Relationship between bisect offset and VL:VM activation ratio for (A) pain-free controls and all PF pain (PFP) subjects, and (B) PFP subjects classified into normal tracking and maltracking groups. No significant relationships existed between offset and VL:VM activation ratio in pain-free controls (R2 = 0.03, p = 0.551), all PFP subjects (R2 < 0.01, p = 0.821), normal tracking PFP subjects (R2 < 0.01, p = 0.761), or maltracking PFP subjects (R2 = 0.30, p = 0.102).