CREEP and SLEEP
by Dr. George DeFranca
Sleeping on a poorly supporting mattress has deleterious effects on the lower back due to a very "creepy" phenomenon of the body's soft tissues. In biomechanics, "creep" refers to the time dependent deformation of a tissue in response to an external load applied to it. In other words, ligaments, discs, muscles, tendons, and even bone will yield and change shape (stretch) due to a strain placed upon them. For instance, if you sleep on a mattress that is too soft or poorly constructed such that the spine is allowed to sag out of a neutral position, ligaments (of which discs are) and joints are stretched and will deform within a short period of time, usually starting within only 20 minutes. Recovery from the stretch occurs once the load is removed, but it is not instantaneous and may require some time, at least 30 minutes. That is why we are stiff upon first arising in the morning, especially on a poorly supporting mattress.
Ligaments in the spine are very well innervated by nerve receptors that monitor their stretch and length. Once a ligament is stretched, especially if creep occurs, it signals the regional muscles supporting it to contract and help with the strain. This will result in muscle activation causing tightness, muscle tension, even spasms. Adequate neuromuscular control is lost and muscle activation can be delayed or over-responsive, setting the stage for injury. Once creep occurs, the muscle system has a much harder time protecting the spinal ligaments and joints from injury. Pretty creepy indeed.
A spine that is stiffer due to inflammation, arthritis, trauma, or surgery will pay more of a creep penalty resulting in pain and more stiffness upon arising. This can set the person up for continued injury if they move or posture themselves the wrong way when they first get up. This is why an injured spine must be properly supported during sleep.
To minimize creep, we must sleep in a well supporting mattress, not necessarily one that is very firm. One study of 268 people with lower back pain found that those that slept on hard mattress had more back pain. The mattress must allow the body curves to be supported while not letting the spinal joints and ligaments sag out of their neutral positioning. The only way to pick a good mattress is to sleep on one and see how it feels. Next time you are at a hotel or a friend's, or relative's house, pay attention to the mattress and how it feels! Not too firm, not too soft.
by Dr. George DeFranca
Sleeping on a poorly supporting mattress has deleterious effects on the lower back due to a very "creepy" phenomenon of the body's soft tissues. In biomechanics, "creep" refers to the time dependent deformation of a tissue in response to an external load applied to it. In other words, ligaments, discs, muscles, tendons, and even bone will yield and change shape (stretch) due to a strain placed upon them. For instance, if you sleep on a mattress that is too soft or poorly constructed such that the spine is allowed to sag out of a neutral position, ligaments (of which discs are) and joints are stretched and will deform within a short period of time, usually starting within only 20 minutes. Recovery from the stretch occurs once the load is removed, but it is not instantaneous and may require some time, at least 30 minutes. That is why we are stiff upon first arising in the morning, especially on a poorly supporting mattress.
Ligaments in the spine are very well innervated by nerve receptors that monitor their stretch and length. Once a ligament is stretched, especially if creep occurs, it signals the regional muscles supporting it to contract and help with the strain. This will result in muscle activation causing tightness, muscle tension, even spasms. Adequate neuromuscular control is lost and muscle activation can be delayed or over-responsive, setting the stage for injury. Once creep occurs, the muscle system has a much harder time protecting the spinal ligaments and joints from injury. Pretty creepy indeed.
A spine that is stiffer due to inflammation, arthritis, trauma, or surgery will pay more of a creep penalty resulting in pain and more stiffness upon arising. This can set the person up for continued injury if they move or posture themselves the wrong way when they first get up. This is why an injured spine must be properly supported during sleep.
To minimize creep, we must sleep in a well supporting mattress, not necessarily one that is very firm. One study of 268 people with lower back pain found that those that slept on hard mattress had more back pain. The mattress must allow the body curves to be supported while not letting the spinal joints and ligaments sag out of their neutral positioning. The only way to pick a good mattress is to sleep on one and see how it feels. Next time you are at a hotel or a friend's, or relative's house, pay attention to the mattress and how it feels! Not too firm, not too soft.