Final answer:
A goniometer measures joint angles, starting from a neutral anatomical position where the limbs are not necessarily at 0 degrees due to natural body alignment, like the carrying angle at the elbow.
Step-by-step explanation:
A goniometer is a device used to measure the angle of joints and the range of motion in a person's body. The neutral position refers to a standardized anatomical position from which measurements start: an upright stance with upper limbs at the side of the body and palms facing forward. In this position, certain parts of the body are naturally not at 0 degrees; for example, the wrist might be slightly flexed, the elbow extended with a carrying angle, the knee extended, and the ankle might be in a neutral position relative to the leg. The exception is the carrying angle at the elbow, where the forearm deviates laterally by 5-15 degrees due to the anatomy of the elbow and this is considered a normal variation.