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Exercises to Strengthen Legs Before Knee Replacement Surgery & After

After knee replacement surgery, the quads lose about 60% of their strength…

Is a knee replacement in your future? You might think reducing activity, avoiding exercise or doing everything to “stay off of it” might be the best gameplan. However, studies show consistent strength training in the weeks and months leading up to knee replacement helps to make a quicker and full recovery compared to those who don’t.

In this article, we discuss what a knee replacement surgery is, how to approach strength training before and after surgery, as well as specific exercises to do. Ready to take care of those knees? Let’s get into it….

Jump to Topic:
What is a Knee Replacement?
Strength Training Before Surgery
Strength Training After Surgery
Exercises To Do Pre & Post Surgery

What is a Knee Replacement?

Simply put, knee replacements replace arthritic and deteriorated joints with well-functioning joints. Knee replacements are an increasingly popular surgery. In the last 15 years, knee replacement surgeries have tripled in the United States (Singh et al., 2019; Topp et al., 2009). Over a million knee replacement surgeries take place annually (Singh et al., 2019). The increase is a positive as these surgeries have immense value.

These surgeries, though, are not a given. Replacing an arthritic knee with a new knee doesn’t guarantee healthy function and movement. Some suffer from long-term knee stiffness, a lack of range of motion, pain, swelling, and instability after a replacement.

Many who go through surgery never fully regain their leg strength and functional ability (Skoffer, Dalgas, & Mechlenburg, 2014). Knee replacements also require a much longer recovery time than hip replacements (Skoffer et al., 2014).

Knee replacements can help solve a problem, but the outcomes are not certain.

How can positive outcomes become more certain? Strength training – both before AND after surgery – addresses critical side effects of knee replacement surgeries.



Strength Training Before Surgery

Focusing on the quadriceps is key when strength training before surgery. In the first month after a knee replacement surgery, the quadriceps on that leg lose about 60% of their strength (Mizner et al., 2005).

If you’re looking for a reason why some people lose function after a replacement and never regain it, this may be it. The quadriceps are a critical muscle group for regular movements, such as walking and standing.

Strength training before surgery helps in a few ways. First, it builds a better baseline level of strength. Therefore, post-surgery, the person has a better chance of still being functional after losing strength.

Pre-surgery training reduces pain in the arthritic joint (Topp et al., 2009). It also leads to better overall balance and functional ability after surgery (Topp et al., 2009). This could be explained by the addition of strength, which underlies balance.



Strength Training After Surgery

Strength training after surgery is also important for the knee joint’s long-term prognosis. In addition to the quadriceps, several other muscle groups lose strength following surgery:

  • hamstrings
  • hip adductors
  • hip abductors
  • tibialis anterior (front of the lower leg) (Skoffer et al., 2014).

Considering all of the impacted muscles, it’s easy to see why many never fully regain function and strength afterwards.

The main benefits of training are increasing the size of the quadriceps muscle size and strength (Skoffer et al., 2014). The muscle growth specifically is seen in the fast-twitch, or type 2 muscles. These muscle fibers are the main ones responsible for challenging movements, such as standing up quickly from a chair or walking up steep stairs.

Recommended Exercises Pre- And Post-Knee Replacement

With the quadriceps being the muscle group most impacted by surgery-induced strength loss, the quad muscles are the main focus of pre- and post-knee replacement training. The following are recommended quad-focused exercises:

  • Leg extension
  • Leg press
  • Sumo squats
  • Wall sits

If pain occurs during any of these exercises, try the following adjustments.

  • Reduce the range of motion. This applies to the leg extension, leg press, or sumo squats. Move through as large of a motion as you can while omitting the part where pain is present.
  • Move your feet. For the leg press, consider rotating your toes outward or move your feet higher on the footplate. For the sumo squats, move your feet further apart. For the wall sits, move your feet further from the wall.

As noted before, other local muscles lose strength following surgery. It’s important to train these muscles (hamstrings, hip adductors, and hip abductors) as well. Here are a few exercises to add into your workouts for pre- and post-operation:

  • Leg curls (hamstrings).
  • Dumbbell deadlifts (hamstrings).
  • Hip adduction. This can be performed with a machine or standing with resistance bands.
  • Hip abduction. Similarly, this can be performed with a machine or while standing with resistance bands.

To obtain the benefits of pre-surgery training, aim for a minimum of six weeks of exercise (Topp et al., 2009). Ideally, training will take place regularly for several months beforehand. Following surgery, be patient. Post-surgery benefits likely require several months to fully obtain (Skoffler et al., 2014).

After surgery, start with a light resistance in a minimal range of motion. Gradually build the range of motion and resistance over time. Pay attention to how the knee responds in the days following the session. These reactions will serve as a guide for determining whether or not to continue progressing at the same pace.




Knee replacements are an increasingly common yet challenging procedure. Many people never fully regain their strength and functional abilities after surgery. Strength training can help ensure a quicker and full recovery.

Pre-surgery training might be most critical. People who train for at least six weeks prior to surgery can reduce their short-term pain, plus benefit from better outcomes after surgery. Post-surgery training also helps with regaining strength and muscle.

The quadriceps are the focus of training, although other leg muscles should be trained as well. Start with a partial range of motion and light resistance. Gradually build both over time.


  • Mizner, R. L., Petterson, S. C., Stevens, J. E., Axe, M. J., & Snyder-Mackler, L. (2005). Preoperative quadriceps strength predicts functional ability one year after total knee arthroplasty. The Journal of Rheumatology, 32(8), 1533-1539.
  • Singh, J. A., Yu, S., Chen, L., & Cleveland, J. D. (2019). Rates of total joint replacement in the United States: future projections to 2020–2040 using the national inpatient sample. The Journal of Rheumatology, 46(9), 1134-1140.
  • Skoffer, B., Dalgas, U., & Mechlenburg, I. (2014). Progressive resistance training before and after total hip and knee arthroplasty: a systematic review. Clinical Rehabilitation, 1-16.
  • Topp, R., Swank, A. M., Quesada, P. M., Nyland, J., & Malkani, A. (2009). The effect of prehabilitation exercise on strength and functioning after total knee arthroplasty. PM&R, 1(8), 729-735.

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