Originally Posted by Ken Cox

Toe clips and straps represent the first means of pulling up on the back side of the spin.

Those who ride on the track and take it very seriously can strap in so tight they can pull backwards on the pedal at the bottom of the spin.

My son, who rides a geared bike (coasting bike) on the street, prefers clips and straps to clipless pedals, and he straps himself in tight; so tight he can't easily pull his foot out of the clip and strap.
He can do this because, when he wants to stop, he can coast and bring his foot up within reach of his hand while he loosens the strap.

On a fixed gear bike, though, riding on the street and not on the track, strapping in that tight requires considerable skill.
I think on the street most people choose or learn to ride with their straps loose enough so they can pull out of them in an emergency.
This also means for a portion of the spin, say from 6 to 8 o'clock (viewed from the right), the rider with loose straps cannot pull backwards and up without pulling his foot out of the straps.