The ankle jerk reflex, also known as the Achilles reflex, occurs when the Achilles tendon is tapped while the foot is dorsiflexed. It is a type of stretch reflex that tests the function of the gastrocnemius muscle and the nerve that supplies it.
Which nerve is responsible for ankle jerk reflex?
The LMN of the Achilles reflex consists of the ventral horn of the S1 nerve root and the tibial nerve.
What does it mean when you have no ankle reflexes?
Usually, absent reflexes are caused by an issue with the nerves in the tendon and muscle. You may have other muscle symptoms along with areflexia, like weakness, twitching, or atrophy.
What does absent Achilles reflex mean?
Your doctor will use a rubber hammer to tap firmly on the Achilles tendon, which connects the muscle at the back of your calf to your heel bone. In a normal test, your foot will move as though you were going to point your toes. A decreased or absent reflex may mean that there is compression in the S1 region.
Why is Achilles reflex important in walking?
In particular, the Achilles tendon is a long tendon that is important for storing and releasing elastic energy during walking, and as such, plays an important role in metabolic energy saving, as it actually “spares” the muscle from performing a large part of the work (3).
What is a normal response for the Achilles reflex?
The Achilles reflex is a monosynaptic stretch reflex similar to the patellar reflex. In the Achilles reflex, the hammer taps the Achilles tendon while the foot is dorsiflexed, and the foot, in response, should jerk toward the plantar surface.
What causes lack of reflexes in legs?
The most common cause of low reflex response is peripheral neuropathy. Diabetes, anemia, and vitamin deficiency are possible causes of absent reflexes.
What can cause slow reflexes?
Reflexes do slow with age. Physical changes in nerve fibers slow the speed of conduction. And the parts of the brain involved in motor control lose cells over time.
What diseases affect reflexes?
Spinal cord injuries are most likely to cause these unusual reflexes, but other disorders that can result in abnormal reflexes include brain tumors, brain trauma, stroke, meningitis, or spinal cord injuries. Reflexes may also be affected by serious conditions including: Parkinson’s disease. Alzheimer’s disease.
What is cauda equina syndrome?
Cauda equina syndrome occurs when the nerve roots in the lumbar spine are compressed, cutting off sensation and movement. Nerve roots that control the function of the bladder and bowel are especially vulnerable to damage.
What does no reflex in left leg mean?
When reflex responses are absent this could be a clue that the spinal cord, nerve root, peripheral nerve, or muscle has been damaged. When reflex response is abnormal, it may be due to the disruption of the sensory (feeling) or motor (movement) nerves or both.
What is an abnormal plantar reflex?
The abnormal plantar reflex, or Babinski reflex, is the elicitation of toe extension from the “wrong” receptive field, that is, the sole of the foot. Thus a noxious stimulus to the sole of the foot produces extension of the great toe instead of the normal flexion response.
When is Babinski reflex normal?
Babinski reflex
When the sole of the foot is firmly stroked, the big toe bends back toward the top of the foot and the other toes fan out. This is a normal reflex up to about 2 years of age.
