You should see your primary doctor first. Then they will tell you if you need to see a specialist.
There are three types of muscle contraction: concentric, isometric, and eccentric.
Concentric: In a concentric contraction, the muscle tension rises to meet the resistance then remains stable as the muscle shortens. During eccentric contraction, the muscle lengthens as the resistance becomes greater than the force the muscle is producing.
Isometric: An isometric exercise is a form of exercise involving the static contraction of a muscle without any visible movement in the angle of the joint.
Eccentric: An eccentric (lengthening) muscle contraction occurs when a force applied to the muscle exceeds the momentary force produced by the muscle itself, resulting in the forced lengthening of the muscle-tendon system while contracting
