Best Exercises To PREPARE For Total Knee Surgery: (The CORRECT Ones!)

The research article Prehabilitation Before Total Knee Arthroplasty Increases Strength and Function in Older Adults With Severe Osteoarthritis confirms my professional opinion as a physical therapist that exercises BEFORE a total knee replacement gives the patient a big jump on the rehabilitation protocol AFTER the surgery.

However, most information I see disseminated, in print as well as video, completely misses the mark on the question: “What are the best exercises to do before my total knee surgery to prepare me for the exercises I will need to do after my total knee surgery?”

Most of the information available online wants to teach the patient the exercises they will be doing AFTER the knee replacement surgery, but they don’t answer the question of “What are the best exercises to do BEFORE the surgery to prepare the leg for the exercises to be done post-surgery”?

What are the best exercises before knee replacement surgery?

  • Closed-chain muscle-isolation exercises of the Gluteus, Quadriceps, Hamstrings, Gastroc, and Adductor Magnus are the primary muscles to strengthen.
  • Flexibility exercises to stretch out the Hamstrings, Quadriceps and Gastroc are the best muscles to target.

Teaching a prospective total knee replacement recipient how to do the post-surgery exercises BEFORE having the surgery is not unreasonable. It will prepare the patient for what to expect when the rehabilitation phase of the recovery program starts,
but it in no way helps the patient GET a HEAD START for that post-op rehabilitation program of exercises.

This is what you need to know:
Strength is NOT muscle bulk!

Most average people without knee replacement surgery, and not working out hard at lifting weights to increase their muscle size (bodybuilders) can only recruit about 50-65% of the muscle fibers in any given muscle.

So every year, just after New Years, the local gyms become very busy with new members wanting to build their muscle size, but by Valentine’s Day the gyms are a lot less crowded.
Why is that?

What the new exerciser does not understand is my initial statement that the average person only recruits about 50-65% of a muscle’s fibers; that’s just the way humans are built.

It takes a person about 5-6 weeks of going to the gym and lifting progressively more weight for them to be able to recruit up to nearly 100% of the muscle’s ability to fire on all cylinders (in this case muscle fibers).

So after about 5-6 weeks, the new gym member looks in the mirror and says: “This ain’t working. I’ve been working at this for a long time, and the amount of weight I’m lifting is almost double what I could do in the beginning, and look at me in the mirror. There’s no change. I Quit!”

What a shame. They were just at a point where they would have begun building muscle bulk if they had stayed with it, but they didn’t understand this concept, so they quit.

Moral Of This Story:
Pre-total knee exercises are not about building muscle bulk; they are about improving the patient’s ability to recruit the muscle fibers they already have.

Guess what:
After total knee replacement surgery, the patient’s brain is going to shut down the amount of fiber recruitment it will allow because it is trying to protect an injured knee.

The brain does not care if it was a skilled surgeon or a hobo in an alley that stabbed you in the knee, brain only knows to shut down the ability to contract the muscles around that knee.

On average, based on the many total knee patients I have seen for physical therapy just a couple days after the surgery, my best guess is they have dropped to about 30-35% ability to recruit the involved muscles.

In fact, I have seen a few patients who can not even get their brain connected to the muscle at all (usually the Quadriceps). Total loss of ability to fire that muscle voluntarily.

The good news is that one session of stimulating the Quadriceps in these patients with a little electrical stimulation, while trying to actively contract the muscle, will re-establish that pathway almost immediately.

The Take-Away
The best exercises to do before total knee surgery:
1. Should start about 5-6 weeks before the scheduled surgery.
2. Should be closed-chain exercises.
3. Pain permitting, should be able to increase muscle strength by 25% or more.
4. If the patient can recruit more of a muscle’s fibers BEFORE total knee surgery, they should be able to recruit more of the fibers AFTER the knee surgery. Rehabilitation will be much easier for those who can prepare before the surgery.

Tip 1: Apply Cold Therapy Before Going To Bed.

All of my total knee surgery patients are using either Ice Packs or Cold Therapy Machines (Amazon affiliate links) multiple times daily to help control pain levels. Applying cold therapy for 40 minutes just before going to bed will reduce your pain while sleeping
See my article: Ice After Total Knee Replacement: A PT’s Complete Guide.

