Q. Can someone who has an artificial hand blow Shofar on Rosh Hashana holding on to the Shofar with that hand.
A. On question 2928 regarding the use of a prosthetic electronic arm hand on Shabbos we wrote:
“Horav Shlomo Miller's Shlit'a opinion is that a melacha or work performed on Shabbos by using only the electrical charges that emanate from ones controlled and willing thoughts, collected by electrodes attached to the head, is considered a proper melacha. However, for someone who does not usually use his thoughts for the creation of electrical discharges, it likely would be a melacha performed with a shinui or a significant deviation from the norm and therefore only Rabbinically prohibited. However, an invalid or paraplegic that uses this method to constantly move and perform other works, for him it becomes the norm and would constitute a Biblical prohibition.”
Therefore, the use of that bionic arm and hand, regardless whether it is done directly, by using the electrical discharges provided by the nerves or the electrical waves provided by the brain, would not be permitted during Shabbos. However, if one turned off the arm before Shabbos, and just wants to use it as a covering or dressing to look like others, it would be permitted.
On question 2929 regarding if one can wear and carry that electrically disconnected arm or hand in the street, on Shabbat when there is no eruv, we wrote: "Horav Shlomo Miller's Shlit'a opinion is that if it was disconnected and is properly attached so it wont fall off and indeed it makes the carrier look normal, it is permitted."
Therefore, it would be permitted to blow Shofar holding it with that hand.
As a mater of fact, Horav Dovid Pam Shlit'a and Horav Aharon Miller Shlit'a maintain that in needed someone else can hold the Shofar for him, since as opposed to a Lulav there is no mitzva to hold the Shofar.
Rabbi A. Bartfeld as revised by Horav Dovid Pam, Horav Aharon Miller and Horav Chanoch Ehrentreu Shlit'a.