The effect of waist twisting on walking speed of an amphibious salamander like robot

Amphibious salamanders often swing their waist to coordinate quadruped walking in order to improve their crawling speed. A robot with a swing waist joint, like an amphibious salamander, is used to mimic this locomotion.A control method is designed to allow the robot to maintain the rotational speed of its legs continuous and avoid impact between its legs and the ground. An analytical expression is established between the amplitude of the waist joint and the step length. Further, an optimization amplitude is obtained corresponding to the maximum stride. The simulation results based on automatic dynamic analysis of mechanical systems（ADAMS） and physical experiments verify the rationality and validity of this expression.

Change in stature by walking and running at a preferred transition speed

This study aimed to measure stature changes during and after walking and running at a preferred transition speed (PTS) and the recovery period, and to examine differences caused by loads imposed on the spinal column. Seven males and three females aged 22-41 years took part in this study. Subjects The subjects underwent 15 minutes of walking or running on a treadmill in a random order. Stature changes were measured during each exercise at intervals of 5 minutes and after a 20 minute standing recovery period within units of 0.01 mm. Two- way ANOVA revealed that both main factors, gait (F = 5.250, P < 0.05) and elapsed time (F = 14.409, P < 0.05), had a significant effect on stature. In the post hoc test, stature shrank with time and its loss was found to be greater in running than in walking, but recovered after both exercises. In conclusion, the spinal load increases with time during both walking and running at PTS, but is greater in running than in walking. After both exercises, spinal shrinkage shows a similar recovery process and recovers faster in walking to its pre-exercise level.

Association between Daily Living Walking Speed and Lifestyle and Physiological Factors in Older, Female Pokémon GO Players

Background: Walking speed is a reliable barometer of adverse health outcomes, particularly among older people. Few studies evaluated factors associated with daily actual walking speed, rather than that measured in a laboratory setting or self-reported data. Methods: In a joint effort with The Pokémon Company, we recruited study participants through a women’s magazine and analyzed data from 63 Pokémon GO players. We measured the true walking speed in daily life among older women using a data-gathering mobile application. Then, using questionnaire survey data collected on these participants in 2019, we estimated the relationship between walking speed and their lifestyle and physiological factors. In the analysis, we employed a bi-directional stepwise linear regression approach, with the Akaike information criterion (AIC) for variable selection. Results: The mean age of the 63 participants was 63.03 years (standard deviation, SD 7.46);the average walking speed was 4.56 km per hour (SD 1.54);and 52 (82.5%) and 55 (87.3%) participants answered that they had excellent/good health physically and mentally, respectively. After adjusted for covariates in a stepwise regression approach, we identified a significant association between −1.33 (95% confidence intervals −2.52 to −0.15) km/hour lower walking speed and the experience of outdoor falls within a year. We also demonstrated that the walking speed was 1.07 (0.33 to 1.81) km/hour faster for those who had played Pokémon GO before the study started. Conclusions: The true walking speed in daily life among older women was measured by a data-gathering mobile application. Although all participants were women recruited on a voluntary basis with an understanding of the purpose of the study, and the surveys were conducted at a cross-sectional setting, a significant relationship with the experience of outdoor falls was demonstrated. We also present evidence suggesting a possible relationship between Pokémon GO play and faster walking speed.

Relationship between Walking Speed and Exercise Habits of Elderly People

Japan becomes the super aged society. For Japan, the proportion of elderly people aged 65 and over is 27.3%. The Ministry of Health, Labor and Welfare estimates that in 2060, the proportion of the elderly people aged 75 or older to the total population will exceed 26.9%. Japan has nursing problems in a rapidly aging society. Therefore, the long-term care insurance system is being reviewed. The state, prefectures, and local governments are carrying out various campaigns from the perspective of long-term care prevention. One of them is fall prevention. Falling of the elderly often causes bedridden and death. Therefore, in this study, in order to examine the influence of exercise habits of the elderly on gait, the results of questionnaire survey and actual 10 m walking speed were obtained for elderly people who participated in the health class. As a result, walking speed was fast for people with exercise habits. As for exercise, walking speed was faster for those who continued with exercise such as walking than for those who did muscle training. By continuing the light exercise like walking, it might be possible to maintain the muscles of the lower limbs and cultivate a sense of balance or lead to the fall prevention of the elderly.

