Superficial cooling inhibits force loss in damaged muscle

The purpose of the study was to determine the effect of muscle damage with and without superficial cooling on force and neural activation of the triceps surae muscles. Seven men performed maximal plantarflexion contractions with and without superficial cooling over the medial gastrocnemius, before, immediate after, and 2 days after transcutaneous electrical stimulation for the medial gastrocnemius, respectively. Transcutaneous electrical stimulation was used to induce muscle damage. The normalized value, which was expressed as percentages of the corresponding relative values obtained before transcutaneous electrical stimulation to after transcutaneous electrical stimulation, of peak torque and integrated electromyogram for the soleus were significantly greater with than without superficial cooling. There was a significant correlation in normalized integrated electromyogram between the medial gastrocnemius and soleus. We conclude that superficial cooling appears to have reduced the magnitude of force loss during maximal voluntary contraction following damage to one of the muscles and the synergistic muscle activation may have contributed to the better force maintenance. The implications of this study are that TES enables more selective damage of muscle than standard protocols, and that superficial cooling over a damaged muscle may have an important role in the acute treatment of muscle injuries.