Muscle Activation Patterns in Chronic Low Back Pain

Chronic low back pain is associated with persistent alterations in the way trunk muscles are recruited and coordinated. Rather than uniform increases in muscle activity, individuals with ongoing pain often display spatially shifted or more cranially focused activation of the erector spinae group, alongside reduced signal homogeneity. These changes may reflect protective strategies or maladaptive motor control that perpetuate discomfort and functional limitation. Quantitative techniques have revealed that stiffness of the lumbar fascia and paraspinal muscles is elevated in patients, and that variations in muscle recruitment timing and magnitude correlate with pain intensity and disability. Evidence also points to delayed-onset soreness and pain modulation influencing motor output, with altered electromyographic coherence and cross-correlation patterns emerging under sustained or repetitive loading. An improved understanding of these activation anomalies has important implications for individualised rehabilitation, suggesting that targeted neuromuscular retraining and biofeedback may restore more balanced muscle coordination and alleviate chronic symptoms.

Research from Nature Portfolio

High-density surface electromyography has been employed to examine how muscle soreness affects trunk extensor recruitment. In healthy volunteers experiencing exercise-induced discomfort, refined analysis of low-frequency coherence and cross-correlation revealed contraction-dependent shifts in muscle-to-torque relationships and corresponding changes in lumbar kinematics, without loss of maximal force. These findings demonstrate that even transient pain can reconfigure recruitment patterns and movement strategies. In foundational work on paraspinal mechanics, reliability of a handheld myotonometer was established for assessing lumbar muscle tone and stiffness. This study confirmed acceptable intra-rater consistency across lumbar levels, laying the methodological groundwork for longitudinal tracking of biomechanical properties in chronic low back pain populations.

Muscle Activation Patterns in Chronic Low Back Pain publication trend

The graph below shows the total number of articles in muscle activation patterns in chronic low back pain across all publications each year (not limited to Nature Index journals).

Technical terms

High-density surface electromyography (HDsEMG): A technique using multiple closely spaced electrodes to map the spatial distribution of muscle activity.

Shear-wave elastography (SWE): An ultrasound-based imaging method that quantifies tissue stiffness by measuring the velocity of induced shear waves.

Integrated electromyography (iEMG): A cumulative measure of the electrical activity of a muscle over time, reflecting overall recruitment intensity.

Root mean square (RMS) in EMG: A statistical measure of the magnitude of the electromyographic signal, indicating muscle activation level.

Myotonometer: A handheld device that applies brief mechanical impulses to measure muscle tone and stiffness non-invasively.

References

1. Shear wave elastography based analysis of changes in fascial and muscle stiffness in patients with chronic non-specific low back pain. Frontiers in Bioengineering and Biotechnology (2024).
2. Eccentric exercise-induced delayed onset trunk muscle soreness alters high-density surface EMG-torque relationships and lumbar kinematics. Scientific Reports (2024).
3. Quantifying paraspinal muscle tone and stiffness in young adults with chronic low back pain: a reliability study. Scientific Reports (2018).
4. People With Low Back Pain Display a Different Distribution of Erector Spinae Activity During a Singular Mono-Planar Lifting Task. Frontiers in Sports and Active Living (2019).