The effects of high-velocity low-amplitude thrust manipulation and mobilisation techniques on pressure pain threshold in the lumbar spine

ObjectiveTo compare changes in pressure pain threshold (PPT) following spinal high-velocity low-amplitude thrust manipulation (HVLAT) and spinal mobilisation.DesignFifty asymptomatic subjects (mean age 27 (6) years; 29 males and 21 females) volunteered to participate in a randomised controlled, singled blinded design study. Subjects were screened for suitability and were randomly allocated into one of three intervention groups where they received either a unilateral spinal HVLAT or a spinal mobilisation of the lumbar spine, or a sham ‘laser’ procedure (control). PPT measurements were made immediately pre- and post-intervention, using a hand-held algometer which was positioned directly over the lumbar spinous process. A two-way ANOVA with repeated measures was conducted to determine PPT changes between the groups. Statistical significance was set at the 0.05 level.ResultsThere were no significant differences in PPT across time for each of the groups (P = 0.584). The mobilisation group displayed a small increase, though not a significant change in the mean pressure pain threshold (0.434(0.55) kg/cm2), although effect size was considered to be large (ES = 0.78). The HVLAT group demonstrated a decrease in the mean PPT (−0.173(0.48)) (ES = 0.36, small), and a smaller decrease was noted for the control group (0.105(0.425) kg/cm2) (ES = 0.25, small).ConclusionNeither spinal HVLAT nor mobilisation had a significant effect on PPT of the lumbar spine in asymptomatic subjects. Only spinal mobilisation appeared to have a greater mean increase in PPT and effect size than the control group. Further investigation into the hypoalgesic effects of these techniques on symptomatic subjects is suggested.