Although knee and hip exercises usually work best from a standing, weight-bearing position, certain injuries and illnesses might impede your ability to stand on your feet. A variety of supine, prone and side-lying exercises can help you accomplish the same goals. In some cases, these lying exercises activate muscle groups that are difficult to engage while standing upright and are valuable even if you are not suffering from an injury.
Hip and Knee Relationships
The muscles of your hip include your gluteus maximus and medius, which extend and externally rotate your hip, and your hip flexors, abductors and adductors. When working as a unit, these muscles take responsibility for pelvic alignment and stability. Correct pelvic and hip alignment influence the alignment of your thighs, which in turn reinforces correct knee alignment. The safety and overall functionality of your knees depend on this relationship. Since mindless repetition of an exercise encourages sloppy form and alignment, choose two exercises that engage similar muscle groups and do fewer reps, but perform them sequentially.
Proper Muscle Sequencing
Training your hip muscles to activate in the most functional sequence improves the efficiency of the exercise. An article published in 2009 in the "Journal of Athletic Training" detailed the importance of engaging the gluteal muscles before the hamstrings. Apparently, women have a tendency to engage their hamstrings before their butt muscles. Since the glutes control your alignment, they need to take priority. Fortunately, the researchers reported that verbally cuing the subjects to contract their glutes altered the muscle-recruitment pattern.
Hip Extensions and Bridges
Lie prone with your legs straight. Contract your right butt muscle, press your pelvic bones into the floor and lift your leg a few inches from the ground. After 15 reps, roll over onto your back, bring your left knee toward your chest and place your right foot on the floor. Contract your right glute and do 10 one-legged spinal bridges, keeping your knee in a centered position. If you follow this series with quad-activating exercises, your hamstrings will stretch as your quads contract.
Knee Support Exercises
Located directly above your knee, your vastus medialis controls its alignment and stability. To work this muscle group, lie supine with one leg bent and the other leg straight. Contract the quadriceps muscle of your straight leg, and raise it to the height of the other knee. Lower it so that it's about 1 inch from the floor, and do 10 to 20 reps. If you have a resistance band, combine this exercise with a supine leg press. Wrap the band around one foot, hold each end with each hand, and press your elbows into the floor. Do a 20-degree bend of your knee, then straighten it against the band's resistance.
Your hip abductors move your leg away from your body's midline. Your adductors move it toward your center. Both of these muscle groups attach at, respectively, the outer and inner portion of your knee joint and play a key role in its stability and alignment. When lifting the top leg, side-lying leg lifts engage your abductors. After 10 reps, hold the leg in a lifted position, and do eight clockwise and eight counterclockwise circles. This activates your external hip rotators. Finish both sides, then lift your straight, bottom leg to work your adductors
Mobilize your spine and hips before performing these exercises, especially if you plan to do them first thing in the morning. Kneel on all fours, contract your belly and round your back like a cat. Return to the starting position and do 10 reps. Next, remain in the position, and slide your hips to the right and your ribs to the left. Switch sides and do eight reps. If you're pregnant, seek your doctor's advice before performing any exercises in the supine position. If you're suffering from postpartum depression, light aerobic activity, like walking and swimming, will enhance your mood, but seek your doctor's advice before starting any new program.