My son's feet size is 22. Can he wear size 24 shoes? His walking and sports shoes should only be bigger by 10 - 13 mm, or one size, than his feet. Tight-fitting shoes are not recommended for sports. The old shoemaker's advice is: "longer and narrower is better". "Narrower" here applies to the volume across the toe joints, not in the boot tip. No shoes stretch in length, natural material shoes sometimes stretch in width.
Hand-down shoes, yes or no? Not recommended for hygiene reasons. Mycosis, eczema and other skin conditions may be transmitted.
My child has flat feet. What can I do for the healthy development of their feet? The human feet start to develop fully around the age of one. This is the time to prepare for treatment of orthopaedic problems. Apart from suitable footwear and orthopaedic aids, a professional doctor - orthopaedist - should also be consulted.