Gender Differences in Metabolic Responses During Water Walking

The purpose of this study was to compare metabolic responses between men and women during water walking. Japanese men (27-73 yr, n = 26) and women (33-70 yr, n = 14) performed water walking at 25 m/min, 30 m/min and 35 m/min. Oxygen consumption (VO2), VO2 per weight (VO2/W), respiratory ventilation (VE), heart rate (HR), energy expenditure (EE), EE per weight (EE/W), and actual walking speed were analyzed at each velocity. VO2/W and EE/W were higher in women compared to men. However, VO2 and EE showed similar values between men and women. HRs were significantly higher for women than those of men at all speeds. The regression analysis with third-ordered polynomial equation by actual walking speed showed high correlation coefficients for VO2 and VO2/W. In relative terms exercise intensity was higher for women than men; however, absolute intensity were similar in both men and women during water walking. Moreover, analysis using third-ordered equations found that absolute intensity during water walking was dominated by walking spee

A KINEMATICAL AND KINETICAL ANALYSIS ON THE SWING PHASE OF AMPUTEE GAIT

The authors investigated the swing phase of the transfemoral and transtibial amputees by using optical motion capture system. The thigh, shank foot were modeled as a three-linked rigid segment model. Kinematical parameters, such as joint angle, angular velocity/acceleration and linear acceleration of the center of mass were also calculated by the obtained coordinates of the anatomical landmark markers. Using the inverse dynamics, the kinetical parameters, such as the joint force and torque acting at each joint were calculated. The authors focused on the initiation of the swing phase caused by the force at both the hip and knee joints. In addition, the relationships between the internal/external rotation and the abduction/adduction of the lower extremity during the swing phase was also discussed in this study

A COMPARISON OF LOWER LIMB JOINTS ANGULAR DISPLACEMENT BETWEEN LAND AND WATER-WALKING USING DYNAMIC TIME WARPING

The purpose of this study was firstly to compare lower limb joints angular displacement between land and water-walking by dynamic time warping. Six subjects (age 30.0±5.3 yr) performed 10 m land and water-walking at self-selected speed. Ankle, knee and hip joint angular displacements were calculated from video (25Hz) and compared to the two wave forms from the dynamic time warping procedure. Results showed the ankle and knee joints demonstrated warping periods in water-walking, when compared with land-walking. However, the warping periods around toe-off was seen at the hip joint in land-walking, compared with water-walking. Overall the ankle and knee joints motion in water walking were comparable to land-walking motion. However, the hip joint kinematics during water walking were not always comparable with land walking kinematics

Features of Acceleration and Angular Velocity Using Thigh IMUs during Walking in Water

Ten participants were assessed while walking in water and on land with wearable inertial measurement units (IMUs) attached to the right thigh. Longitudinal acceleration, anterior-posterior acceleration, and frontal axis angular velocity were measured at 100 Hz, matched with video analysis sampled at 25 Hz during the walking trials. The longitudinal acceleration showed almost 1 g from initial heel contact to 70% of one cycle, and the anterior-posterior acceleration showed a sinusoidal pattern, synchronizing the approximate posture of the thigh in water. The frontal axis angular velocity fluctuated less while walking in water compared with on land, because thigh motion speed was slower in water than on land. The acceleration and angular velocity in water were stable and did not fluctuate. Walking exercises in water may be effective in individuals with knee- or thigh-related medical issues

Underwater Electromyogram for Human Health Exercise

The physical qualities of water are well established and include buoyancy, water drag force, hydrostatic pressure and thermal conductivity. The large difference in these physical qualities, compared to land-based activities, affect the human body in both physiologic and biomechanical aspects. An example of this is buoyancy, which acts vertically against gravity on the immersed object thus decreasing weight of the human body. The buoyancy level is equal to the mass of water displaced by the immersed object and is based on the accepted Archimedean principle. When a human is immersed in water up to the level of pubis around 40% of weight is accounted for, 50% at umbilical, 60% at xiphoid, and almost 80% at the level of axillary. When immersed to their lower limb joint and waist in a water environment, humans can easily move, without gravitational overload, due to the buoyancy effect

人物歩行予測における歩行軌跡取得方法の検討

本稿では,人物歩行予測における歩行軌跡の取得方法の検討について述べる.既存の歩行軌跡取得方法である背景差分法では輝度変化による観測ノイズが考慮されていない.そのため,観測ノイズを考慮した人物歩行軌跡取得方法であるパーティクルフィルタを用いる.2つの取得方法によって人物の歩行軌跡を学習し,予測軌跡と実際の軌跡との差を比較する.このとき,学習の歩行経路として単純な歩行経路と複雑な歩行経路を設定する

人物歩行予測における歩行軌跡取得方法の検討

平成19年度電気・情報関連学会中国支部連合大会発表資料。開催地:広島大学 ; 開催日:2007年10月20

Upgrading eigenspace-based prediction using null space and its application to path prediction

This paper proposes a method for an Eigenspace-based prediction of a vector with missing components by modifying a projection of conventional Eigenspace method, and demonstrates the application to the prediction of the path of a walking person. This modification is based on domain-specific knowledge of data, and a linear combination of vectors in the null space of Eigenspace is added so that a cost function of smoothness of path is minimized. Some experimental results on actual paths are shown to demonstrate how the proposed method works

Prediction of a path of pedestrian using combination of Eigenspace and null space

本稿では,固有空間を用いて学習した人物の歩行軌跡をもとに,ある時点までの人物の歩行軌跡から,それ以降の歩行軌跡を予測する手法について述べる.この予測は軌跡の固有空間への射影と逆射影に基づいている.しかし,予測された軌跡は画像中での人物の歩行軌跡としての特性を考慮していないため滑らかでない.そこで,本研究では固有空間に直交する零空間に属するベクトル(零ベクトル)を用いて,予測された軌跡を修正する手法を提案する.固有空間への射影と逆射影によって得られた予測軌跡に零ベクトルの線形和を加えることで,滑らかな軌跡へ修正する.零ベクトルの線形和の係数は,軌跡の滑らかさを評価関数とする最急降下法によって推定する.本手法を実際の人物の歩行軌跡に適用した結果を示す.This paper proposes a method for Eigenspace-based prediction of a person's path in future with current path. This method uses projection and back projection of the current path onto Eigenspace. However, the prediction does not take the nature of a path of pedestrian and results in non-smooth path. The proposed method modify the prediction by using null vectors in the orthocomplement of the learned Eigenspace and adding linear combinations of the null vectors to the prediction so that the path becomes smooth. Coe?cients of the linear combinations are computed by decent gradient method. Some experimental results on actual pathes are shown

Upgrading eigenspace-based prediction using null space and its application to path prediction

Subspace 2007 Workshop on ACCV2007, poster and slide ; Place : Tokyo, Japan ; Date : November 19, 200