Ice it. Ice your injury for 20 to 30 minutes every 3 to 4 hours to reduce pain and swelling. Continue this for 2 or 3 days, or until the pain is gone. Compress your leg. Use an elastic bandage around the lower leg and ankle to keep down swelling.
Finally, two terms you may run across in the future are oxidizing agent (or oxidant) and a reducing agent (reductant). An oxidizing agent causes oxidation and is reduced in the reaction. A reducing agent causes the reduction in the redox reaction. The reducing agent is oxidized in the reaction.
In the course of this reaction, CuO is reduced to copper metal. Thus, H2 is the reducing agent in this reaction, and CuO acts as an oxidizing agent. An important feature of oxidation-reduction reactions can be recognized by examining what happens to the copper in this pair of reactions. The first reaction converts copper metal into CuO, thereby transforming a reducing agent (Cu) into an oxidizing agent (CuO).