調節式腋窩ループによる能動義手ハーネスへの工夫とその効果

Adaptation of a shoulder harness with an adjustable axilla loop and its effect in improving the fitting of body-powered prosthesis

要旨：能動義手を使用している片側上肢切断者の中には，ハーネスによる圧迫によって腋窩に不快感を感じていることがある．例えば書字などの作業時である．筆者らは片側上腕切断者に対し，従来の8の字ハーネスの腋窩ループにプラスチックバックルを取り付け，ADL(activities of daily living)の種類によって切断者自身が腋窩ループの長さを調節し，腋窩の圧迫感を軽減させる試みを行った．その結果，装着感を改善することができた．これに対して筆者らは，腋窩ループの加圧を測定し腋窩前壁が最も高圧部位となることが分かった．また腋窩ループを緩めると加圧の程度が減少した．調節式腋窩ループの導入によって，義手の装着感が改善できるものと考える．

　Some amputees who wear upper-extremity, body-powered prosthesis experience discomfort in the nonprosthetic side axilla due to pressure exerted by a figure-of-eight harness. For example, while an amputee with a figure-of-eight harness was writing with his nonprosthetic hand and was stabilizing the paper with the other, his arms often felt discomfort because of pressure in the axilla.

　We designed a plastic buckle to the traditional figure-of-eight harness in order to adjust the length of loop, in order to reduce the pressure by himself. And then an amputee succeeded in doing any activities of daily living with his prosthesis.

　We measured the pressure along the axilla loop, and found that the pressure at the anterior wall of the axilla indicated the highest value. Moreover, we detected reduction of pressure by loosening the harness. The adjustable axilla loop improved the fitting condition of the artificial limb.