fall, stumble, falter, hindered
疐 centers on losing one's footing or progress: falling, stumbling, faltering, or being hindered. The meanings all describe a sudden stop or loss of stability.
The exact historical development of 疐 is uncertain. It visually contains 田 and 疋, but the original component relationships are not clearly established.
The top part looks like a field (田) with something tangled above, and the bottom is a foot (疋). Picture a foot catching on a hidden obstacle in a field, causing a stumble.
For チ, imagine a foot stumbling and making a sharp 'chi!' sound as it trips: chi -> チ, and the stumble matches the kanji's meaning.