Abstract
Purpose of the study
To assess the ability of magnetic resonance spectroscopy (MRS) to detect changes in spinal muscle metabolism after a 4-week exercise intervention.
Background
Spinal muscle atrophy is associated with back pain and exercise interventions have been shown to reduce pain and improve function. It is not always clear, however, whether improvements are due to enhanced muscle performance or occur for other reasons (e.g. psychological, neurological). MRS can be used to measure muscle metabolism and could therefore be useful for assessing the mechanisms by which exercise improves function in back pain patients.
Methods
Eleven healthy participants took part in a 4-week exercise intervention to strengthen the spinal muscles. Before and after the intervention, the participants underwent an assessment that included using MRS to monitor the phosphocreatine levels in the spinal muscles around the level of L3L4 whilst they performed a modified Biering-Sorensen test to fatigue.
Results
Relative to the pre-intervention assessment, the post-intervention endurance time significantly increased (mean=20 s, 95% CI 7–34 s, p=0.01). The phosphocreatine depletion, taken at an equivalent time point in both assessments, significantly decreased (mean=12%, 95% CI 5–19%, p=0.006). Even at the point of the fatigue, the phosphocreatine depletion was lower post-intervention (mean=8%, 95%CI 1–15%, p=0.045).
Conclusion
MRS can be used to detect changes in the metabolism of the spinal muscles after a 4-week exercise intervention.