The abdominal reflex is elicited with a blunt object stimulating the lateral regions of the abdomen (upper, middle, and lower) toward the middle line, and, when present, a contraction of the stimulated musculature is observed. Just like the deep reflexes, the superficial ones must be compared with the opposite side at each of the three levels.
The response is normal when a unilateral contraction occurs and abnormal when the reflex is absent or asymmetric.
The superficial reflex (abdominal, cremasteric), in the initial stage of a pyramidal injury of acute onset as occurs with a stroke, may disappear contralaterally to the injury, even before a change in strength, and remain absent or hypoactive, as occurs in children with cerebral palsy (CP). In obese individuals or after abdominal surgery, muscle contraction may be absent.