In Vivo measurements of Pressured in the Intervertebral Discs on Daily Life

Intervertebral discs do not require a straight spine to replenish with fluid

Impressive self-experiment by orthopedists

The core thesis of the mattress suppliers that only a straight aligned spinal column guarantees the recovery of the intervertebral discs when lying down is no longer tenable after this examination.

Dr. Wilke’s team had implanted an electrical measuring probe into an intervertebral disc of the lumbar spine of a member of this group (also an orthopaedist) in order to be able to precisely measure the pressures in the intervertebral disc in various postures and movement sequences.

It was determined that the pressure in the intervertebral disc is lowest in the supine position at 1 bar, whereas in the lateral position the pressure is slightly higher at 1.1 bar.
It was found that the pressure in the disc does not depend on the angle of flexion, i.e. not on how the spine is aligned, whether it is straight or curved. Rather, the decisive factor is what tensions are transferred to the spine.

Even with a hearty laugh, the pressure increases to 1.5 bar, with a sneezing to 3.8 bar, when changing the lying position the pressure in the tips even goes up to 7-8 bar (this can be compared to the air pressure in a truck tyre, for example).

It is also interesting that the pressure in the intervertebral disc rises during the night from 1 bar at the beginning of the resting phase up to 2.4 bar towards tomorrow, when the intervertebral disc accumulates with fluid again.

It has been shown that when sitting, supported and relaxed sitting postures generate less pressure in the intervertebral discs than sitting and standing upright: Sitting, relaxed leaning backwards, resulted in a value of 2.7 bar, sitting forward and supported on the elbows, resulted in a value of 4.3 bar. Relaxed sitting without a backrest (slightly curved or slumped) increased the measured value to 4.6 bar, whereas straight upright sitting resulted in a value of 5.5 bar and is thus slightly higher than the result of relaxed standing at 5 bar.

Source: Spine, Volume 24, 1999 “New In Vivo Measurements of Pressures in the Intervertebral Disc on Daily Life”.
The following conclusions can be drawn for lying down: The alignment of the body is not decisive. The intervertebral discs take care of themselves when lying down and do not need a special position to replenish themselves with fluid. Moreover, increased pressure in the intervertebral discs cannot be regarded as negative, rather the opposite seems to be the case. See our notice under “Preventing a slipped disc by strengthening the back muscles”.

Our commentary:
If peak pressures of up to 8 bar in the intervertebral disc are measured by simply turning from the back to the prone position, a completely different connection should come to the centre of attention when asked about the “right mattress”. The aim is not to consider how the spine is aligned, but rather how the musculoskeletal system as a whole can be helped to become in harmony. The body must feel comfortable, the muscles, ligaments and connective tissue must be able to stretch, balance and relax. How soft a mattress should be in the end, how deep shoulders or buttocks should sink in, can therefore largely be determined individually, depending on personal habits or the habituation of the respective “musculoskeletal system”.