Fast Gait Research Articles

Robust biped locomotion using deep reinforcement learning on top of an analytical control approach

This paper proposes a modular framework to generate robust biped locomotion using a tight coupling between an analytical walking approach and deep reinforcement learning. This framework is composed of six main modules which are hierarchically connected to reduce the overall complexity and increase its flexibility. The core of this framework is a specific dynamics model which abstracts a humanoid’s dynamics model into two masses for modeling upper and lower body. This dynamics model is used to design an adaptive reference trajectories planner and an optimal controller which are fully parametric. Furthermore, a learning framework is developed based on Genetic Algorithm (GA) and Proximal Policy Optimization (PPO) to find the optimum parameters and to learn how to improve the stability of the robot by moving the arms and changing its center of mass height. A set of simulations are performed to validate the performance of the framework using the official RoboCup 3D League simulation environment. The results validate the performance of the framework, not only in creating a fast and stable gait but also in learning to improve the upper body efficiency.

The effects of forearm movements on human gait during walking with various self-selected speeds

The forearms significantly contribute to the upper extremity movements and, consequently, whole-body responses during locomotion. The purpose of this study is to provide a more in-depth understanding of the mechanism controlling forearm movements during walking by comprehensively investigating the effects of the forearms on the lower and upper limb movements. Such an understanding can provide critical information for the design and control of robotic upper-limb prostheses. Twelve healthy young participants were recruited to compare their gait during (1) natural walking, (2) walking while wearing a pair of artificial passive forearms and having their actual forearms restrained by orthopedic braces, and (3) walking with only having their forearms restrained by the braces (i.e., no artificial forearms). While the passive forearms in condition 2 were to determine if the forearm movements were passively or actively controlled, condition 3 was to account for the effects of restraining the forearms in condition 2. The participants' lower-limb joint angles and spatiotemporal parameters remained unchanged across the three conditions while walking at their normal and fast self-selected gait speeds. However, significant decreases were observed in the shoulder and trunk angles, the interlimb coordination, and the shoulder-trunk correlations when walking with the artificial forearms. These observations were in tandem with the increased muscle activity of the biceps, trapeziuses, and posterior deltoids, which controlled the shoulder motion and trunk rotation during walking with the artificial forearms across both normal and fast self-selected speeds. Although not significant, the metabolic energy analysis of five participants revealed an increase during walking with artificial forearms. The results support the idea that the body actively controls the forearm movements through the shoulder and trunk rotations to mitigate the undesired disturbances induced by the passive forearm movements during locomotion.

Understanding early horse transport in eastern Eurasia through analysis of equine dentition

Across Eurasia, horse transport transformed ancient societies. Although evidence for chariotry is well dated, the origins of horse riding are less clear. Techniques to distinguish chariotry from riding in archaeological samples rely on elements not typically recovered from many steppe contexts. Here, the authors examine horse remains of Mongolia's Deer Stone-Khirigsuur (DSK) Complex, comparing them with ancient and modern East Asian horses used for both types of transport. DSK horses demonstrate unique dentition damage that could result from steppe chariotry, but may also indicate riding with a shallow rein angle at a fast gait. A key role for chariots in Late Bronze Age Mongolia helps explain the trajectory of horse use in early East Asia.

Faster or longer steps: Maintaining fast walking in older adults at risk for mobility disability.

The ability to walk at various speeds is essential to independence for older adults. Maintaining fast walking requires changes in spatial-temporal measures, increasing step length and/or decreasing step time. It is unknown how mobility affects the parameters that change between preferred and fast walking. How does preferred walking performance and measures of strength and mobility relate to the approach (decreasing step time or increasing step length) older adults at risk for mobility disability use to maintain fast walking speeds?. Peak isokinetic dynamometry of knee and ankle and several mobility evaluations, including the Timed Up-and-Go, Short Physical Performance Battery, and Dynamic Gait Index, assessed mobility and strength in 57 participants, aged 65-80. Biomechanical gait analysis was used to analyze step length, step time, gait speed at preferred and fast gait speeds and ground reaction force during preferred walking. A score combining the differences between step length and time at fast and preferred speeds (Length-Time Difference) separated participants into two groups: (1) Length, representing a predominant increase in step length to walk fast and (2) Time, a predominant decrease in step time. Those who decreased step time to produce increased speed performed worse during repeated chair stands (p = .006) with no difference in isokinetic strength (p ≥ .15). During preferred walking, the Time group displayed increased propulsive impulse compared to the Length group (p = .007), despite no differences in preferred speed, step length, or time (p ≥ .50). While kinetics of preferred walking differed between groups separated by Length-Time Difference, basic spatial-temporals of preferred walking did not in this homogenous population. Length-Time Difference relates to a common mobility assessment and could be easily calculated by clinicians to provide a quantitative and more sensitive measure of ambulatory performance.

