I have been using the pneumax "pneu-weight" unweighting device for over 12 years now, both with a neurological and sporting population. I would agree that the harness type systems do impeed some of the normal gait in the stroke/head injured patient however the positive effects on moral, safety, general body systems as a result of standing, and the ability to remove the arms from as support base far outweighs any negative aspects.

There are many different systems out there and the first and perhaps most important factor is the actual harness rather than the lifting device itself. As physios we should see this as a tool that can be combined with a lot of other techniques that are designed to restore proximal stability. We should not simply stand the client in a sling device without first addressing sitting balance and and presence of righting reactions. Otherwise simply standing someone and assisting them to "walk" will perpetuate learned compensation. That can later lead to withdrawal of the harness work to fix those issues. Unfortunately this can have a negative effect on patient moral.

If you really want to see a company that have put a lot of work into gait retraining with a truely amazing design, and unfortunately price, take a look at www.hocoma.com/

Also here is a useful article titled: Physical Activity and Exercise Recommendations for Stroke Survivors