A modern life has meant that prolonged sitting ihas become unavoidable. Whether it’s long hours at a desk, driving for work, commuting, or working remotely from home, many people now spend most of their day seated. While this may seem harmless, prolonged sitting can have a significant effect on one of the most important stabilising muscles in the lower back, the lumbar multifidus.

The multifidus is a deep spinal muscle located close to the vertebrae. Its primary role is to stabilise the spine during movement and help maintain proper control of the lower back. Unlike larger muscles that create big movements, the multifidus works quietly in the background, providing support and protection for the spinal joints and discs.

The Multifidus Muscle is Highly Sensitive to Inactivity

Research has shown that prolonged sitting can reduce activation of the multifidus muscle, particularly in individuals who spend long periods driving or performing desk-based work. Over time, reduced use of the muscle can lead to atrophy — a loss of muscle size and strength. MRI studies have demonstrated that the multifidus can gradually shrink and develop fatty infiltration, where healthy muscle tissue is replaced with fat tissue. These changes are commonly associated with persistent or recurring lower back pain.

This is especially concerning for office workers, HGV drivers, delivery drivers, taxi drivers, and anyone whose job requires prolonged sitting with limited movement variation. Sitting for extended periods places the lumbar spine in a static posture, reducing the natural muscular engagement required to stabilise the back. As the multifidus becomes weaker and less efficient, the spine may become more vulnerable to excessive strain, stiffness, and mechanical stress.

Interestingly, research has also found that multifidus dysfunction may continue even after back pain symptoms improve. In other words, the pain may settle, but the underlying muscle weakness can remain if it is not specifically addressed. This may partly explain why many people experience repeated episodes of lower back pain over time.

These Changes are Not Necessarily Permanent

Studies suggest that targeted rehabilitation programmes focusing on spinal stabilisation, controlled movement, walking, and strengthening exercises can help reactivate and restore the multifidus muscle. Regular movement throughout the day, reducing uninterrupted sitting time, and improving overall physical conditioning can all help support spinal health.

Simple strategies such as standing regularly, taking walking breaks, improving workstation ergonomics, and incorporating core stability exercises into a weekly routine can make a meaningful difference. The body was designed to move — and the spine functions best when movement is frequent and varied.

If you spend most of your day sitting, your lower back may not simply be “tight” — it may actually be losing one of its key stabilising systems. Addressing this early through movement and exercise may significantly reduce the risk of developing chronic lower back pain in the future.

References

Barker, K.L., Shamley, D.R. and Jackson, D. (2004) ‘Changes in the cross-sectional area of multifidus and psoas in patients with unilateral back pain: the relationship to pain and disability’, Spine, 29(22), pp. E515–E519.

Fortin, M. and Macedo, L.G. (2013) ‘Multifidus and paraspinal muscle group cross-sectional areas of patients with low back pain and control patients: a systematic review with a focus on blinding’, Physical Therapy, 93(7), pp. 873–888.

Hides, J.A., Richardson, C.A. and Jull, G.A. (1996) ‘Multifidus muscle recovery is not automatic after resolution of acute, first-episode low back pain’, Spine, 21(23), pp. 2763–2769.

Kader, D.F., Wardlaw, D. and Smith, F.W. (2000) ‘Correlation between the MRI changes in the lumbar multifidus muscles and leg pain’, Clinical Radiology, 55(2), pp. 145–149.

Parkkola, R., Rytökoski, U. and Kormano, M. (1993) ‘Magnetic resonance imaging of the discs and trunk muscles in patients with chronic low back pain and healthy control subjects’, Spine, 18(7), pp. 830–836.

Woodham, M., Coppieters, M.W., Emery, C. and Barker, K.L. (2014) ‘Long-term lumbar multifidus muscle atrophy changes documented with magnetic resonance imaging: a systematic review’, Journal of Manipulative and Physiological Therapeutics, 37(8), pp. 603–611.