Combined Motor Control and Isolated Extensor Strengthening vs. General Exercise: Effects on Paraspinal Muscle Morphology, Composition, and Function

Current research directly compares combined motor control and isolated extensor strengthening (MC+ILEX) with general exercise (GE) for patients with neck and low back pathologies, focusing on paraspinal muscle health and clinical outcomes. MC+ILEX leads to greater improvements in paraspinal muscle size and thickness, but both approaches similarly improve pain, function, and quality of life.

Key Findings from Recent Research

Muscle Morphology and Composition

• MC+ILEX produces greater increases in multifidus and erector spinae cross-sectional area (CSA) and multifidus thickness at lumbar levels (L4-L5, L5-S1) compared to general exercise after 12 weeks of supervised intervention (Fortin et al., 2023).

• Both interventions improve muscle function, but MC+ILEX shows more pronounced structural changes in deep paraspinal muscles (Fortin et al., 2023).

Clinical Outcomes (Pain, Function, Quality of Life)

• Both MC+ILEX and GE significantly reduce pain and disability and improve quality of life in patients with chronic low back pain (Fortin et al., 2023; Tagliaferri et al., 2020; De Zoete et al., 2020).

• The magnitude of improvement in patient-reported outcomes is similar between groups, indicating that while MC+ILEX enhances muscle morphology, this does not necessarily translate to superior clinical outcomes over general exercise (Fortin et al., 2023; Tagliaferri et al., 2020; De Zoete et al., 2020).

Neck Pathologies

• For chronic non-specific neck pain, motor control and strengthening exercises are equally effective for pain and disability, with no clear superiority of one approach over the other (De Zoete et al., 2020).

Fatty Infiltration

• Exercise interventions, including MC+ILEX and GE, do not reliably reverse fatty infiltration in paraspinal muscles, though localized improvements may occur (Wesselink et al., 2022).

Summary Table: MC+ILEX vs. General Exercise

Outcome	MC+ILEX	General Exercise	Citations
Muscle size/thickness	Greater improvement	Moderate improvement	(Fortin et al., 2023)
Pain reduction	Significant	Significant	(Fortin et al., 2023; Tagliaferri et al., 2020; De Zoete et al., 2020)
Disability/function	Significant	Significant	(Fortin et al., 2023; Tagliaferri et al., 2020; De Zoete et al., 2020)
Fatty infiltration reversal	Limited	Limited	(Wesselink et al., 2022)

Figure 1: Table comparing MC+ILEX and general exercise on muscle and clinical outcomes.

Conclusion

Combined motor control and isolated extensor strengthening yields superior improvements in paraspinal muscle morphology compared to general exercise, but both approaches are similarly effective for reducing pain and disability. Structural muscle changes do not always equate to greater clinical benefit, so exercise selection can be tailored to patient preference and goals.

References

Fortin, M., Rye, M., Roussac, A., Montpetit, C., Burdick, J., Naghdi, N., Rosenstein, B., Bertrand, C., Macedo, L., Elliott, J., Dover, G., DeMont, R., Weber, M., & Pepin, V. (2023). The Effects of Combined Motor Control and Isolated Extensor Strengthening Versus General Exercise on Paraspinal Muscle Morphology, Composition, and Function in Patients with Chronic Low Back Pain: A Randomized Controlled Trial. Journal of Clinical Medicine, 12. https://doi.org/10.3390/jcm12185920

Tagliaferri, S., Miller, C., Ford, J., Hahne, A., Main, L., Rantalainen, T., Connell, D., Simson, K., Owen, P., & Belavy, D. (2020). Randomized Trial of General Strength and Conditioning versus Motor Control and Manual Therapy for Chronic Low Back Pain on Physical and Self-Report Outcomes. Journal of Clinical Medicine, 9. https://doi.org/10.3390/jcm9061726

De Zoete, R., Armfield, N., McAuley, J., Chen, K., & Sterling, M. (2020). Comparative effectiveness of physical exercise interventions for chronic non-specific neck pain: a systematic review with network meta-analysis of 40 randomised controlled trials. British Journal of Sports Medicine, 55, 730 - 742. https://doi.org/10.1136/bjsports-2020-102664

Wesselink, E., Pool, J., Mollema, J., Weber, K., Elliott, J., Coppieters, M., & Pool-Goudzwaard, A. (2022). Is fatty infiltration in paraspinal muscles reversible with exercise in people with low back pain? A systematic review. European Spine Journal, 32, 787-796. https://doi.org/10.1007/s00586-022-07471-w