What spikes can my child wear?

Under ASA Rule 25.19 (following World Athletics shoe rules):

• Each spike may stick out no more than 9mm from the sole or heel, except in high jump and javelin, where 12mm is allowed.
• At least the half of each spike nearest the tip must fit through a 4mm square gauge.
• If the track manufacturer or stadium operator sets a shorter maximum, that applies. Call room judges check that athletes have the right spikes fitted.

ASA's guidance on spike shapes:

• Synthetic tracks: spikes that don't pierce the rubber surface, such as tower-shaped spikes.
• Grass tracks: pyramid-shaped spikes for grip.
• Asphalt tracks: needle-shaped spikes.
• Blank spikes fill unused holes in the sole.