Rule Book Page 17 Rule 4-3 Section 3 Special Equipment
Art 1 Special equipment is defined as any equipment worn that is not required by rule. Any equipment which does not permit normal movement of the joints and which prevents one's opponent from applying normal holds/maneuvers shall not be permitted.
a. legal hair coverings attached to the ear guards, face masks, braces, casts, supports, eye protection and socks.
b. any protective equipment which is hard and/or abrasive must be covered and properly padded with a closed-cell, slow recovery foam padding no less than 1/2 inch thick.
Art. 2 All parts of a pad must fit snug against the wrestler's body. Loose pads are prohibited. A sleeve is not permitted.
@yellowbelly12 picture is the proper protection of a knee pad or elbow pad.
@lewdwar's pictures of a knee/elbow sleeve is not permitted. These can be altered if the sleeve at the top and bottom is shortened. But needs to be verified by the official. This was an issue a couple of years ago, if was brought to the attention of the NFHS, they are illegal because of the sleeve.
Jim Russell
IHSAA Rules Interpreter