Manual therapy, 2016/02, 21220-6. doi: 10.1016/j.math.2015.08.008, type of study: ,rct,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

Full text    (https://www.sciencedirect.com/science/article/abs/pii/S1356689X15001708?via%3Dihub)

Keywords:

spinal manipulation [83]
regional blood flow [2]
sympathetic nervous system [20]
vasoconstriction [1]
peripheral skin blood flow [1]
randomized controlled trial [947]

Abstract:

BACKGROUND: Peripheral skin blood flow (SBF) changes during and after spinal mobilization (SM), evaluated with laser Doppler flowmetry, may document physiological responses associated with SM. OBJECTIVES: To document variations in SBF during and after application of an SM and evaluate influence of pressure on SBF by applying the same standardized SM with 3 different nonnoxious pressures. DESIGN: Cross-over design with 4 interventions on 4 different days: control (no touch) and 3 SMs applied rhythmically at 5%, 40%, or 80% of pain pressure threshold (sham SM, low-pressure SM, or high-pressure SM, respectively). METHOD: Thirty-two individuals participated. The inspiratory gasp (IG) test was our positive control of vasoconstriction through excitation of the skin sympathetic nervous activity (SSNA). Each session comprised 5 phases: (1) baseline at the end of a 20-min acclimatization, (2) IG test, (3) post-IG phase, (4) SM phase or no manual contact for control, and (5) post-SM phase. A Biopac MP36 system collected SBF data, and a Novel Pliance-X system recorded pressure data. RESULTS/FINDINGS: Equal and significant bilateral vasodilation occurred during application of unilateral sham SM, low-pressure SM, and high-pressure SM. Post-SM significant vasodilation persisted after high-pressure SM. CONCLUSIONS: The current study is the first to describe bilateral peripheral SBF changes occurring during and 5 min after application of standardized SMs. Our post-SM vasodilation suggests involvement of mechanisms other than the putative SSNA-excitatory mechanism proposed with skin conductance measurements. Persistence of post-SM vasodilation following only high-pressure SM suggests possible pressure-dependent mechanisms. However, further research is warranted to clarify our findings.