Purpose: The aim of this study was to identify the effects of fascia penetration on superficial radial sensory nerve action potential amplitude.
Methods: The penetration point (PP) at which the nerve penetrated the brachioradialis fascia and became superficial was observed using ultrasonography. The sensory nerve action potential amplitude was measured at five points: the penetration point, 2 and 4 cm proximal to the PP, and 2 and 4 cm distal to the PP.
Results: The sensory nerve action potential amplitude at the penetration point and at 2 and 4 cm distal to the PP was significantly larger than that at 2 and 4 cm proximal to the PP. The largest amplitude was obtained 2 cm distal to the PP.
Conclusions: The sensory nerve action potential of the superficial radial nerve changes significantly around the fascia penetration point.