Getting a quality ab and butt workout after an injury to your knee may seem like an impossible task, but it isn't. Many low impact exercises target these muscle groups while placing little to no strain on the knee joint itself. Using a few simple modifications, these exercises strengthen the butt and stomach muscle groups without the risk of further knee injury.
Posterior Pelvic Tilt
This exercise targets your transversus abdominis muscle. This important muscle sits deep in your abdomen and provides stability to your back.
How To: Lie on your back with your knees bent and your feet on the floor. If your injured knee is unable to bend to this angle, straighten the legs slightly to find a more comfortable position. Draw in your stomach as you allow your pelvis to rock back and your spine to flatten against the ground. Breathe normally as you do the exercise. Maintain this position for 5 to 10 seconds and then relax.
Pikes work the rectus abdominis, a large muscle in your abdomen that helps to flex your body forward, while placing minimal strain on your knees.
How to: Place your hands on the floor beneath your shoulders and your feet on an exercise ball. Keeping your elbows and knees straight, lift your butt in the air and roll the ball forward. Hold this upside-down "V" for 5 to 10 seconds before rolling back to the starting point.
Prone Hip Extension
Hip extension is a great way to activate the gluteus maximus muscle without subjecting your injured leg to undue stress.
How To: Lie on your stomach with your legs straight. Place a pillow under the painful leg if this position is uncomfortable. Without bending your knee, lift your right leg in the air as high as you can without allowing your right hip to lose contact with the ground. Keep the leg in the air for 5 to 10 seconds before lowering it down again. After a set with the right leg, repeat the exercise on the left side.
Planks provide a great abdominal workout without requiring you to bend your knees.
How To: Lie on your stomach with your forearms under you and your elbows at shoulder level. Again, a pillow may be placed under your knees if it is more comfortable. Lift your body off the ground onto your toes until your spine forms a straight line with your legs. As you do this, keep your abs engaged and try to avoid letting your back arch. Hold this position for 10 seconds and then lower your stomach to the ground again.
Swiss Ball Bridge
Bridging with a ball adds instability to an already challenging butt exercise.
How To: Lie on your back with your arms by your side and your feet on an exercise ball. Keeping your knees completely straight, squeeze your stomach and lift your butt in the air. After a count of 5 to 10 seconds, return to the initial position. If this becomes too easy, add to the challenge by crossing your arms over your chest as you bridge.
Side planks active the oblique muscles, which wrap around your abdomen and assist with motions like side bending and rotation.
How To: Lie on your side with your legs on top of each other and your knees straight. With your elbow bent at a 90-degree angle and placed directly beneath your shoulder, lift your bottom hip in the air. When your spine is straight, hold this position for 10 seconds before lowering back down again. After a set, flip over and repeat the exercise on your other side.
Guidelines and Precautions
For a proper butt and abdominal workout, complete two to four sets of eight to 12 repetitions of each of the exercises. This routine can be done two to three times per week. Exercises that cause additional knee pain should be stopped as they may worsen your condition. Be sure to speak with your doctor if you have any questions about beginning an exercise regimen after your injury.