4D PRO® ReAction Sling Trainer

The 4D PRO® ReAction Sling Trainer was developed by Dr Homayun Gharavi MD PhD, team doctor and internationally renowned fitness coach to professional athletes. His idea was to create a device that worked all of the muscles dynamically to meet the demands of sports and everyday life. This trains the muscles to move faster and independently from each other. It had to be simple, comfortable, effective, easy on the joints – and fun.