Годы хребет горбят

When a man gets old, he suffers from the infirmities of his age, he becomes weak. See На старого и немочи валятся (H), Старость не радость (C), Укатали Сивку крутые горки (У)

Cf: Age breeds aches (Am.). The feet are slow when the head wears snow (Am., Br.). An old ass is never good (Br.)