Estimation of Knee Joint Angle Using Textile Capacitive Sensor and Artificial Neural Network Implementing with Three Shoe Types at Two Gait Speeds: A Preliminary Investigation.

The lower limb joints might be affected by different shoe types and gait speeds. Monitoring joint angles might require skill and proper technique to obtain accurate data for analysis. We aimed to estimate the knee joint angle using a textile capacitive sensor and artificial neural network (ANN) implementing with three shoe types at two gait speeds. We developed a textile capacitive sensor with a simple structure design and less costly placing in insole shoes to measure the foot plantar pressure for building the deep learning models. The smartphone was used to video during walking at each condition, and Kinovea was applied to calibrate the knee joint angle. Six ANN models were created; three shoe-based ANN models, two speed-based ANN models, and one ANN model that used datasets from all experiment conditions to build a model. All ANN models at comfortable and fast gait provided a high correlation efficiency (0.75 to 0.97) with a mean relative error lower than 15% implement for three testing shoes. And compare the ANN with A convolution neural network contributes a similar result in predict the knee joint angle. A textile capacitive sensor is reliable for measuring foot plantar pressure, which could be used with the ANN algorithm to predict the knee joint angle even using high heel shoes.

Gait phase detection by using a portable system and artificial neural network

Gait phases are important to evaluate the walking function and to identify the characteristics of pathological gaits. However, it is difficult to differentiate gait phases outside gait laboratories, thus, this study aimed to develop a method to detect 8 gait sub-phases using a wearable multiple sensor system and artificial neural network (ANN). Motion sensors were used to acquire the acceleration of lower limbs, and force sensitive resistors were used to detect contact state and force between the foot and the ground. Walking was recorded using a high-speed camera. Two feed forward back-propagation (BP) neural networks were developed. The resilient BP algorithm was used to train ANN. A total of 66 volunteers participated in this study. For the stance and swing phase detection, simulation of the training data showed an accuracy of 98.0 ​%. The data from the test set showed a recognition accuracy of 97.75 ​%. Because the ending point of the last phase ‘Terminal Swing’ is always 100 ​% GC, we only listed seven phases. The prediction accuracy of seven phases were: 35.9 ​%, 63.8 ​%, 93.6 ​%, 94.9 ​%, 94.8 ​%, 97.9 ​% and 98 ​% using the limb acceleration data only. The average accuracy for seven phases were 68 ​%, 91.3 ​%, 97.8 ​%, 98.9 ​%, 98.8 ​%, 99.1 ​%, and 99.5 ​% using the limb acceleration and foot pressure data for fast, normal, and slow gait speeds. This study provides a new method for eight gait sub-phases detection with high accuracy combining a wearable system and ANN, which may make gait phase analysis possible under free-living conditions.

The Distance Covered in Field Tests is more Explained by Walking Capacity than by Cardiorespiratory Fitness after Stroke

ObjectivesTo investigate if the distance covered in the Six-Minute Walk Test (6MWT) and in the Incremental Shuttle Walk Test (ISWT) is most strongly explained by walking capacity or cardiorespiratory fitness (CRF) measures in individuals after chronic stroke. Materials and MethodsThis is a cross-sectional study. Individuals after chronic stroke aged at least 20 years old and able to walk at least 10 minutes independently were included. The distance covered (meters) in the 6 MWT and ISWT (dependent variables), comfortable and fast gait speed obtained by the 10 m walk test (10 mWT) (walking capacity measures; independent variables) and peak oxygen consumption (VO2peak; CRF measure; independent variable) (ml.kg–1.min–1) obtained by the cardiopulmonary exercise test (CPET) were obtained. Linear regression analyses were performed (α = 5%). ResultsFifty individuals (mean age of 55±12 years and mean time after stroke of 67±74 months) were included. Comfortable and fast gait speeds were the variables that most strongly explained the distance covered in the field tests: 6MWT (R² = 0.614, β = 0.784, p < 0.001 and R² = 0.615, β = 0.778, p < 0.001, respectively) and ISWT (R² = 0.450, β = 0.671, p < 0.001 and R² = 0.456, β = 0.746, p < 0.001, respectively). On the other hand, for the VO2peak, the following models were generated: 6MWT (R² = 0.280, β = 0.530, p < 0.001) and ISWT (R² = 0.154, β = 0.393, p = 0.005). ConclusionsThe distance covered in the field tests (6MWT and ISWT) is more suitable to support inferences about the walking capacity than about the CRF of individuals after chronic stroke.

