The principal basis for estimation of muscle changes and inflammation in the rabbit soleus and gastrocnemius muscle after unilateral EMS/E.

The parameters used are variability in fiber size (overall existence of small and large sized fibers), fibrosis (abnormal presence of connective tissue), frequency of internal nuclei (percentage of fibers containing internal nuclei), frequency of fiber splitting per unit area (split fibers per mm2 muscle cross-sectional area), frequency of necrotic fibers per unit area (necrotic fibers per mm2 muscle cross-sectional area) and inflammation (degree of inflammatory cell infiltration in the muscle).