Root value of tendocalcaneus reflex?

ANSWER: (C) S1, S2REF: Harrison's 18th ed ch: 367Repeat (**)Root value of some important deep tendon reflex: (Major contribution m bold;Jaw jerkBoth the sensory and motor aspects of this reflex are through CN V (Trigeminal nerve)Biceps(C5, C6),Brachioradialis(C5, C6)Triceps(C7, C8)Patellar or quadriceps: knee jerk(L3, L4)Achilles: ankle, tendocalcaneal jerk(SI, S2)Deep tendon Reflexes may be enhanced by asking the patient to voluntarily contract other, distant muscle groups (Jendrassik maneuver). For example, upper limb reflexes may be reinforced by voluntary teeth-clenching, and the Achilles reflex by hooking the flexed fingers of the two hands together and attempting to pull them apart.GRADING OF REFLEXES0Absent1present but diminished2Normoactive3Exaggerated4Clonus