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If you’re prone to knee injuries, weak hip adductors might be to blame. “These inner-thigh muscles are very important for a lot of different athletic motions, but one of the key functions of these muscles during running is stabilizing the pelvis and knee,” says Kevin Laudner, Ph.D., a certified athletic trainer and professor of kinesiology at Illinois State University. “When working in concert with other muscles, the adductors keep the hips and knees balanced, creating a natural alignment during these athletic motions.”
Weakness in hip adductor muscles can cause changes in biomechanics, resulting in decreased athletic performance and increased risk of injury. Strengthening these muscles, however, is not complicated. In a study published in The Journal of Sport Rehabilitation, Laudner and colleagues identified some simple exercises to best activate the hip adductors.
“Our study showed that these exercises produced the highest levels of muscle activation, so you know you are getting the most out of your adductors,” Laudner says.
For ideal results, he suggests triathletes perform the below exercises in three sets of 12–15 repetitions, 2–3 times per week.
How to tell if your hip adductors are in balance
Lie on the floor on your side, placing weight on your hip. Move the opposite (upper) hip and leg so it is resting behind the lower leg. Lift the lower leg off of the floor. If this is easy and doesn’t cause any pain, try to add some resistance with a resistance band, ankle weight, or force applied by a friend. Repeat on opposite side. The amount of strength noted should be equal.
Squats can also be a telltale sign of hip adductor weakness, says Laudner: “If your knees point outward during a squat, then there could be an imbalance of hip strength with your hip adductors being weaker than the reciprocal hip muscles (hip abductors).”
Exercises for weak hip adductors: Sumo squats
Exercises for weak hip adductors: Ball squeezes
Exercises for weak hip adductors: Rotational squat
Exercises for weak hip adductors: Standing adduction on a Swiss ball
Exercises for weak hip adductors: Side lunges