M Haas1, D Peterson, D Hoyer, G Ross. 1. Research Department, Western States Chiropractic College, Portlan, OR 97230-3099.
Abstract
OBJECTIVE: To evaluate the relationship of muscle strength response to a provocative vertebral challenge and to spinal manipulation. DESIGN: Prospective double-blind randomized controlled trial: crossover and between subjects designs. SETTING: Laboratory: Center for Technique Research. PARTICIPANTS: Sixty-eight naive volunteers from the student body, staff and faculty of the college. INTERVENTIONS: Provocative vertebral challenge: standardized 4-5 kg force applied with a pressure algometer to the lateral aspects of the T3-12 spinous processes. INTERVENTION: manual high velocity low amplitude adjustment or switched-off activator sham. MAIN OUTCOME MEASURES: Piriformis muscle response was defined in two ways: reactivity (a decrease in muscle resistance, yes or nor, following a vertebral challenge); responsiveness (the cessation of reactivity following spinal manipulation). Relative response attributable to the maneuver (RRAM): the percent of an outcome attributable to the challenge or adjustment itself. RESULTS: Average RRAM = 16% reactivity to vertebral challenge; average RRAM = 0% responsiveness to spinal manipulation. Six to 10% of muscle tests were positive regardless of examiner, previous finding or intervention. CONCLUSIONS: For the population under investigation, muscle response appeared to be a random phenomenon unrelated to manipulable subluxation. In and of itself, muscle testing appears to be of questionable use for spinal screening and post-adjustive evaluation. Further research is indicated in more symptomatic populations, different regions of the spine, and using different indicator muscles.
RCT Entities:
OBJECTIVE: To evaluate the relationship of muscle strength response to a provocative vertebral challenge and to spinal manipulation. DESIGN: Prospective double-blind randomized controlled trial: crossover and between subjects designs. SETTING: Laboratory: Center for Technique Research. PARTICIPANTS: Sixty-eight naive volunteers from the student body, staff and faculty of the college. INTERVENTIONS: Provocative vertebral challenge: standardized 4-5 kg force applied with a pressure algometer to the lateral aspects of the T3-12 spinous processes. INTERVENTION: manual high velocity low amplitude adjustment or switched-off activator sham. MAIN OUTCOME MEASURES: Piriformis muscle response was defined in two ways: reactivity (a decrease in muscle resistance, yes or nor, following a vertebral challenge); responsiveness (the cessation of reactivity following spinal manipulation). Relative response attributable to the maneuver (RRAM): the percent of an outcome attributable to the challenge or adjustment itself. RESULTS: Average RRAM = 16% reactivity to vertebral challenge; average RRAM = 0% responsiveness to spinal manipulation. Six to 10% of muscle tests were positive regardless of examiner, previous finding or intervention. CONCLUSIONS: For the population under investigation, muscle response appeared to be a random phenomenon unrelated to manipulable subluxation. In and of itself, muscle testing appears to be of questionable use for spinal screening and post-adjustive evaluation. Further research is indicated in more symptomatic populations, different regions of the spine, and using different indicator muscles.
Authors: Wadie I Najm; Michael A Seffinger; Shiraz I Mishra; Vivian M Dickerson; Alan Adams; Sibylle Reinsch; Linda S Murphy; Arnold F Goodman Journal: BMC Complement Altern Med Date: 2003-05-07 Impact factor: 3.659