The effectiveness of voluntary modifications of gait pattern to reduce the knee adduction moment Josien C. van den Noort a,⇑ , Ilse Schaffers b , Jasper Snijders b , Jaap Harlaar a,b a Department of Rehabilitation Medicine, Research Institute MOVE, VU University Medical Center, Amsterdam, The Netherlands b Faculty of Human Movement Science, VU University Amsterdam, The Netherlands article info Article history: Available online 4 May 2013 psycINFO classification: 3380 Keywords: Joint moments Knee Osteoarthritis Gait Rehabilitation abstract It has been suggested to use gait modifications in the retraining of patients with knee osteoarthritis (OA), in order to reduce the exter- nal knee adduction moment (KAdM). This study focused on the effect of walking speed, foot position and trunk sway, and on the 3D knee moments. Gait analyses of fourteen healthy volunteers were per- formed in a gait laboratory. Subjects walked at three different speeds in their normal gait pattern, as well as with toe-in and toe-out gait and with medio-lateral trunk sway at a self-selected speed. Fast walking speed increased the KAdM (17–30%) and flexion moment (32%). A slower walking speed did not decrease the KAdM. Toe-in mainly decreased the KAdM (45%) and the transverse moment (38%) during early stance. Toe-out decreased the KAdM during late stance (56%), but increased the KAdM during early stance and midstance (21–24%), due to decreased endorotation of the hip with knee flexion. Trunk sway decreased the KAdM during early stance and midstance (31–33%). Gait modifications mainly affected the KAdM, but changes in sagittal and transverse knee moments and kinematics were also observed. This indicates that, when esti- mating knee load, taking only the frontal plane kinetics into consid- eration may lead to erroneous simplifications. No conclusive beneficial effects were found in any of the gait modifications throughout the entire stance phase. Ó 2012 Elsevier B.V. All rights reserved. 0167-9457/$ - see front matter Ó 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.humov.2012.02.009 ⇑ Corresponding author. Address: Department of Rehabilitation Medicine, VU University Medical Center, P.O. Box 7057, 1007 MB Amsterdam, The Netherlands. Tel.: +31 20 444 3192; fax: +31 20 444 0787. E-mail address: j.vandennoort@vumc.nl (J.C. van den Noort). Human Movement Science 32 (2013) 412–424 Contents lists available at SciVerse ScienceDirect Human Movement Science journal homepage: www.elsevier.com/locate/humov