Positive FPPA values reflected knee valgus, excursion of the knee towards the midline of the body so the knee marker was medial to a line between the ankle and thigh markers. Negative FPPA values reflected knee varus.
The average FPPA from 3 trials was used for analysis. Between-session reliability of this method has been established using intraclass correlation coefficients and range from 0.72 to 0.91 (Munro, Herrington, & Carolan, 2012).