Closed-Chain Muscle-Isolation Resistance Exercises

Closed-chain exercises are simply any exercise where the person exercising keeps the foot on the floor and moves the body (and consequently any weight that person is lifting).
The good news is that all these exercises can be done at home with just your own body weight.
The trick is to do muscle isolation closed-chain exercises.

Functionally, the Gluteus, Quadriceps, Hamstrings, Adductors, and Gastroc muscles all work together at the same time to move the body around in space, such as standing up from a seated position.

Using muscle isolation closed chain exercises we can focus the brain on making each of these different muscles be the primary mover of the body and allowing all the other muscles normally equally involved in that movement to be only minimally recruited and allowing them to act as a “safety net” to be activated if the muscle being focused fails to be able to complete the activity, such as getting up out of a chair.

This allows the total knee replacement candidate to strengthen the leg muscles using much less weight to recruit that specific muscle to its full potential without risk of injury.
Working all the leg muscles at the same time makes the patient vulnerable to injury 100% of the time the exercise is being performed.

Since we already know the patient has a bad knee, rules need to be implemented to prevent flare-ups from doing these exercises:

  • If it hurts a little during the exercise that’s OK, BUT DON’T PUSH THROUGH THE PAIN. This means that when the exercise is stopped, most of the pain should go away almost immediately and any increased pain during the exercise should be gone within 5 minutes after stopping the exercise.
  • In the beginning, after each exercise, stop for a few minutes and compare the pain levels before and after the exercise. It should be the same or less within 5 minutes.
  • In these exercises, the knee should stay behind the toes with the feet flat on the floor throughout the exercise motion.

CAUTION:

Always place a chair behind the patient just in case the leg strength fails and the patient needs to sit down because there is not enough leg strength to come to the standing position.
There is no need to squat any lower than would be required to sit in a chair.

Chair-Squat Muscle-Isolation HOME Exercises Focusing The Gluts, Hamstrings, Adductors, and Quad Muscles:

All three of the following chair-squat exercises start with the same start positions, but the focus is modified for the different specific muscles through foot position, push-off contact of the foot with the floor, and most importantly, isolation of the specific targeted muscle with brain connection to that muscle using thought process.

Starting Position For The Chair-Squat Exercises:
The patient stands facing the kitchen sink with a chair behind them like they were going to sit down in the chair.

Chair-Squat Muscle-Isolation HOME Exercises Focusing The Gluteus Maximus And The Hamstrings:

Chair Squat watermarked Cropped
Chair-Squat Exercise.
  • Stand facing the kitchen sink and grasp the sink’s front ledge with both hands for support.
  • Position a chair behind the patient’s back 3 or 4 inches behind the legs (enough to prevent the knees from moving in front of the toes at the full depth of the squat).
  • Keep the toes pointed straight forward.
  • Keeping the torso erect (not bending forward), move into the squat position as if to sit down. Do not sit down, only allow the butt to barely touch the chair seat.
  • In the squat position, it is critical to get the brain connected to the Gluteus Maximus and Hamstrings to ISOLATE these muscles and strengthen them individually from the rest of the leg muscles. This is done by bearing all the weight on the HEELS of the foot and the “focused thought” of pulling the knees backward toward the wall. The Patient should feel the contraction of the Hamstrings and Gluts dominate the act of returning to the upright standing position.
  • It helps focus to actually lift the toes off the floor while doing this specific exercise.
  • At the end of coming to full upright standing, tighten the Glut muscles as tight as possible, this should make the front of the pelvis move slightly forward at the full upright isometric contraction of the Gluteus muscles.
  • The goal is to repeat this exercise for three sets of ten repetitions every other day until surgery but START with one set in the morning and another set in the afternoon. Then combine the two sets together but do them only once on an exercise day.
  • Add a third set as able and tolerated.
  • If one set is too much, start with fewer repetitions and consider not going as deep into the squat.
  • Remember, we are not going into a squad deeper than if the patient was sitting down in a chair.