Comparison of walking quality variables between incomplete spinal cord injury patients and healthy subjects by using a footscan plantar pressure system

The main goal of spinal cord rehabilitation is to restore walking ability and improve walking quality after spinal cord injury(SCI). The spatiotemporal parameters of walking and the parameters of plantar pressure can be obtained using a plantar pressure analysis system. Previous studies have reported step asymmetry in patients with bilateral SCI. However, the asymmetry of other parameters in patients with SCI has not been reported. This was a prospective, cross-sectional study, which included 23 patients with SCI, aged 48.1 ± 14.5 years, and 28 healthy subjects, aged 47.1 ± 9.8 years. All subjects underwent bare foot walking on a plantar pressure measurement device to measure walking speed and spatiotemporal parameters. Compared with healthy subjects, SCI patients had slower walking speed, longer stride time and stance time, larger stance phase percentage, and shorter stride length. The peak pressures under the metatarsal heads and toe were lower in SCI patients than in healthy subjects. In the heel, regional impulse and the contact area percentage in SCI patients were higher than those in healthy subjects. The symmetry indexes of stance time, step length, maximum force, impulse and contact area were increased in SCI patients, indicating a decline in symmetry. The results confirm that the gait quality, including spatiotemporal variables and plantar pressure parameters, and symmetry index were lower in SCI patients compared with healthy subjects. Plantar pressure parameters and symmetry index could be sensitive quantitative parameters to improve gait quality of SCI patients. The protocols were approved by the Clinical Research Ethics Committee of Shengjing Hospital of China Medical University(approval No. 2015 PS54 J) on August 13, 2015. This trial was registered in the ISRCTN Registry(ISRCTN42544587) on August 22, 2018. Protocol version: 1.0.

Retrospective study of effect of whole-body vibration training on balance and walking function in stroke patients

BACKGROUND Dysfunction in stroke patients has been a problem that we committed to solve and explore.Physical therapy has some effect to regain strength,balance,and coordination.However,it is not a complete cure,so we are trying to find more effective treatments.AIM To observe the effect of whole-body vibration training(WVT)on the recovery of balance and walking function in stroke patients,which could provide us some useful evidence for planning rehabilitation.METHODS The clinical data of 130 stroke participants who underwent conventional rehabilitation treatment in our hospital from January 2019 to August 2020 were retrospectively analyzed.The participants were divided into whole-body vibration training(WVT)group and non-WVT(NWVT)group according to whether they were given WVT.In the WVT group,routine rehabilitation therapy was combined with WVT by the Galileo Med L Plus vibration trainer at a frequency of 20 Hz and a vibration amplitude of 0+ACY-plusmn+ADs-5.2 mm,and in the NWVT group,routine rehabilitation therapy only was provided.The treatment course of the two groups was 4 wk.Before and after treatment,the Berg balance scale(BBS),3 m timed up-and-go test(TUGT),the maximum walking speed test(MWS),and upper limb functional reaching(FR)test were performed.RESULTS After 4 wk training,in both groups,the BBS score and the FR distance respectively increased to a certain amount(WVT=46.08±3.41 vs NWVT=40.22±3.75;WVT=20.48±2.23 vs NWVT=16.60±2.82),with P<0.05.Furthermore,in the WVT group,both BBS score and FR distance(BBS:18.32±2.18;FR:10.00±0.92)increased more than that in the NWVT group(BBS:13.29±1.66;FR:6.16±0.95),with P<0.05.Meanwhile,in both groups,the TUGT and the MWS were improved after training(WVT=32.64±3.81 vs NWVT=39.56±3.68;WVT=12.73±2.26 vs NWVT=15.04±2.27,respectively),with P<0.05.The change in the WVT group(TUGT:17.49±1.88;MWS:6.79±0.81)was greater than that in the NWVT group(TUGT:10.76±1.42;MWS:4.84±0.58),with P<0.05.CONCLUSION The WVT could effectively improve the balance and walking function in stroke patients,which may be good for improving their quality of life.

A review on the coordinative structure of human walking and the application of principal component analysis

Walking is a complex task which includes hundreds of muscles, bones and joints working together to deliver smooth movements. With the complexity, walking has been widely investigated in order to identify the pattern of multi-segment movement and reveal the control mechanism. The degree of freedom and dimensional properties provide a view of the coordinative structure during walking, which has been extensively studied by using dimension reduction technique. In this paper, the studies related to the coordinative structure, dimensions detection and pattern reorganization during walking have been reviewed. Principal component analysis, as a popular technique, is widely used in the processing of human movement data. Both the principle and the outcomes of principal component analysis were introduced in this paper. This technique has been reported to successfully reduce the redundancy within the original data, identify the physical meaning represented by the extracted principal components and discriminate the different patterns. The coordinative structure during walking assessed by this technique could provide further information of the body control mechanism and correlate walking pattern with injury.

