Steve Briggs, head of Shifnal based SB Sports Injury and Physiotherapy Clinic, has reported seeing an average of 10 patients per week with back pain found to be emanating from their Quadratus Lumborum (QL).
Some have never heard of the important muscle lying deep in the posterior abdominal wall on both sides of the spine.
Mr Briggs said: “Reaching from the last rib to the iliac crest of the pelvis, the QL stabilises the pelvis and the spine, allowing us to bend, extend and move laterally.
"Without the QL it would be impossible to bend from side to side, or to remain upright.
“When the QL tightens up it can pull at your bottom ribs, vertebrae, or pelvis, causing not just back pain but a whole bunch of other problems too, for example the inability to roll right or left in bed.
“Often the problem is just on one side, due to the fact that we all have a tendency to favour one side of our body when we are doing things.
"This can lead to serious asymmetry, sometimes even making it look like you have one leg shorter than the other by holding one side of your pelvis higher.
“Being seated for long periods is probably one of the greatest causes I see, as it means the QL is in a constantly contracted state, which then leads to decreased blood flow to the QL muscle, and subsequently to serious muscle spasm.
“QL related pain can manifest itself in the back, hip, groin or gluteal region, making self-diagnosis of the root cause of the problem difficult.
"However, with the correct diagnosis, treatment, and exercise regime, it is usually possible to find relief.
"Furthermore, people can often then identify possible causes and reduce the risk of a recurrence.”