By Mark Zamerowski, PT, MPT, Physical Therapist, Virtua Physical Therapy & Rehabilitation

Today’s advanced and minimally-invasive surgical techniques mean you can expect to be up and walking before you leave the hospital after your knee replacement. Most patients find that arthritis pain is gone immediately, though post-surgical discomfort can persist for a while (usually around a month but varies by individual).

Once you’re discharged, you’ll begin a course of physical therapy that can start as early as your second day home. Doing these exercises with your physical therapist—starting gently and increasing in intensity over time—can shorten your recovery and get you fully back on your feet. And, the recovery is often faster than you might imagine. Committing to these exercises, at the gym and at home, is the single most important component of successful long-term recovery. Each physician has a slightly different surgical technique, please check with your physician when you can begin each of these exercises.

Here are a few physical therapy basics that I always share with my knee replacement patients:

• Get started early. Don’t be afraid of the post-surgical pain and discomfort. Lean into it, knowing the rewards will be worthwhile. Physical therapists are experts at recommending or modifying exercises so you feel comfortable doing them. The sooner you get started, the more successful your recovery will be.
• Follow the directions. It’s easy to pay attention and work hard during a session, but you’ll also be given homework for replicating exercises at home or the gym. It’s crucial that you follow your doctor’s and physical therapist’s instructions for the best results.
• Focus on the outcome. In a year or less, you can rid yourself of the daily pain and discomfort that led you to choose knee replacement. But, you have to do your part and work hard. The most essential part of recovery are your exercises. You’ll strengthen the key supporting muscles that take pressure off the knee joint, and your whole body will thank you for it.

The regimen I choose for each patient is always customized. However, it’s always built around these range-of-motion and functional exercises, or those that help you do everyday tasks at home.

Stationary bike (ride or stretch)

Riding a stationary bike is the basis for every course of physical therapy after knee replacement. It’s the gold standard for achieving and maintaining range of motion. I generally prefer recumbent bikes, which have a seat with a back rest. The seat should be adjusted so that your knee is just slightly bent when the pedal is pushed its farthest. If you can’t move the pedal all the way around at first, push your leg forward as far as you can and hold for 10-15 seconds, then reverse and bring your leg backward, again holding the stretch for 10-15 seconds. The idea is to progress to the point where you can ride with full range of motion every day for 30 minutes. If you don’t have access to a stationary bike at home, I recommend joining a gym. 

Step flexion stretches

Step flexion stretches also are essential for range of motion. From a standing position, raise the leg you had surgery on (surgical leg) onto a step, and lean forward into the stretch, holding onto the wall or a railing for balance. Hold the stretch for roughly 30-40 seconds, and repeat 3-4 times. These should be done 1-2 times a day or as recommended by your therapist or physician. Remember, scar tissue forms early in the recovery process. These exercises will ensure the scar tissue molds in a way that allows you to fully bend and extend your new knee.

Heel slides

Lie on your back on a bed, even if it’s soft. Bend your non-surgical knee so you’re more comfortable and put less strain on your back. Warm up gently by slowly sliding your surgical knee towards your bottom, holding a few seconds, and then returning your leg straight to a straight position. Do about 5 of these warmups. Once you’re warmed up, I would use a dog leash, bath towel, or a stretching strap to help with the heel slides. Secure one of these items around your foot on your surgical leg. You can place your foot in a pillow case and then use it to pull and slide your leg. These items will help give you extra range of motion when you can’t slide your heel any further due to weakness, stiffness, or pain. Start in the same position as the warm up, slide your heel towards your bottom, and go as far as you can. Once you can’t go any further, use one of the aids above to pull your foot towards you. The extra force provided by your arms will help you get an extra range of motion that you might not get otherwise. Generally, I have patients repeat this 10 times, holding each heel slide for 10 seconds. I would recommend doing these as much as every hour.

Step ups

For this exercise, your physical therapist will help you choose an appropriate step, box, or stair height to start. You might begin with a 4-inch or 8-inch height, for example, and increase to the typical 10-12-inch stair height found in homes. To do the exercise, step up with your surgical leg, and then follow with the nonsurgical leg. Step back down with your nonsurgical leg, leaving your surgical leg on the step, then step back up with your nonsurgical leg, and so on. Repeat this for 2 sets of 10, 1-2 times a day or as recommended by your therapist or physician. Besides helping you conquer a flight of stairs, this exercise will strengthen your quadriceps (front of the thigh) and hip extensors (hip muscles). Those muscles give you support for all kinds of daily activities, from gardening to grocery shopping.

Step downs

With step downs, you begin with both legs on the same step. You keep the surgical leg on the step, and step down and forward with the nonsurgical leg. You then step backward up onto the step with the nonsurgical leg. As with step ups, aim to repeat this for 2 sets of 10, 1-2 times a day or as recommended by your therapist or physician. It’s harder on your joints to go down stairs than to climb them, so you  definitely don’t want to skip this exercise.

Wall squats

After surgery, assisted squats are more appropriate than freestanding squats. Start by leaning against a wall with your feet shoulder-width apart and about 12-18 inches from the wall. Slide as far down and back up the wall as is tolerable. As with all squats, your knees should never bend past your ankles. Most people can’t achieve a full 90-degree squat right away, but a 20-30 degree bend is a great way to get started. Aim for 2 sets of 10, several times each day, but be mindful of your level of fatigue. You may find you can’t do as many right away, but you will get better as you work at it. If you’re not feeling fatigued after doing 20, try for 30. Squats work muscles that ensure quality of life at home, as sitting on and rising from a chair or the toilet depend on them.

Single leg stance

This exercise is crucial for balance and coordination. Find a safe area where you can hold on to a wall, sturdy furniture, or a rail or banister. From a standing position, leave your surgical leg on the ground and raise your nonsurgical leg (a slight knee bend/lift is fine). Try to hold this position for 5-10 seconds at first, and repeat 10 times. To challenge yourself, only hold on to your support as lightly as is needed to keep you from falling. In later sessions, you might find you can hold it 5 times for 20 seconds, or 3 times for 30 seconds. If you work hard, you'll get there.

Virtua Physical Therapy and Rehabilitation offers convenient locations throughout South Jersey, as well as telehealth visits. Call 888-847-8823 to learn more.