Specific force measurements are sensitive and reproducible physiological assessments of a muscle’s maximum force producing capacity. Unlike some of the in vivo functional testing, this test is not influenced by animal behavior or animal handling. Measurements may be carried out on the extensor digitorum longus (EDL), soleus or diaphragm muscles. Muscles are electrically stimulated to contract while attached to a force transducer to measure the maximum force output. The specific force is calculated by normalizing the maximal force produced by the muscle to its cross-sectional area.