Our spine is made up of 24 moveable bones, called vertebra, between the skull and the sacrum. The spine continues as the sacrum, which is actually 5 more vertebra fused together, and the coccyx or tail bones. The front part of each vertebra is called the body, and between the bodies of two adjacent bones is the disc. The body is designed to support your weight and structure and although the disc is technically a joint but is better considered a flexible union to cushion shock and allow movement. Behind the body on either side is a joint, these facet' joints control the movement allowed by the disc, they are also the managers' of movement receiving information about the position and the loads through the are and organising the support necessary form the muscles.
The ligaments between the bones hold the vertebrae together preventing excessive movement and reporting to the controlling facet joints about loads and position. The disc, the facet joints, ligaments and muscles contain small sensors that tell the body what loads are present in the spine and what position it is in.
The muscles then may alter the position of the bones and joints to control the loads put through the spine. The muscles support the posture and enable movement to occur responding to the instruction of the facet joints and the instructions of the brain and central nervous system.
According to Boos and Hodler (1998), lower back pain is often spontaneous, not identified using current technology and traditional care is rarely curative.
What happens in a soft tissue injury?
Ligaments hold the bones in the body together; they also support the joints. If you sprain your ankle you tear the ligaments holding the bones together. If the ligaments surrounding the joint capsule are damaged the joint will swell as the healing cells of the body pour into the joint. Unfortunately the swelling quickly stretches the joint, which increases the pain.
With an ankle you know how you damaged the joint, you can see the swelling, most people understand that treating the swelling with Rest, Ice, Compression and Elevation (RICE) will allow the swelling to go down and the injury will heal, usually within 2 to 6 weeks. This is very painful, but you know it is not usually serious and therefore it is not frightening. Within 2 to 3 days you know you are getting better and can start to use the ankle gently.
The joint needs to be mobilised, using it will help the swelling, stop it from getting too stiff and improve the healing. However, if you do too much too soon then the problem will worsen and the time for recovery will lengthen. It requires a little common sense.
Back Injuries
Back pain caused by injury may well begin in the same way as a sprained ankle. Most of the patients we see know when the pain started and often describe it in much the same way as an ankle sprain. However the mechanism of onset is seldom traumatic, there is almost never evidence of bleeding from damaged tissues (consider the bruising seen in an ankle sprain) and on reflection the feel that the reason for the onset is not clear.
Acute back pain (ABP)
Acute back pain is defined as back pain lasting a short period if time. A reasonable definition would be that it makes a recovery within normal tissue healing time. It does not relate to severity of pain, injury or damage.
The disc, the facet joints and the ligaments contain small sensors that tell the body what loads are present in the spine and what position it is in (proprioception). The muscles then control the position of the bones to make it as strong as possible. When things go wrong it is this mechanism that fails to work properly. If a disc, a ligament or one of the controlling joints is damaged, even a little, the load sensors send a message to the muscles to tighten up and protect the damaged structure from being stretched; this is called a Protective Muscular Reflex, it is automatic. This response always takes place into extension (arching backwards). Here is the difference between a back injury and a sprained ankle.
Unfortunately if the joint is damaged then the protective muscular reflex responds at the same time as the swelling takes place, this muscular tightness causes arching backwards and can compress the swollen joint too much making the sensors call for more muscle tightness because they feel you are applying more load and the joint is at risk of further injury.
At this point a vicious circle leads to a spiral or cascade: the injury causes soreness, tightness and swelling, the tightness causes more soreness, more swelling and more tightness until it is in complete spasm and very sore. This gives the sharp pain that you feel when you stand on a sprained ankle, but when it is the back it could be there even when you are lying down. It is so sharp that patients may describe it as a "trapped nerve" but it is usually not.
