Evaluate the collective function of references cited together in a given text segment.
Classify their combined role into one of the following categories: 'method', 'background', or 'result'.

Text:After the LMTU of MG and Sol data were resampled at 100 Hz, the length changes of TT were calculated by subtracting the horizontal length component of the identified MG and Sol fascicle from the LMTU (7, 12, 13, 20):
LTT LMTU Lfa cos
where LTT is the TT length, and is the angle between the fascicle line and the aponeurosis (pennation angle).
Category: