Some time ago we reported here about the effect of visual induced analgesia on experimental pain in chronic back pain patients. In short to remind you: we used real-time video feedback; a video camera filmed the back and presented the video in real-time on a monitor in front of the subjects, and that was compared to watching a plain hand video. We found that pain intensity reduced when the participant watched the back video. In the interim we have continued this line of research. We have demonstrated that simply watching the back is sufficient to reduce habitual back pain in chronic back pain patients and that the effects of a massage could be increased by watching the back while being treated.
In our recent study we investigated whether real-time visual feedback offers additional pain relief and cervical proprioceptive improvement when used in combination with manual therapy of the cervical spine in neck pain patients. Cervical proprioception was assessed with the cervical joint position sense acuity.
We found that real-time visual feedback combined with manual therapy enhanced the analgesic effect of manual therapy in neck pain patients, but had no positive effect on the cervical joint position sense, actually it decreased after manual therapy.
In this study, manual therapy was applied as cyclic stretching of passive structures. Speculatively, alterations in the viscoelastic properties of passive structures may have caused altered reflex activity in segmental muscles, thus resulting in a potential mismatch between afferent input and stored memory of the neutral head position in the body schema. This mechanism may have counteracted the beneficial effects of visual feedback on sensorimotor function in the cervical spine. Whether the cervical joint position sense acuity improves some time after the manual therapy or with visual feedback alone still needs investigation. For the daily treatment routines the technical demands and the costs for integrating real-time visual feedback are low and easy to apply.
About Martin Diers
Martin Diers, PhD, is Professor for Clinical and Experimental Behavioral Medicine, at the Department of Psychosomatic Medicine and Psychotherapy, LWL University Hospital, Ruhr University Bochum. He was trained in neuroscientific pain research and has an additional clinical training in behavioral treatment. Any questions about his work can be directed to him at email@example.com
 Diers, M., Zieglgansberger, W., Trojan, J., Drevensek, A.M., Erhardt-Raum, G., Flor, H. (2013). Site-specific visual feedback reduces pain perception. Pain 154, 890–896.
 Diers, M., Loffler, A., Zieglgansberger, W., Trojan, J. (2016). Watching your pain site reduces pain intensity in chronic back pain patients. Eur J Pain 20, 581–585.
 Loffler, A., Trojan, J., Zieglgansberger, W., Diers, M. (2017). Visually induced analgesia during massage treatment in chronic back pain patients. Eur J Pain 21, 1623–1631.
 Beinert, K., Lutz, B., Zieglgansberger, W., Diers, M. (2019). Seeing the site of treatment improves habitual pain but not cervical joint position sense immediately after manual therapy in chronic neck pain patients. Eur J Pain 23, 117–123.