This pain is very much more severe than the injury which triggered it and although it hurts a lot when you move there is no evidence to suggest that it does more damage. Pain in this case does not mean harm. You need to move carefully and relax, and most of all avoid long periods of rest. Panic and anxiety about your problem will make it worse. Thinking about what is happening that your pain is mostly caused by your body reacting rather than the damage you have done and understanding that the pain you feel is not going to cause more problems will help you to relax and you soon you will find that you can learn to control your pain, gradually being more and more active and go on to make a good recovery.
Chronic back pain (CBP)
Chronic pain has been varyingly defined, usually in the context of LBP it is between 7 and 13 weeks, chronic pain is purely a definition based on time. It does not relate to severity of pain, injury or damage.
A more relevant definition would be based on tissue healing time. Of the 97% of LBP patients who have simple back pain most have a soft tissue injury of some sort, for example a strain. This kind of injury cannot be seen on even the most sophisticated scanning and therefore it is not possible to measure it. However in appearance and history these cases are usually recognisable from other types of back pain. A strain takes between 2 and 6 weeks to heal so if back pain lasts longer than that time there is something preventing the healing, or something preventing the pain easing once tissue healing has occurred.
Recent research suggests that CBP that is likely to go on to last more than 8 weeks can in fact be identified at 2 weeks; this suggests that it is a different condition to ABP rather than an unresolved episode of ABP.
Confused? We are not surprised. At Back Trouble UK we know a great deal about back pain, unfortunately there is still a great deal that nobody knows!
Understanding of chronic pain has increased hugely since the early 1990's. An in depth knowledge of the precise neurophysiology and psychology is not necessary, to grasp the principles may be enough, however you will need to have your wits about you and you will need to look hard at yourself. Think about it though, there is a lot of evidence that if you have long term back pain this is the only way you can get better. You may at this pointy decide you need help and guidance, The vast majority of Registered Back Trouble (UK) Practitioners or Therapists can provide that, as can some of the other better informed health care professionals in the back pain field. You can read on and see how you do.
Pain
Pain is not a sensory feeling; rather it is a response from the brain to a plethora of information being fed to it after an initial warning message of tissue damage (nociception). The pain message detected by distant sensors in damaged tissue transmit to the dorsal horn of the spinal cord, and then via an ascending pathway to the primitive (lower) parts of the brain. These have a responsive action and will usually serve the patient well; it is the higher centres that can get the patient into trouble.
If the pain does not provoke fear in the lower brain centres, the amygdala (responsible for fear, fear conditioning and addiction) will naturally use descending pathways to the spinal cord to suppress the pain message. The amygdala has been described as the emotional computer' of the brain.
Shall I stop there and explain?
Damage is detected in the tissues, a message is sent to the spinal cord. Here it divides and one part initiates an appropriate response. If the damage is to the skin, touching something hot with a finger for example, the response will be to withdraw the limb. This is achieved by activating the flexor muscles of the arm. If the damage is to the deeper tissues the response is to extend, to spasm around a back injury for example. The other part makes its way up the spinal cord to the brain to inform it of the damage so an appropriate strategy can be constructed. The initial response is in the primitive parts of the brain. Should you run away, hide or fight etc. No consideration as to the cause of the pain is given it is an emotionally driven response based on is the pain a threat? Is the building burning down or is there a sabre tooth tiger hanging onto your arm?
So far so good? Excellent.
Now a message is sent to the mapping part of the brain, the sensory cortex. The area of damage (don't forget it is still not pain) is reported and considered, a report is sent to the thinking part of the brain, the frontal cortex. Here it meets the emotional report from the primitive part of the brain. The thinking part of the brain tries to make sense of what is going on, it will recruit all other information from the senses, sight, sound, smell, taste, and touch. It will consider its previous experiences and beliefs about a particular threat and then decide whether to consider you should feel pain, PAIN.
