箸を用いた食事に必要な全身の関節角度と角度変化

Whole-body joint angles necessary for eating with chopsticks

要旨：箸を用いた実際の食事に必要とされる正常な全身の関節角度と，その角度変化を検討することを目的に，三次元（3D）動作解析を行った．健常者45名の食事動作を，モーションキャプチャーシステムにて測定し，上下肢・頸部・体幹の関節角度を明らかにした．このうち，肘関節屈曲が最大約133°および最小約99°，手関節背屈が最大約30°および最小約10°であることを示した．また，関節角度の経時変化から，箸で食物を挟む時期に最も肩関節が内旋し，食物を口へ取り込む時期に最も肩関節が屈曲と外転し，頸部が伸展・右側屈・右回旋することがわかった．これらは，われわれが対象者の食事を評価し介入するための基礎知識になると考えられた．

　This study investigated joint angles and whole-body angle changes required for realistic eating with chopsticks. We assessed the eating movements of 45 healthy, right-handed subjects using a three-dimensional motion capture system and observed the upper and lower limb, neck, and trunk angulations. Among these angles, the maximal and minimal flexion angles of the right elbow joints were approximately 133 and 99 degrees, respectively, and the dorsal flexion angles of the right wrist joints were approximately 30 and 10 degrees, respectively. Internal rotation of the shoulder joints was largest when picking up food with the chopsticks, while putting food into the mouth resulted in the largest flexion and abduction of the shoulder joints. Putting food in the mouth also led to extension, right lateral bending, and right rotation angles of the neck. We assume that these results will add to our basic understanding of positional assessments and interventions in patients.