Altered Trunk Motor Planning in Patients with Nonspecific Low Back Pain

ABSTRACT

The authors investigated differences in trunk muscle activation timing between patients with chronic nonspecific low back pain (NSLBP) and asymptomatic controls during a self-initiated postural challenge. The authors compared 30 participants with NSLBP to 30 controls. Surface electromyographic data were collected from bilateral trunk muscles. Dependent variables were trunk muscle onset and offset relative to extremity muscle activation and duration of the trunk muscle burst and abdominal–extensor cocontraction. Patients with NSLBP demonstrated significantly delayed trunk muscle onset latency (p < .01), and shorter burst (p = .02) and cocontraction durations (p < .01). Results suggest that patients with NSLBP may be inefficient in regulating trunk posture during voluntary extremity movements. These alterations could also represent a compensatory control pattern imposed by the CNS to avoid pain.

Keywords:

• feedforward postural adjustments
• low back pain
• postural control

ACKNOWLEDGMENTS

This study was supported in part by grants from the Orthopedic Section of the American Physical Therapy Association, U.S. Department of Education, National Institute on Disability and Rehabilitation Research (H133F030024) and NIH, National Institute of Child Health and Human Development (K01HD053632).