The objective of this study was to determine if\u00a0 mechanical force, manually-assisted (MFMA) spinal manipulative therapy\u00a0 (SMT) affects paraspinal muscle strength assessed using surface\u00a0 electromyography (sEMG).<\/p>\n
A disorder in the\u00a0 neuromusculoskeletal system may result in excessive load sharing of the\u00a0 passive system that can cause abnormal motion and increased deformation\u00a0 of its highly innervated structures resulting in LBP. SMT has been found\u00a0 associated with reflex responses in the back musculature, however the\u00a0 clinical relevance of such findings are not understood. The role of\u00a0 rehabilitation programs of improving objective outcomes including\u00a0 increases in trunk muscle strength are important goals of patient care.<\/p>\n
This study is a prospective controlled clinical trial\u00a0 comparing sEMG output in an active treatment group and two control\u00a0 groups.<\/p>\n
Twenty consecutive LBP patients (SMT treatment group)\u00a0 performed maximum voluntary contraction (MVC) isometric trunk extensions\u00a0 while lying prone on a treatment table. Surface, linear enveloped sEMG\u00a0 was recorded from the erector spinae musculature at L3 and L5 during the\u00a0 trunk extension procedure. Subjects were then assessed using the\u00a0 Activator Methods Chiropractic Technique (AMCT) protocol, during which\u00a0 time they were treated using MFMA SMT. The MFMA SMT treatment was\u00a0 followed by a dynamic stiffness and algometry assessment, after which a\u00a0 second or post MVC isometric trunk extension and sEMG assessment was\u00a0 performed. Another twenty subjects were randomized into two control\u00a0 groups, a sham-SMT group, and a control group. The sham-SMT group\u00a0 underwent the same experimental protocol with the exception that the\u00a0 subjects received a sham-MFMA SMT and dynamic stiffness assessment. The\u00a0 control group received no SMT treatment, stiffness assessment, or\u00a0 algometry assessment intervention. Within group (pre-SMT vs. post-SMT\u00a0 sEMG output) and across group analysis of sEMG output from MVC (pre\/post\u00a0 sEMG ratio) was performed using a paired observations t-test (POTT) and\u00a0 analysis of variance (ANOVA), respectively.<\/p>\n
Outpatient chiropractic clinic, Phoenix, AZ, USA. Subjects: Forty total subjects participated in the study.\u00a0 Twenty LBP patients (9 females and 11 males, 35 years and 51 years,\u00a0 respectively) and twenty age and gender matched sham-SMT\/control LBP\u00a0 patients (10 females and 10 males, 40 years and 52 years, respectively)\u00a0 were assessed.<\/p>\n
Surface electromyographic recordings\u00a0 during isometric maximum voluntary contraction trunk extension were used\u00a0 as the primary outcome measure.<\/p>\n
Nineteen of the 20 patients in the SMT\u00a0 treatment group showed a positive increase in sEMG output during MVC\u00a0 (range -9.7% to 66.8%) following the active MFMA SMT treatment and\u00a0 stiffness assessment. The SMT treatment group showed a significant\u00a0 (POTT, P<<0.001) increase in erector spinae muscle sEMG output\u00a0 (21% increase compared to pre-SMT levels) during MVC isometric trunk\u00a0 extension trials. There were no significant changes in pre vs. post- SMT\u00a0 MVC sEMG output for the sham-SMT (5.8% increase) or control (3.9%\u00a0 increase) groups.<\/p>\n
Reference:<\/strong> Tony S. Keller, Ph.D. and Christopher J.\u00a0 Colloca, D.C.; Mechanical Force Spinal Manipulation Increases Trunk\u00a0 Muscle Strength Assessed By Electromyography: A Comparative Controlled\u00a0 Clinical Trial; Proceeding of the 27th Annual Meeting of the International Society for the Study of the Lumbar Spine, Adelaide, Australia, April 9-13, 2000.<\/p>\n