Non-thrust manual therapy reduces erector spinae short-latency stretch reflex asymmetries in patients with chronic low back pain

David A. Goss, James S. Thomas, Stevan Walkowski, Shawn C. Clark, John C. Licciardone, Guang H. Yue, Brian C. Clark

Research output: Contribution to journalArticle

6 Scopus citations


The purpose of this study was to determine if non-thrust manual therapy (MT) attenuated side-to-side differences (asymmetry) of the erector spinae (ES) stretch reflex amplitude in nine patients with chronic LBP. We used electromechanical tapping to elicit short-latency stretch reflexes (SR) from the ES muscles before and after non-thrust MT. A large asymmetry in the SR was observed at baseline, with the higher of the paraspinal sides exhibiting a 100.2 ± 28.2% greater value than the lower side. Following the intervention, this SR asymmetry was reduced (100.2 ± 28.2% to 36.6 ± 23.1%; p=0.03). This change was largely due to reduced amplitude on the side that was higher at baseline (35% reduction following treatment; p=0.05), whereas no change over time was observed in the low side (p=0.23). Additionally, there was no difference between the respective sides following the intervention (p=0.38), indicating that the asymmetry was normalized following treatment. These findings provide insight into the mechanism(s) of action of non-thrust MT, and suggest that it acts to down regulate the gain of the muscle spindles and/or the various sites of the Ia reflex pathway. Ultimately, developing a better understanding of the physiologic effects of manual therapies will assist in optimizing treatment strategies for patients with LBP.

Original languageEnglish
Pages (from-to)663-669
Number of pages7
JournalJournal of Electromyography and Kinesiology
Issue number5
StatePublished - 1 Oct 2012



  • Chiropractic
  • EMG
  • Muscle
  • Osteopathic
  • Spinal manipulation
  • Spine

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