Pain is considered one of the most relevant symptoms of musculoskeletal disorders (MSD). Myofascial pain with taut bands and trigger points (Tr Ps) of muscles involved is common in the medical practice. Myofascial pain arises by overuse, strain and exhaustion of muscle and after precision work. Chapter One conjectures that these factors cause sustained activity of intrafusal gamma motor units, adjusting the sensitivity of muscle spindles. Chapter Two evaluates the usefulness of deep dry needling and intratissue percutaneous electrolysis in the treatment of temporomandibular myofascial pain. Chapter Three describes the perception of pain and quantifies its intensity among office workers.