Posterior Cricoarytenoid Muscle Oral

The PCA can be accessed by inserting the hooked-wire electrodes from the pharyngeal side 10 mm caudally to the interarytenoid area.

EMG Activity

• If the electrode is inserted too cranially, the interarytenoid muscle will be recorded instead of the PCA.
• If the needle is placed too caudally, recording the activity of the cricopharyngeal muscle, a strong constant EMG activity will be observable, decreasing during swallowing.
• The correct position is confirmed through the detection of increased EMG activity during sniffing, and with considerably weaker EMG activity during swallowing (in differentiation to the cricopharyngeal muscle) and phonation of the sound /i:/ (in differentiation to the interarytenoid muscle).