What is the Tibial Posterior Reflex?
The Tibialis-Posterior Reflex belongs to the muscular reflexes. This means that the blow to the tendon of the muscle triggers the reaction in the same muscle. The posterior tibialis muscle is located in the lower leg.
When the corresponding tibialis posterior tendon is struck – i.e. a reflex is triggered – the edge of the foot is lifted upwards on the inside. This is also called supination. The reflex is always checked by comparing the sides, and the one-sided weakening may indicate a herniated disc, for example. The connection of this reflex takes place in the spinal cord at the level of the vertebral bodies L5 and S1. These are located in the lower back.
How do you test the Tibialis-Posterior Reflex?
Muscle reflexes are tested by the examiner hitting the tendon of the muscle to be tested briefly. For this purpose, the muscles must be completely relaxed. For the Tibialis-Posterior Reflex, the patient’s supine position is best suited.
The examiner lifts the knee slightly with his arm and palpates just below or above the inner ankle of the foot (malleolus medialis) for the tibialis posterior tendon. The reflex is triggered by a short, rapid striking movement with the reflex hammer on the tendon and the inner side of the foot is lifted (supination). This test is always carried out in side comparison, since the reflex strength is different in all people and only a side difference can reliably indicate damage.
If the reflex strength is very low, the patient can clench his teeth firmly or cross his hands and pull them apart strongly. This increases the reflex level and the examiner can better assess the reflexes. For a more precise examination, the examiner can also place electrodes on the muscle and nerves and measure the time it takes for the body to transmit the reflex. However, this is only done for very specific questions or for scientific reasons.
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