Connection Between a Short Leg and an Upper Cervical Subluxation
It is often clinically noted that when there is an upper cervical subluxation present, a discrepancy in leg lengths is observed as well. It is also recognized that when the upper cervical subluxation is adjusted, the legs will often balance out. How and why a leg length discrepancy is associated with an upper cervical vertebral subluxation is based on neurophysiological and biomechanic compensations.
While an anatomical short leg is possible, the majority of short legs observed are physiological in nature. Some functional cause is creating a short leg effect not a structural variance. In Chiropractic, our focus is on the neurophysiology and biomechanics of the spine and how it can effect all other areas of the body is some way, shape or form.
A vertebral subluxation occurs when a spinal bone loses its normal position to one or both of the corresponding segments and interferes with nerve system communication. This malpositioning negatively effects proprioception. Proprioception is how the body communicates with the brain its position in space.
When the vertebral bone subluxates, it effects all the muscles, ligaments and structures that attach and associate with it. In general, when the upper cervical spine subluxates, it will laterally shift either left or right, move up or down and rotate either forward or backward. This in effect, causes the head to tilt out of balance, making the eyes unlevel.
When there is a subluxation, it will stretch fibers found in the corresponding muscles, tendons, facet joints and intervertebral discs. A vertebral subluxation disrupts four primary structures of proprioception. Receptors in these areas detect a change in static and dynamic positions. A disruption in the spine has been identified.
This message of disruption is then sent through nerve tracts up to the cerebellum. The cerebellum processes the abnormal stretch action. The cerebellum handles proprioception and motor control information. This information is then sent to the thalamus so the brain can integrate it. In general, the cerebellum tells the brain what is occurring in the body.
The information from the thalamus is then sent to the sensory cortex. The sensory cortex contains information about what should be happening in the body. At this point, the brain compares what should be happening in the body to what is actually happening in the body. If the information is the same, the brain considers this as normal and doesn’t send a compensation response to the body.
A subluxation creates a disruption between what is occurring in the body and what should be happening in the body. The brain must send a compensatory response through the motor cortex to “right the wrong.” The motor cortex sends a response through nerve tracts that travel through the brainstem.
The tracts receive constant messages from the cerebellum and cortex to help control the regulation of muscle tone, smoothness of movement, posture and balance. One tract in particular, the vestibulospinal tract, facilitates the contraction of postural muscles located in the low back, pelvis and lower limb region.
So when the brain interprets the upper cervical subluxation, it sends information through the vestibulospinal tract to activate muscles to help level the head and eyes. This causes a physiological shortening of the postural muscles. The result is a short leg.
When we correct an upper cervical subluxation through a specific chiropractic adjustment, the leg lengths can balance very quickly. This is because we are decreasing local muscle tension which is sensed by the fastest nerve fibers in the body. These nerve fibers can send neurological information between 80-100 meters per second, which is roughly the speed of traveling a football field in 1 second. The Chiropractic adjustment helps turn compensations into proper neurophysiological and biomechanical adaptations.
Jarek Esarco, DC, CACCP is a pediatric, family wellness and upper cervical specific Chiropractor. He is an active member of the International Chiropractic Pediatric Association (ICPA). Dr. Jarek has postgraduate certification in Pediatric Chiropractic through the ICPA. Dr. Jarek also has postgraduate certification in the HIO Specific Brain Stem technique through The TIC Institute. Dr. Jarek is happily married to his wife Regina. They live in Youngstown, Ohio with their daughter Ruby.