Gait speed and hospitalization among ambulatory hemodialysis patients: USRDS special study data

AIM： To assess the association of measured gait speed with hemodialysis （HD） patients’ hospitalization, in conjunction with, and apart from, recent fall history.METHODS： Gait speed was measured by a standard protocol and falls during the past 12 mo were ascertained for a prevalent multi-center HD cohort （n = 668） aged 20-92. Hospitalization during the past 12 mo was identified in the patient’s clinic records, and the first hospitalization after gait speed assessment （or the competing event of death） was identifed in the 2013 United States Renal Data System Standard Analysis Files.characterized 34.7% of the patients, and 27.1% had experienced a recent fall. Patients with slow gait speed but without a history of recent falls were 1.79 times more likely to have been hospitalized during the past 12 mo （OR = 1.79, 95%CI： 1.11-2.88, P = 0.02）, and patients with slow gait speed and a history of recent falls were over two times more likely to have been hospitalized （OR = 2.10, 95%CI： 1.19-3.73, P = 0.01）, compared with patients having faster gait speed and no recent fall history. Prospective examination of gait speed/fall history status in relation to frst hospitaliza-tion （or death） incurred by the end of follow-up Decem-ber 31, 2011 also showed that slow gait speed was as-sociated with these events in conjunction with a history of falls （HR = 1.54, 95%CI： 1.04-2.30, P = 0.03）.CONCLUSION： The International Task Force on Nutri-tion and Aging reported that gait speed is a powerful predictor for older adults of adverse outcomes such as hospitalization. In our data, gait speed-apart from, as well as in conjunction with, recent fall history-was as-sociated with HD patients’ hospitalization for multiple causes. Gait speed may be a sensitive health indicator among HD patients across the age spectrum.

人行悬索桥的步行参数研究

以九峰山人行悬索桥为观测点,采用视频记录与人工筛选相结合的方法获取了2236个行人样本的实测数据,进而统计得到人行悬索桥上的行人步行参数(步频、步幅和步速)的分布特性和统计值,并给出了人行悬索桥上的步频-步速、步幅-步速和步频-步幅之间的转换关系式,得到以下结论:1)在人行悬索桥上,全部行人的步行参数都服从正态分布,即步频~N(1.726,0.258)Hz、步幅~N(0.596,0.094)m、步速~N(1.013,0.260)m/s,它们的合理性也在某工程实例的应用中得以验证;2)人行悬索桥上的行人步行参数的均值(标准差)要小于(大于)其他行走环境所统计得到的行人步行参数的均值(标准差);3)中国人的步频和步幅的均值(标准差)都小于(大于)西方人的步频和步幅的均值(标准差).因此,在设计我国的人行悬索桥时,不能直接采用其他人种和行走环境的行人步行参数的统计值,而应采用适合于人行悬索桥的步行参数.

