what is a strain
1 Strain (injury) , an injury to a muscle in which the muscle fibers tear as a result of over-stretching.2  Strain (manga) , a 1996 manga written by Yoshiyuki Okamura, and illustrated by Ryoichi Ikegami. Strain (injury) , an injury to a muscle in which the muscle fibers tear as a result of over-stretching. 2  Strain (manga) , a 1996 manga written by Yoshiyuki Okamura, and illustrated by Ryoichi Ikegami.