Reactive Strength Index (RSI)
RSI = Jump Height / Ground Contact Time
The reactive strength index measures the reactive jump capacity of the athletes and is obtained by completing a drop jump.
The athlete must first start at ground level and step up onto a block or box prior to stepping off and immediately rebounding back off the floor, with the intent to jump as quickly and high as possible.
Note: If the start position is NOT set at floor level then RSI will not calculate