Moderate-intensity exercise versus high-intensity interval training to recover walking post-stroke: protocol for a randomized controlled trial

BackgroundStroke results in neurologic impairments and aerobic deconditioning that contribute to limited walking capacity which is a major barrier post-stroke. Current exercise recommendations and stroke rehabilitation guidelines recommend moderate-intensity aerobic training post-stroke. Locomotor high-intensity interval training is a promising new strategy that has shown significantly greater improvements in aerobic fitness and motor performance than moderate-intensity aerobic training in other populations. However, the relative benefits and risks of high-intensity interval training and moderate-intensity aerobic training remain poorly understood following stroke. In this study, we hypothesize that locomotor high-intensity interval training will result in greater improvements in walking capacity than moderate-intensity aerobic training.MethodsUsing a single-blind, 3-site randomized controlled trial, 50 chronic (> 6 months) stroke survivors are randomly assigned to complete 36 locomotor training sessions of either high-intensity interval training or moderate-intensity aerobic training. Main eligibility criteria are age 40–80 years, single stroke for which the participant received treatment (experienced 6 months to 5 years prior to consent), walking speed ≤ 1.0 m/s, able to walk at least 3 min on the treadmill at ≥ 0.13 m/s (0.3 mph), stable cardiovascular condition (American Heart Association class B), and the ability to walk 10 m overground without continuous physical assistance. The primary outcome (walking capacity) and secondary outcomes (self-selected and fast gait speed, aerobic fitness, and fatigue) are assessed prior to initiating training and after 4 weeks, 8 weeks, and 12 weeks of training.DiscussionThis study will provide fundamental new knowledge to inform the selection of intensity and duration dosing parameters for gait recovery and optimization of aerobic training interventions in chronic stroke. Data needed to justify and design a subsequent definitive trial will also be obtained. Thus, the results of this study will inform future stroke rehabilitation guidelines on how to optimally improve walking capacity following stroke.Trial registrationClinicalTrials.govNCT03760016. Registered on November 30, 2018.

Importance of core stability for coordinated movement of the human body in stroke rehabilitation

ABSTRACT Objectives To examine the effect of core stability on parameters of coordinated movement of the trunk and lower extremities in post-stroke rehabilitation. Methods A total of 55 subjects (mean age, 58 years) were included in the study: 33 patients after stroke (17 with ischemic cerebral stroke and 16 with cerebellar) and 22 neurologically healthy subjects with lower back pain. Participation was voluntary. All subjects were asked to complete two exercises: a dynamic movement in the seated position (leaning forward and back) and a march-in-place exercise with a high elevation of the knees. The two exercises were performed with and without contraction of the abdominal muscles. The frontal and sagittal inclination of the trunk during movement, gait speed, elevation of the feet, and muscle tension was recorded. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT04886466. Results Core stability (abdominal contraction) was associated with more precise trunk movement in the frontal and sagittal plane, as well as higher elevation of the feet and a faster gait. This occurred in both post-stroke patients and neurologically healthy subjects with lower back pain. Discussion Muscle tensions were generally lower in post-stroke patients compared to those with lower back pain syndrome but active abdominal tension muscles caused the increase of core stability and alter the trunk movement path, and improves gait and range of movement. Core stability training during stroke rehabilitation may help patients to achieve a higher level of coordinated movement.

