Imagine a magic that allows the person to decide in which 'direction' the forces of an impact or imparted force are applied with regards to newton's 3rd law of motion. Either all of the force goes into that which the force is applied to and none into that which applies the force, or all of the force goes back into that which applies the force and none into that which the force is applied.
Think of a ball that is dropped and this magic is applied to it, with one direction the floor might crack if the ball had enough weight while the ball simply doesn't bounce, and with the other direction the ball bounces almost perpetually with all of the force of its bounces going back into it and none into the floor and the only thing that might eventually stop it is the drag it experiences(actually I don't know how drag would affect such an object, maybe it would not really? I haven't thought that far ahead with this magic, which is why this question exists XD).
One direction's applications are obvious, attacking something with a weapon would be more effective and you'll suffer no recoil, and no one would be able to move you even if they tried, and you'd easily survive falls with only the ground experiencing the forces associated with the impact. The other direction's applications are where I'm struggling a little bit with. Among other things I want the people to be able to use it to jump higher, with all of the force their legs impart going back into them instead of half into them and half into the ground, with the objective that they'd jump twice as high(or a little bit less, drag and gravity and everything), but I don't know if such forces going into the legs would have a risk of breaking them.
Would making newton's 3rd law of motion unidirectional in this manner allow you to jump higher or will you break your legs?