Example of temporal summation in response to pressure applied either to the knee joint or to the anterior tibialis muscle at the pressure-pain threshold in people with osteoarthritis. VAS scores were normalized for comparison by subtracting the first stimulus pain score from subsequent pain scores. Group A had more clinical pain with VAS scores of 6/10 or greater and Group B had clinical pain scored less than 6/10. These two groups were compared to age and sex-matched controls. The greatest temporal summation occurred in the group with the highest pain scores. *, p<0.05 Group A different from controls and Group B; Group B different from Controls. Reprinted from  with permission of the International Association for the Study of Pain.