral step-ups are a slight variation on the ipsilateral suitcase step-ups. To perform contralateral step-ups correctly, you will step onto your ARENA or other surface using the opposite leg from where you are holding the weight.

Notice the change of balance required to perform the step-ups from this side relative to the ipsilateral exercise?

Your muscles are relearning their prior sense of proprioception quickly!

Lateral Step Over Squats

Lastly, lateral step over squats give your ACL rehabilitation regimen a dynamic twist. Keeping under control while performing step over squats is key to preventing any repeat aggravation to your knee joint.

As you lower yourself into a fully squatted position, keep your knee joint stable and composed.

This ACL rehabilitation exercise is meant to strengthen your ability to lift and lower yourself while moving in lateral directions, rather than just up and down.

Best practice tips to optimize your ACL recovery speed

Use reasonable rep volumes & weight increases

When you are strength training to prevent or recover from ACL injury, it is important to use the correct reps, sets, and weight!

For ACL prevention, you should do 3-5 sets of 8-12 reps of each exercise.

For ACL recovery, you should do 2-3 sets of 12-15 reps of each exercise.

For ACL injury prevention, 2-3 times per week is sufficient.

For ACL recovery, 3-5 times per week is ideal.

Increase the weight incrementally from week-to-week, anywhere from 2-10 lbs. If you have an ARENA unit, you can track these stats automatically, or aim to increase your Work/Volume by 2-5%. This is a much more accurate measure of your muscular effort.

The weight should be heavy enough that you can only just complete the desired number of reps. You might miss on some days–and that’s okay!

What's key is to focus on not pushing beyond discomfort–especially if you are recovering from injury.

Ensure the ACL exercises are low impact

In addition to strength training and plyometrics, there are other types of exercise that can support ACL recovery too!

Cardio exercise, such as walking, biking, or swimming, is important for improving blood flow and helping the ACL to heal.

Flexibility exercises (such as stretching or yoga) can help improve range of motion and even reduce inflammation!

Lastly, balance exercises can help improve proprioception and joint stability.

How often to do these exercises will depend on your individual situation and should be discussed with your physical therapist or strength coach. Depending on how much you can move, some yoga positions and stretches may not be good for an ACL injury.

At the other end of the spectrum, there are certain types of exercise and sports that you should avoid during ACL recovery.

High-impact exercises, such as running or jumping, can put significant amounts of stress on the ACL and delay your healing process. In addition, contact sports, such as football or basketball, should be avoided until the ACL has fully healed.

If you do any type of exercise or sport that involves twisting or turning your knee, be sure to use proper form and technique to avoid re-injury!

Improve your knee's mobility with stretching

If you want to do some stretching to help prevent ACL injury, here are a few of the best stretches we recommend from athletes and trainers to people that are highly sedentary:

• Hamstring stretch
• Lie on your back with one leg straight and the other leg bent at the knee.
• Place a strap or towel around the arch of your foot and gently pull your leg towards you. You should feel a stretch in the back of your thigh.
• Hold this position for 30 seconds, and repeat 3 times on each leg.
• Quadriceps stretch:
• Stand up and hold onto something for balance.
• Bend one knee and bring your heel towards your butt.
• Using your hand, grab hold of your ankle and pull it gently towards you. You should feel a stretch in the front of your thigh.
• Hold for 30 seconds, and repeat 3 times on each leg.
• Calf stretch:
• Stand with your feet hip-width apart and place your hands on a wall in front of you.
• Step one foot back and keep your heel down as you lean forward into the wall. You should feel a stretch in the back of your calf.
• Hold this position for 30 seconds, and repeat 3 times on each leg.

Recovery is a marathon, not a sprint

ACL injuries can take some time to heal, depending on the severity of your injury. Most people require 6-12 months of rehabilitation before they are able to return to their normal activities.

This timeframe can vary depending on your individual situation. In general, you should start with light aerobic exercise and progress to more strenuous exercises as you get stronger.

You should also avoid any activities that involve twisting or turning your knee until you have been cleared by your doctor!

ACL injuries are notorious for having a high chance of re-injury after rehabilitation. This is why it is so important to follow the instructions of your physical therapist and strength coach closely, and to avoid any activities that involve twisting or turning your knee.

Be patient with your rehabilitation, and practice the above exercises regularly and you'll find yourself back to full strength in no time!