Chopart's joint load during gait. In vitro study of 10 cadaver specimen in a dynamic model.
BACKGROUND
Chopart's joint is fundamental to foot function. Until today, intra-articular force and peak pressure has not been investigated under dynamic conditions.


METHODS
The study used a cadaver model to measure intra-articular force and peak pressure with electronic sensors. Force was applied to extrinsic tendons via cables attached to computer-regulated hydraulic cylinders. A ground reaction force of 350 N was simulated in a tilting angle- and force-controlled translation stage.


RESULTS
We observed a characteristic rising curve with a peak during push-off for intra-articular force and peak pressure. The increase of intra-articular force at the talonavicular and calcaneocuboid joint from a low level at heel-on varies up to a maximum of 174 N/149 N and a peak pressure of 3877 kPa/3396 kPa, respectively, at push-off. We observed highest loading at the dorsal aspect of the talonavicular joint and the plantar aspect of calcaneocuboid joint.


CONCLUSIONS
The highest loading on Chopart's joint is attained during push-off. We observe higher force and peak pressure on the medial column of the foot compared to the lateral column. The higher load of the dorsal aspect of talonavicular joint and plantar aspect of calcaneocuboid joint confirms the theory of a previous described locking mechanism for forceful push-off.
Suckel
A
A
Orthopaedic Department, Tubingen University Hospital, Hoppe-Seyler Strasse 3, 72076 Tubingen, Germany. Andreas.Suckel@med.uni-tuebingen.de
Muller
O
O
Langenstein
P
P
Herberts
T
T
Reize
P
P
Wulker
N
N
D000843:Ankle Joint / Q000502:physiology*; D001696:Biomechanical Phenomena; D002102:Cadaver; D006801:Humans; D066298:In Vitro Techniques; D011312:Pressure; D016138:Walking / Q000502:physiology*; D016474:Weight-Bearing / Q000502:physiology