An investigation of grade III posteroanterior mobilisations to the thoracic spine on pain pressure threshold and sympathetic nervous system activity comparing joints above and below.

Previous findings suggest that spinal manual therapy (SMT) has the ability to induce pain relief and increase sympathetic nervous system (SNS) activity. This is suggested to occur due to stimulation of the descending inhibitory pathways, projecting from the dorsi periaqueductal gray (dPAG) matter of the midbrain. The current study investigated the effects of grade III posteroanterior mobilisations to three thoracic vertebrae, utilising pain pressure threshold (PPT) and SNS activity as measures. PPT was measured at T4 only in order to compare the effects of mobilising a vertebra directly as well as above and below. 12 healthy male participants (age 77.3 ± 11.2: height, 76.6cm ± 11.3: mass, 80.9kg ± 12.5) took part in this randomised, repeated measures, cross-over design study. Results reflected an immediate hypoalgesic effect of spinal manual therapy, demonstrated through increased PPT, occurring concurrently alongside increased SNS measures of skin conductance (SC). PPT percentage change (PC) was higher in adjacent vertebrae in comparison to T4, however a Friedman’s test revealed no significant difference between the three vertebrae mobilised (χ22 = 3.167, P = 0.205). Therefore SMT demonstrated global effects as well as local. A 2 way repeated measures ANOVA deemed SC as significantly different from pre to post treatment in T3 (t (11) = -3.381, p= 0.006) and significant differences were noticed in HR over the same time period, in T3 (t(11) = -3.381, p= 0.006) and T4 (t(11) = -3.643, p=0.004). However HR unexpectedly demonstrated a significant decrease. In summary, this study demonstrates immediate effects of SMT both locally and globally, utilising PPT and SNS activity as measures to justify this