不同速度运动状态中竞走运动员下肢动力学特征研究

目的通过对中国竞走学校优秀运动员不同速度运动状态中下肢动力学特征的分析,为优化专项技术动作,减少运动损伤发生,强化竞走后备人才训练及竞技水平提高提供参考依据。方法选取中国竞走学校男、女一级及以上重点运动员各8名。依据目前青少年竞走运动员不同速度区间的划分,应用SONY DSC-RX10M4高速摄像机和Kistler三维测力台同步采集运动员中、高速时下肢的地面反作用力、峰值力和下肢各关节反作用力等动力学数据,应用SIMI运动解析软件和Matlab软件进行计算,采用单因素方差分析对不同速度下的数据进行比较。结果男运动员高速和中速相比,足外侧地面反作用力峰值高速大于中速,且具有显著性差异(P<0.05),足内侧、水平方向和垂直方向的峰值力,均无显著性差异(P>0.05),髋、膝、踝关节水平和垂直方向峰值力均增加,其中髋、膝、踝关节水平方向峰值力增加幅度分别为22.9%、17.5%、20%,垂直方向峰值力增加幅度分别为2.0%、8.2%、2.7%;女运动员高速与中速相比,足外侧和水平前方向地面反作用力峰值高速大于中速,且具有显著性差异(P<0.05),足内侧、水平后和垂直方向峰值力均无显著性差异(P>0.05),髋、膝、踝关节水平和垂直方向峰值力均增加,其中髋、膝、踝关节水平方向峰值力增加幅度分别为31.6%、26.8%、41.7%,垂直方向峰值力增加幅度分别为7.9%、12.8%、7.4%。结论竞走运动员不同速度运动状态下,男、女运动员在一个步态周期中的地面反作用力在不同方向均为高速大于中速,且均表现为垂直方向分力值最大,内外方向的分力最小,而水平方向制动力峰值均大于加速力峰值,此结果为日常训练加强足跟着地动作技术规范性,同时增加蹬地力量训练,提高下肢肌肉用力水平提供了有力证据;另一方面,男、女运动员髋、膝、踝各关节水平和垂直方向峰值力高速均大于中速,在足跟着地时膝关节和踝关节垂直方向受力较大,髋关节受力较小,而前脚掌蹬离地面时,髋部水平方向转动明显大于垂直方向摆动力度,因而青少年竞走运动员日常训练中需加强髋、膝、踝关节运动链的协同和补偿作用,准确掌握竞走技术动作的用力特点和顺序,对于提高其技术动作合理性和科学性,减少下肢损伤,提高运动表现和比赛成绩具有重要意义。

老年人工具性生活活动能力水平与常速行走步态特征的关联分析

目的探讨老年人常速行走下步态参数特征及其与工具性生活活动能力(instrumental activity of daily living,IADL)水平的关系。方法2023年2-8月,应用方便抽样,选取北京医院60岁及以上自愿接受调查的老年人为研究对象进行横断面调查,收集研究对象的一般特征资料,采用IADL量表评估IADL水平,依据IADL是否受损将研究对象分为两组,使用多传感器可穿戴步态分析仪IDEEA采集研究对象常速行走状况下的步态参数。采用多因素Logistic回归模型分析老年人常速行走下步态参数与IADL受损发生风险的关联。结果共739例纳入研究,受损组293例,正常组446例。与正常组比较,受损组老年人时空步态参数如步速、步频和步长等降低,动力学参数如大腿摆动功、地面冲击力和脚离地角度降低,步态周期参数如单脚支撑时间等增加,差异有统计学意义(P<0.05)。多因素Logistic回归分析结果显示,步频、步长、跨步长、足落地控制和脚离地角度与IADL受损存在关联(P<0.05)。年龄分层分析中,≥70岁老年人群步态特征与IADL受损发生风险呈现更为显著的相关性(P<0.05)。结论IADL受损老年人步态性能下降,时空步态参数与动力学参数与老年人IADL受损关系密切。

腰椎管狭窄症患者的步行速度与术后疼痛灾难化的相关性

目的 探讨腰椎管狭窄症(LSS)患者的步行速度(步速)与术后疼痛灾难化(PC)的相关性。方法 选择2018年1月至2021年12月于该院接受手术治疗的93例LSS患者作为研究对象,收集患者术前、术后3个月、术后6个月、术后12个月时的疼痛灾难化评分(PCS)、步速、疼痛数字评分量表(NRS)评分、日本骨科协会(JOA)评分,观察术后3个月、术后6个月、术后12个月时PCS与步速的关系。结果 术后12个月时,患者无助、放大、沉思等维度及PCS总得分均较术前显著降低(P<0.05)。术后12个月时,患者步速、JOA评分均较术前显著升高,差异有统计学意义(P<0.05);术后12个月时,患者腿痛NRS、腰痛NRS均较术前显著降低(P<0.05)。Pearson相关性分析显示,患者术前、术后3个月、术后6个月、术后12个月时的PCS与步速和JOA评分均呈显著负相关(P<0.05),PCS与腿痛NRS、腰痛NRS均呈显著正相关(P<0.05)。多元线性回归分析显示,术后3个月、术后6个月、术后12个月时的PCS与步速均呈负相关性(P<0.05)。结论 LSS患者术后1年内PC与步速呈显著负相关,步行速度评估对于术后疼痛的管理可能具有重要指导作用。

水灾场景下的地铁车站人员疏散效率研究

为提升地铁车站在水淹倒灌情况下的人员疏散效率,制定合理的地铁疏散应急预案,本文基于Anylogic仿真软件,构建了淹水倒灌场景下的地铁站,以杭州地铁金沙湖站为例,研究不同水深情况下的地铁人群疏散效率。结果表明:水深、出入口数量等都能对人员安全疏散效率产生影响,设置导流栏能节省18%以上的疏散时间,当站内水深超过20 cm时,因行人行走速度慢导致疏散时间会超过6 min,无法满足安全疏散要求。

