Specific and general exercises: How and for whom?
Danneels L., Willems T. & Hodges P.
10th Interdisciplinary World Congress on Low Back and Pelvic Girdle Pain
October 2019 Antwerp.
The population of patients with low back pain is different. Some patients recover after the first pain episode; some patients have recurrent low back pain and others have chronic low back pain.
The authors discovered differences in muscle structures and muscle activity between patients in these different stages.
In recurrent low back pain back muscle structure changes. There was fat infiltration. The muscle-fat-index (MFI) was higher in patients with recurrent low back pain than in patients in low back pain remission and correlated with the frequency of low back episodes.
More fat in the muscles means lower contractile ability.
Also, the m. multifidus decreased in volume (not the erector trunci or psoas) in the low lumbar levels.
Muscle atrophy tends to recover but changes in muscle quality persist beyond acute low back pain resolution.
The changes that they found were:
• Fat deposits.
• Slow- to fast muscle fiber transition.
Activation of deep muscle fibers (Multifidus) is generally decreased and most at the painful side of the low back.
Concerning rehabilitation from low back pain:
• During the acute phase (in recurrent low back pain) it is considered best to reduce the impact of nociception (medication, rest, comfort treatments).
• Exercise and mobilisation (pain free) can promote anti-inflammatory macrophage polarisation and reduce inflammatory cytokine expression in m. multifidus. and promote the transition from fast-to slow muscle fibers. Also accumulation of connective tissue can be prevented with exercise or mobilisation.
• Although these fibrotic changes can be avoided preventively, it is not sure whether exercise or mobilisation can reverse the changes.
• Physical and resistance training can tackle the inflammatory process.
• Isometric, low load and tonic contractions (exercise) of the m. multifidus will balance the activity between the deep and superficial muscle fibers.
In persisting low back pain (chronic) the back muscle structural changes become much more extensive.
Fat deposits, trophicity changes and ongoing fiber transition go from localized to generalized in time.
Dominant neuropathic pain mechanism and psychosocial factors can be barriers to recovery of chronic long-term low back pain.
Studies demonstrated that patients with chronic low back pain have changes in peripheral dysfunctions but also alterations in brain structure and function. These changes should also be addressed in chronic low back pain patients.