Recently, a study published in "European Journal of Pain" demonstrated a significant reduction in spinal nociception of chronic back pain patients and also improved their descending pain inhibition under nociceptive flexor reflex (RIII reflex) feedback training.

Descending pain inhibition causes the suppression of spinal nociception which further decreases the nociceptive input to the brain. Descending pain inhibition is accentuated by cognitive and emotional processes. It is impaired, possibly contributing to pain persistence in the subjects who are suffering from chronic pain. An earlier stated feedback method trains patients to activate their descending inhibition. Participants are encouraged to use cognitive-emotional strategies to decrease their spinal nociception, as quantified by RIII reflex, under visual feedback about their RIII reflex size.

The study was conducted to assess if the subjects with chronic back pain can attain modulation of their descending pain inhibition under RIII feedback.

A total of 33 participants suffering from chronic back pain received either true (n = 18) or sham RIII feedback (n = 15), 15 healthy control subjects received true RIII feedback.

A significant RIII suppression was noted in all the three groups. The largest RIII was seen in controls (to 76 ± 26% of baseline), intermediate in chronic back pain subjects receiving true feedback (to 82 ± 13%) and smallest in chronic back pain subjects receiving sham feedback (to 89 ± 14%, all p < 0.05). But, only those chronic pain patients who received true feedback showed significant improvement in descending inhibition over the feedback training, quantified by the conditioned pain modulation effect.