本研究では, 足長サイズが25.0の男性24名と23.0の女性38名を対象に, 足の外郭投影図と現在市販されている代表的な3種類の靴型 (N, M, W, 紳士靴では25EE, 婦人靴では23E) の外郭投影図とを重ね合わせて比較した.これらの比較は, 距離に関する14の計測項目と面積に関する12の計測項目に基づいて行った.得られた結果は以下の通りである.
1) 靴型の部の形状が細くなるに従って, 余裕長, 余裕長I, および余裕長IIの平均値が大きくなる傾向が男女ともに認められた.
2) 第1趾接点はみだし長, 第2趾接点はみだし長, 脛側中足点はみだし長, 腓側中足点はみだし長の平均値から, 男女とも足の第1趾および第5趾の接点が靴型よりも外側にはみ出しているといえる.さらに, 部の形状がかなり太い靴型Wを除くと, これらのはみだし長については男性よりも女性のほうが大きく, 特に第1趾側の計測項目でこの傾向が顕著である.
3) 面積による比較において靴型による平均値に有意な差が認められた計測項目は, 男性では, 第1趾前部はみだし量と外踵部はみだし量, 女性では, 内後部余裕, 外後部余裕, 第1趾前部はみだし量, 第1趾後部はみだし量, 第3・4趾はみだし量であった.

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本稿では,平地歩行時と段差乗り越え時におけるの剛性について実験的に調べた.歩行時における足裏荷重分布と関節角度の変化を開発した下肢機能測定装具(LFME:Lower limb Function Measuring Equipment)を用いて測定した.さらに,測定結果から剛性としてモーメント角度線図を求め,観察した.これらの結果から,平地歩行では歩幅が大きい場合に剛体のような剛性が,段差乗り越えでは段差が高いほど高剛性が必要であることが示唆された.

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ワーキングメモリの概念を利用して，二重課題歩行特性と副次課題の成績との関係をモデル化し，過去の転倒経験を表す評価指標を提案する．11名の健常高齢者を対象に，都道府県名のような想起問題に回答しながら歩行を行う二重課題歩行実験を行い，問題の難易度と，装着型慣性センサで測定した重複歩距離および歩行率を測定した．課題の難易度は，1秒あたりの問題の回答数と定義した．さらに，ワーキングメモリ内での歩行への注意および問題回答に要する占有率をモデル化し，課題の難易度の変化に対する歩行パラメータの変化の傾向を関連づける歩行注意係数を提案した．二重課題歩行実験の結果，転倒未経験者の歩行への注意度の占有率および提案した歩行注意係数は，転倒経験者より有意に大きくなることを確認した．このことから，提案した歩行注意係数は，転倒経験の有無を数値的に表す指標として利用可能である．

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本研究では、室内空気の換気回数を測定する方法が、靴空間の換気回数測定に応用できるか否かについて検討した。検討した項目は、I) 二酸化炭素標準ガスの供給時間、II) 二酸化炭素濃度の減衰経過、III) 本測定法の応用例である。本実験に用いた指標ガスは、室内空気の換気同数の指標ガスと同じ二酸化炭素であり、二酸化炭素濃度の測定はガスクロマトグラフにより行った。測定条件を検討した結果、靴空間に放たれた二酸化炭素は室内空間に放たれた二酸化炭素と同様の減衰を示すことが分かった。靴空間においても室内空気の換気回数算出式が準用できることが示された。靴空間の換気回数測定法として、次の測定法の有用性が示唆された。靴空間へ10%二酸化炭素標準ガスを5分間供給する。供給中止後、初期二酸化炭素濃度の80～20%の減衰率を示す時間に、靴空気を採取する。採取した二酸化炭素濃度を、ガスクロマトグラフにより測定する。その値を用いて換気回数を算出する。本測定法は、算出された換気同数の誤差として±20%までを許容できる事象解明に応用できることが示唆された。

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ヒトの足は長い年月をかけて二足歩行に適したものへと進化してきた．足は多数の骨と靭帯から成る複雑な構造を有し， いわゆる「土踏まず」と呼ばれるアーチ構造や関節は歩行において重要な役割を果たしている．これまでに開発されてき た人型ロボットは比較的単純な足部を持っているものが多いが，二足歩行の実現にはヒトの持つ足の機能を実現することが重 要である．本稿では特に関節に焦点を当てて，人型ロボットの足部機構の開発に関する従来研究を紹介する．

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It is clarified based on the analysis of foot movement in walking that there is very little danger of stumbling if the height of difference in level is within 5 mm. Sensory and perceptual evaluations concerning the pain at stumbling and the danger of tumbling were quantified as evaluation scales by means of a sensory test. Then proper physical quantities corresponding to the scales were established using a newly-depeloped measuring apparatus. Finally the relationship between the scales and the quantities were presented as evaluation indexes of the safety of difference in level.

