Chronic pain, defined as pain lasting for >3 months, typically develops from injuries to deep tissues such as muscle, yet little is known about how long-lasting pain affects a person’s blood pressure or capacity to control their muscles. The experience of pain is not limited to the subject’s perception: both the autonomic and somatic motor systems respond to pain. By undertaking this invasive research in awake human subjects, without the confounding effects of general anaesthesia required for invasive animal experimentation, we can correlate our objective measures of the neurophysiological and cardiovascular responses to experimentally-induced pain with the subject’s perceptual responses. This project assesses the effects of tonic muscle pain on sympathetic nerve activity and stretch sensitivity of muscle spindles.