Mirza Ghulam Ahmad was unable to do anything with his right arm.  Below is the reference.

Masroor’s Friday Khutbah of 1-15-16

“””Sometimes some people employing hast do not understand the finer points and formulate an opinion without delving into the thing fully. And then the faith of some weak natured persons also becomes affected as a result. Hazrat Musleh Maud mentions an incident. He says that once at a gathering an individual was drinking water with his left hand and I told him to not do so. He was told to drink with his right hand unless there is some valid reason. He said that the Promised Messiah (as) also used to drank water with his left hand whereas there was a reason for him to do this. And this was that the Promised Messiah (as) had fallen down in his youth and his right hand was injured so much so that although he could pick a glass with it he could not take it to the mouth to drink. Nevertheless to comply with the requirement of the sunnah [the practice of the Holy Prophet (sa)] he would drink with the left hand but he would give the hand support with his right hand.

The Promised Messiah (as) has mentioned the weakness of his right hand himself also. He says that once, in front of some people who were opponents, who had come for some discussion, I picked a glass or a cup of tea with the left hand and upon seeing this they made a criticism that you do not practice the sunnah and you are trying to drink holding the vessel with the left hand.

The Promised Messiah (as) himself says that hastiness and thinking ill forced the person to level this criticism at me whereas my hand is weak on account of the injury it had suffered and I cannot take the cup to my mouth for drinking from it with my right hand. Nevertheless I do definitely always place my right hand below the hand holding the vessel I am drinking from.

So while haste is making the enemy commit ill thinking those who belong to us their lack of understanding and haste has made them think that the Promised Messiah (as) was doing this deliberately. Whereas they should have tried to find the reason behind this and when Hazrat Musleh Maud (ra) had stopped them they should have stopped. These hasty decisions lead to innovation and incorrect commentaries.””””””””””

The scans
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Also see this narration:

Seeratul_Mahdi_3.pdf
page pdf 41/316
Narration no. 526

“Dr. Mir Ismail stated to me that Masih Mouood used to shake hands with right hand only and sometimes with right and left hands. Sincere followers used to kiss his hands and touch them to their eyes and sometimes touch his clothes to get blessings.”

Related Essays

https://ahmadiyyafactcheckblog.com/?s=right+arm

https://ahmadiyyafactcheckblog.com/2016/09/06/lecture-ludhiana-was-not-a-lecture-it-was-a-riot/