Mislim da je to
proba tonjenja ili test tonjenja

https://www.google.rs/search?q="pronator drift test"&ie=utf-...

http://www.nejm.org/doi/full/10.1056/NEJMicm1213343
During a pronator-drift test, a patient is asked to hold his or her arms outstretched with palms facing upward.
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In the presence of an upper motor neuron lesion, the supinator muscles in the upper limb are weaker than the pronator muscles, and as a result, the arm drifts downward and the palm turns toward the floor.

https://www.google.rs/url?sa=t&rct=j&q=&esrc=s&source=web&cd...
5a. Motorika – počinje se sa neparetičnom stranom – lijeva ruka (test tonjenja – kod sjededih bolesnika podići ekstendiranu ruku za 90°, a kod ležedih bolesnika za 45° od kreveta; glasno ili prstima brojati sekunde)
(kod kome skorovati „4“; kod amputacije i slično skorovati „0“)
0 – bez tonjenja poslije 10 s
1 – pronacija i tonjenje u 10 s, ali ne dotiče krevet
2 – ruka tone do kreveta, ali moguć otpor
3 – ruka pada, nema otpora, minimalan pokret
4 – bez pokreta

https://en.wikipedia.org/wiki/Pronator_drift
Pronator drift
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The patient is asked to hold both arms fully extended at shoulder level in front of them, with the palms upwards, and hold the position. If they are unable to maintain the position the result is positive.
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Interpretation

This is a test of upper motor neuron disease.

If a forearm pronates, with or without downward motion, then the person is said to have pronator drift on that side reflecting a contra-lateral pyramidal tract lesion. A lesion in the ipsilateral cerebellum or ipsilateral dorsal column usually produces a drift downward, along with slow pronation of the wrist and elbow.