The text mentioned the size principle but gave no references to who is credited with the principle. Can you share a little more detail about this principle.
Larry, good afternoon I hope you are well and having a great Thursday. With regard to your question, consider the following. Forty-nine years ago Elwood Herman was the man credited with the Size Principle in 1965. According to Mr. Herman motor axons branch in the peripheral nerve to supply muscle fibers in a single muscle; the motoneuron and the dozens to hundreds of muscle fibers it innervates are referred to collectively as the "motor unit." Individual muscles are composed of numerous motor units, ranging from a few to several hundred, depending on the muscle. Contraction of a muscle occurs by activating motoneurons in the pool of motoneurons innervating that muscle. Understanding the control of muscle contraction requires knowledge of how motor units are recruited in response to various inputs.