system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: why does repetitive hand movement such as typing cause damage, while repetitive use of other muscles makes them stronger?
gpt
Your fingers are controlled by tendons while your arms are controlled mainly by muscles. Tendons can possibly damage over long-term use, while muscles regenerate after microtears and get stronger. Muscles have a type of regeneration that adapts to heavier things over time. Tendons, not so much.