Pelvic tilt

The pelvic tilt, an essential movement in the functioning of the pelvis, plays a crucial role in maintaining balance and body posture. It is divided into two distinct types: the anterior pelvic tilt and the posterior pelvic tilt.

Anterior pelvic tilt, also called forward flexion rotation, is characterized by a short arc of the pelvis around the hip joints. In this movement, the trunk is kept straight and stationary, allowing the pelvis to move naturally. This forward rotation results in an extension of the lumbar spine, thus promoting an increase in lumbar lordosis. Lumbar lordosis is the natural curvature of the lower spine, and its optimal maintenance is crucial for a healthy and balanced posture.

Conversely, posterior pelvic tilt, characterized by backward extension rotation, involves a short arc of the pelvis that flexes the lumbar spine. In this movement, the pelvis tilts backwards, thus reducing lumbar lordosis. The lumbar spine, which naturally has a concave forward curvature, undergoes flexion due to this backward rotation. This results in a decrease in lumbar curvature, which can have implications for posture and body stability.

These two types of pelvic tilts are crucial in the dynamics of daily body movement. Anterior pelvic tilt frequently occurs during movements such as walking, running and even simple standing. It helps maintain body balance while promoting a stable vertical posture. On the other hand, the posterior pelvic tilt is often used during movements such as leaning backwards, flexion or during prolonged sitting.

The importance of understanding these pelvic movements lies in their influence on overall spinal health and the prevention of musculoskeletal disorders. An imbalance in the pelvic tilt can lead to muscle tension, lower back pain and long-term postural problems. Thus, proper awareness and maintenance of these pelvic movements is essential for promoting healthy posture, preventing injuries, and maintaining optimal functionality of the body on a daily basis.

Anterior pelvic tilt  is a short arc forward flexion rotation of the pelvis around the hip joints, with the trunk held straight and stationary, naturally extends the lumbar spine and increases lumbar lordosis.

Posterior pelvic tilt  is a short-arc backward extension rotation of the pelvis that flexes the lumbar spine and therefore decreases lumbar lordosis.

Anterior and posterior pelvic tilts of the pelvis and their effects on the lumbar spine. (A and C) Anterior pelvic tilt increases lumbar spine lordosis. This action tends to move the nucleus pulposus forward and reduce the diameter of the foramen. (B and D) Posterior pelvic tilt flexes the lumbar spine and decreases lumbar lordosis. This action tends to move the pulp nucleus posteriorly and increase the diameter of the foramen.

According to Neumann DA: Kinesiology of the musculoskeletal system: foundations of physical rehabilitation, ed 2, St Louis, 2010, Mosby, Fig. 9.63.

Flexion

• Migration of the nucleus pulposus backwards, towards the neural tissue
• Increased conjugation gap
• Transfers the load from the apophyseal joints to the intervertebral discs
• Increases tension in the posterior connective tissues (ligament flava, apophyseal joint capsules, interspinous and supraspinous ligaments, posterior longitudinal ligament) and the posterior margin of the annulus fibrosus
• Compresses the anterior surface of the annulus fibrosus

Extension

• Migration of the nucleus pulposus forward, away from neuronal tissues
• Reduction of the conjugation gap
• Transfers the load from the intervertebral disc to the apophyseal joints
• Decreases tension in the posterior connective tissues and in the posterior margin of the annulus fibrosus
• Stretches the anterior side of the annulus fibrosus

Therapeutic prescription

Posterior pelvic tilt  : A patient with stenosis (narrowing) of the intervertebral foramen will be encouraged to maintain their pelvis in a more posteriorly inclined position

• The rocker flexes the lumbar spine, widening the foramen
• Reduction of painful symptoms caused by compression with an exiting nerve root.

Anterior pelvic tilt:  An individual suffering from a posterior herniated disc, on the other hand, will be encouraged to maintain their pelvis in a more forward tilted position, maintaining or increasing the lordosis of the lumbar spine.

• This posture may help prevent posterior migration of the nucleus pulposus, limiting or preventing pressure on neighboring neuronal elements.