The prime mover for internal or inward rotation of the hip is the gluteus minimus muscle, which is the smallest of the three glute muscles. Other muscles that assist in this action are the tensor fasciae latae, gracilis, pectineus and the adductors. All of these muscles are in the upper leg. Rotating your hip to bring your knee toward the center of the body is internal rotation, and exercises that involve this action target these muscles.
Seated cable hip internal rotation
Sitting to do a hip internal rotation exercise makes it so you don't have to challenge your balance as you work your hip muscles. You will need a resistance band and a chair, stool or bench to do this exercise. Tie a band around your ankles so that it forms a circle around your lower legs. You can wrap each end around each ankle twice to keep the band from slipping up your calf during the exercise. Sit with your thighs parallel to the floor and your feet on the floor, hips-width apart. Rotate your right knee inward, which also rotates your right ankle outward and pulls against resistance from the band. Work your left hip the same way.
Standing hip flexion internal rotation
The standing cable internal rotation exercise is more efficient for functional training but more difficult for maintaining your balance. Adding hip flexion increases the load to the gracilis, tensor fasciae latae and the adductors because all of these muscles assist with hip flexion too. The pectineus is a prime mover for hip flexion. To perform this exercise, tie one end of a resistance band around your left ankle and tie the other end to an object at floor level. You can also use a cable weight machine with an ankle cuff and a low pulley that is at floor level. Face away from the machine or object and stand on your left leg. Bend your right knee and lift it until your thigh is parallel to the floor. Twist your right knee inward and your right ankle outward to internally rotate your right hip. Lower your right foot to the floor. Repeat on the left leg.
Hip internal rotation stretch
The hip internal rotation stretch provides the opposite function as the other two exercises, but still involves inward hip rotation. Instead of strengthening the muscles that internally rotate the hips, this exercise elongates the other hip muscles to increase flexibility in the hips. Lie on your back with your arms crossed on your chest. Bend your knees with your feet flat on the floor. Drop your knees toward the center of your body until they touch. Let your feet slide apart and rotate the big toe side of your feet only to touch the ground. Hold for 15 seconds or more and do the desired number of reps.