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a sudden reflex or involuntary movement.
Achilles jerk (ankle jerk) plantar extension of the foot elicited by a tap on the achilles tendon, while the patient is seated on a bed or chair, with feet hanging freely; called also Achilles reflex and triceps surae jerk or reflex.
biceps jerk biceps reflex.
elbow jerk involuntary flexion of the elbow on striking the tendon of the biceps or triceps muscle.
jaw jerk jaw-jerk reflex.
knee jerk see knee jerk.
tendon jerk tendon reflex.
triceps surae jerk ankle jerk.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.
The contraction of a muscle after tapping its tendon.
See also: jerk
Medical Dictionary, © 2009 Farlex and Partners
tendon jerkA reflex contraction of the muscle to which a tendon is attached when the tendon is struck sharply so as to exert a sudden pull on the muscles. This reflex demonstrates the integrity of both the sensory and the motor nerve supply to the muscle. An exaggerated response may indicate the absence of higher nervous control on the reflex.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005