2.4 Team Equipment

Shoes must be flexible and lightweight with rubber or leather soles, without heels (Rule 4.3.3). Players are not permitted to wear objects that may cause injury or give artificial advantage; smooth and/or protective braces may be worn (Rule 4.3.5).

Source: Rule 4.3, Rule 4.3.4, Rule 4.3.3, Rule 4.3.5

Send this to your friend — argument over.