When you hear the letters “BLT,” you’ll most likely think about the iconic bacon, lettuce & tomato sandwich. I submit that the same “BLT” initials are more critical for your low back than the sandwich is for your appetite. B stands for bending, L signifies lifting, and T represents twisting; proper bending, lifting and twisting influence the health and well-being of your low back (lumbar) spine more than you might imagine.
The lumbar spine is designed to perform bending, twisting, and lifting motions. All three are essential to our everyday function for self-care activities. When these activities become excessive during work, chores, or exercise, these three factors can contribute to the progressive breakdown of the lumbar spine discs through a process called degenerative disc disease.
Discs are the shock absorbers between the vertebral bones of the spine. They also allow the spine to bend in all directions. There are two parts to a disc: an outer wall called the annulus fibrosus and a central region called the nucleus pulposus. The outer annulus has a firm, rubbery texture formed in layers, like the year rings of a tree trunk.
Collagen is a protein that gives strength and structure to the layers of the annulus. The collagen fibers in each layer are oriented almost perpendicular to the collagen fibers in the neighboring layers, which adds additional strength due to this basketweave design. The center nucleus has a softer gel-like consistency and is responsible for maintaining the fluid content of the disc to keep it functioning optimally.
B is for Bending
The bending motion is when the front of the chest gets closer to the front of the thighs. This motion places compression on the front of each lumbar disc, which displaces force within the nucleus toward the back annulus wall of each disc. This effect is like squeezing a watermelon seed between your fingertips. Pressure on one side of the seed forces it to move in the opposite direction. Repeated bending leads to the weakening of the rear disc annulus wall. This still occurs during “healthy” bending during exercise. The sitting posture causes the same result in the disc, which is why prolonged and uninterrupted sitting is also problematic for the rear disc annulus wall.
T is for Twisting
The twisting motion is when the shoulders and hips rotate in opposite directions or move in the same direction but at different speeds. Twisting impacts the collagen fibers in the individual disc annulus layers. Turning in one direction causes tension in the collagen fibers of alternating annulus layers while allowing slack in the layers where collagen fibers are oriented differently. Twisting the opposite direction reverses that process in each respective layer of the annulus. Repetitive twisting eventually causes the failure of individual collagen fibers, ultimately weakening the disc annulus wall. Unfortunately, discs are negatively impacted even by specific exercises advised by well-intentioned fitness experts. Many exercises are excellent for challenging various muscle groups but simultaneously harm the spine.
L is for Lifting
Lifting adds weight to the process and amplifies the negative impact on the disc annulus wall during bending and twisting. The concept of lifting in this discussion includes anything that adds force to the system. Pushing, pulling, or holding resistance can be problematic, like lifting or carrying weight. Reaching out and away from the body adds torque to the low back and negatively impacts the situation. Reaching far from the torso to grasp a light object may place more negative force on the lumbar discs than holding a much heavier object close to the torso.
The Power of Compounding
In the world of investing, the concept of compounding has a positive connotation. Compounding lumbar BLT is bad; in isolation, bending, twisting, or lifting all challenge the lumbar discs through their unique mechanisms. When two of these factors are combined, the negative impact on the lumbar disc annulus tissue increases significantly. This is amplified even further when all three factors are connected simultaneously.
Coupling these three negative factors together ensures the worst possible outcome for your spine. The final element to consider is the frequency at which these activities are performed. The lumbar spine was designed to accommodate these activities; however, degenerative disc disease usually results when performed highly repetitively.
Degenerative Disc Disease
When disc annulus collagen fibers fail, cracks (fissures) begin to form in the disc annulus. Exposure to ongoing BLT forces causes these fissures to get longer and broader and develop a more complex branching pattern. Annulus fissures can never heal independently because the disc lacks an adequate blood supply. The fissures themselves cause pain, but the fissures allow the disc nucleus to leak fluid, resulting in disc dehydration. The leaking fluid also causes inflammation and irritation to nerve tissue within the spine resulting in nerve pain in the legs. The problem with degenerative disc disease is that once it starts, it continually progresses, even in healthy people. Although new technology exists to resolve degenerative disc disease with a non-surgical procedure called Discseel, it is much more strategic to avoid the problem in the first place. Learn more about Discseel at RegenerativeSpineAndJoint.com
It is impossible to avoid all bending, lifting, and twisting. An important goal is to modify the BLT factors whenever possible, which preserves the lumbar spine when activity modification is impossible. Most essential is awareness when a combination of any two (and especially all three) factors are combined at once, which is most detrimental for the lumbar discs. Uncoupling the BLT factors is always a priority. Trunk bending can be modified by adding knee bending and squatting. Trunk twisting can be adjusted by repositioning feet to “front” what is being interacted with. Lifting can be adjusted by lightening the load lifted. Instead of reaching to grasp an object far from the torso, reposition the body to get closer to what is being lifted. These modifications add time to activities, which is the major obstacle to their implementation. Mastering these concepts will lessen unnecessary wear and tear on the lumbar spine.
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