Ankle foot orthosis controlled dorsal-plantar flexion of ankle joint
Makio Yamaga, Katsumasa Takagi, Miki Ookushi, Kotarou Oohashi and Mitsunobu Watanabe
(Kumamoto University School of Medicine, Kumamoto, Japan)
Purpose: We designed the new type plastic AFO which control dorsal-plantar flexion of ankle joint (Double direction assist type; DDA type) for bilateral ankle paresis due to polyradiculoneuropathy or myelomeningocele etc. DDA type AFO has both the elastic band which assists dorsal flexion and the polypropyren sheets which assist plantar flexion. Methods: 12 patients with bilateral ankle paresis were evaluated by walking speed, step length, stabilometry (Gravicorder GS-1000), 3D-motion analyzer (Locus III-D) in under the condition of bare foot, anteflor type (Yunoko type) AFO, posterior type (Shoehorn type) AFO and DDA type AFO.
Results: Using DDA type, walking speed was increased 13.0±5.2% and step length was extended 11.0±6.2% as compared with bare foot. The shaking of the center of gravity during standing and walking was smallest on DDA type AFO.
Conclusion: DDA type AFO is useful for bilateral ankle paresis.
APPLICATION OF A SHAPE MEMORY POLYMER TO ANKLE-FOOT-ORTHOSIS
Hiroshi Nagasawa, Masaharu Maeda, Shuichi Obuchi, Iwao Yokoyama (Kitasato University, Sagamihara, Japan)
Hiroyuki Toshima, Yoshitaka Shiba (Kitasato University East Hospital, Sagamihara, Japan)
Shape memory alloy and shape memory polymer are applied with various forma in our daily life. The purpose of this study is to report application of a shape memory polymer (Mitsubishi Heavy Industries, Japan) to ankle-foot-orthosis. We examined the characteristic and durability of the orthosis in eleven healthy subjects.
The shape memory polymer was transformed gum like materials in 55 degrees centigrade of water, and it was easily fitted to the subjects in detail. The durability, measured by number of steps at the time of crack, was average of 4,724 steps, and the part of cracking was the forefoot. When distal part of the orthosis was removed from the metatarsal joint and reinforcement glass fibers were added into the orthosis, the durability greatly improved to average of 92,691 steps.
Although the durability still included the problem for everyday use, we concluded that the shape memory polymer is useful for a treatment orthosis.