Even if the assembly manual for a fairly complicated contraption explicitly states that two people are needed to successfully complete the work, a determined and resourceful individual should be able to come up with ways of achieving the desired end result all by himself.
If said individual has a history of back problems directly linked to working with heavy objects, there is no surer way to a relapse than an attempt to do something that normally requires two people all by oneself.
Ah, excessive pride has been a boon to our family.
Ack! Hope you’re OK.
Ouch. Been there, done that. Have a heating pad!