Among the foremost practitioners in the art and science of treating spinal pain is the renowned New Zealand physical therapist, Robin McKenzie. According to McKenzie, there are three (3) predisposing factors underlying the epidemic of back pain we observe in industrialized countries.
The most important of these factors is the sitting posture. Sitting when unsupported reverses our lumbar curve placing important ligaments under full stretch. Additionally, a poor sitting posture in and of itself can produce pain even without trauma.
Further, poor sitting postures will worsen and perpetuate existing back pain. Indeed most back pain patients complain of pain while sitting or rising from sitting. It has been well established that sitting in a kyphotic position (spine flexed), tends to increase intra-disc pressure in the lumbar region.
Thus, poorly designed workstations conspire with the frequent and prolonged sitting position to dramatically increase the incidence of back pain.Hand in hand with prolonged sitting is our second predisposing factor, a general loss in lumbar extension. According to McKenzie, significant loss of lumbar extension becomes apparent at age thirty.
Without adequate training to prevent this trend, the loss of extension predisposes the spine to a kyphotic posture with concomitant increased disc pressure and compromised ligament length.
With these adaptive changes, the threshold for stress to provoke pain is that much more readily reached.
The third predisposing factor in the epidemic of low back pain is the relative increased frequency of tasks requiring forward flexion of the spine. In analyzing our daily routine we see flexion with brushing the teeth, shaving, driving, sitting at the computer, leaning across the table, etc.
It is safe to say that our routine mostly causes us to flex the spine and not to extend. Consequently, the sensible use of spinal extension in back care is what McKenzie refers to as the “beginning of a prophylactic concept”.