What the term ' strain ' means? A muscle strain, or a pulled muscle, is a type of injury that commonly occurs when a muscle is overstretched or torn as a result of excessive force or pressure. This can happen when the muscle is either forcefully contracted or suddenly stretched beyond its normal range of motion. Strain can be classified according to its severity, as follows: Grade 1 : This is a mild strain where the muscle is stretched or slightly torn, but the muscle fibers remain largely intact. Symptoms may include some pain and stiffness, but there is typically no loss of strength or function. Grade 2 : This is a moderate strain where the muscle fibers are partially torn. Symptoms may include more significant pain, swelling, and bruising, as well as some loss of strength and function. Grade 3 : This is a severe strain where the muscle fibers are completely torn, and the muscle may be completely separated from its attachment point. Symptoms may include severe pain, swelling,