Injury

For now and since last friday I'm not training due to an injury on twin muscles on my legs. I don't know if this is the correct muscle name in english! I feel better, already no pain, but I will still more a few days without run to do a safe recovery. I don't know what is the cause of this injury, but this is a recurring ijury, every time I keep a bigger period of timewith regular runs! I should checkout wnat if really the problem!