Lunges are effective strength-building exercises if performed properly, helping improve the musculature of the low back, hips, abdomen and legs. However, doing any kind of exercise can put you at risk of back pain or injury, especially if you're out of shape or not used to exercising. It's important to learn the proper techniques for lunges and to understand what may be contributing to your back pain.
Certain exercises, including lunges, can help realign the pelvis, strengthen associated muscles and correct an exaggerated curve in your spine known as the anterior pelvic tilt. When done correctly, lunges stretch the tightened hip flexor muscle and strengthen the weakened gluteus muscle. The correct position for lunging is with the back straight and the shoulders aligned directly above the hips. With one foot behind the other, pointing straight ahead, the hips are tucked under to reduce the lower back curve. Both knees are bent at the same time, dipping downward without touching the floor. The front knee should remain directly above the ankle, not moving forward.
Anterior Pelvic Tilt
The anterior pelvic tilt occurs when the pelvis is tilted forward, creating an exaggerated curve in the back. The stomach protrudes forward contributing to an imbalance in the muscles in the pelvis and hip area. Caused most frequently by sitting at a desk for extended periods, the hip flexors and gluteus muscles become misaligned pulling your pelvis forward and causing the anterior pelvic tilt. The result is often lower back pain. Doing lunges is one type of effective back strengthening exercise when done properly.
Leaning forward during the lunge can prevent you from getting the fullest benefit of the exercise and may cause added back pain in the lumbar region. If you don't tuck the hip under correctly, you may end up arching your back, which will only aggravate the anterior pelvic tilt and cause pain. Additionally, the front knee must be kept from moving forward during the lunge; when that knee moves forward it causes you to arch your back, encouraging pain in the lower back. When the lunge is done correctly, it should strengthen your back and prevent pain.
If doing regular lunges hurts your back regardless of which ones you do, they can be modified to possibly relieve pain. If you continue to experience pain, choose a different version of the modification or try another exercise entirely. Assisted lunges allow you to hold onto a chair or the wall to help you keep your balance, concentrate on holding the right position and avoid hurting your back. Or you can use a smaller range of motion, only bending your knees halfway. This may help avoid arching your back or pushing your leg forward too far, causing pain. Another modification is to raise the front foot into an elevated position on a footstool or other raised platform. This position will help take some of the pressure off your knees and provide you with better control, enabling you to avoid arching your back.