The Best Way to Do Lunges Without Hurting Your Knees

Knee Flexion

Avoid going too far down on a lunge and bending your knee beyond 90 degrees. If you drop your weight beyond that degree of knee flexion, you can injure the cartilage located between the bones of your knee joint. Tears in this cartilage can cause your knee to click or swell. Athletes recovering from knee injuries will limit the range of motion of a lunge or a squat to an even shorter arc than 60- to 90-degree angles, according to “High-Performance Sports Conditioning” by Bill Foran. Also, check to see if your calves are perpendicular to the floor. If they’re angled forward or on a diagonal, then you’re putting too much stress on your knee joint. Draw your hips back slightly to straighten your calves.

Good Form

Focus on executing a lunge with correct form. A common mistake is to lean too far forward in the lunge, which pushes your knee past your foot and overloads the joint. When performing a lunge, lower and lift your weight on a vertical trajectory as opposed to shifting your weight forward and backward. Align your front knee directly over your ankle. Use your back foot only as a balancing aid. By keeping the heel of your back foot slightly lifted throughout the exercise, you can distribute your weight evenly between your knees. Another mistake is to allow your front knee to either point outward or buckle in. In both cases, your knee twists. Perform lunges slowly and with controlled motion. Bouncing up and down like a jack-in-the-box can strain your joints.

Back Lunges

You can avoid some of the alignment mistakes made doing forward lunges by performing back lunges first. Instead of stepping forward and sinking your weight down, you step back and lower your body into the lunge. By performing the back lunge, you can resist the urge to reach too far forward and flex your knee beyond 90 degrees. Once you grow comfortable with a back lunge, you can progress to the front-to-back lunge, which is an exercise that alternates between front and back lunges.

Minimizing Risk

Perform a general warm-up before you perform lunges. For example, ride a stationary bike or jog for five to 10 minutes to raise your body temperature. If your hamstrings are tight, do a dynamic stretching exercise, such as leg lifts, in which you move your leg muscles slowly and repetitively through a comfortable range of motion. You can also perform an isolation exercise, such as leg extensions, to work your knee flexion before you undertake lunges. As you grow older, the cartilage in your knees wears down. If you exercise regularly, the cartilage can also atrophy and soften. Avoid doing too many lunges if you find your knee clicking or grinding.