Dr. Clint Woo, DPT, PT
Knee Hyperextension and What To Do About It
Updated: Sep 2, 2020
Whether you are a teenage athlete or someone who has recently experienced a stroke, knee hyperextension can really ruin your day! Constantly over-extending the knee can cause pain, swelling, instability, poor muscle firing, stiffness, and general fear of standing/walking! This phenomenon can occur from a variety of reasons that make it so common such as sports injuries (stopping too hard or an impact leading to damage of the ligaments (ACL, PCL, LCL, MCL), wear-and-tear, muscle imbalance between knee extensors (quads) and flexors (hamstrings) like after a stroke, too much weight on the leg, etc.
The first step is to bring "awareness" to the joint. This concept ties in with people often saying "it just hyperextends without warning"! In other words, people who hyperextend their knee often can't tell when it is about to give out. Start off by standing in front of a mirror and slowly go in and out of a soft knee bend while contracting both the quads and hamstrings. The mirror is excellent for letting you know what position your knee is in when you feel different tensions at different points of knee bend. You can mess around with looking at your knees from a front view and side view as well.
Then we should strengthen the weaker hamstrings. This can be achieved with slow standing butt kicks with a resistance band wrapped around the foot/ankles. You can also do a bridge while on the bed or floor. If your experience back pain, then either don't lift your bottom as high or discontinue the exercise all together. If the bridging feels like it is not engaging your hamstrings at all, then slide your heels a few inches away from your bottom. If the bridges are making your hamstrings spasm, the pull in the heels toward you.
If you are having trouble activating the hamstrings outside of exercise, then kinesiotaping might help you with that by bring awareness to it as you feel a gentle tension along where the desired contraction should be (consult a PT or physician prior to use). The picture below is for taping the front of the knee whereas I would be recommending the back just FYI.
Improving the motor control at the quads is also important. We can do activities such as sitting from a low surface with the stronger foot slid a few inches away from you. This will challenge the weaker leg more.
Finally if the knee has completely no control, you can use a brace to keep it from buckling either direction. Be careful though as this is meant to be temporary for the most part as you don't want to rely too much on it. Using a knee brace instead of building up your knee control/strength leads to more issues down the road from disuse. Now in the situation that a professional has told you the knee will most likely not gain return of its stability function, then a knee brace may be used for long term.
Recovery can take time and as someone who has had to both treat myself and others for this issue, understand that it takes daily work! You got this!
This is not intended to be professional advice. Please speak with a physician or physical therapist. Invest in yourself by bring the physical rehab to your home! We at Woo Physical Therapy and Wellness are proud to serve the Anne Arundel, Howard, and Prince George's counties in-home and online anywhere in the U.S.A. for wellness!!