The effect of experimentally induced acute pain on lumbar movement control: a single blinded three-arm cross-over...

Non-specific low back pain exhibits high prevalence and is commonly correlated with deficits in lumbar movement control. Whether pain precipitates these impairments or arises as their sequela remains uncertain. This study investigates how experimentally induced acute pain influences lumbar movement control.

Forty-five healthy, pain-free participants underwent three experimental conditions in randomized order: hypertonic saline injection to the lumbar paraspinal muscle (inducing local pain), hypertonic saline injection to the deltoid muscle (inducing remote pain), and isotonic saline injection to the lumbar paraspinal muscle (sham). A standardized, reliable and validated battery of lumbar movement control tests was performed before, during and after each condition and rated by an examiner blinded towards the experimental intervention. Perceived pain intensity was evaluated every 30 s using the numeric rating scale.

While initial analysis revealed a significant overall effect (χ²(8) = 23.45; p = 0.003, W = 0.26), post hoc pairwise comparisons showed no significant differences of movement control test results either within or between experimental conditions. Mean differences following the injections were small (pain_LB vs sham: MD -0.29, 95% CI -0.70 - 0.12; pain_ARM vs sham: MD -0.16, 95% CI -0.56 - 0.25; pain_LB vs pain_ARM: MD 0.07, 95% CI -0.41 - 0.55). As expected, pain intensity was significantly lower in the sham condition than in either experimental condition, confirming successful pain induction. Exploratory regression analyses revealed no significant associations between pain intensity on lumbar movement control.

Experimentally induced acute pain exerted no detectable effect on lumbar movement control. Across analyses, performance remained stable, indicating short-term robustness to transient nociceptive input.

DRKS00038877 (retrospectively registered; January 6th, 2026).