Though your spine normally curves from front to back, weak or tight muscles can cause too much curvature, resulting in bad posture, pain and injury risk. Your hip flexors are muscles on the front of your thighs. If your hip flexors are tight or your abs are weak, this can cause an increased curvature of your lower back, a medical condition called hyperlordosis, which is commonly shortened to lordosis. Strengthen your abs with situps in addition to stretching your hip flexors to prevent or correct hyperlordosis.
When the hip flexors are strong relative to your abs, the top of your pelvis is tilted forward. This sticks the belly out and curves the lower back inward. Where tension is normally spread over the entire back, lordosis causes pressure to concentrate on a few vertebrae where the back curves inward the most. This can cause lower back pain, poor posture and increase your risk of back injury.
Your normally think that crunches will strengthen your abs, although much of the work is done by the hip flexors pulling the hips forward. SportsInjuryClinic.net advises strengthening abs, hamstring and glutes, and stretching hip flexors and the erector spinae of your lower back, to correct hyperlordosis. According to kettlebell trainer Pavel Tsatsouline, many people suffer from hyperlordosis because people are either physically inactive or training their abs incorrectly.
Tsatsouline recommends a situp variation developed by World Health Organization consultant Dr. Vladimir Janda, a renowned back specialist. The Janda situp involves placing a weight behind your heels while performing a situp. Pressing the weight between your heels and butt will disengage your hip flexors, allowing you to focus on your abs and obliques. The weight, such as a kettlebell or pile of textbooks, should be large enough that your knees are bent comfortably, and heavy enough to remain in place. Hip flexors stretches gently push your leg backward, where your thigh is behind the center of your hip. Start gently and never move into pain.
Though hyperlordosis can arise from weak muscles, treat it as a medical problem rather than a fitness problem. If you already have hyperlodosis, or other back problems, consult your doctor before beginning new exercise programs. While exercise is an important part of improving back health, exercising with back problems places you at a much higher risk of injury. Your doctor can help tailor exercises to your individual medical and physical condition.