Chair-Squat Muscle-Isolation HOME Exercises Focusing The Adductors Of The Leg:

  • Stand facing the kitchen sink and grasp the sink’s front ledge with both hands for support.
  • Position a chair behind the patient’s back 3 or 4 inches behind the legs (enough to prevent the knees from moving in front of the toes at the full depth of the squat).
  • Place the feet flat on the floor but turn the toes outward about 45 degrees (1st position in ballet).
  • Keeping the torso erect, move into the squat position allowing the buttocks to touch the chair seat, but do not sit down.
  • In the squat position, it is critical to get the brain connected to the leg Adductors to ISOLATE these muscles and strengthen them individually from the rest of the leg muscles. This is done by bearing all the weight on the ARCH of the foot and the “focused thought” of pulling the knees together, pushing the body upward into the erect position. The Patient should feel the contraction of the Adductors dominate the act of returning to the upright standing position.
  • This is done by turning the toes outward to 45 degrees (1st position in ballet) bearing all the weight on the ARCHES of the foot and the “focused thought” of pulling the knees together as the body returns to the erect position. The Patient should feel the contraction of the Adductors on the inside of the thigh dominate the act of returning to the upright standing position.
  • The goal is to repeat this exercise for three sets of ten repetitions every other day until surgery but START with one set in the morning and another set in the afternoon. Then combine the two sets together but do them only once on an exercise day.
  • Add a third set as able and tolerated.
  • If one set is too much, start with fewer repetitions and consider not going as deep into the squat.
  • Remember, we are not going into a squad deeper than if the patient was sitting down in a chair.

Chair-Squat Muscle-Isolation HOME Exercises Focusing For The Quadriceps:

  • Stand facing the kitchen sink and grasp the sink’s front ledge with both hands for support.
  • Position a chair behind the patient’s back 3 or 4 inches behind the legs (enough to prevent the knees from moving in front of the toes at the full depth of the squat).
  • Keep the toes pointed straight forward.
  • Keeping the torso erect, move into the squat position allowing the buttocks to touch the chair, but do not sit down.
  • In the squat position, it is critical to get the brain connected to the Quadriceps to ISOLATE these muscles and strengthen them individually from the rest of the leg muscles. This is done by bearing all the weight on the BALLS of the foot and the “focused thought” of pushing vertically. The Patient should feel the contraction of the Quadriceps dominate the act of returning to the upright standing position.
  • Sometimes elevation of the heel of the foot off the floor just a little helps shift the weight to the balls of the feet.
  • The goal is to repeat this exercise for three sets of ten repetitions every other day until surgery but START with one set in the morning and another set in the afternoon. Then combine the two sets together but do them only once on an exercise day.
  • Add a third set as able and tolerated.
  • If one set is too much, start with fewer repetitions and consider not going as deep into the squat.
  • Remember, we are not going into a squad deeper than if the patient was sitting down in a chair.

These “muscle isolation” techniques will become more and more “focused” as the brain establishes a much better recruitment path to the muscle components than to the muscles as a group.

A huge benefit to muscle isolation technique is that the patient is not 100% vulnerable to injury during the exercise.

In a non-isolation technique of strengthening (called Power-lifting) the patient is recruiting every muscle contributing to the desired motion, and if anything goes wrong, there are no reserve muscle strengths to recruit to prevent an injury. They are 100% vulnerable.

With muscle isolation techniques, the patient’s goal  is recruiting 100% of a specific muscle and relaxing the remaining “assist” muscles used in power-lifting. If anything goes wrong with this exercise there is a reserve of muscle power that can be recruited to prevent complete collapse and injury.

Wall Sit Isometric HOME Exercise To Strengthen The Leg Muscles:

Wall Sit Pre Surgery cropped 200708
Wall Sit Isometric Exercise,

All muscles are composed of two different type of muscle fibers, red fibers, and white fibers.
White fibers are the quick-twitch fibers that contract very fast and lift heavy loads, but only for very short periods of time. They are the muscle fibers seen in bodybuilders.
Red fibers are slow-twitch fibers that contract more slowly but are also very slow to fatigue.
These are the fibers seen in a runner’s leg.

While the chair-squat muscle-isolation exercises are great exercises for building the recruitment ability of the white fibers to make one stronger in functions such as getting up out of a chair, red fibers are used more in the function of walking distances without fatiguing.
These fibers are best strengthened by doing a sustained isometric contraction over a long period of time.

Patients will feel this most in the Quadriceps muscles and these muscles are usually the limiting factor.

