They are essentially phenomena of decerebrate rigidity. The lower extremities are extended and adducted, the forearm pronated the wrist and hand often flexed and generally everted or supinated.

Under reflexes are generally included deep (or tendon and periosteal) and superficial or cutaneous reflexes. To these may be added pathologic reflexes of spinal automatism and other organic reflexes. The value of the reflexes consists in the objective evidence which they furnish about the muscles, peripheral nerves, and the central segmental nervous system. They are comparatively easily elicited.

But the mere presence or absence of a reflex is not in it self sufficient to indicate the nature or even the definite presence of organic disease, unless properly correlated with other findings. This is particularly true of the deep reflexes, which may be unduly lively in some normal persons, naturally sluggish in others and strongly inhibited under conditions of tension in still others. If the deep and some superficial reflexes on both sides and equally lively or equally sluggish they may or may not be significant: but if they differ on two sides they then become diagnostically important. Even then it is sometimes difficult without additional evidence to state whether the deep reflexes are decreased on one side or increased on the other.

It is extremely important to know the reflex arc, both the peripheral nerve and the central motor segment upon whose integrity the particular reflex tested for depends. It is well to specify in the more or less arbitrary numerical terms given below the strength of each reflex both on the right and the left side, thus are:

Deep :

Right Biceps (2) and Left Biceps (2)

Right Patellar (1) and Left Patellar (2)

Right Achilles (0) and Left Achilles (0)

Superficial :

Right Upper abdominal (2) and Left Upper abdominal (0)

Right Lower abdominal (2) and Left Lower abdominal (0)

Right Cremasteric (2) and Left Cremasteric (0)