<s>[INST] My husband started feeling a pain radiating across his chest from his right shoulder right under the collar bone.  After doing more strenuous activity, the pain moved down to an area inside the right arm that I suppose could be the triceps.  He noticed while trying to apply deodorant this very painful thin something (tendon or muscle?) that protuded across the armpit, extending out obviously under the skin.  It was extremely painful to touch and it is now quite painful to reach with that arm.  Could he have torn something?  Is it a muscle or tendon or what? [/INST] Thanks for your question on Chat Doctor. I can understand your concern. By your history and description, possibility of musculoskeletal pain due to pulled muscle is more. So ask him to follow these steps for better symptomatic relief. 1. Avoid heavyweight lifting and strenuous exercise. 2. Avoid movements causing pain. 3. Avoid bad postures in sleep. 4. Give him painkiller like ibuprofen. 5. Apply warm water pad on affected areas. Don't worry, he will be alright with all these in 1-2 weeks. Hope I have solved your query. I will be happy to help you further. Wishing good health to your husband. Thanks. </s>