The Wall Sit Isometric Exercise is the best exercise to accomplish this:

  • WEAR RUBBER-SOLED NON-SLIP SHOES!
  • Choose a door that opens toward the patient (so that the door can not accidentally be opened during the exercise.
  • A door (instead of a wall) is chosen to decrease the friction of the patient’s back against the door. This will make it much easier for the patient to return to erect.
  • The door friction can be further reduced by applying Pledge to the door.
  • The buttocks and mid-back stay in contact with the door.
  • The feet are moved forward away from the wall about 18” (far enough forward that the knees do not move in front of the toes in the squat position).
  • Place a chair sideward, just slightly to one side of the patient. This will allow the patient to grab the chair and pull it under the buttocks in case the patient does not have enough strength to return to erect. They can just sit down on the chair.
  • The patient slides down the door into a squat of about 45 degrees (about halfway to the sit position).
  • The patient stays in this 45-degree squat position for as long as tolerated.
  • The gold standard I choose as a goal for my patients is 3 sets of holding this squat position for 3 minutes each.
    Most of my patients can only tolerate about 30” in the beginning but I usually see quick progress with this exercise.
  • Remember: we are only going into a squat of ½ way to sitting.
  • Start where the exercise is tolerated and progress as able.

Heel Raise HOME Exercises to Strengthen the Calf Muscles (Gastrocs):

Heel Raises watermarked Cropped
Heel Raise Exercise.
  • The patient stands facing a counter-top with both hands on the counter-top for balance and support.
  • Lift the heels off the floor as high as possible and come up onto the toes.
  • Hold that heel raised position for 5 seconds.
  • The goal is to repeat this exercise for three sets of ten repetitions every other day until surgery but START with one set in the morning and another set in the afternoon. Then combine the two sets together, but do them only once on an exercise day. Add a third set as able and tolerated.

Gym Members:

For those with gym memberships, the same technique will be used but they will have the option of using the gym’s hack machine.

Word to the wise for those working out in a gym:
After 40 years of working out in gyms regularly, and meeting lots of people preparing for bodybuilding competitions, the one thing I have learned is that there are thousands of ways to work a muscle, but almost all bodybuilders use muscle isolation techniques to get specific muscle bulk and definition and to prevent injury.

Bodybuilders understand the risk of injury using power lifting techniques, but at some point in their training, if they hit a wall where muscle bulk is not growing, they will move over to power lifting techniques for 5-6 weeks and then right back to the safe muscle isolation/bodybuilding techniques. (Sounds suspiciously like muscle fiber recruitment training rather than muscle bulk building to me). Just a thought.

So once the total knee replacement candidate has built the ability to recruit the muscles to the best of their ability, they should have a much easier time in the early rehabilitation phase of that total knee replacement, including getting that leg into and out of bed independently, a common complaint I hear from patients at our first home therapy session.

Flexibility Exercises

Pre-surgery flexibility exercises for the total knee candidate are important because after surgery the knee will have a decreased range of motion for a few weeks, and that loss of knee flexibility will need to be countered with increased flexibility of the muscles to help prevent knee injury during activities of daily living.

Any activity of daily living prior to surgery was the symbiotic relationship of knee range of motion and leg muscle flexibility.

Any decrease in one affects the other, and the knee will have less range of motion, for a while, after the surgery.

The knee had full range of motion in the surgical suite after the total knee replacement surgery but within one day after surgery, the range of motion can be greatly reduced by inhibition signals coming from the brain and/or the swelling post-surgery.
See my article Ice After Knee Replacement…..

Adding increased flexibility of the leg muscles will help decrease the loss of function secondary to the loss of range of motion of the knee after surgery.

Adding increased flexibility of the leg muscles will help decrease the loss of function secondary to the loss of range of motion of the knee after surgery.
Increased flexibility of the Hamstrings, Quadriceps and Gastroc muscles give the patient the best bang for their buck, so to speak.

Flexibility Exercise General Rules:

  • There is an ongoing debate about whether flexibility exercise should be done before or after resistance exercises. Either way is fine, I prefer flexibility exercises after resistance exercises.
  • Flexibility exercises are a SUSTAINED stretch. Never “bounce” on the end range of motion during a stretch, this will cause the muscle to shorten and tighten, not increase in flexibility.
  • Flexibility exercises, unlike strengthening exercises, do not have a “refractory” period, therefore they do not need a day of rest between the exercises and should be done daily.

