Two-week balneotherapy in a spa setting for chronic low back pain in older adults: a pilot randomized controlled trial

Abstract Background Chronic low back pain (CLBP) is common and disruptive in older adults, whose multiple illnesses and medications restrict the pharmacological treatments available. This pilot study assessed the short-term effects of a two-week balneotherapy programme on pain, physical function, fatigue, and mechanical pain tolerance, and changes in lumbar skin temperature measured by infrared thermography. Methods A pilot randomized controlled trial in a spa environment, 32 participants aged 65 or older with CLBP were randomly assigned to balneotherapy ( n = 19) or to an untreated control group ( n = 13). The intervention consisted of two treatments daily for 14 consecutive days: immersion in a thermal pool with hydromassage followed by spinal flexibility exercises, taken in turn with partial spinal steam and a localized massage shower. The main outcome was average pain over the past seven days on an 11-point numeric rating scale. Secondary outcomes were pain at rest and on movement, disability (Oswestry Disability Index), fatigue (Fatigue Assessment Scale), spinal mobility, lumbar pressure pain thresholds, and lumbar skin temperature at seven regions. Differences between groups were estimated by analysis of covariance adjusted for baseline; secondary outcomes were corrected for multiplicity (Benjamini–Hochberg). Results Balneotherapy was linked to a greater decrease in mean pain intensity than no treatment (adjusted difference − 1.51 points, 95% CI − 2.84 to − 0.17; p = 0.028; Cohen d = − 0.83), a finding consistent across six sensitivity analyses. At least a 30% pain reduction was achieved by 44% of the balneotherapy group and 17% of controls (difference + 27.8% points, 95% CI − 6.7 to + 52.7). No secondary outcome differed between groups, including all seven thermographic regions, and none remained significant after adjustment for multiplicity. Baseline pressure pain thresholds were not balanced between groups, and no conclusions are drawn from this outcome. No adverse events were recorded. Conclusions In older adults with CLBP, two weeks of balneotherapy were linked to a lower mean pain intensity than no treatment, without noticeable changes in lumbar skin temperature or the other secondary outcomes. The trial was not designed to detect efficacy, so these findings need confirmation in a properly powered study with an active comparator. Trial registration ClinicalTrials.gov NCT05078008 (https//clinicaltrials.gov/study/NCT05078008), registered 13 October 2021. Differences between the registered record and the trial as conducted are described in the Methods and Limitations.