@nony - When I started doing workouts I started out by looking at a human body diagram and identifying all of the different muscle groups on the body.
While it’s useful to isolate named muscles one by one, you quickly discover that a lot of muscles work together. This is the reason that people who suffer injury in one muscle will often have to strengthen an entire group of muscles in order to recover.
Those additional muscles help to compensate for the weakened use of the injured muscle, so if you make them stronger you can regain full use of your body more quickly. As a result, whenever I sprained something like a forearm muscle I made it a point to work out all of the relevant muscle groups, and I recovered a lot faster.