Hamstring Stretches Home Exercise:

Hamstring Stretch Watermarked
Hamstring Stretch.
  • While sitting on a hard surface (even sitting sideways on the hard edge of the sofa in the front), place one outstretched leg on the hard surface and the other knee bent.
  • Keeping the knee straight, with hand overpressure on the knee cap, lean forward until a strong stretch is felt in the hamstrings.
  • While holding this stretch, take a deep breath and blow it out slowly over about five seconds, allowing the body to sink further over the knee.
  • While holding this new position, repeat this deep breathing/stretch sequence again by taking another deep breath and slowly bending forward as the breath is released.
  • Repeat this process for five full breaths.
  • The goal is to repeat this stretch twice daily every day but start with once daily and see how the Hamstrings react. The Hamstrings are the most likely muscles to complain about the stretch, and they are the easiest muscles to cramp!

This stretching exercise is done to isolate the hamstring muscles for stretching and I prefer to keep the hamstrings isolated for the stretch.

I see many recommendations to modify this exercise by having the patient pull the toes back toward the knee during this hamstring stretch. This modification is now combining the Gastroc and Sciatic nerve into the Hamstring stretch which can decrease the effectiveness of stretching the Hamstrings. I prefer to do these stretches individually, I get better results individually.

Quadriceps Stretches Home Exercise:

In a normal non-surgical candidate for knee replacement, the expectation is that the patient can lie on the stomach and bring the heel up and touch the buttocks; but most normal people come about 5-6 inches short of the heel to buttocks; many are much more restricted than even the 5-6 inches short of the heel to buttocks.

This stretch exercise of the Quadricep is most effective if assisted by another person but can be done independently with some modification.
I will describe both techniques:

Quadriceps Stretch Without Assistance Of Another Person:

Quad stretch sidelying Pre Surgery Watermarked Cropped 200707 1
Quadricep Stretch
  • With the patient side-lying, targeted leg to stretch on the top side, bring the top knee up toward the chest until the patient can grasp the ankle.
  • Bring the heel up toward the buttocks as far as the patient tolerates.
  • Holding this position of knee bend, start to pull the leg backward with the grasping hand and start to straighten out the hip from the flexed position to the straightened position (like it would be in standing).
  • Hold this stretch for 5 seconds then flex the hip a little to release the Quadriceps stretch but maintain the starting position of heel to buttocks.
  • Repeat this stretch 5-10 times as the patient tolerates.
  • Repeat twice daily with a few hours between sessions.

Quadriceps Stretch With Self-Assist Using A Belt:

Quad stretch Prone with belt Pre Surgery Ex Watermarked200707
Quadricep Self-Stretch With Belt Assist.
  • With the patient lying on a flat firm surface (a firm bed will work), have the patient lie on their stomach.
  • The patient scoots to the edge of the bed and places one foot on the floor, bringing the knee upward as close to the shoulder as possible (this protects the low back during the stretch).
  • The patient places a belt around the ankle of the leg of the Quadriceps muscle to be stretched.
  • The patient brings the heel up toward the buttocks while assisting bending the knee with the belt until the patient feels a good stretch in the Quadriceps.
  • Hold that stretch for 5-10 seconds, then release the stretch.
  • Repeat this assisted stretch for 5 to 10 times per session, depending on the patient’s tolerance.
  • Repeat this session twice a day with a few hours between sessions.

Quadriceps Stretch With Assistance Of Another Person:

Quad Stretch One Person Assist Pre Surgery 200708
Quadricep Stretch With Help From Another Person
  • With the patient lying on a flat firm surface (a firm bed will work), have the patient lie on their stomach.
  • The patient scoots to the edge of the bed and places one foot on the floor, bringing the knee upward as close to the shoulder as possible (this protects the low back during the stretch).
  • The assistant places a hand on the patient’s buttocks to hold the pelvis down.
  • The assistant grasps the patient’s ankle with the other hand and brings the patient’s heel up toward the buttocks until the patient feels a good stretch in the Quadriceps.
  • Hold that stretch for 5-10 seconds, then release the stretch.
  • Repeat this assisted stretch for 5 to 10 times per session, depending on the patient’s tolerance.
  • Repeat this session twice a day with a few hours between sessions.

