Low back pain is the number one cause and cost of work related disability
More than 90% of cases can be effectively managed with conservative measures
60% – 90% of adults experience back pain at some point in their lives and
it is rated second to respiratory illness as a reason for symptom-related
visits to family doctors.
Low back pain is the number one cause and cost of work related disability ($26.3 Billion in 2008). A significant cause of lost work and productivity, (it is the second most common cause of missed work) back pain causes significant levels of anxiety, pain and discomfort, and has been linked to psychological depression.
Even though more than 90% of cases can be effectively managed with
conservative measures there is a plethora of conflicting advice and
therapies and patients are often left confused, in pain, and compelled to
Whatever the underlying cause, the body always attempts to protect
us. Trigger points are part of our ‘protect and defend’ mechanism.
Any change in spinal mechanics over time can manifest as areas of tight
muscles or tender spots (‘trigger points’).
Trigger points can develop in muscles for a number of reasons. When present they cause the host muscle to be shorter, tighter, and tenser; they also add to the cycle of increased input to the peripheral and central nervous system.
In the video above, Physiotherapist Paul Townley presents an overview of lumbar back pain and provides some tips to help with assessment
Low Back Pain - Anatomy Overview
It has been suggested that low back pain is an inevitable result of walking upright (Harari). As the force of gravity acts upon the skeleton and its muscular and ligamentous armature it is distributed via the fascia into three dimensions.
Myers (2013) talks of an internal cohesion-compression of the body where it is both collapsing in on itself and pushing out from itself in a constant state of equilibrium, a concept called ‘tensegrity’.
Tensegrity is seen nowhere better than in the spine; if the spine were a straight, rigid stick it wouldn’t be able to compensate for the multiple forces acting upon it.
Therefore, it is specifically arranged in a series of curves (cervical and lumbar lordosis and thoracic kyphosis).
Along with the spinal discs, these curves are essential for shock absorption and are maintained by an inter-blend of muscles and ligaments that fire up in cyclical sequences.
Even though all of the spinal vertebrae are designed to move, the spine also demonstrates specialization in its movement patterns, allowing us to exploit our three dimensions.
The direction of movement is mainly determined by the orientation of the spinal “facet joints”: forward and backwards movements (flexion and extension) from the low back, sideways from the neck (side bending), and rotation from the thoracic
spine (although this is limited by the ribs).
It is worth noting here that these facets themselves can be the source of lower back pain. The other important movement is a type of nodding backwards and forwards which is translated through the sacroiliac joints (nutation and counter-nutation).
Layered on top of the vertebrae are a series of ligaments that are strong and specialized to resist directional forces.
They again can be a source of pain and may even develop “trigger points” (see below).
On top of the ligaments is a complex but beautiful system of muscles; moving from deep to superficial will give us vital insight into spinal mechanics.
The deepest spinal muscles are used to make minute adjustments in vertebral orientation (rotatores, interspinalis and intertransversalis).
The next group we meet is the multifidus; its fibers are large and strong, bridging
several vertebrae at once and helping to maintain posture.
The next layer of muscles connects the vertebrae to another from one to six segments upwards. This is the erector spinae and it is divided into three columns.
Moving outwards from the center it forms a “wing like” structure - spinalis,
longissimus and iliocostalis.
The erector spinae don’t really keep the spine erect (that’s the job of the psoas and the multifidus) but they do extend the spine from a flexed position. Side-bending is mainly performed by the quadratus lumborum muscles.
Arranged over these muscles we have broader, flatter, and more superficial muscles such as the latissimus dorsi.
Added to this hardware is the software that the brain uses to coordinate and sequence movement.
All of the above structures feed information to the brain in a constant stream affording it orientation (proprioception), as well as force and direction (velocity). The brain responds by organizing movement sequences hierarchically in functional units.
These functional units mainly consist of a prime mover (agonist), an opposing muscle force (antagonist), and other muscles that either fix the local joint (fixators) or help the prime mover (synergists). 86% of low back pain is mechanical and may come from any one of the above structures (bones, discs, facet joints, ligaments, and/or muscles).
Some research has shown that up to 14% of low back pain, however, may come from a more sinister origin so it’s vitally important to understand which tissues are causing the symptoms.
Epidemiology – who gets low back pain?
• 60% - 90% of adults experience back pain at some point in their life.
• Incidence with age (peak 35 - 55)
• 90% resolve in 6 weeks
• 7% become chronic
• M/F equally affected
• 85% never given precise pathological or anatomical diagnosis
• 5th leading reason for medical office visits
• 2nd to respiratory illness as reason for symptom-related MD visits
Which muscles are implicated in low back pain?
• Deep spinal mm (small) - multifidus
• Lumbar erector spinae
• Gluteus medius
• Rectus abdominis
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