Chances are, you know about your gluteus maximus, the large muscle in your rear end. But have you ever heard of the gluteus medius, a very important muscle just beneath it? The relatively small fan-shaped muscle connects the pelvis with the outer thigh and is typically underdeveloped because most people do not know how to properly activate it during activity. But learning to do so is important because the gluteus medius controls the motions of your pelvis as you stand on one leg, which you need during running, jumping and kicking – all vital parts of exercise and sports. Strengthening the gluteus medius also helps maintain a stable pelvis during activities, which is important because an unstable pelvis creates excessive motion that can lead to knee, hip and lower back pain. To improve both the strength and endurance of your gluteus medius, try the following four exercises until your muscle gets too fatigued to maintain good form. Aim to complete these exercises on two to three nonconsecutive days each week. If you can complete 40 to 50 repetitions without tiring, alter the exercise to make it more difficult. A word of caution, since this is an underutilized muscle: Expect to be sore. You will likely have muscle pain for two to three days following the exercises. The good news is that some muscle soreness is an indication of improvement. Integrating these exercises into your typical strengthening routine will help you stay injury-free: 1. Clam Shells Lying on your side with your knees bent, glue your knees and ankles together. To start the exercise, open your top knee away from the one on the ground while keeping your pelvis stable. Lower your leg to its starting position and repeat 30 times, or stop when you become fatigued. Then, switch sides. For an extra challenge, try to complete these exercises with a resistance band tied around your legs. 2. Side Planks Lying on your side, prop yourself up on your forearm so that your body forms a straight line. Lift your hip and knees off the ground and hold for 30 seconds or until you fatigue. Complete the exercise on both sides. Keep your forearm under your shoulder to prevent undue stress on your joints. To create an extra challenge, try lifting your top leg a few inches above your lower leg. 3. Single Leg Squats Stand perpendicular to a wall so that one of your hips is pressing into it. Lift that leg off the ground with your knee bent at a right angle and your thigh pressing into the wall. At the same time, squat on the opposite leg. To get the greatest benefit, descend slowly and with control. To ensure you are using proper form, lead with your backside as though you are trying to sit down in a chair behind you. Also, be sure to prevent your squatting leg from caving in toward the wall, keep your knee straight ahead and don't let your knee jut out past your toes. 4. Fire Hydrants While on your hands and knees, lift one leg out to the side so that your thigh is parallel to the ground. Your knee should be bent to a 90-degree angle, and you should look like a dog relieving itself on a hydrant. Hold this position for one second and slowly lower your leg back to the starting position. Repeat 30 times on both sides, or until you fatigue. To avoid undue wrist or knee pain, keep your hands directly underneath your shoulders and your knees in line with your hips. Source