Colin has been on bed rest for many months. due to this situation, he has not had much physical movement and starts to feel weakness in his muscles. what is colin’s diagnosis?

Myasthenia would be your correct answer. Hope this helps.

This is what you call Myasthenia it is a type of diagnoses that is due to muscle weakness it can happen when you work out a lot then  quit for a long time  it happens by you not feeding your muscles when you exercise your muscles take in more energy but then you stop and your muscles dont need as much energy so they get weak and decrease in size 
hope I helped!