I am badly bunged up,
Can't do a thing,
Still in the ring.
-- Thomas O'Brien, handicapped dog cart rider, ca. 1900.
The category and designation handicapped and/or helpless is one that considers that many persons who sold their likenesses as souvenirs may not have been performers in the conventional sense, but nonetheless they made their living performatively, in public.
Likewise, they didn't necessarily appear in a sideshow or dime museum venues, but instead plied the streets and byways for their living, often in custom-built wagons or carts. Or they appeared in tented religious shows-- so-called revivals, and/or evangelical "healing crusades."
Freak, disabled, handicapped or helpless, they nonetheless chose to make portraits of themselves which they sold while on exhibit. Many of these performers traveled, going from town to town displaying themselves in public, occasionally for pay, but always in the realm of public display.
Selling trifles such as pencils, postcards, and pitchcards, many of the latter that fall into the category of what we call pity cards. Specific to this genre of "performer," these cards detail the personal travails and handicap that led to the peripatetic life, and hopefully evoked enough pity in bystanders that they forked over a few coins in support.
Pity cards as a performer-sold artifact often feature "misery boasting," bragging about their difficulties to elicit larger donations. The worse the personal misery described on the card, the better the chance to get the public to donate, or buy one of the souvenir cards sold by the performer. This is the opposite of a humblebrag, ie. bragging about yourself by couching it in a phony show of humility.
Misery-boasting pity cards were a genre of pitchcards sold by those injured and unable to make a living any other way. They are related to the performance of the maimed and disabled in the larger world of the sideshow, though these handicapped performers typically didn't travel with shows, but independently exhibited themselves.