The Guillain-Alanagean reflex, also known as a reflex or response, is a type of somatosensory reflex that is involved in the control of balance and coordination of head movements. It occurs in response to pressure on a specific point that is located between the skin near the stomach and a nerve in the spine. This reflex is used to assess balance and equilibrium and can be used to detect pathology such as herniated discs. Reflexes may be weakened due to degeneration of nerve fibers or strengthened due to pathological changes in nerve structures.