How To Restore Normal Knee Function?

So you just hurt your knee and are in the in-between phase of seeing the doc and starting formal rehab. What do you do? The more motion you can restore before rehab starts, the more your PT will like you and the better your rehab will be. Below will be some exercises to restore normal knee function before you get to rehab. Before we start check here for knee fracture concerns, here for knee sprain concerns and here for meniscus concerns

The checklist for early rehab is as follows:

  • Restore knee flexion
  • Restore knee extension
  • Restore balance/proprioception
  • Begin isometric strengthening of quads and hamstrings

How Do I Restore Flexion After A Knee Injury?

I always have my athletes begin performing wall slides in the event that they lose knee flexion after a knee injury. I prefer to do these up against a wall so that gravity is able to assist and provide some overpressure to the end range of motion. Fully flex the knee into a position that is somewhat pain free (some pain, 3-4/10 is ok). Hold this position and then extend the knee back to the starting point. I prescribe athletes do this for time as opposed to a sets and reps scheme. 5 minutes for a single session works here. Perform twice a day as long as needed.

Slide the heel down the wall as far as tolerable and hold the position for 2-3 seconds

How Do I Restore Extension After A Knee Injury?

Knee extension is lost less than flexion and I’ve found I can restore full extension with quad
strengthening. However, if extension is lost a knee extension stretch can help. This can be done passively which makes it convenient. Again we get the assist from gravity here in addition to being able to add weight for more overpressure. This is most commonly done after surgery in the early stage of rehab, but if your ROM is limited, it will work acutely. This is also done for time. 5 minutes at a time, twice a day will suffice. ROM should be restored in a few days assuming your knee isn’t blown out.

    Put your foot on a chair or stool. This allows gravity to work on the posterior knee to help improve knee flexion

    How Do I Restore Balance After A Knee Injury?

    Next goal will be to restore proprioception (balance) If you are unable to weight bear then begin with weight shifting. Stand with most of your weight on the uninjured side and then shift your weight to the injured side as much as tolerable. Hold for 3 seconds and shift the weight back.

    Repeat this for 3 sets of 30 reps. The goal is to progress this to a complete single leg balance on the floor. I do not suggest ever balancing on a disc or Bosu ball. This environment does not exist in the real world and actually decreases the ability to recruit motor units. If you want to progress this and make it harder add weight.

    Stand on one leg and raise one knee to your chest.

    How Do I Strengthen My Quadriceps After A Knee Injury?


    The best way to restore strength to an acute injury is isometric training. The goal of these is to recruit motor neurons and restore normal control over the muscles as injury/inflammation can shut them down. Quad sets will get the quads reactivated. Restoring quad strength will also help to restore knee extension.

    Start in a long sitting position. The goal is to squeeze the quads and press the back of the knee into the floor. Hold the contraction for 10 seconds. Complete 10 reps of this twice a day, separated by 6 hours. This can be progressed by adding weight on top of the quad to force it to contract harder

    Squeeze your quads and try to drive your knee through the floor beneath you

    How Do I Strengthen My Hamstrings After A Knee Injury?

    The same concept applies here as it did to the quads above. Restoring normal muscle strength/motor recruitment will in turn improve your knee ROM. Yes, getting stronger will help you.

    Start by sitting in a chair, drive your heel into the leg behind you. Hold the contraction for 10 seconds. Complete 10 reps of this twice a day, separated by 6 hours. Most people get isometrics wrong. They perform them at a very low intensity. Isometrics should be done at close to 80% max effort; they should be difficult

    Squeeze your hamstring as hard as possible and try to drive your foot through the chair leg

    Again, this is EARLY, ACUTE management of a knee injury. The list is far from all encompassing but it will get you to a good starting place for successful rehab.

    As always, the caveat is that the acute phase can vary greatly. It can be anywhere from 2 days-2 weeks. Another caveat is that you may be able to avoid these exercises entirely pending how your body responds to injury