Determination of loading rate in the absence of a vertical impact peak

[Tim Blackmore]

Hi all

I am interested in acquiring information on the determination of the vertical loading rate in the absence of a vertical impact peak which is generally characteristic of a forefoot strike pattern.

Any information would be appreciated.

Regards

Tim

[Jocelyn Hafer]

Re: Determination of loading rate in the absence of a vertical impact peak

Hi all

I am interested in acquiring information on the determination of the vertical loading rate in the absence of a vertical impact peak which is generally characteristic of a forefoot strike pattern.

Any information would be appreciated.

Regards

Tim

Hi Tim,

In some cases where we've had midfoot or forefoot strike runners there is a deflection point rather than a distinct impact peak. I've treated this point as the impact peak (identifying the point as the minimum of the first derivative of the force profile before the overall peak GRF). I've attached an example data set in case this explanation isn't clear. example.xlsx

If there is no identifiable deflection point, I don't know if vertical loading rate is an appropriate measure. Perhaps if you're doing a repeated-measures comparison where one condition has an impact peak you could take the same portion of the curve for within-subject comparisons. Hopefully someone else can weigh in on this thread as I'd also like to know how others would analyze this.

-Jocelyn