Definition: Neuromuscular disorders refers to a group of conditions that affect the nerves that control the muscles you can control. These types of muscles are called voluntary muscles and are found in places like your face, chest, neck, abdomen, hands, arms, feet, and legs. In neuromuscular disorders, the nerves stopping working well or die, which in turn affects the communication between the nerves and voluntary muscles. When communication is affected, the muscles weaken and waste away. Symptoms of these types of conditions may include twitching, cramps, aches and pains, and joint and movement issues. Neuromuscular disorders may be genetic or autoimmune.