Further,

NOT cinching the strap down tightly means that a rider, when on the upstroke (the 5 o'clock through the 10 o'clock positions of the pedal stroke.), will have to use the tibialis anterior muscle (on the outside of your shin) to lift up the front of the foot to stay in the straps. Or not pull up on the upstroke at all and simply mash with the glutes and quads through the 1 o'clock through 5 o'clock positions. Either way, there is no support of the foot during the pull across the bottom of the pedal stroke as the shoe will simply slide backwards out of the strap.

If you were in the straps tightly, you can use the much stronger hamstrings (back of your upper leg) to improve the output of your pedal stroke during the 5 o'clock through the 10 o'clock positions of the pedal stroke.


In short, if you are not using the straps properly, you aren't getting the most out of your pedal stroke. This is why when people go to clipless they are amazed at how efficient it is. It's because they get to use their powerful hamstrings during the pull-through and upstroke. Clip & Strap riders could have the same experiences if they use the proper shoes with the old school cleat and tightened them down.