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Rehabilitation programs for patients after anterior cruciate ligament (ACL) reconstruction have generally focused on redeveloping functional strength of the knee musculature through a combination of closed kinetic chain (CKCE) and open kinetic chain exercises, although closed kinetic chain exercise has been more popular. Previous studies have demonstrated increased anterior tibial translation with open chain compared to CKCE. Normal static squat is generally one of the most popular CKCE. Basically, this exercise is hamstring and gluteus muscle exercise. The most important rehabilitation program after ACL reconstruction is quadriceps exercise. However, no studies have been published documenting the differences in tibial translation with trunk flexion and examining the effects of quadriceps contraction. The purpose of this study is to compare the electromyographic variables and anterior tibial translation when squatting on both legs in two different weight bearing positions and to examine the influence in the change in the trunk flexion angle.
Maximal sagittal plane knee translation during squatting was investigated in 10 healthy subjects without any previous history of knee joint trauma using an electrogoniometer system (CA-4000, OS Inc., Hayward CA, USA). The CA-4000 was also used to measure tibial translation with two methods squatting at the variable trunk flexion. For each condition, angle of maximum translation were recorded and compared between the two conditions. The two exercises, normal squatting and tip toe weight bearing squatting, were simulated by adjusting tibial anterior translation across the knee at each flexion angle. The subjects then performed five bilateral squatting movement with no external load. Anterior tibial displacement was measured at every five degrees of knee flexion from 0 to 90 degrees. The electromyograms (surface EMG, Universal Ltd.) were monitored via telemetry for the vastus medialis, biceps femoris of the right leg. Surface EMG data were normalized to the percentage of the maximum voluntary contraction, the third highest surface EMG activity.
The trunk flexion angle increased, and anterior drawer displacement decreased with normal squatting. As the trunk flextion angle increased, anterior drawer displacement did not increase with tip toe weight bearing squatting. Upon full extension of the trunk, anterior drawer displacement showed no significant differences between the two squatting methods. The amplitude observed on the electromyograms of the hamstrings increased as the trunk flexion angle increased, and the amplitude on the quadriceps increased with tip toe weight bearing squatting.

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This paper proposes a knee stretch walking method for biped robots; the method involves the use of the toes and heel joints to increase walking strides. A knee can be stretched by switching control variables. By a knee stretch walking with heel contacts to the ground and toe takeoffs from the ground, biped robots can increase their walking stride and speed. The validity of the proposed method is confirmed by simulation and experimental results.

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A stairway in homes is an important structure for movement between floors. However, the number of fall accidents on stairways is very high in Japan. The present study aimed at investigating the dimensions of safe stairways especially by subjective assessments and three-dimensional motion in both sexes and three age’s groups. Eighteen healthy men and women aged between 21 and 75 years climbed up and down five kinds of stairs at different dimensions (rise and tread of a step). While going up the stairs, the height of a step influenced the track movement of their toes, which decreased distances between the toes and edge of the stairs, especially in the elderly group. Furthermore, the female group trended to feel more subjective strain with a larger height of a step. While going down stairs, a smaller tread of a step decreased the contact area of the soles on the surface of the step. These findings suggest that requirements of stair’s dimensions for preventing fall are different for climbing up and down, and for users of different ages and sex.

