If the ratio of the leg to the length of the pedal causes an incorrect cycling position, a crank shortener can offer a solution. With a crank shortener, this distance becomes smaller and the pedaling movement you make while cycling can also be reduced. This makes the knees bend a little les. This option can be used in various ways, for example:
someone with a difference in leg length;
someone who cannot bend their knee or hip completely;
a person with short legs;
or for a person in growth as a temporary solution, so that they can cycle on a bicycle bought for growth.