Final answer:
Muscle strains are categorized by severity, from first-degree as the mildest to third-degree as the most severe. Each degree indicates more extensive damage to muscle fibers, affecting pain levels, bruising, and range of motion, with third-degree strains being complete muscle ruptures.
Step-by-step explanation:
The degree of muscle strains refers to their severity and indicates the extent of muscle fiber damage. First-degree strains are the mildest, involving only minor tearing of the muscle fibers, usually resulting in some pain and stiffness but allowing for full range of motion. Second-degree strains involve more extensive damage with more muscle fibers being torn; this leads to increased pain, swelling, and sometimes bruising, along with a decreased range of motion. Third-degree strains are the most severe, with complete rupture of the muscle; they cause significant pain, swelling, bruising, and a complete loss of function in the affected muscle.
It is crucial to treat muscle strains appropriately. Mild first-degree strains often require rest, ice, and over-the-counter pain relief, while severe third-degree strains can necessitate medical intervention and sometimes even surgery.