By: by Amino Science
The muscles in your lower body should be some of the strongest ones you have since they're tasked with supporting your entire frame every day. However, if you have one or two damaged knee joints, or general knee pain that you don't want to exacerbate, how are you supposed to perform leg exercises to gain better strength? Never fear: it can be done, and we have the details on how to build leg muscle with bad knees right here.
The knee is the space where our femur (thighbone) and tibia (shinbone) meet behind the kneecap, with protective cartilage in between. It's known as a hinge joint—like our elbows, it is designed to bend one way and not the other.
The knee is also made up of ligaments and tendons that secure the bones in place, and muscles that run the whole operation. A "bad knee" could mean anything from degenerative joint disease, pain from a previous injury to the ACL or MCL, a tendency to overpronate when you walk, or a dozen other ailments that may compromise your range of motion.
If you're recovering from an injury, your best bet is to consult a physical therapist for knee-friendly exercises that won't further damage the knee or hinder your recovery. However, for some general low-impact leg exercises that won't put extra pressure on your knees, read on.
Here are some of the best exercises you can do to strengthen your legs without causing knee pain.

Simple yet effective, the kettlebell swing can help strengthen your hamstrings, glutes, and back muscles, all with low impact on your knees.
Another simple operation designed to challenge your muscles and not your knee joint: the banded lateral walk. By looping an exercise band around your thighs, you target your glutes and hip rotators without calling on the knees to do any heavy lifting.
An excellent warm-up stretch for the lower body, a few hip openers can also help stretch and ease your lower back.
It sounds more intimidating than it is: the deadlift. This is not a squat, but instead a lift that works your core muscle groups along with your glutes and hamstrings, and it can be done with a single barbell or a set of dumbbells (whichever you prefer).
Here's another variation of the deadlift, the single-leg deadlift. You'll know your own limits, so whether a single-leg lift is something you can't do to one or both knees, or it's something you need to work up to, it's nevertheless an extra step above the original that can build more strength.
To tone your glutes and strengthen your hamstrings, the donkey kick is a great exercise with leg extensions that can be done from a stable position on all fours (without having to balance your upper body).
This exercise utilizes your own bodyweight to strengthen your glutes and flex your hips.
These lower body workouts are options you can choose from to strengthen and stretch your legs while simultaneously guarding against knee injuries. If you experience too much soreness, remember that stretching and foam rolling your muscles and connective tissues both before and after a workout can cut down drastically on that delayed onset pain.
One of the best ways to avoid injury is to build up strength in the muscles around the joints, so by exercising safely, you increase your knee's stability and lower your risk for reinjury moving forward. Nutritional interventions, like supplementing with essential amino acids, can help strengthen the muscles around the knees even further.
In order to build and strengthen muscles, your muscle tissues must have a sufficient supply of essential amino acids to promote muscle protein synthesis, the creation of new muscle tissue as old muscle tissue is broken down. The body cannot make essential amino acids, which can only be provided through dietary means. Studies show that taking free-form essential amino acids increases the rate of absorption and is the most efficient way to boost muscle mass.
Amino Co scientists have formulated an essential amino acid supplement designed for muscle building alongside resistance training. You can learn more about how it can help you build leg muscle here.