I've a damaged thumb, a non-healed Bennett's fracture, a small one. This makes certain manoeuvres with my thumb, painful while others bother me not a whit. Clipping the connectors together is painful and it takes a fair bit of force. I wondered what might help.
A wooden clothes-peg. You can grip the upper wire above the connector with it, there being a convenient slot in the standard peg. You can grip the lower bit with the other hand.
It's simple and it helps.