Algorithm based on one monocular video delivers highly valid and reliable gait parameters

Despite its paramount importance for manifold use cases (e.g., in the health care industry, sports, rehabilitation and fitness assessment), sufficiently valid and reliable gait parameter measurement is still limited to high-tech gait laboratories mostly. Here, we demonstrate the excellent validity and test–retest repeatability of a novel gait assessment system which is built upon modern convolutional neural networks to extract three-dimensional skeleton joints from monocular frontal-view videos of walking humans. The validity study is based on a comparison to the GAITRite pressure-sensitive walkway system. All measured gait parameters (gait speed, cadence, step length and step time) showed excellent concurrent validity for multiple walk trials at normal and fast gait speeds. The test–retest-repeatability is on the same level as the GAITRite system. In conclusion, we are convinced that our results can pave the way for cost, space and operationally effective gait analysis in broad mainstream applications. Most sensor-based systems are costly, must be operated by extensively trained personnel (e.g., motion capture systems) or—even if not quite as costly—still possess considerable complexity (e.g., wearable sensors). In contrast, a video sufficient for the assessment method presented here can be obtained by anyone, without much training, via a smartphone camera.

Domain-specific self-perceptions of aging are associated with different gait patterns in older adults: a cross-sectional latent profile analysis

BackgroundPrevious studies have pointed to the impact of self-perceptions of aging (SPA) on self-reported physical function in later life. However, less is known about associations of SPA with objectively measured physical function, especially gait. Research that examined other psychological variables and objectively measured gait has focused on single gait parameters such as gait speed, which seems to fall short for the complexity of this movement. Some approaches have proposed ways to identify gait patterns in specific patient groups, but not in community samples. Our goal was (a) to identify gait patterns based on a combination of important gait parameters in a community sample, and (b) to investigate differential associations of gain- and loss-related SPA with these gait patterns.MethodsThe study used an electronic walkway to assess gait parameters of 150 community dwelling adults aged 71–93 years (61.0% women) at their usual and maximum gait speed. SPA were assessed with a questionnaire. We used latent profile analysis (LPA) to identify groups exhibiting distinct gait patterns and binary logistic regression to investigate associations of SPA with these groups, controlling for personality traits, number of illnesses, age, gender, and education. To compare overall function between groups, a t-test for scores in the Short Physical Performance Battery was used.ResultsLPA revealed two distinct groups in both gait speed conditions. The fit group exhibited a stable, well-coordinated and faster gait pattern, while the functionally limited group’s gait pattern was less stable, less coordinated and slower. The odds of belonging to the functionally limited group were increased by loss-related SPA at usual gait speed, while the odds of belonging to the fit group were increased by gain-related SPA at individual maximum speed.ConclusionsThe findings (a) suggest LPA as a useful approach to investigate complex gait patterns considering several gait parameters simultaneously, and (b) provide first evidence for differential associations of gain- and loss-related SPA with gait patterns at usual and maximum gait speed. Intervention studies addressing gait in older adults should additionally address gain-related views on aging.

Measuring recovery after open lower limb fractures: combined objective functional tests and global perceived recovery outperform narrower metrics and a standard generic patient reported outcome measure

BackgroundOpen lower limb fractures are serious injuries requiring combined ortho-plastic surgery and have significantly worse outcomes than similar closed fractures. There is little objective published data to determine which functional outcome measures best reflect progress or completeness of physical recovery.Our hypothesis was that objective measures combining strength, mobility and balance would better reflect recovery than isolated parameters (e.g. range of motion ROM) and would compare well to patients’ perceived recovery.MethodsAdult open lower limb fracture patients were reviewed 6 and 12 weeks, 6, 9 and 12 months post-injury. The mechanism, injury pattern, age, gender and treatment were recorded. Isolated parameter objective functional outcome measures (OFOMs) (ROM and MRC strength grade) were compared to combined OFOMs (timed up and go, comfortable gait speed and fast gait speed, Edgren Side Step Test (TUAG, CGS, FGS, ESST) and Single Leg balance. Patient reported outcomes were recorded (Global Perceived Effect (GPE) score and Disability Rating Index (DRI)). Statistical analysis used non-parametric tests (e.g. Spearman correlation) compared each with time since injury.ResultsSixty-eight patients (54 male) with a median age of 45(20–75) years. Of the 19 isolated OFOMs, only knee flexion and ankle plantar flexion ROM and strength improved with time (Spearman correlation p = 0.042, 0.008, 0.032, 0.036 respectively). TUAG, ESST, CGS, FGS and GPE scores showed significant improvement (Spearman correlation p < 0.001). Patients’ estimation of recovery paralleled these measures (Spearman correlation p < 0.001) with all but 2 patients achieving the minimum clinical important difference in DRI by 12 months compared to baseline. However, the GPE score had a higher proportion of improving responses than DRI at each time-point.DiscussionFunctional recovery is a key determinant in patients returning to work, providing for themselves and their family or resuming independent living for older patients. This study has demonstrated time-related improvements in combined OFOMs measuring mobility, strength, agility and balance paralleling patients’ perception of recovery in the 12 months after open lower limb fractures. Over the same time-frame, the simple GPE score compared favourably with the DRI. Such parameters could become part of a defined core outcomes set. Focussing rehabilitation towards these combined OFOMs may help hasten recovery.Trial registrationSouth West Wales REC 06/WMW02/10).

