About the problems on Albedo's shoulders.

You've probably seen Albedo fixing the problem with his joints. But now, I want to know the cause of this.

1. Chronic Pain. When Albedo has chronic pain in his joints, the sensation can range from discomfort to severe pain.

2. Not Accustomed. Albedo may not be used to having a sword fight, or he may not do it on a daily basis. As long as he can do other types of fighting (like hand-to-hand combat, etc.) even someone considered sedentary.

3. Others. Give your suggestions.