Recently I discovered an article online which researched a simple but important aspect of spinal health and motion. In a study entitled “People with chronic neck pain walk with a stiffer spine” the researchers studied whether people with chronic neck pain walked with less rotation of their body.
Essentially when we walk our normal gait involves a certain amount of rotation of our spine, this is referred to as thorax-pelvis rotations. When we walk we also activate what is call the “cross extensor mechanism” this is the simple but important reflex that means when one of our arms move forward the opposite leg moves backwards, and vice versa. This reflex develops when we are babies learning to crawl. This is why it is important for babies not to skip the crawling step in their development, children who do so may have disruptions to their gait as they get older. This may impact on the efficiency of walking and running.
As we repetitively activate this cross extension mechanism, as our arms and legs rhythmically swing back and forth, the mid back (thoracic spine) twists (rotates), this is thorax-pelvic rotation. The thoracic spine is adapted to twisting and as it does it allows efficient and balanced transmission of energy form the limbs to enable propulsion.
In the study, a group of patients with chronic neck pain were assessed with motion capture technology to measure exactly how much their thoracic spine rotates during walking compared to normal controls. The examination was performed at 3 speeds, 3km/h, 5 km/h and self-selected, with the patients walking with their head in neutral and rotated to 30 degrees.
The results of the study demonstrated that overall, the neck pain group showed shorter stride length compared to the control group. Moreover, the patients with neck pain showed smaller trunk rotations, regardless of their speed of walking or their head rotation. In addition the difference in the amount of trunk rotation between groups became larger for the conditions of walking with the head rotated.
This lead to the researches concluding that people with chronic neck pain walk with reduced trunk rotation, especially when challenged by walking with their head positioned in further rotation, thereby further stressing their spine. Indicating that chronic neck pain not only affects the neck but also directly affects the thoracic spine and gait.
This kind of research is very important to clinicians. In day to day practice most patients don’t concern themselves with the current research into the exact biological mechanisms behind their care. For most people, as long as they feel better in your care, that is enough for a patient to continue to seek your advice and refer their friends to you over the years. However this kind of research does help clinicians like myself explain complex reflex mechanisms in simple, understandable and real world terms. It also helps us in Chiropractic explain how treatment of the spine does affect us holistically. It is easy to explain to a patient the benefits of Chiropractic when they have pain or disability, as we know that when that pain or disability resolves we know the patient has improved. It can be harder to explain concepts like “improved function” or greater efficiency or movement” this kind of research conducted by our Physiotherapy colleagues does provide tangible evidence for how the function of your neck can affect basic mechanical functions like walking. And as concluded by the researchers reduced rotation of the trunk during gait may have long-term consequences on spinal health that we are currently not fully aware of.
Falla D, et al. People With Chronic Neck Pain Walk With a Stiffer Spine. J Orthop Sports Phys Ther. 2017 Apr;47(4):268-277.