 Original Tartan tracks left long holes to secure the blocks but most tracks today require blocks to be held by small spikes similar to the ones used in shoes.Block slippage was common enough that it is an allowable loophole in the rules to recall the start of a race without calling a false start against an athlete whose blocks slip.In some amateur settings, such as high school track, since block slippage is much more common due to lower quality track surface material and/or starting blocks' spike quality, it is a commonly accepted practice to allow another person (usually a teammate) to sit on the ground behind the starting block and place their feet behind each block, using their leg power to further reduce the chance for the blocks to slip back upon the runner launching out of them.