An ACL tear or rupture can be one of the most devastating knee injuries, because it incapacitates the knee and affects range of motion. Exercises after ACL surgery are designed not only to strengthen the knee, but to build muscle in the quadriceps and hamstrings, the two major muscle groups that support the knee. The exercises are usually prescribed by a doctor through a physical therapy regimen.
Quad sets are likely one of the first exercises your doctor will have you do after ACL surgery, according to the University of Minnesota. Perform a quad set by sitting on the ground with your injured leg extended and your other leg bent so your foot is flat on the ground. Put a small rolled-up towel under your injured knee for comfort. Press your knee down towards the floor as hard as you can without feeling major discomfort. Hold for six seconds, then rest for up to 10 seconds. Repeat up to 30 times multiple times per day, or as prescribed by your doctor or physical therapist. This will tighten your quadricep muscles, the ones on the top of your upper leg.
Standing Hamstring Curls
Once you’ve progressed in your ACL rehabilitation program, your physical therapist will likely have you progress to weighted exercises. One of the most common is the standing hamstring curl. For this exercise you will need a cable weight machine. Attach a cable to your injured leg and stand straight. Hold onto the weight machine for balance. Bend your knee slowly so that your foot curls behind you. Hold the curl for 2 to 3 seconds, then return to the starting position. Perform 30 repetitions at a time with a weight recommended by your physical therapist or doctor.
Straight Leg Raises
Another exercise done with a cable weight machine, straight leg raises help develop strength and build muscle in the quadriceps. Attach the cable to the ankle of your injured leg and stand with your back to the cable machine. Hold onto something or find a partner to help you brace yourself and keep your balance. Lift up your injured leg, keeping your leg straight, as far as you can. Hold at the top of the leg raise for two to three seconds, then lower your leg for one repetition. Repeat this exercise 30 times for one set, or as advised. Your physical therapist will likely have you do multiple sets per day, sometimes up to 10 times.