Impact Loading on the Foot and Ankle during Level Walking and Effect of the Ankle Fixation using Common Ankle Foot Orthosis
K. Miyazaki, N. Shiba*, Y. Tagawa***, S. Matsuo***, M. Yoshizuka**, and A. Inoue
Department of Orthopaedic Surgery, Division of Rehabilitation*, and 1st Anatomy**, Kurume University School of Medicine, and Kurume Institute of Technology***.
PURPOSES: The purposes of this study were to examine reliability of the skin mounted accelerometer, the impact on the foot and ankle and its attenuation, and the effect of ankle fixation using AFO.
MATERIALS & METHODS: 1) Cadaver test was carried out if the skin mounted accelerometer could estimate the bone or joint impact acceleration. 2) Gait test was performed to evaluate the impact at the foot and ankle and its attenuation during level walking using skin mounted accelerometer. Effect of the ankle fixation was also examined using common ankle foot orthosis. 3) Computer simulation using rigid-body model estimated the impulse st landing during level walking.
RESULTS: The skin mounted accelerometer showed the same tendency as the bone mounted accelerometer in the cadaver test. In the gait test, impaction was attenuated at the medial malleolus, and was less attenuated with ankle fixation using AFO. In the simulation, impact became greater in the ankle fixation model, and such impact was attenuated by alternating the leg configuration at landing.
CONCLUSION: These results suggested that foot and ankle would play an important role in attenuating the impact at heel strike during level walking.
A DYNAMIC ORTHOSIS WITH A PNEUMATIC FITTING UP OF PISTON
S. Delattre, C. Donze, A. Thevenon (Swynghedauw Hospital, University, LILLE)
We present a dynamic orthosis of extension back of the knee, for which, the originality is to comprise a system of stabilization of the knee constituted by a pneumatic fitting up of piston.
This orthosis realized with traditional materials after plaster cast, includes a jack which the strength is selected according to the importance of the deficit of the vastus intermedius variable from 50 to 200 Nw.
During the gait, the jack is compressed in the flexion phase and it brings back the knee in extension in the swing phase.
The disposition of the jack allows the short sitting and the transfers to the upright position.
The advantages are the possibility to have a progression in the assistance of the orthosis, its integration in a program of rehabilitation and its discretion.
The indication is the deficit of the knee extension in central and peripheral neurological pathologies.
The limit is the existence of a severe deficit with a risk to unbolt the knee: the orthosis doesn't prevent the fall. The bolt of the knee is obtained owing to a device utilizing a drop ring lock.