Prognostic value of disease risk score versus gait speed in older adults with lymphoma

Measures of physical function predict survival in older patients with lymphoma but their prognostic ability has not been compared to disease-specific risk scores. We prospectively recruited patients ≥75 years with lymphoma. Patients underwent a frailty screen including 4-m gait speed. Disease-specific risk scores were obtained retrospectively. Among 168 patients, there was no association between disease-specific risk score and survival. Conversely, faster gait speed was significantly associated with survival in the entire cohort (HR = 0.16; 95%CI, 0.06–0.42; p = 0.0003) indicating a HR of 0.63 for an increase in gait speed of 0.25 m/s. When gait speed was added to the DLBCL IPI and FLIPI separately, it was significantly associated with OS (p = 0.004 for DLBCL, p = 0.03 for FLIPI) which increased its predictive power. Our study of older lymphoma patients demonstrates gait speed may improve outcome prediction beyond standard prognostic scores.

How groove in music affects gait.

Rhythmic auditory stimulation (RAS) is a gait intervention in which gait-disordered patients synchronise footsteps to music or metronome cues. Musical 'groove', the tendency of music to induce movement, has previously been shown to be associated with faster gait, however, why groove affects gait remains unclear. One mechanism by which groove may affect gait is that of beat salience: music that is higher in groove has more salient musical beats, and higher beat salience might reduce the cognitive demands of perceiving the beat and synchronizing footsteps to it. If groove's effects on gait are driven primarily by the impact of beat salience on cognitive demands, then groove's effects might only be present in contexts in which it is relevant to reduce cognitive demands. Such contexts could include task parameters that increase cognitive demands (such as the requirement to synchronise to the beat), or individual differences that may make synchronisation more cognitively demanding. Here, we examined whether high beat salience can account for the effects of high-groove music on gait. First, we increased the beat salience of low-groove music to be similar to that of high-groove music by embedding metronome beats in low and high-groove music. We examined whether low-groove music with high beat salience elicited similar effects on gait as high-groove music. Second, we examined the effect of removing the requirement to synchronise footsteps to the beat (i.e., allowing participants to walk freely with the music), which is thought to remove the cognitive demand of synchronizing movements to the beat. We tested two populations thought to be sensitive to the cognitive demands of synchronisation, weak beat-perceivers and older adults. We found that increasing the beat salience of low-groove music increased stride velocity, but strides were still slower than with high-groove music. Similarly, removing the requirement to synchronise elicited faster, less variable gait, and reduced bias for stability, but high-groove music still elicited faster strides than low-groove music. These findings suggest that beat salience contributes to groove's effect on gait, but it does not fully account for it. Despite reducing task difficulty by equalizing beat salience and removing the requirement to synchronise, high-groove music still elicited faster, less variable gait. Therefore, other properties of groove also appear to play a role in groove's effect on gait.

Subclinical vasculopathy and skeletal muscle metrics in the singapore longitudinal ageing study.

