The Imbalance Index column
A brief explanation of the column "imbalance" in the Sprint/Gait tests
The Imbalance Index column (Imb%) in Sprint tests (Run Data) is an indicator of running 'asymmetry' between the right and the left foot.
At first a linear interpolation of two supports the same type can be assumed.
Consequently, the contact time of an ideal athlete's support would be halfway between the previous and the following; whereas in a real run there will always be a certain difference, the deviation between two times indicating asymmetry.
After having calculated the difference between ideal and real time, the relation between the difference and the ideal time (expressed in %) can be defined as imbalance index.