understanding lower back pain symptoms

When we injure our lower back, it is normal for there to be pain, - just like if we cut ourselves badly we expect it to be sore. This pain serves as a reminder for us to rest, avoid certain movements and allow healing to begin, and some degree of pain may be present for a few months. The difference with our back is that it has a complex anatomy and it is hard for our brain to localise a source of pain in our spine and the surrounding muscles. Furthermore, we cannot rest our back like an injured limb, so we tend to feel more discomfort. This makes back pain more worrying and hard to interpret without appropriate knowledge.


'Pain serves as a reminder for us to rest, avoid certain movements and allow healing to begin, and some degree of pain may be present for a few months.'


A key feature of lower back pain, especially when acute, is sharp grabbing sensations, particularly with movement. The majority of this is due to muscle spasms. When our back is sore the surrounding muscles go into ‘lock down’ to restrict movement to try to promote healing. This response is normal and part of acute back pain. Sometimes muscle spasm produces altered postures or curves in the spine as the body attempts to stay in a position of comfort. Whilst muscle spasms are alarming, their bark is worse than their bite, and the actual pain related to the underlying injury may be minimal.  With return to normal movement as healing occurs muscle spasms generally subside.


In addition to spasms, lower back pain usually involves some sort of aches and pains, sometimes felt in body areas away from the spine – called ‘referred pain’. These aches and pains usually relate to damaged tissues or inflammation. Because our spine is a deep structure in our body (not like our skin, which is very sensitive), it is hard for our brain to localise the source of a pain message. As a result, back pain often presents as bands of pain, generalised aches, fluctuating pain, or pain that radiates or refers into our groin, buttocks, thighs or legs. Sometimes you may only feel this referred pain and have no apparent back pain at all! Where a specific portion of the spine has been injured pain may be more localised and symptoms more characteristic. For instance, pain relating to disc injury tends to be worse when bending or sitting, whereas injury involving a facet joint tends to be worse in standing or extending of the back. Because the back is a mechanical structure, pain will usually vary with movement and positions depending on which structures are involved.


Sometimes lower back pain is felt as pain into the groin, buttocks, thigh and legs. If nerve tissue is involved in your back pain there may even be strange sensations - such as pins and needles, numbness, or in some cases specific muscle weakness.


In some cases, an injury to the lower back may involve nerve tissues that exit from the spinal cord between vertebrae. If these nerves become irritated by inflammation, or physically disrupted by an injured or thickened structure such as a disc, arthritic facet joint or ligament, they can cause some other symptoms. Typically, an irritated or compressed nerve will cause sharp, shooting or burning type pain to be felt into your legs (where the nerves from your lower back travel to and supply), and sometimes some pins and needles, numbness or weakness. These symptoms are sometimes referred to as ‘sciatica’ or ‘radicular pain’, and they may vary with certain movements and positions. Sometimes the spinal cord and nerve roots may also become compressed in the spinal canal with certain injuries or lower back conditions, leading to more profound symptoms, weakness and sensory disturbances in the legs.


Where back pain has become chronic in nature, the pattern of symptoms can be less clear, and when we are stressed or anxious about back pain it often feels worse. With persistent pain our nervous system (brain, spinal cord, nerves) starts to undergo changes that can make pain more variable and more sensitive, even after tissues of the spine have healed. Furthermore back pain, much like an ulcer, is sensitive to our emotional state - flaring up when we are stressed or worried. Therefore, with long term pain, stress and anxiety, chronic or recurrent lower back pain can occur. It's not all a mind game but understanding that chronic pain has a physiological basis and that stress and anxiety can exacerbate your symptoms is important to know.