Ankle jerk reflex


Ankle jerk reflex

The ankle jerk reflex, also known as the Achilles reflex, occurs when the Achilles tendon is tapped while the foot is dorsi-flexed. A positive result would be the jerking of the foot towards its plantar surface.

The Achilles reflex checks if the S1 and S2 nerve roots are intact and could be indicative of sciatic nerve pathology. It is classically delayed in hypothyroidism. This reflex is usually absent in disk herniations at the L5-S1 level.

A reduction in the ankle jerk reflex is also indicative of peripheral neuropathy.

See also

*Tonic vibration reflex


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  • ankle jerk — n a reflex downward movement of the foot produced by a spasmodic contraction of the muscles of the calf in response to sudden extension of the leg or the striking of the Achilles tendon above the heel called also Achilles reflex …   Medical dictionary

  • ankle jerk — a deep tendon reflex elicited when the Achilles tendon is stretched and then struck with a tendon hammer. The normal response is reflex contraction of the calf muscles and plantar flexion of the ankle. The ankle jerk may be increased if the… …   The new mediacal dictionary

  • ankle jerk — noun : a reflex downward movement of the foot due to a spasmodic contraction of the muscles of the calf caused by sudden extension of the leg or by striking the Achilles tendon above the heel * * * a reflex extension of the foot, caused by… …   Useful english dictionary

  • ankle jerk — a reflex extension of the foot, caused by contraction of the muscles of the calf, resulting from a sharp tap on the Achilles tendon; Achilles reflex. [1885 90] * * * …   Universalium

  • Jaw jerk reflex — The jaw jerk reflex or the masseter reflex is a stretch reflex used to test the status of a patient s trigeminal nerve (CN V).[1] The mandible or lower jaw is tapped at a downward angle just below the lips at the chin while the mouth is held… …   Wikipedia

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  • jerk — 1. A sudden pull. 2. SYN: deep reflex. ankle j. SYN: Achilles reflex. chin j. SYN: jaw reflex. crossed j. SYN: crossed reflex. crossed adductor j. SYN: crossed adductor reflex. crossed knee j. SYN: crossed knee reflex. elb …   Medical dictionary

  • jerk — n. the sudden contraction of a muscle in response to a nerve impulse. The knee jerk (see patellar reflex) is the reflex kicking movement produced by contraction of the quadriceps muscle of the thigh after it has been stretched by tapping the… …   The new mediacal dictionary

  • Stretch reflex — The stretch reflex (myotatic reflex) is a muscle contraction in response to stretching within the muscle. It is a monosynaptic reflex which provides automatic regulation of skeletal muscle length. When a muscle lengthens, the muscle spindle is… …   Wikipedia