By DR. CONWAY MCLEAN Pain, an unpleasant sensation, is part of the human existence. Everyone is subject to it at some point in their life. The why and where of pain naturally varies, with low back pain apparently the most common location. As to why so much discomfort is generated by this part of the body is the million dollar question.

Certainly there are numerous causes of pain from this region, with its complex anatomy and extreme physical tasks. But with the number of individuals afflicted, more than half of older adults according to some reports, this is a huge issue in both healthcare and industry. The hours of work time, the loss in productivity, make this an issue for millions of residents of this and every country.

Low Back Syndrome (abbreviated to LBS) is the term used to refer to this condition, whereby pain from this region is experienced on a regular basis. LBS is the leading cause of chronic disability. This is a problem many simply live with, although obviously undesirable. The character of the pain, referring to the type of discomfort, varies greatly but is often described as a dull ache, although many note a sharper pain.

Predictably there are numerous causes. It can be classified into those causes intrinsic to the individual (like how their feet, legs, hips line up or how your spine is aligned) or extrinsic reasons, like activities requiring the body to twist excessively. Our bipedal status, the fact we stand and walk on two legs, leads to many stressors to the structures making up this part of the body.

Numerous muscle groups pass through this region, as well as millions of nerve tracts. And there are the critically important vertebrae, the bones composing the spine, which can be subjected to minor, subtle trauma in the course of a normal day, absent any injury or inciting event.

As to why some people experience these problems and not others is a complex question. Many of these conditions develop over time, without a history of trauma. One’s occupation can be an obvious reason for degeneration of the discs or vertebrae. Carrying heavy objects, lifting, twisting, all are activities common in the work place but serve to place these structures under undo stress.

Some of the more frequently provided explanations for LBS are muscle or ligament strains. Due to the physical challenges of keeping the human body upright and mobile, pain may develop from these structures via simple “wear and tear.” And yet, the amount of forces exerted on these structures will vary greatly depending on such items as body weight, skeletal alignment, occupation, and, of course, hereditary factors.

One structure frequently impacted by the forces resulting from our upright posture are the fibrous discs separating the bones of the spine, a condition labeled appropriately degenerative disc disease. Sufficient bone loss can lead to collapse of one the bones of the spine and this will generally lead to discomfort of some sort although, once again, symptoms vary. Not only can this decrease the individual’s height, the altered shape means the bone won’t fit correctly in its space and this will typically impair function.

But there are still many other causes. Degenerative changes to a facet, one of the small joints separating the vertebral bodies, is a reason for recurrent low back pain. Another, although less frequent, is an inappropriate connection forming between two neighboring vertebra termed spinal stenosis.

Both the disc problem and a compression fracture of a vertebral bone can lead to a pinching of one or more nerves exiting the spinal canal. The pain of a nerve entrapment, termed a radiculopathy when referring to the nerves exiting the spine, is characteristic and often described as a burning or shooting sensation. The sciatic nerve is a common one, resulting in the prototypical ‘sciatica’ and the pain traveling behind the buttocks and down the back of the thigh.

A newly appreciated cause for chronic low back pain is the result of lower extremity biomechanics, the study of how the various structures involved in stance and gait (standing and walking) are affected by the positioning and functioning of the foot, ankle, and leg. Vitally important in this conversation is the repetitive nature of gait, with thousands of steps a day.

Human Biomechanics is a newer branch of medicine. It attempts to quantify the moment to moment functioning of the body, precisely describing the process which allows the human body to take thousands of steps a day, all while adapting to varying surfaces, without falling, without pain. When the foundation for this system, the feet, are in an abnormal position during some portion of the gait cycle, the interconnectedness of the human musculoskeletal system logically means other parts will be affected……and this list frequently includes the low back.

Perhaps the most common deviation from the norm is an arch that rolls down excessively which is termed hyperpronation syndrome. Interestingly, a majority of LBS patients with hyperpronation who receive properly prescribed, accurately configured, prescription arch supports (aka foot orthotics) experience relief of back pain. And the number of knee replacements performed could be halved if biomechanics were an integral part of daily medical practice.

Going from life as a quadruped (an animal on four legs) to bipedal changed everything when the subject of biomechanics is brought up. Gravity is a demanding force, one few of us escape in this lifetime. Our fight against it goes unappreciated by most, but it’s a battle I see raging in clinics and offices daily. It results in chronic heel pain, knee ‘arthritis,’ the aforementioned slipped discs, radiculopathies, and so much more. How your feet and legs are (not) working may be at the root of your chronic low back pain or ‘arthritic’ knee.