Comparisons of trunk and knee mechanics during various speeds of treadmill running between runners with and without patellofemoral pain: a preliminary study.

[Purpose] To determine if runners with patellofemoral pain (PFP) exhibit higher patellofemoral joint (PFJ) stress and trunk extension compared to pain-free runners during treadmill running. [Participants and Methods] Twelve runners (7 with PFP and 5 pain-free) participated in this study. Participants ran at 3 different running conditions: self-selected, fast (120% of self-selected), and slow (80% of self-selected) speeds.