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.

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.

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.

Plasma brain natriuretic peptide level in older outpatients with heart failure is associated with physical frailty, especially with the slowness domain

Objective To determine the association between plasma brain natriuretic peptide （BNP） level in patients with heart failure （HF） and physical frailty as well as with each domain of physical frailty. Methods Two hundred and six outpatients of cardiovascular medicine aged 60 years and older who had been hospitalized for HF or had been given a prescription medication for HF were included. Physical frailty was assessed using the following five domains： slowness, weakness, exhaustion, low activity, and shrinking, according to the Cardiovascular Health Study. Patients were divided into nonfi-ailty and frailty groups according to frailty scores. Plasma BNP level was measured. The 6-min walk test was performed to measure endurance. Results Plasma BNP was significantly different between the two groups （frailty group： 158.0 i 214.7 pg/mL, nonfrailty group： 65.2 ~ 88.0 pg/mL, P 〈 0.01）. Multivariate logistic regression analysis revealed log-transformed plasma BNP （Log BNP） was significantly associated with physical frailty （OR： 1.68, 95% CI： 1.11-2.56）, and Log BNP was significantly associated with the slowness domain （walking speed 〈 1.0 m/s） of physical frailty （OR： 1.75, 95% Ch 1.15-2.67）. Additionally, Log BNP was negatively correlated to the 6-minute walk distance （6MWD） （p=0.37, P 〈 0.01）, while 6MWD was positively correlated to walking speed （p = 0.66, P 〈 0.01）. Conclusions Plasma BNP level was related to physical frailty, especially in the slowness domain. Endurance may intervene in the associations between plasma BNP level and walking speed.

Constraint-induced movement therapy promotes brain functional reorganization in stroke patients with hemiplegia

Stroke patients with hemiplegia exhibit flexor spasms in the upper limb and extensor spasms in the lower limb, and their movement patterns vary greatly. Constraint-induced movement therapy is an upper limb rehabilitation technique used in stroke patients with hemiplegia; however, studies of lower extremity rehabilitation are scarce. In this study, stroke patients with lower limb hemiplegia underwent conventional Bobath therapy for 4 weeks as baseline treatment, followed by constraint-induced movement therapy for an additional 4 weeks. The 10-m maximum walking speed and Berg balance scale scores significantly improved following treatment, and lower extremity motor function also improved. The results of functional MRI showed that constraint-induced movement therapy alleviates the reduction in cerebral functional activation in patients, which indicates activation of functional brain regions and a significant increase in cerebral blood perfusJon. These results demonstrate that constraint-induced movement therapy promotes brain functional reorganization in stroke patients with lower limb hemiplegia.

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.

Soldiers' load carriage performance in high mountains: a physiological study

Background: The present study was designed to evaluate load carriage performance at extremely high altitudes with different loads and walking speeds in terms of physiological evaluation. The degree of maximum oxygen consumption changes at high altitudes was also examined.Methods: Twelve Indian Army soldiers were acclimatized at altitudes of 3,505 m and 4,300 m. They walked for 10 minutes on a motorized treadmill at 2.5km/h and 3.5km/h speeds during carrying no loads and three magnitudes of load(10.7kg, 21.4kg, 30kg) at both altitudes. Physiological parameters such as oxygen consumption, energy expenditure, heart rate, and ventilation were recorded for each breath using a gas analyzer. The rating of perceived exertion was also noted after each load carriage session. Maximal oxygen consumption(VO2max) was measured at sea level and the two high altitudes, and respective relative workloads(% of VO2max) were calculated from oxygen consumption. Repeated measure ANOVA was applied to reveal the significant effects of the independent variables.Results: The participants had significant reductions in VO2 max with rising altitude. Marked increases in almost all physiological parameters were observed with increasing load, altitude, and speed. The soldiers expressed heavy perceived exertion levels with higher loads at 3.5km/h at the two high altitudes.Conclusions: Considering the physiological responses, expressions of perceived exertion and changes in relative work load at both of the high altitudes. Indian soldiers are advised to walk slowly with adequate rest in between their schedules and to carry not more than 32% of their body weight.

Association between improved trunk stability and walking capacity using ankle-foot orthosis in hemiparetic patients with stroke： evidence from three-dimensional gait analysis

Background Restoration of both normal movement of the pelvis and centre of mass is a primary goal of walking rehabilitation in post-stroke patients because these movements are essential components of effective gait. The aim of this study is to quantitatively analyze the effect of ankle-foot orthosis on walking ability, and to investigate the correlation between improvements in trunk motion and walking capacity.

Lameness prediction in broiler chicken using a machine learning technique

Broiler flock welfare is usually assessed through mortality,physiology,behavior,and walk-ing ability.The possibility of assessing broiler chicken lameness using the bird walking abil-ity was investigated using the machine learning approach for the first time.Data on broiler walking speed and acceleration,genetic strain,and sex were recorded and input in a data-set.Broilers were classified according to the 6-point gait score(GS0 is a sound bird,and GS5 is a severely lame bird).Decision trees were built initially using all datasets.The confusion matrix of each developed model was analyzed.The pruning technique was used,removing from the dataset the variables that did not infer in the classification results.We reorganized the dataset and re-arranged the data by grouping the intermediate target class of gait score using the Borda Count method.Re-processing data,we obtained a new set of decision trees.Using the 3-point gait score(GS0 is a sound bird,and GS2 is a lame bird),we obtained a new model with better accuracy(78%);however,the model had a lower accuracy for classifying lame broilers(GS2,5%).The final decision tree was selected for classifying broilers,either sound or lame,according to their walking speed.The developed model presented good accuracy(91%),and it ordered properly sound(86%)and lame birds(92%).The novel model might be used to assess broiler lameness on-farm by registering the bird displacement velocity.Further developments using the model might allow flock lameness detection automatically.

Comparison of Neuromotor and Progressive Resistance Exercise Training to Improve Mobility and Fitness in Community-Dwelling Older Women

Purpose Neuromotor exercise,which stimulates motor fitness components(balance,agility,coordination),has been less investigated than other forms of exercise such as resistance or aerobic training to counteract the age-related impairment in mobility.The aim of the study was to verify whether neuromotor exercise was as effective as resistance training in improving mobility and related fitness components in healthy older women.Methods Thirty-five women(mean age 69.6±3.2 years)were assigned to a neuromotor(NMT)or a progressive resistance training(PRT)group,both exercising 1 h,twice weekly for 12 weeks.The NMT group exercised static and dynamic balance,agility,speed,reaction time and coordination,while the PRT performed prevalently machine based,strengthening exercises.All participants were tested before and after the intervention for walking speed under different conditions,chair rise time,cardiorespiratory fitness,muscular strength and power.A 2×2 MANOVA and subsequent ANOVAs were performed to ascertain the effects of the two trainings.Results Similar improvements were observed for mobility(P=0.000, η^(2)_(p)=0.73)and for fitness(P=0.000, η^(2)_(p)=0.96)in both groups.Conclusions The present results suggest that in healthy older women improvements in mobility may be obtained through both strength and neuromotor exercise.The present results contribute to further our knowledge on the effects of neuromotor exercise for older people and add relevant information on exercise interventions targeting mobility in the elderly.