If the tensile strength of the rubber band is 50 units and we pull the rubber band one final inch (which should produce 40 more units of SEE, for a total of75), the tensile strength of the rubber band has been exceeded. Failure has resulted, and it snaps in two. High degrees of flexibility outside of the natural range of motion of the joint make snapping much more likely. Some teachers have used this knowledge to make a leap in logic that injuries occur when a muscle is stretched beyond its limit. Therefore, one ought to prevent injuries by elongating the muscles of the connective tissues.
This assumption is a physiological falsehood. Tears do not happen because tissues have been maximally stretched (as the stretching pundits would have us believe) but due to the special combination of sudden stretch and contraction called the stretch reflex.
The stretch reflex is where the tissue that is stretched by an external force too far or too fast will contract to oppose the stretch. When a stretch from one side happens simultaneous to a contraction on the other, we have a tear. We have seen this frequently in the dance and fitness industry, and unfortunately as a result of the recent craze in the pollution of the yoga discipline (where commercialized, pop yoga represents itself as static stretching).