Frailty is associated with future cardiovascular events in older adults. This cross-sectional study examined the relationship between subclinical vasculopathy with measures of skeletal muscle mass and function. Asymptomatic community-dwelling Asians ≥55 years underwent assessments for subclinical vasculopathy (carotid intima-media thickness (cIMT), aortic and carotid stiffness, and endothelial function), muscle mass (calf circumference adjusted for body mass index) and function (knee extension strength, 6-meter fast gait speed). Multivariable regression analyses for associates of muscle mass/function controlled for demographics and cardiometabolic risk factors. Among 336 participants (median age 62 years, 55.1% male, 3.6% sarcopenia), cIMT, aortic and carotid stiffness inversely correlated with muscle mass, strength and gait speed; cIMT remained independently associated with gait speed (β=-0.26) in multivariable analyses. Age and sex significantly modified the relationship between subclinical vasculopathy and muscle mass/function. Associations, only found in those aged ≥70, included cIMT with gait speed (β=-0.48) and knee strength (β=-9.33), and aortic augmentation index and aortic stiffness composite z-score with gait speed (β=-0.11 and β=-0.19 respectively). Among males, cIMT correlated with gait speed (β=-0.31). The association of subclinical vasculopathy with skeletal muscle mass and function in asymptomatic adults ≥55 years is best reflected by cIMT. The roles of mediating pathways deserve further evaluation.

Strategies for increasing gait speed in patients with hip osteoarthritis: their clinical significance and effects on hip loading

BackgroundChanges in gait speed are required in various situations and can be achieved by changing stride length, cadence, or both. Differences in strategies for increasing gait speed may have different effects on hip joint and physical function. The purpose of this study was to determine the effects of strategies for increasing gait speed on hip pain, physical function, and changes in hip loading during gait in patients with hip osteoarthritis (OA). We hypothesized that patients who increase gait speed mainly by increasing cadence would have lesser hip pain, a higher physical function, and a lower rate of increase in hip moments with increasing gait speed.MethodsForty-seven patients with secondary hip OA (age, 48.3 ± 11.0 years) were included. Gait speed, stride length, cadence, and peak and impulse of the hip moments were measured during gait at self-selected normal and fast gait speeds. The patients were classified as types S (with mainly increasing stride length, n = 11 [23.4%]), C (with mainly increasing cadence, n = 23 [48.9%]), and SC (with increasing stride length and cadence, n = 13 [27.7%]) according to whether they used changes in stride length and/or cadence to transition from normal to fast gait. Hip pain, physical function, and hip moment changes during gait were compared between types.ResultsThe physical function was higher in types C (38.0 ± 8.8, P = 0.018) and SC (40.6 ± 8.5, P = 0.015) than in type S (28.2 ± 7.8), even after adjustment for age and minimum joint space width. Hip pain was not significantly different between types. The robustness of these results was confirmed with sensitivity analysis. The rates of increases in peak external hip adduction (P = 0.003) and internal rotation moments (P = 0.009) were lower in type C than in type SC.ConclusionsType C tended to suppress the increase in hip moments during fast gait. Types C and SC, which included increased cadence, maintained higher physical function levels than type S. Encouraging the use of cadence-increasing strategy may be useful for reducing hip loading and maintaining physical function in patients with hip OA.

Functional performance tests in interstitial lung disease: Impairment and measurement properties

BackgroundThere is limited information regarding impairment in functional performance tests and their measurement properties in ILD. The present study aimed to verify the impairment and measurement properties of functional performance tests in ILD. MethodsILD and healthy individuals underwent assessments of pulmonary function, peripheral muscle strength (handgrip force and maximum isometric contraction of quadriceps femoris – MIVCq) and exercise capacity (6-min walk test – 6MWT). Functional performance was assessed by timed-up-and-go with usual (TUGu) and fast (TUGf) gait speeds, 4-m gait speed (4MGS), sit-to-stand in 30 s (30sec-STS), 1 min (1min-STS) and with 5 repetition (5rep-STS) and Short Physical Performance Battery (SPPB). Functional performance was compared between groups, validity (correlation with 6MWT and MIVCq) and reliability of tests were checked in subjects with ILD (intra- and inter-rater agreement analysis). ResultsSeventy-six participants (40 ILD [25 women, 61 ± 11 years, FVC 75 ± 17 %pred] and 36 healthy [22 women, 61 ± 9 years, FVC 97 ± 11 %pred]) were included. Functional performance in ILD was worse than in healthy individuals in all tests, except for the 30sec-STS (p = 0.13). Pre-specified validity criteria were reached for TUGu, TUGf, 4MGS and 5rep-STS (−0.69 < r < 0.55; p < 0.05 for all). Except for 4MGS and SPPB, all tests showed good to excellent inter-rater (0.85 < ICC<0.93; p < 0.05 for all) and all tests showed good to excellent intra-rater (0.83 < ICC< 0.94; p < 0.05 for all) reliability. ConclusionsSubjects with ILD present worse functional performance than healthy individuals. According to reliability and validity results, TUGu, TUGf and 5rep-STS seem to be the most appropriate tests to evaluate functional performance in ILD.

