title: Non-thrust manual therapy reduces erector spinae short-latency stretch reflex asymmetries in patients with chronic low back pain.
abstract: 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.
authors.affiliation: Ohio Musculoskeletal and Neurological Institute, Ohio University, Athens, OH 45701, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Goss
authors.forename: James S
authors.initials: JS
authors.lastname: Thomas
authors.forename: Stevan
authors.initials: S
authors.lastname: Walkowski
authors.forename: Shawn C
authors.initials: SC
authors.lastname: Clark
authors.forename: John C
authors.initials: JC
authors.lastname: Licciardone
authors.forename: Guang H
authors.initials: GH
authors.lastname: Yue
authors.forename: Brian C
authors.initials: BC
authors.lastname: Clark
mesh_terms: D001415:Back / Q000503:physiopathology; D059350:Chronic Pain / Q000503:physiopathology* / Q000534:rehabilitation*; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000503:physiopathology* / Q000534:rehabilitation*; D008297:Male; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000294:innervation / Q000503:physiopathology*; D026201:Musculoskeletal Manipulations / Q000379:methods*; D012026:Reflex, Stretch; D016896:Treatment Outcome; D055815:Young Adult