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Spine (Phila Pa 1976). 2003 Jun 1;28(11):1091-6; discussion 1096.

Full Text Comment in
Aust J Physiother. 2004;50(1):57.

Abstract
STUDY DESIGN: Double-blind, randomized, placebo-controlled trial.

OBJECTIVES: To evaluate the effect of manual endplay assessment on neck pain and stiffness outcomes in neck pain patients receiving spinal manipulation.

SUMMARY OF THE BACKGROUND DATA: There have been no studies on the efficacy of palpation used as an indicator for manipulation in the management of back and neck pain.

METHODS: Neck pain patients (n = 104) were randomly assigned to two groups. The study group received manipulation targeted to individual cervical vertebrae according to endplay restriction noted by the examining clinician. The control group received manipulation determined by sham, computer-generated examination findings; endplay examination was ignored and served as a placebo assessment. Treatment was rendered on a single occasion by a chiropractor. Outcomes were neck pain and stiffness assessed before and after manipulation and at least 5 hours following treatment.

RESULTS: The study and control groups showed clinically important improvement in neck pain and stiffness. However, there were no clinically important or statistically significant differences between the study and control groups in terms of pain or stiffness outcomes. Findings were robust across patient, complaint, and treatment characteristics.

CONCLUSIONS: Endplay assessment in and of itself did not contribute to the same-day pain and stiffness relief observed in neck pain patients receiving spinal manipulation. The impact on a longer course of treatment remains to be investigated. The data suggest that pain modulation may not be limited to mechanisms associated with manipulation of putative motion restrictions.

PubMed Reference:  http://www.ncbi.nlm.nih.gov/m/pubmed/12782973/