César Fernández-de-las-Peñas, Marta Pérez-de-Heredia, Miguel Brea-Rivero, Juan C. Miangolarra-Page
The objective of this syudy was to compare the immediate effects on pressure pain threshold (PPT) tested over the lateral elbow region following a single cervical high-velocity low-amplitude (HVLA) thrust manipulation, a sham-manual application (placebo), or a control condition; and to analyze if a different effect was evident on the side ipsilateral to, compared to the side contralateral to the intervention. Fifteen asymptomatic volunteers attended 3 experimental sessions where they received either the manipulation, placebo, or control intervention provided by an experienced therapist. The manipulative intervention was directed at the posterior joint of the C5-6 vertebral level. PPT over the lateral epicondyle of both elbows was assessed preintervention and 5 minutes postintervention by an examiner blinded to the treatment allocation of the subject. The analysis of variance detected a significant effect for intervention. Post hoc analysis revealed that the application of a HVLA thrust manipulation produced a greater increase of PPT in both elbows, as compared to placebo or control interventions. No significant changes in PPT levels were found after the placebo and control intervention. The authors conclude that the application of a manipulative intervention directed at posterior joint of the C5-6 vertebral level produced an immediate increase in PPT over the lateral epicondyle of both elbows in healthy subjects. Effect sizes for the HVLA thrust manipulation were large, suggesting a strong effect of unknown clinical importance at this stage, whereas effect sizes for both placebo and control procedures were small, suggesting no significant effect.
Journal of Orthopaedic and Sports Physical Therapy, 2007, 37(6), 325-329.