Naturally, when we feel pain, the thought is that we are doing too much and need to rest more or "take it easy." However, adopting this as a long-term strategy can get a person with lower back pain into a bigger hole. Researchers refer to this as "Deconditioning Syndrome."
Because of their association of physical activity with increased pain, chronic lower back pain patients often avoid using their backs. Their decreased joint mobilization is associated with the wasting of trunk musculature, a decrease in muscular strength/endurance and cardiovascular fitness, stiffness of ligaments and joints, reduced metabolic activity, and an increased susceptibility to sprains, strains, and muscle spasms. These deleterious effects of muscle/joint disuse provoke symptoms, causing greater avoidance of activity .
In other words, people with lower back pain become less active, which leads to a decreased range of motion, weaker muscles, and an increased risk of further injury. All of those results lead to even more pain, and then people respond by using their backs even less often, which continues the downward spiral of Deconditioning Syndrome.
This is why lumbar extension helps in many cases. A lumbar extension exercise strengthens the muscles, improves muscle function, maintains a healthy range of motion, and provides an above average level of blood flow into the area (blood flow provides nutrients to the tissues while removing waste).
Cases for Using Lumbar Extension
Not all lower back injuries are created the same. My friend Nate, a physical therapist who specializes in spine-related pathologies, characterizes lower back injuries as "flexion-biased" and "extension-biased." Essentially, some lower back injuries benefit from spinal flexion exercises, such as crunches. Others benefit from spinal extension exercises, as shown in the diagram below (the trainee is leaning back against the resistance pad).
The Montana miners study, which was discussed in the last post, demonstrated huge improvements from performing a lumbar extension exercise once per week . The miners all likely suffer from similar injuries, as they all perform the same work. For them, performing lumbar extension is a huge relief to their spine after a long day of working while hunched over.
However, I'm guessing that you aren't a miner but may be wondering if this is an option for you. In my experience, this exercise is effective in preventing lower back injuries. For existing injuries, clients with herniated and bulging discs as well as those who simply have discomfort after long periods of sitting, have benefited from lumbar extension.
On the other hand, people who have fused lumbar vertebrae are contraindicated - performing lumbar extension could cause great pain. Those with sciatica seem to not be harmed or greatly benefit from the exercise, as long as they avoid slouching to any great degree during the exercise.
The last few paragraphs are simply what I have learned from working with clients and my own lower back pain. If you have lower back pain, you should see a physical therapist or other personal health professional to receive a diagnosis. After that, get his or her opinion on lumbar extension exercises and other potential treatments.