I explain how to assess each part of the arms in my book Tending the Body. But the part of the arms most frequently in trouble, being restricted, weak, and uncoordinated, is the forearms. Our ability to turn our forearms, which turns the palm upward and downward, is the most likely root cause of arm pain and problems.
Tight forearms are almost always due to tight muscles in the forearms, and tight muscles in the forearms are either too cold or too dry. At least, that's how Hippocrates (ca 460 BC), the Father of Medicine, would have looked at it. Cold tissues are frozen, unable to move, and dry tissues are hard tissues that refuse to soften to allow motion. Cold tissues need to be warmed, while dry tissues need to be moistened. If your forearms are tight, consider whether they are cold, dry, or a combination of cold and dry:
1) Cold forearms: Cold forearms usually feel cold, or at least don't feel warm to the touch. They can usually move through a reasonable range of motion, but they feel weak and uncoordinated when they do so. To warm forearms that are too cold, you can use exercise or massage. Exercise heats the tissues by pumping blood into them, and massage heats the tissues by rubbing them. Both are useful for overcoming cold forearms. Squeezing a tennis ball is a simple way to exercise and thereby warm the forearms. Massaging the forearms with some oil can be very helpful to add warmth. You don't have to press hard. It's the pressure and movement of the massage that warms the tissues.
2) Dry forearms: Dry forearms usually feel tight when stretched and feel hard when touched. The tissues are stiff. Dry muscles are also easily fatigued. When exercised, they tire quickly. Dry forearms respond best to gentle massage with oil. The oil is moistening and the gentle pressure helps to soften the hard tissues. This is very important: hard massage hardens tissues and soft massage softens tissues. So if your forearms feels hard, then soft massage is best. A word of warning: lots of exercise and long massages are both drying. They will make dry forearms worse. Dry forearms are often caused excessive amounts of exercise. I once dried my forearms out by putting together furniture for eight hours straight. And I have to be constantly careful about drying out my forearms because I used them all day in my work. Doing things weren't not used to doing for excessive amounts of time is the most common way to dry out a tissue.
3) Cold and dry forearms: Cold and dry forearms show a combination of both cold and dry problems: the forearms are both cold and hard to the touch, they are weak and easily fatigued in exercise, and they are stiff and tight when stretched. We need to be a bit careful with forearms that are both cold and dry because exercise is not only heating but also drying. It's fine to do some tennis ball squeezes, but we don't want to tire out the forearms, leaving them even more dry. Short but frequent gentle massage with oil is the key for the cold and dry forearms. The massage will heat the tissues, the oil will moisten the tissues, and the gentle pressure will help to soften the tissues. The difference between our regimen for dry forearms versus cold and dry forearms is that cold and dry forearms should be exercised a bit (but not at all excessively) and should be massaged more frequently to help to keep the tissues warm.
A note on cold and dry tissues: According to the ancient tradition of Hippocrates, as we age we grow colder and drier, and so our tissues are also heading in this direction. The older we get, the more likely we are to suffer with cold and dry tissues. I recently gave a talk at a retirement community entitled Tending the Old Body. You can read the essay I wrote to accompany the talk by clicking on the file to the right. It discusses many things, including some more details about what Hippocrates says about old age. Anyone who is already old (or who is planning to someday become so) may want to consider what it has to say.