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Why Does My Back Hurt in the Morning?

Why Does My Back Hurt in the Morning?
April 21, 2016 Dr. Phillip Snell

why-does-my-back-hurt-in-the-morningPeople that come into our clinic for treatment after lumbar disc herniation frequently have a history of pain which is worse in the morning and then improves after they’ve been up moving around for a bit. Often they have some questions about what exercises and stretches they can do in the morning to make them feel better. We learned more about morning back pain in a disc – injured patient after the research of Michael Adams in the 1980s.(1,2) Adams referred to the “diurnal behavior of the disc” which mostly refers to the tendency for the discs to absorb moisture from the tissues around them overnight. When this happens the disc becomes a bit more plump. Why is this significant? In reviewing the anatomy of the lumbar disc you can see from the cross-section below that the interior of the disc, called the nucleus pulposus, is surrounded by a layered container called the annulus fibrosus, or annulus for short. The annulus is layered like an onion and is extremely tough.

anatomy-review-lumbar-discOne of the interesting features about the annulus is that the inner two thirds of the annulus has no nerves in it and it and is thus unable to report injury to those layers. Other research has shown us that one of the most likely injury vectors for the lumbar disc is combined compression and flexion which occurs when a person hinges in the lower back when lifting or sitting with a pronounced slumped posture.(3,4,5) This does not mean that you can’t tolerate quite a bit of that lumbar hinging, it just means that if you do enough of it to injure the inner layers of the lumbar disc you will not likely know about it until later when the injury begins to encroach upon the outer one third of the disc. The material in the nucleus is highly pro-inflammatory and it worms its way toward the peripheral layers as the inner layers of the annulus are injured. As the nerves in the outer portion of the disc become sensitized due to inflammation in that area that lumbar hinging can become less tolerable. Now…back to the morning back pain…

Remember that Adam’s research showed us that the discs soak up the fluids from the tissues around them while a person is recumbent in bed overnight. So in the morning when they wake up the outer layers of the disc are under a bit more tension, which we refer to as hydrostatic pressure. After you get up and walk around for a bit that extra moisture works its way out of the disc due to the effect of gravity. That’s why your back might feel a bit better after you’ve been up and about. During that time while the moisture is working its way out, the disc might report discomfort to you a bit quicker if you happen to hinge in the low back with your morning movements. So let’s think about common morning movements that involve hinging.

Often people will roll up to a sitting position initially and sit slumped over the edge of the bed while they consider the oncoming day and while they put on their pants. That hinging movement in the lower back with the torso’s weight bent forward on that lumbar hinge causes the well imbibed disk to report discomfort quicker while the hydrostatic pressure is increased. That individual is often greeted by that first stab of pain at this point in the day. Many will recall times when their back spasmed and locked on them at this very moment. After this initial insult to start the day, they shuffle off to the bathroom to take care of their morning constitutional. Bending to sit down on the toilet they once again initiate the movement in the lumbar hinge and feel the discomfort once again when they land on the toilet. It happens again when they try to stand up and the torso’s weight hinges on the lumbar spine. Once again when they continue on to brushing their teeth, they will often again initiate the forward bending from the lumbar spine and feel pain as they lean over the sink. The next challenge comes when they bend forward to turn the water on in the shower. Remember…forward bending is not the aggravation here, rather it’s where the movement of forward bending initiates from. Is it in the hips or is it in the lower back? For a few quick things that you can do in the morning to help with that painful wake-up call,you can check out the video below and the accompanying information on fixyourownback.com.

References

1. Adams MA, Dolan P, Hutton WC, Porter RW. Diurnal changes in spinal mechanics and their clinical significance. J Bone Joint Surg Br. 1990 Mar;72(2):266-70.

2. Adams MA, Dolan P, Hutton WC. Diurnal variations in the stresses on the lumbar spine. Spine (Phila Pa 1976). 1987 Mar;12(2):130-7.

3. Adams MA, Hutton WC. Gradual disc prolapse. Spine 1985; 10:524-31.

4. Adams MA, Hutton WC. Prolapsed intervertebral disc. A hyperflexion injury 1981 Volvo Award in Basic Science. Spine 1982; 7:184-91.

5. Wade KR, Robertson PA, Thambyah A, Broom ND. How healthy discs herniate: a biomechanical and microstructural study investigating the combined effects of compression rate and flexion. Spine (Phila Pa 1976). 2014 Jun 1;39(13):1018-28.