This article presents the results of two in-vivo studies providing measurements of human static ankle mechanical impedance. Accurate measurements of ankle impedance when muscles were voluntarily activated were obtained using a therapeutic robot, Anklebot, and an electromyographic recording system. Important features of ankle impedance, and their variation with muscle activity, are discussed, in...

Following the acceptance for publication of the article by Hazlewood et al. in a recent issue of Gait & Posture we were invited by the Editor in Chief to comment on the challenging issue of measuring tibial torsion [1]. Tibial torsion describes the axial or transverse plane alignment of the shank segment of the lower extremity. In utero, lower extremity limb bud formation occurs during the 4th ...

Ankle fractures are among the most common injuries treated by orthopaedic surgeons. 1 Most of the rotational ankle fracture mechanisms described by Lauge-Hansen can lead to posterior malleolar fractures by avulsion of the posterior tibial fibular ligament especially the posterior external rotation (PER) injury. Trimalleolar fractures are known to have a worse prognosis than bimalleolar fracture...

OBJECTIVE To evaluate the effects of heel-opened ankle foot orthosis (HOAFO) on hemiparetic gait after stroke, especially on external foot rotation, and to compare the effects of HOAFO with conventional plastic-AFO (pAFO) and barefoot during gait. METHODS This cross-over observational study involved 15 hemiparetic patients with external rotation of the affected foot. All subjects were able to...

INTRODUCTION: Combination of measurement and mathematical modeling has provided a powerful tool for investigating the complicated behavior of human joints [2, 6]. In the previous studies the ankle joint complex was usually modeled as ideal hinge joints with fixed rotation axes or spherical joints [3, 7]. These models ignored some important kinematic features of the joints. In this study, a thre...

This paper describes the development of a novel humanoid robot foot/ankle based on an orientation Parallel Kinematic Mechanism for intelligent and flexible control. With three identical Universal-Prismatic-Spherical prismatic-actuated limbs and a central Universal-Revolute passive limb, the PKM can perform three degrees of freedom rotation motions. In order to enable the humanoid robot safely t...

This study presents a free-fall mechanical supination sprain simulator for evaluating the ankle joint kinematics during a simulated ankle supination sprain injury. The device allows the foot to be in an anatomical position before the sudden motion, and also allows different degrees of supination, or a combination of inversion and plantarflexion. Five subjects performed simulated supination spra...

BACKGROUND The purpose of this study was to report findings of exploratory arthroscopic assessment performed in conjunction with removal of internal fixation device placed in the initial surgery for rotational ankle fracture. METHODS A total of 53 patients (33 male, 20 female) who underwent surgery for rotational ankle fracture between November 2002 and February 2008 were retrospectively revi...