Subjective pain sensation is linearly correlated with the flexion reflex in man.
In an attempt to define the relationship between physiological and psychological correlates of pain during low-level voluntary contraction, electrical stimuli between threshold and maximally tolerable intensities were delivered to the sole of the foot in 7 normal subjects. The two measures used to assess the response magnitude are: (1) the flexion reflex (FR) in the ipsilateral biceps femoris (BF), and (2) the estimate of perceived intensity reported on a visual analog scale (VAS). Our results showed that both BF FR area and VAS ratings bore a direct linear relationship with stimulus intensity and with each other, suggesting that at least under our paradigm, the sensory component of a nociceptive stimulus may already be largely set at the spinal interneuronal level.
Chan
C W
CW
School of Physical and Occupational Therapy, McGill University, Montreal, Que., Canada.
Dallaire
M
M
D000328:Adult; D005260:Female; D006801:Humans; D009119:Muscle Contraction; D010146:Pain / Q000503:physiopathology*; D010147:Pain Measurement; D012018:Reflex / Q000502:physiology*; D012684:Sensory Thresholds