The spine is made up of 24 vertebrae, which are cushioned by tough, fibrous and gelatinous intervertebral disks arranged in three curves that form a natural S shape. The cervical spine supports the head. The ribs, which protect the internal organs, are attached to the thoracic spine. The lumbar spine, which is the workhorse of the spine and the site of low-back pain, absorbs nearly all torso stress when you stand, sit or move. When the cervical curve, thoracic curve and lumbar curve are properly aligned; you are less vulnerable to injury and pain.
Before we discuss physical activity and exercise, let’s review what we know, at this time, about low-back pain:
- At some time in their lives, 60 to 80 percent of people in the U.S. will have low-back pain. In 30-70 percent of sufferers, the pain will recur.
- For 80-90 percent of acute assaults of back pain, recovery takes from three days to six weeks. The problem becomes chronic for 5 to 10 percent of sufferers.
- Men and women are affected equally.
- In the absence of scientifically validated guidelines for the treatment and prevention of low-back pain, the determination of exercise programs has been guided largely by empirical knowledge
The Role of Muscular Strength
Much emphasis has been placed on muscular strengthening exercises to stabilize and support the trunk area. Several arguments justify this rational for the treatment and prevention of low-back pain, For instance, the degree of stability and support of the trunk area depends largely on the strength of the supporting structures and the muscles.
Improper vertebral alignment can result from weak back extensor muscles, which may lead to undue loading on the spine. Stronger muscles can enhance the spine’s ability to withstand various degrees of external loads. In industry, workers with high levels of muscular strength are less prone to back injury.
The fact that patients suffering from low-back pain exhibit lower levels of trunk extension, trunk flexion and lateral flexion strength than non-suffering persons suggests a need to alleviate this dissimilarity.
The greatest losses in strength have been found in the trunk extensor muscles. In healthy, normal persons, a natural imbalance is expected, with the lumbar extensors being stronger than the lumbar flexors. The trunk extensors in a healthy person are approximately 30 percent stronger than the trunk flexors.