The effect of manipulation on pressure pain thresholds in the lumbar spine in asymptomatic participants

High-velocity, low amplitude manipulation is commonly advocated by manual therapists for the treatment of low back pain (LBP), however there is little evidence to support its efficacy. This study examined the immediate effects of a single manipulation intervention on pressure pain thresholds (PPT) in the lumbar spine in an asymptomatic population. Sixty-four asymptomatic participants (45 female, 19 male, aged 18-39) were recruited from an osteopathic student population. Participants were screened by palpation for the lumbar spinous process most sensitive to manual pressure, which was marked with a skin pencil. Three pre-intervention PPT measurements were recorded at the marked lumbar segment using a pressure algometer. Participants were randomly allocated into either a treatment group or a sham treatment control. The treatment group received a single application of high-velocity low amplitude (HVLA) manipulation. A post intervention PPT measurement was recorded immediately following the treatment. A small mean increase in PPT was demonstrated in the manipulation group. A dependent t-test revealed this change to be not significant, and a small pre-post effect size was determined. The sham treatment group mean PPT decreased significantly and produced medium effect size. An independent t-test reveled a significant difference between the changes in the control and manipulation group. All pre-post changes were found to be within the error range of the testing procedure. Manipulation of the lumbar spine in asymptomatic participants did not produce a statistically significant change in PPT. Research using symptomatic subjects is recommended for future studies.\ud This minor thesis was written by a post-graduate student as part of the requirements of the Master of Health Science (Osteopathy) program