Upright Posture Controlled by Brainstem and Cerebellum

Members do not see these Ads. Sign Up.

Rothbart's Neurophysiological Postural Model

How the foot, brainstem and cerebellum interact to maintain upright posture

The Neurophysiological Postural Model (which I first described in my book, Forever Free From Chronic Pain), can best be understood by observing the function that the foot’s mechanosensory receptors play in postural maintenance.

All feet have millions of mechanoreceptors (e.g., Meissner and Merkel) embedded in the plantar dermis. When we walk or stand, hundreds of thousands of these receptors are compressed and activated, generating a coded pattern referred to as the Foot’s Sensory Feedback (FSF). This FSF is transmitted to the brainstem.

The brainstem has a hard-coded pattern it expects to receive when a person is walking on level ground—this pattern corresponds to the typical center of pressure generated by a plantargrade (normal) foot on a flat surface.

If a person walks on an inclined surface, the sensory feedback from the foot no longer matches the brainstem’s expected pattern. In response, the brainstem redirects this sensory information from the foot to the cerebellum. The cerebellum then processes the input and generates the necessary postural adjustments to help the person maintain a stable, upright posture despite the slope.

In essence, the brainstem handles routine, expected walking patterns, while the cerebellum acts as a dynamic “corrective system” when the sensory input differs from the norm.
​

The PreClinical Clubfoot Deformity alters the CoP Patterns

When walking on a level surface, a twisting foot, the Preclinical clubfoot deformity, shifts the center of pressure (CoP) patterns medially. This medially shifted CoP pattern is transmitted to the brainstem.

The brainstem compares this incoming sensory information with its hard-coded pattern for level-ground walking. Detecting a difference, it redirects the CoP sensory information to the cerebellum. The cerebellum interprets this sensory input as walking on an inclined surface, automatically shifting the posture forward.

This explains why patients' born with a PreClinical Clubfoot Deformity almost invariably have a forward lean posture.