The difference as a percentage between the measurements taken in B compared to those taken in A.
In this case the eccentric quadriceps values of the right leg compared to the concentric quadriceps values of the right leg.
You would expect (at this speed) that the eccentric values would be 30% - 40% higher than the concentric values which would give us a figure of 130 - 140%. As can be seen this has not happened (because I made this one up as an example).