When the physiatrist says Caleb has a grade 2 tear to the pectoralis major, she means that Caleb has a moderate muscle injury where a significant number of muscle fibers in the pectoralis major (the large chest muscle) are partially torn but not completely ruptured. This type of tear indicates moderate loss of muscle function, with symptoms such as pain, swelling, bruising, and some weakness or difficulty moving the arm or shoulder on the affected side. Grade 2 tears are more severe than minor strains (grade 1) but less severe than complete ruptures (grade 3).
The pectoralis major is a powerful muscle on the front of the chest that helps move the arm forward, rotate it inward, and pull it across the chest. Injuries like this usually occur from sudden and forceful contraction of the muscle during activities such as weightlifting (especially bench pressing), pushing heavy objects, or other strenuous arm movements.
In summary, a grade 2 tear to the pectoralis major means moderate damage with a significant number of muscle fibers torn, causing pain, bruising, swelling, and some loss of strength or function in the chest and arm area.