Thanks for the commenters' input. I'm still fairly new to writing on DK and still learning what works and what doesn't. It looks like my familiarity with the subject led me to leave out too much info from the intro.
Here's an explanation from the Smithsonian Institution:
Migrant farm workers had to use the short-handled hoe or el cortito for thinning and weeding. Because it required them to stoop during long hours in the fields, the hoe became a symbol of the exploitive working conditions. Campaigns by the United Farm Workers and others helped outlaw use of the hoe in 1975.
(In English "el cortito" means "the short one.")
Cesar Chavez himself, the legendary leader of the United Farm Workers, suffered lifelong back pain from having used "the devil's arm" when he worked in the fields. It was a huge victory for farmworkers when this torturous implement was outlawed in 1975. And that would not have happened without the massive nationwide movement of ordinary people actively supporting the UFW.