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Recently, the research of humanoid robotics is very popular. However, few humanoid robots usually have the tiptoe due to complicated mechanism and control, etc. though the degrees of freedom of the joint increase by appending a tiptoe to the robot foot and a leg construction with the high movement ability can be expected. In this paper, an autonomous attitude stabilization control based on a repetitive bending and stretching movement with standing on the tiptoe is proposed. Namely, the control performance is verified under a narrow situation of the stable range by using a tiptoe of one-legged robot. When a one-legged robot moves each joint by using the tiptoe without an attitude stabilization planning, the ZMP (Zero-Moment Point) of robot goes over the boundary of a contact surface often. As the result, the robot falls down due to the occurrence of an unstable situation.
The compensation of ZMP by using a force sensor set up the ankle is a general method in conventional humanoid robots. However, the center of gravity and ZMP are calculated from motion data because providing a force sensor for the verification of movements using a tiptoe is so difficult. The autonomous stabilization is achieved by controlling an imaginary inverted pendulum (IIP) that passes through the center of gravity from the robot tiptoe. In other words, the VSS adaptive control suppresses as much as possible the disturbance concerning a change of the center of gravity caused by the robot movement. The I-PD control system is designed to both joints of an ankle and a knee, and two reference angles of sinusoid wave are given to their joints without inverse kinematics in an experiment. Simultaneously, VSS adaptive control input for the attitude stabilization is given to a tiptoe joint. Finally, the validity of the proposed system is demonstrated through some simulations and experiments.

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It has been suggested that the experience of falls by older adults is closely related to their decreased foot clearance during walking. The aging effect on foot clearance, however, is inconsistent in previous studies, probably because they used few subjects and a laboratory setting. In this study, we examined the relationship between foot clearance and aging for older adults participating in the TMIG-LISA (Tokyo Metropolitan Institute of Gerontology, Longitudinal Interdisciplinary Study on Aging). The participants were 628 older adults (65 to 91 years old) living in Nangai Village located in northern Japan. The participants were classified by sex and in four age groups (aged 65 to 69 years, 70 to 74 years, 75 to 79 years, and above 80 years). They walked on an 11-meter straight walkway at their own preferred speed. The coordinates of markers attached to participants' toes and heels were measured by the Vicon-370 system (Oxford Metrics, Oxford, England) during 5 meters toward the middle of the walkway. The sampling frequency was 60 Hz. Foot clearance was defined as the lowest height of the toe trajectory during the swing phase. The foot clearance was normalized by height. The mean value of foot clearance was 16.3mm (SD: 8.9mm) for males and 13.5mm (SD: 8.4mm) for females. The normalized foot clearance mean was 0.103 (SD: 0.06) for males and 0.093 (SD: 0.06) for females. A two-way analysis of variance (sex*age group) showed that the normalized foot clearance was not significantly different between the age groups and sexes. This result suggests that further investigations are needed to elucidate the functional relevance of foot clearance of the elderly.

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森林作業道作設作業における作業の効率化と施工精度の向上を目的として、油圧ショベルの姿勢やバケット位置を作業道の設計図面とともに運転席のモニタ等に表示させることで、オペレータの作業を支援する情報化施工技術の開発を進めている。本研究では、情報化施工に供する油圧ショベルの各部位に搭載したIMUのデータからバケット位置を演算し、トータルステーションにより精度検証を行った。その結果、高さ方向の標高誤差は平均1.03cm となり、国土交通省の基準である誤差5.0cm以内の基準を十分に満たしたが、3次元方向の誤差が7.05cm と大きい結果となった。この原因を精査したところ、IMUの方位角計測精度に、最大6.0度、平均0.7度の誤差があることが分かった。そこで、IMUの代替となる方位角計測方法として、油圧ショベルの位置を特定するためのトータルステーションによる後部プリズムの測量データを用いて方位角を算定する方法を用いたところ、3次元方向の誤差についても平均1.75cm と小さくなることが分かった。これらのことから、情報化施工に資するための油圧ショベルの姿勢は、IMUセンサとトータルステーションを用いることで、十分な演算精度が得られることを明らかにした。

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〔目的〕TKA術後の遊脚期の膝関節屈曲角度と前遊脚期の膝関節周囲筋活動との関係を検討した．〔対象と方法〕対象はTKAを施行した24膝とした．歩行中の膝関節角度は，歩行側方からの動画上で測定した．筋電図の導出筋は，術側の大腿直筋と外側広筋，大腿二頭筋とした．歩行評価は術後4週に行った．歩行各相の相対的筋活動および同時活動指数と，

離地時と最大屈曲時の膝関節角度との間の関係を解析した．〔結果〕遊脚期の膝関節最大屈曲角度と，前遊脚期の大腿直筋の相対的筋活動および外側広筋と大腿二頭筋の同時活動指数に中程度の相関を認めた．〔結語〕前遊脚期中の大腿直筋の過活動および外側広筋と大腿二頭筋の過剰な同時活動が，Stiff-knee gaitの原因になり得ることが示された．

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