Fig. 3.

Individual classification of group III and IV muscle afferents. There were no statistical differences in the percentage of thermally (cold or heat) or chemically (metabolite) sensitive muscle afferents between the group III and group IV fibers. However, there were significantly more mechanically sensitive group III muscle afferents compared with group IV muscle sensory neurons (*P < 0.05). Although there were no differences in the percentage of cells that responded to each of these different stimulus modalities within the group III afferents, there were significantly more chemosensitive group IV muscle afferents compared with thermally or mechanically sensitive group IV fibers (**P < 0.05).