Another more aggressive assisted way to stretch the quadriceps:

Quad Stretch Foot on Shoulder Pre Surgery 2100708
More Aggressive Quadricep Stretch
  • With the patient lying on a flat firm surface (a firm bed will work), have the patient lie on their stomach.
  • The patient scoots to the edge of the bed and places one foot on the floor, bringing the knee upward as close to the shoulder as possible (this protects the low back during the stretch).
  • Assistant stands over the patient of the Quadriceps to be stretched.
  • Assistant bends the patient’s knee to the patient’s tolerance.
  • Assistant places the patient’s foot on the assistant’s shoulder and the assistant places their hands flat on the surface just to the side of each hip.
  • The assistant leans forward taking the Quadriceps into a reasonably strong but tolerable stretch.
  • At the patient’s tolerance of flexion, the assistant asks the patient to try and straighten out the knee but holds the foot on their shoulder, in position, not allowing any straightening to happen.
  • The patient is requested to only use 50% effort with trying to straighten the knee.
  • The patient is instructed to continue this straightening out effort for 5 seconds and then relax.
  • Upon relaxing, the knee is not permitted to straighten out any and the assistant leans further forward to the new flexion limitation after the first stretch. This can be a very short gain in range, maybe only a ½” of movement.
  • This sequence is repeated with the goal of being able to repeat this stretching technique for 5 repetitions (or patient tolerance if 5 sessions is too much for the patient).

Gastrocnemius Stretches Home Exercises: Three-Way Stretches

The Gastroc muscle has two separate muscle heads that cross the knee.
To stretch this muscle optimally requires three stretches.

The difference between the stretches are only the foot placement on the ground in three different orientations:

  • Toes pointed outward (duck-walk position).
  • Toes pointed straight ahead.
  • Toes pointed inward (pigeon-toed)

For patients that have reasonable Gastroc flexibility and don’t really feel the stretch in the Gastroc muscle, placing a 2×4 chunk of wood under the ball of the foot will give the patient a good stretch.

Instructions For All Three Positions Of Gastroc Stretch:

JBB Calf stretch edited
Gastroc Stretch
  • Stand facing a blank wall.
  • Stand far enough away that when the hands are raised to shoulder level, the palms of the hands are 6-12 inches away from the wall.
  • Place the open hands against the wall.
  • Take a half-step in toward the wall with the non-stretch leg, with the foot flat and knee bent, to provide support and balance.
  • Keep the operated knee straight and the heel on the ground.
  • Push the belly-button in toward the wall until a stretch is felt in the Gastroc muscle.
  • Hold that stretch of 5 seconds.
  • Repeat 10 times.
  • Repeat with all three foot positions at one session.
  • Repeat session twice daily.
  • Placing a 2×4 under the toes of the Gastroc to be stretched will add flexibility.

Final Thoughts:

  • Doing these recommended strengthening and stretching exercises pre-surgery will give the total knee replacement patient a huge jump-start on the rehabilitation after the knee replacement surgery.
  • I see a big difference in the patients that have been working out and strengthening regularly before the surgery as opposed to patients that have not prepared in advance of the surgery.
  • Start the strengthening exercises as far in advance of the surgery as possible. It takes a new gym member 5-6 weeks to reach optimal recruitment. I expect it will take longer for a waiting total knee patient, the pain will slow them down.
  • Be sure to exercise within your tolerance. Pain that lingers longer than 5 minutes after stopping the exercise is an indicator that specific exercise needs to be modified in reps, weight, or technique.

Read my other articles about Total Knee Replacement

Wishing You A Speedy And Full Recovery.

Paying It Forward

Perhaps you are approaching or already retired and wondering how you could earn extra money in retirement.
One option would be to do as I am doing.
Read my article How To Generate Retirement Income: Cash In On Your Knowledge.

Dr. Robert Donaldson

Dr. Donaldson is dually licensed; physical therapy in 1975 and doctor of chiropractic in 1995. He held credentials of Orthopedic Clinical Specialist in physical therapy for 20 years, QME in California, and taught at USC. He owns and operates an orthopedic physical therapy practice. See "About Me" page.

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