weak, lame
趄 centers on physical weakness or impairment, specifically being lame or unable to move properly. The meanings 'weak' and 'lame' both describe a lack of strength or mobility.
趄 combines 走 (run) with 且, which likely contributes the sound. The meaning 'lame' or 'weak' may derive from the idea of impaired running or movement, but the exact historical development is uncertain.
The running enclosure 走 surrounds 且, like a runner whose legs are weak and lame, struggling to move forward.
For ショ, imagine a weak, lame runner trying to show off but stumbling: show -> ショ, and the runner's weakness is clear.