A comparison of subtalar joint motion during anticipated medial cutting turns and level walking using a multi-segment foot model
Received 14 October 2008; received in revised form 23 September 2009; accepted 28 September 2009. published online 09 November 2009.
Abstract
The weight-bearing in-vivo kinematics and kinetics of the talocrural joint, subtalar joint and joints of the foot were quantified using optical motion analysis. Twelve healthy subjects were studied during level walking and anticipated medial turns at self-selected pace. A multi-segment model of the foot using skin-mounted marker triads tracked four foot segments: the hindfoot, midfoot, lateral and medial forefoot. The lower leg and thigh were also tracked. Motion between each of the segments could occur in three degrees of rotational freedom, but only six inter-segmental motions were reported in this study: (1) talocrural dorsi-plantar-flexion, (2) subtalar inversion–eversion, (3) frontal plane hindfoot motion, (4) transverse plane hindfoot motion, (5) forefoot supination–pronation twisting and (6) the height-to-length ratio of the medial longitudinal arch.
The motion at the subtalar joint during stance phase of walking (eversion then inversion) was reversed during a turning task (inversion then eversion). The external subtalar joint moment was also changed from a moderate eversion moment during walking to a larger inversion moment during the turn. The kinematics of the talocrural joint and the joints of the foot were similar between these two tasks.
During a medial turn, the subtalar joint may act to maintain the motions in the foot and talocrural joint that occur during level walking. This is occurring despite the conspicuously different trajectory of the centre of mass of the body. This may allow the foot complex to maintain its function of energy absorption followed by energy return during stance phase that is best suited to level walking.
aWolf Orthopaedic Biomechanics Laboratory, Fowler Kennedy Sport Medicine Clinic, The University of Western Ontario, London, Ontario, Canada
bDepartment of Mechanical and Materials Engineering, Faculty of Engineering, The University of Western Ontario, London, Ontario, Canada
cSchool of Kinesiology, Faculty of Health Sciences, The University of Western Ontario, London, Ontario, Canada
dDepartment of Surgery, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada
eSchool of Physical Therapy, Faculty of Health Sciences, The University of Western Ontario, London, Ontario, Canada
Corresponding author at: Department of Mechanical and Materials Engineering, Spencer Engineering Building, Room 2075, The University of Western Ontario, London, Ontario, Canada N6A 5B9. Tel.: +1 519 661 2111x88339; fax: +1 519 661 3020.
ABSTRACT