system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 why is it so much harder to pick someone up when they clench?

If I try to pick up my son, it’s easy as pie. However if he sees it coming he clenches and trying to pick him up feels like twice the weight. What gives?
gpt
It is actually easier to pick up someone who is simply "clenching". Except that they are not simply clenching, they are putting their body weight further from you, and that's what makes it harder.

What is also hard, is picking up someone who is completely relaxed, like unconscious (or dead). Because, unless you do it properly, their flailing limbs will keep on moving their center of gravity.