Because of their close proximity and their tendency to work together, the psoas major and iliacus muscles are commonly referred to as the iliopsoas. The two muscles are located at the front of the hips, originating at the top of your pelvis and sides of your spine, and run across the front of your hips where they insert at the top of your lower leg bone. Exercises that strengthen the psoas major and iliacus require hip flexion, which involves lifting your leg.
Before starting, warm up for five to 10 minutes to prepare the muscles for exercise. Walk, jog or jump rope for a few minutes to get your blood flowing and increase body temperature, and then perform an array of dynamic stretches. High knees, leg swings and body-weight squats will help prep your hip flexors. The only equipment you'll need is an overhead bar, which you can find at a gym or a playground, and an exercise mat.
These psoas major and iliacus exercises utilize your own body weight as resistance. As you develop strength, you can increase the difficulty of many of the exercises by wearing ankle weights or squeezing a medicine ball between your legs. For each exercise, perform one to two sets, with 15 reps in each set, and rest about a minute in between sets. Incorporate the workout into your training regimen two to three days per week and on nonconsecutive days.
Beginning Hip Flexor Exercises
Begin building strength in your psoas major and iliacus with the lying leg raise and scissor kick. Keeping your legs straight, lift one leg up off the floor until it's straight up in the air. Return it toward the floor, but stop just short of touching the floor before going right into the next rep. After you're done with one set, switch legs. You can also do the exercise while lifting both legs at a time.
To perform scissor kicks, lie on your back on an exercise mat with your legs straight. Place your hands under your lower hips to protect your spine. While keeping your legs straight, lift one so that it's at a 45-degree angle and lift the other so it is about an inch off the floor. Alternate the positions of your legs while moving them simultaneously. Continue moving your legs back and forth until you finish 15 reps.
More Advanced Options
Kick up your hip flexor workout a notch by incorporating a hanging leg raise and a modified glute bridge into your workout. You'll need an overhead bar to hang from to perform the hanging leg raise. Reach up and grip the bar with both hands so that they're positioned shoulder-width apart and your palms face forward. Raise your legs and bend your knees to bring your thighs up to your torso. Straighten your knees and hips to return to a full hanging position and then repeat. Try to avoid swinging when you're performing the exercise so that you're not using momentum to help lift your legs.
The glute bridge exercise primarily develops your glutes and quadriceps, but by adding a tennis ball, you can challenge your psoas major and iliacus even more. Bend your knees while lying on the floor. Place a tennis ball at the fold in your hip and then lift one leg with the knee bent so that you're holding the ball in place by squeezing it between your upper thigh and pelvis. While you're holding the ball with the leg, lift your hips off the floor by pressing your heel of the other leg into the floor. Pick your hips up as high as you can and then lower to the floor.