Depends on what you mean by "feedback". The Leap Motion controller tracks fingertips and objects absolutely in real space. Applications can easily tie cursor movement (or viewspace/camera movement, or other interface elements) to absolute hand position or to spatial offset from an arbitrary position in three-space. This actually works really, really nicely for applications designed from the ground up to think this way.
Here, for example, is demo video of a three-space navigation app built on these principles that uses the Kinect: http://vimeo.com/65937620
There's no muscle fatigue or stress using these kinds of applications. You get muscle fatigue (gorilla arm, forearm pain, hand pain) when your ergonomic setup -- which includes both hardware and software -- forces your body to conform to motion patterns that are rigidly repetitive, forces you to position yourself in ways that are awkward relative to your joint kinematics, or forces you to over-correct inaccuracy or unpredictability in the interface.
Here, for example, is demo video of a three-space navigation app built on these principles that uses the Kinect: http://vimeo.com/65937620
And a simpler demo using the Leap: http://vimeo.com/66196803
There's no muscle fatigue or stress using these kinds of applications. You get muscle fatigue (gorilla arm, forearm pain, hand pain) when your ergonomic setup -- which includes both hardware and software -- forces your body to conform to motion patterns that are rigidly repetitive, forces you to position yourself in ways that are awkward relative to your joint kinematics, or forces you to over-correct inaccuracy or unpredictability in the interface.