If you have a sabre tooth tiger hanging off your arm you will confirm with all your senses that the tissue damage represents a threat, your experience and beliefs will confirm that you are in danger (of being eaten) and your brain will conclude that a good bolt of PAIN might jolt you into some kind of action to preserve your life. But let us consider a more contemporary threat. Stinging nettles cause a minor skin irritation, a small swelling response and a slight itching. The huge majority of people stung recover without concern. Should that be considered pain? Well that rather depends upon your expectation. The damage report will be the same in most people, the response will vary. Would you expect a small child to cry if stung? Would you expect a grown adult to cry? The difference would be experience and belief. A child being stung for the first time does not know what to expect, and what the consequences may be, and adult does. Interesting isn't it?
So then what happens?
The thinking' parts of the brain will consider the pain message and make a value judgement' based on beliefs, expectation and experience. As already explained if the pain does not provoke fear in the lower brain centres it will naturally use descending pathways to the spinal cord to suppress the pain message.
However if the damage is considered a threat then the thinking part of the brain will inform the amygdala, which will stop the pain suppression, this is called negative affect. Once this pattern of reduced pain message suppression is established the brain may increase the importance of the pain report using descending nerve pathways that will increase or amplify the tissue damage message.
So is that it? Well no, not really, it gets worse.
As a result of the increase in damage report because of the descending nerve pathways there is an alteration of neurophysiologic mechanisms, which increase the frequency, duration and magnitude of nociceptive transmission giving increased sensitivity to damage from the original site to the spinal cord (hyperalgesia). Over a period of a few days changes in the layout of the nerve pathways (the wiring of the body) known as neuroplastic change' allows other sensations to be transmitted as damage reports (nociception) giving the sensation of pain instead of other sensation (allodynia). Together these changes are called central sensitisation. The brain then attends to this increase in damage reports (nociception) with fear, perpetuating the attention paid to the injury site.
This is looking bad, surely that must be it? Not exactly.
The injury may then heal but the reaction to it is perpetuated, as we have already explained any change in sensation in the area of original damage is interpreted as pain. The more intense this reaction and the longer it continues the more negatively conditioned the amygdala becomes and the harder it is to recondition, and therefore recover. This is chronic pain.
So what happens in Chronic Back Pain?
There must be an explanation as to why the pain caused initially by a minor injury (don't forget there is seldom enough tissue damage to cause bleeding) persists beyond tissue healing time. The changes seen in central sensitisation in the spinal cord that lead to hyperalgesia or allodynia can occur just as easily in the soft tissues of the spine as in the skin. Here the threatening impulse is a mechanical load or movement sensor (proprioceptor). Normal proprioceptive output due to normal loads are transmitted via a neuroplastic connection or sprout' with the ascending nociceptive (damage report) neurone (nerve pathway) and is re-interpreted as nociception. Thus movement perpetuates pain even in the absence of continuing injury; movement is therefore painful unsurprisingly giving the impression that movement causes damage.
This reluctance to move will be associated with de-conditioning changes resulting from inactivity giving a tightening of long muscles and a weakening of short muscles. This imbalance will lead to postural fatigue and increase chemical irritation in the muscles and yet further reports of damage.
Terry has been involved in General Medicine for over 20 years, he is a keen sports player and still turns out most Saturday's on the Rugby pitch, although his body wishes that he didn't!
Dragged up in Liverpool and supporting the BLUE half of Merseyside. Terry went on to study Medicine and initially serve in HM Forces, serving all over the world and completing just over 15 years service.
Terry launched Back Trouble UK, during 2007, however the Therapist Directory did not go online until January 2008. www.backtrouble.co.uk The main reason that Terry launched the website was so that people in the UK who were suffering from a Back Condition. Would have access to quality, clear, jargon free Back Pain Health Information, and online access to UK Registered Back Pain Practitioners & Therapists promoting non invasive natural treatment options.
This author of this Article has choosen to make this article available with free reprint rights. Click here to copy this article.
» left by Mo Adams from Sheffield (132 days 6 hours ago.)
Your articles are brilliant Terry, Keep up the good work, I hope that your campaign succeeds! Back Trouble (UK)
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