Pedestrian walking speed at un-signalized midblock crosswalk and its impact on urban street segment performance

The Urban Street Segment Chapter of the Highway Capacity Manual(HCM)includes a methodology for evaluating the level of service urban street segments provide to automobile users.The methodology does not account for pedestrian activity at un-signalized midblock crosswalk on an urban street segment.Pedestrian activity at un-signalized midblock crosswalk on urban street segments causes friction conditions between automobiles and pedestrians.As a consequence,the average time it takes vehicles to travel along the segment is increased.Increasing segment running time decreases both the travel speed of automobiles and the level of service provided to automobile users.There is an inverse relationship between the delay incurred by interrupted vehicles and the speeds at which pedestrians walk while crossing at midblock.To account for this delay,there is a need to investigate pedestrian walking speeds at un-signalized midblock crosswalks.This study measured pedestrian walking speeds by age-group at two un-signalized midblock crosswalks on urban street segments.The first objective of this paper is to perform statistical analyses to examine the measured free-flow pedestrian walking speeds.The second objective is to demonstrate how the findings of this study can be incorporated into the Urban Street Segment Analysis Chapter of the HCM.Pedestrian walking speeds were recorded and analyzed for 2937 pedestrians.The results show teenagers walk at an average speed of 1.45 m/s,young adults walk at an average speed of 1.55 m/s,middle age pedestrians walk at a speed of 1.45 m/s,older pedestrians walk at speed of 1.09 m/s,and elderly or physically disabled pedestrians walk at a speed of 1.04 m/s.

Motion speed modulates walking direction discrimination: The role of the feet in biological motion perception

The human visual system is tuned to the motions of biological entities, which provide potentially vital information for survival. The current study examines the interplay between motion speed and motion direction perception. Following a brief presentation of a point-light walker walking straight ahead or slightly leftward or rightward, observers were asked to quickly judge the walking direction (left or right). Participants showed better direction discrimination when the walker walked at a fast pace compared to a natural or slow pace, and this was not simply due to a difference in motion cycles. Moreover, walking direction sensitivity could be enhanced by increasing the feet motion speed alone, so long as the direction of feet movement was consistent with that of the other body parts. These findings demonstrate that our perception of walking direction is influenced by local motion speed, and highlight the role of the feet in biological motion perception.

基于Prewitt算子和Radon变换的雷达高速微弱目标检测

正交频分复用(OFDM)调制雷达中跨距离单元走动问题降低了高速微弱目标检测性能,为此,提出一种基于Prewitt算子和Radon变换的OFDM雷达高速微弱目标检测算法。首先分析了多脉冲积累出现的跨距离单元走动以及Radon变换受噪声干扰问题,然后采用Prewitt算子卷积运算抑制噪声并保留回波能量,采用Radon变换沿距离单元走动斜线进行能量积累。理论分析和仿真结果表明,该算法具有比Hough变换和动目标检测(MTD)更优的低信噪比背景下的高速微弱目标检测性能,并能有效实现多目标检测。

掘锚机用电机驱动行走减速机设计

掘锚机行走机构需配置减速机来增大扭矩,合理地拟定行走减速机的传动方案是保证行走机构设计质量的基础。传统掘锚机的行走减速机采用液压马达驱动,由于掘锚机自重大、接地比压大,对于机重100 t左右整机所需的驱动力,使用效果并不好。为了增大行走部驱动力,使其具有良好的通过性能,阐述一种变频电机驱动的低速大扭矩行走减速机的设计。

不同信号控制路段行人过街速度分析

为了解不同信号灯控制下路段行人的过街平均速度,选取数字型倒计时和非数字型倒计时2种典型类型的信号灯路段过街设施作为研究对象。根据采集的行人过街速度样本,得出两种情况下不同人群、不同年龄段、不同过街剩余时间下的行人过街平均速度,结合行人的意愿调查分析在此路段上更适用于哪种类型的信号灯。最后,基于行人的年龄、性别、过街方式、过街剩余时间对过街平均速度影响的分析结果,使用SPSS软件,建立2种情况的行人过街速度的线形回归模型,并标定系数。

LEARNS宣教模式联合八段锦干预对老年高血压伴衰弱患者的影响

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