Originally Posted by
bikerjp
SPDs have two cleat options. One allows for an upward release (I guess it's kind of an emergency bailout for the inexperienced) and I've pulled out once or twice. The other cleat isn't supposed to do that but if the tention is low enough I don't know.
SPDs, meaning literally Shimano and not generically any 2-bolt cleat, use spring tension to retain the cleat. If you slack the tension to make it easier to unclip, you also make it possible to accidentally unclip under heavy strain.
further complicating this is the matter that the springs fatigue and the cleats wear, so that unclipping becomes easier.
contrast this with any speedplay pedal, including the frog-- which I previously mentioned would work with the OP's 2-bolt shoes. speedplay doesn't use spring tension to retain the cleat. it is a circular system that spins and locks into place.
any pedal that doesn't have a cage on one side, or pins if it's a DH platform pedal, will eliminate the type of injury the OP suffered. that problem is easy to solve. but there are also pedals which specifically solve the problem of unclipping easily while never unclipping from pedalling hard.