Efficacy of osteopathic manipulative treatment for low back pain in euhydrated and hypohydrated conditions: a randomized crossover trial.

CONTEXT: Low back pain (LBP) affects up to 85% of all persons at some time in life and is a condition for which osteopathic manipulative treatment (OMT) has been shown to be beneficial. Measures that can improve the efficacy of OMT would further benefit patients; one such measure, hydration status, was explored in this study. OBJECTIVE: To determine whether there is a relationship between a patient's hydration status before OMT for LBP and the outcome of that treatment. DESIGN: A randomized, single-blind crossover study conducted from March to December 2010. SETTING: Outpatient academic center. PARTICIPANTS: Eight women and 11 men with LBP of 1 to 12 months duration. INTERVENTIONS: Both euhydrated and hypohydrated conditions were achieved in each participant by modifying water consumption for 36 hours before OMT sessions. PARTICIPANTS received 2 sessions of OMT, each in a different hydration condition and with a 1-week washout period in between. MAIN OUTCOME MEASURES: Pre- and posttreatment visual analog scale scores for pain, number and severity of somatic dysfunction as scored on the somatic dysfunction severity scale, and number of asymmetric landmarks found on the osteopathic standing structural examination. RESULTS: Improvements in total and severe number of lumbar somatic dysfunction (P=.001 and P=.013, respectively) and number of asymmetric landmarks on standing structural examination (P=.002) were found to be greater in the euhydrated vs the hypohydrated condition. PARTICIPANTS had a mean of 2 fewer areas of posttreatment somatic dysfunction when euhydrated than when hypohydrated, and they had a mean decrease of 2 asymmetric landmarks on the standing structural examination when euhydrated but none when hypohydrated. Osteopathic manipulative treatment improved self-reported pain immediately after treatment regardless of hydration status. CONCLUSION: Outcome measures improved for all participants, with greater improvement observed after participants were treated in the euhydrated condition than when in the hypohydrated condition. It is reasonable for clinicians to recommend that patients increase their hydration to optimize treatment.