In spinal surgery and neurosurgery clinics stenosis is a common presenting symptom. A person over 60 years old complains of leg pain, typically worse in walking and standing and better sitting or bending forward.
In physiotherapy consultations many patients complain of troublesome leg symptoms, and it is unclear whether there may be nerve root involvement.
Severe leg pain occurs in two main age groups, the 30s and 40s with nerve root compression from disc prolapses and the 60s+ with nerve root compression from stenotic changes affecting the exit canals.
There may be another group however. People may hold themselves in a state of pseudo-nerve compression or joint discomfort due to the way we typically react to back pain and leg pain.
Overdoing the Lordosis
We adopt repeated patterns of posture to reduce our back and leg pain. One of the commonest is the active maintenance of a lumbar arch or lordosis for long periods and in most functional postures. And we carefully avoid flexing our back when we bend over, when we think we are at most risk of back injury.
An increased lumbar lordosis reduces the space available in the lateral nerve root canals and compresses the facet joints. Keeping the lumbar spine in end-range extension could increase the pressure on any nerve root or other sensitive structures in that area.
This is a functional stenosis, the symptoms maintained by continually contracting the spinal erector muscles, keeping the lordosis as much as possible and using a lumbar roll in a chair or a car.
Clinical observation indicates that encouraging a patient to relax their lumbar muscles and to flex forward can improve their symptoms. Backache from maintaining the lumbar extensor muscles in contraction can ease and then the leg symptoms also ease. With routine practice of lumbar flexion in a relaxed manner, the tightness or compression may be reduced enough to lessen leg symptoms.
A continuing focus on a structural tissue interpretation of symptoms and on MRI findings may be leading us to ignore this simpler and more functional issue. Holding the lumbar spine actively in extension could give nerve root-like symptoms and facet joint pain, referring pain to the buttocks, thigh, calf or foot.
Fear underlies the maintenance of lumbar extension. Fear of increasing the pain or aggravating whatever we think is going on anatomically. The McKenzie technique’s ideas on lumbar flexion causing posterior displacement of the disc and thereby worsening symptoms is relevant. Physiotherapists have taken this idea that keeping a lumbar lordosis at all times is vital and that lumbar flexion will worsen symptoms.
Our backs love flexion. Repeated lumbar flexion is good for our discs and our spine, increasing blood flow and relaxing the extensor muscles that are often in perpetual contraction. Encouraging people to perform lumbar flexion is an exercise in reducing the anxiety around doing something they feel would be harmful, or have been told not to do.
There is little evidence that keeping our back straight and bending our knees when we lift is necessary or reduces stress or risk to the lumbar spine. It may do the opposite.
Getting Out of the Way
We could get our of our own way. Our bodies know what to do when sitting, lifting, walking or lying, we just have to relax and let them get on with it. And our job as physios may be to facilitate this change and strip away the layers of protective beliefs and behaviours that many of us build up around our spines.
Many back and leg pain problems appear to be functional syndromes. They are maintained by the actions and behaviours of the person and not related to any particular anatomical abnormality. We should be able to help these people and avoid the ‘there’s x or y wrong with your back’ ideas that excessive concentration on anatomical features leads to. It’s not technical but it takes skill to do it.