The pelvis moves back and forth between two positions: anterior pelvic tilt and posterior pelvic tilt. Whereas anterior pelvic tilt involves an exaggeration of the natural lumbar curvature (the S-shape of the spine), posterior pelvic tilt is a reduction in the natural lumbar curvature. Posterior pelvic tilt is the opposite of anterior pelvic tilt; the back of the pelvis has dropped, and the front of the pelvis has risen. Posterior pelvic tilt is not as common as anterior pelvic tilt. Like anterior pelvic tilt, posterior pelvic tilt is a postural deficiency, although a less common one.
The muscular imbalance in a posterior pelvic tilt is the exact opposite of an anterior pelvic tilt. Posterior pelvic tilt is caused by muscle imbalances in the core and legs. Muscle imbalances in the lower body can pull the pelvis down and under, flattening out the lumbar lordosis from the bottom. The typical muscle imbalance scenario that causes posterior pelvic tilt involves tight hamstrings, glutes and lower abdominal muscles coupled with weak quadriceps, psoas and lower back muscles. Tight muscles exert a pull on body structures that is not counterbalanced by the pull of weak muscles. The pelvis is pulled downward by the glutes and hamstrings and under by the lower abdominals. Posterior pelvic tilt is not as common as anterior pelvic tilt, or the titling of the pelvis downward in front, which is caused by the opposite muscle imbalance.
The most common cause of anterior pelvic tilt is muscle imbalance. People with anterior pelvic tilt generally have shortened, tight quadricep, erector spinae and psoas muscles. The erector spinae muscles run up the lower back along the spine. The psoas muscles are hip flexors; stretching from the thigh bone to the lumbar spine on each side, they work to lift the legs and rotate the thighs outward. The pull of these tight muscles will not countered by overstretched and weak hamstrings in the back of the thigh, gluteal muscles in the buttocks and deep abdominal muscles in the stomach. This causes the pelvis to tilt downward in front.
Muscle imbalances can be caused both by active and sedentary lifestyles. Individuals who exercise in an imbalanced way or participate regularly in an activity that taxes the body unevenly will develop muscle imbalances. Individuals who spend long periods of time sitting develop imbalances as well. The sitting position shortens the psoas and weakens the gluteal muscles. In addition to directly correcting muscle imbalances, preventing them in the future is an essential component of back pain treatment. If you are athletic, make sure to cross-train, working all muscle groups evenly. If sedentary, work on maintaining proper posture and gradually introduce a fitness plan into your routine daily.
Laurie Zerfass, CPT
With a Bachelor’s degree in Health, Behavior, and Exercise Sciences, Laurie graduated from the University of Delaware while concentrating on Fitness Management and Strength and Conditioning. Her passion for fitness and health stems from a background in sports, playing soccer at all levels including high school varsity, elite club teams, and at the collegiate level. Infusing her love for soccer into a career, Laurie has experience in sports conditioning, functional training, weight management, and nutrition.