Treadle
/ˈtredl/
Definition 1 of 1
Pro Tip 1/3Historical Usage
Originally common in manually operated machines, such as spinning wheels or looms. 
At the museum, the guide demonstrated a loom with a treadle.
Pro Tip 2/3Physical Action
The word implies continual foot movement to keep a machine running. 
The artisan kept the pottery wheel spinning by routinely pressing the treadle.
Pro Tip 3/3Present Relevance
While less common today, treadles are still used in some equipment to allow hands-free operation. 
He used a treadle-operated scroll saw to craft intricate wood designs.