Strengthening a muscle could be done with simple static flexing of the muscles without moving the body, try 10 to 20 static flexing of certain muscle groups with breath in and out and feel the increase in blood circulation and decrease in pain symptoms.
It could be as simple as that.
Note: These blog posts are general ideas that I find could help people to cope with their daily aches and pains and muscle tension they are experiencing in their daily lives. Keep in mind that it is best to get a proper physical exam assessment with a therapist in order to meet your personal health goals. If you are seeking a diagnosis of an issue it’s best to see a medical doctor.