"Posture."

Hmm, heads up to keep your posture correct...! Your bones need to grow in a healthy way to function nicely as you grow :) Shoulders apparently can round if a slumped posture is kept for long-term.

A good exercise that I had found was to reach your arms up against a wall, and push your elbows back towards the wall (you don't need a wall but it's just there for reference). Take care of yourself :)
- teriyakkii_1203