Using Stubby Prosthesis after Bilateral Transfemoral Amputation: A Biomechanical Case Study

Background: After bilateral transfemoral amputation, people may experience limitations in everyday life due to limited mobility and prosthesis problems. Materials and method: The case study covered a 54-year-old man after bilateral traumatic amputation of his lower limbs. Transfemoral amputations were performed using the Caldwell method; disproportion in the length of stumps was 5 mm. The motion task was recorded using the SMART-E optoelectronic system (BTS Bioengineering, Milan, Italy) according to the standard Davis protocol (the Newington model). Biomechanical evaluation included the measurement of angle-time relationships, characterizing the range of motion (ROM) in lower limb joints and Ground Reaction Force (GRF). The analyzed tasks are walking with self selected speed, fast gait and walking in stubby prostheses. Results: Step width was the most similar to the gait of healthy persons walking with stubby prostheses (0.17 ± 0.01 m for healthy people, 29% higher for stubbies, 35% for prosthetic gait with self-selected gait speed and 41% for fast gait speed). Step width was the smallest when walking with stubbies. Conclusions: The reduction of body height allows to reduce the risk of fall. Higher metabolic cost of gait in people after amputation result from a greater need to maintain balance and posture, and to perform walking movement.

Intensity Matters for Musculoskeletal Health: A Cross-Sectional Study on Movement Behaviors of Older Adults from High-Income Scottish and Low-Income South African Communities.

This study aimed to investigate differences in physical activity (PA) patterns and the associations between objectively measured 24-h movement behaviors and musculoskeletal measures (muscle strength, muscle mass, physical performance, and bone mineral density) in a high-income and a low-income community. This cross-sectional study recruited independent living older adults aged 60–85 years from high-income Scottish (n = 150) and low-income South African (n = 138) settings. Participants completed demographic and health questionnaires, and testing included body composition and bone mineral density (dual energy X-ray absorptiometry), physical performance (grip strength, gait speed), and PA (accelerometry). Participants accumulated similar amounts of weekly total PA, however, the Scottish cohort engaged in more moderate-to-vigorous intensity PA (MVPA) and sedentary behavior (SB), while the South African cohort spent more time sleeping and in light intensity PA (LPA). From compositional data analysis, more time spent in MVPA relative to the other movement behaviors was positively associated with higher muscle mass (p < 0.001) and strength (p = 0.001) in the Scottish cohort. Conversely, more time spent in MVPA was associated with faster gait speed (p < 0.001) and greater hip bone mineral density (p = 0.011) in the South African cohort. Our findings confirm the beneficial role of MVPA in both high- and low-income cohorts, however, the relationship MVPA had with components of musculoskeletal health in older adults differed between settings.

Bariatric Surgery: Consequences on Functional Capacities in Patients With Obesity.

IntroductionBariatric surgery leads to loss of fat and fat-free mass (FFM). To preserve FFM it is recommended that weight loss interventions are accompanied by physical activity. However, it remains unknown if functional capacities spontaneously improve after a substantial weight loss. Study’s aim was to assess the effect of bariatric surgery on strength, functional capacities and quality of life of participants with a body mass index (BMI) ≥ 35 kg/m2.MethodAnthropometric parameters (weight, BMI, waist circumference), physical functions (quadriceps strength, walking capacity, spatio-temporal gait parameters, dynamic balance, lower limb power) and quality of life were assessed before and at three months after the bariatric surgery in 33 individuals who did not follow any physical activity program.ResultsThe anthropometric parameters, quality of life and three functional abilities (walking capacity, normal gait speed and lower limb power) improved significantly three months post-surgery. In contrast, fast gait speed, absolute strength, normalized strength, and dynamic balance did not improve.DiscussionA massive weight loss should be accompanied by an exercise program aiming to maintain FFM and to enhance muscle strength and balance. Such a program might also enhance functional capacities and help to sustain the weight loss over time.