Pain Sensitivity

Sleep is a critical determinant of physiological recovery and pain regulation. Growing evidence suggests that sleep disruption directly heightens central and peripheral pain sensitivity to sensory stimuli (e.g., mechanical pressure, thermal stimuli), serving as a significant risk factor for the onset and persistence of musculoskeletal pain. However, the precise mechanisms through which sleep quality regulates bodily sensory sensitivity and influences the onset, progression, and recovery trajectories of acute musculoskeletal pain in the general public remain insufficiently understood. This study aims to investigate the relationship between sleep condition, pain sensitivity, and musculoskeletal pain dynamics in healthy adults from the general population, regardless of their physical activity levels. Utilizing a standardized, safe, and fully reversible exercise-induced muscle soreness (EIMS) protocol as an experimental pain model, this project will continuously evaluate participants' quantitative sensory testing (QST) profiles and sleep parameters. The findings from this study will advance the mechanistic understanding of sleep-mediated pain modulation, providing evidence-based insights to inform future targeted sleep management and pain prevention interventions.

Insomnia exacerbates pain sensitivity and impairs physiological recovery from acute musculoskeletal pain. Repetitive transcranial magnetic stimulation (rTMS) has emerged as a promising non-invasive neuromodulation intervention to alleviate pain and modulate central sensory processing. However, whether rTMS can effectively mitigate insomnia-induced pain hyperalgesia and accelerate the recovery trajectory of acute musculoskeletal pain remains unclear, as does the optimal neuroanatomical stimulation target. Building upon an established experimental pain model, this randomized, sham-controlled study aims to evaluate the restorative effects of three distinct rTMS interventions - targeting the left primary motor cortex (L M1), the right dorsolateral prefrontal cortex (R DLPFC), and a sham condition - on individuals experiencing insomnia. Following a standardized eccentric exercise protocol to induce muscle soreness, participants will receive three sessions of the allocated rTMS intervention at 0, 24, and 48 hours post-exercise. Pain sensitivity, recovery dynamics, and quantitative sensory testing (QST) metrics will be continuously monitored across the recovery timeframe. The findings from this trial will clarify the therapeutic efficacy of rTMS in modulating acute pain under insomnia states and identify the target-specific mechanisms of cortical stimulation, offering evidence-based non-invasive interventions for musculoskeletal pain management.

In this study, we want to investigate how pain processing and sensation are related to a certain part of the nervous system, the so-called autonomic nervous system. For this purpose, we apply heat and pressure stimuli to the skin and test pain processing by means of ratings scales and sensory tests. Breathing, heart rate and sweat response are also measured. To assess the spinal cord level, we measure muscle response (measured by electromyography, EMG) to electrical stimulation. Additionally, sensory nerves will be stimulated at the ear and participants will also be given various questionnaires to complete.