scholarly journals The efficacy of a motorized lower-limb prosthetic device: a pilot study

2020 ◽  
Author(s):  
Jo Ghillebert ◽  
Joost Geeroms ◽  
Louis Flynn ◽  
Sander De Bock ◽  
Renée Govaerts ◽  
...  
Keyword(s):  
Stride Length ◽  
Metabolic Cost ◽  
Functional Independence ◽  
Stair Climbing ◽  
Daily Activities ◽  
The Novel ◽  
Transfemoral Amputation ◽  
Active Device ◽  
Cost Of Transport ◽  
Experimental Trial

Abstract BACKGROUND Performing daily activities is challenging for individuals with a transfemoral amputation. Technological advancements in prosthetic prototypes aim at improving functional independence. A state-of-the-art active device, the CYBERLEGs-gamma (CLs-ɣ) prosthesis, consisting of powered ankle and knee joints, has been designed and constructed. The control system combines pressure-sensitive insoles and inertial motor units to synchronize both joints to work together. To date, the novel device has not een clinically evaluated. Therefore, the objective of this study was to investigate the efficacy of the CLs-ɣ prosthesis during daily activities compared to current passive and quasi-passive devices . METHODS Participants performed a familiarization trial, an experimental trial with the current prosthesis, three adaptation trials and an experimental trial with the CLs-ɣ prosthesis. Participants completed a stair climbing test, a timed-up & go test, a sit to stand test, a two-minute dual task (i.e. the psychomotor vigilance task during treadmill walking) and a six-minute treadmill walk test at normal speed. Nonparametric Wilcoxon-signed rank tests were conducted with critical alpha set at 0.05. RESULTS Eight individuals with a transfemoral amputation (age: 55 ± 15 years, K-level 3) were included. Stride length significantly increased during walking with the CLs-ɣ prosthesis (p=0.012) because of a greater step length of the amputated leg (p=0.035). Normal walking speed was significantly slower (p=0.018), the net metabolic cost of transport was significantly higher (p=0.028) and reaction time significantly worsened (p=0.012) when walking with the CLs-ɣ compared to the current prosthesis. When participants took stairs, they adopted a step-over-step strategy with the CLs-ɣ prosthesis in contrast to step-by-step wearing the current prosthesis. CONCLUSION S A higher physical effort and cognitive demand were required during activities wearing the novel motorized prosthesis. Although performance outcome measures did not improve, participants had a greater stride length and better simulated able-bodied stair ambulation.

scholarly journals Gait changes in a line of mice artificially selected for longer limbs

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3008 ◽  
Author(s):  
Leah M. Sparrow ◽  
Emily Pellatt ◽  
Sabrina S. Yu ◽  
David A. Raichlen ◽  
Herman Pontzer ◽  
...  
Keyword(s):  
Stride Length ◽  
Stance Phase ◽  
Metabolic Cost ◽  
Limb Length ◽  
Stride Frequency ◽  
Practical Reasons ◽  
Cost Of Transport ◽  
Terrestrial Locomotion ◽  
Hind Limbs ◽  
Body Sizes

In legged terrestrial locomotion, the duration of stance phase, i.e., when limbs are in contact with the substrate, is positively correlated with limb length, and negatively correlated with the metabolic cost of transport. These relationships are well documented at the interspecific level, across a broad range of body sizes and travel speeds. However, such relationships are harder to evaluate within species (i.e., where natural selection operates), largely for practical reasons, including low population variance in limb length, and the presence of confounding factors such as body mass, or training. Here, we compared spatiotemporal kinematics of gait in Longshanks, a long-legged mouse line created through artificial selection, and in random-bred, mass-matched Control mice raised under identical conditions. We used a gait treadmill to test the hypothesis that Longshanks have longer stance phases and stride lengths, and decreased stride frequencies in both fore- and hind limbs, compared with Controls. Our results indicate that gait differs significantly between the two groups. Specifically, and as hypothesized, stance duration and stride length are 8–10% greater in Longshanks, while stride frequency is 8% lower than in Controls. However, there was no difference in the touch-down timing and sequence of the paws between the two lines. Taken together, these data suggest that, for a given speed, Longshanks mice take significantly fewer, longer steps to cover the same distance or running time compared to Controls, with important implications for other measures of variation among individuals in whole-organism performance, such as the metabolic cost of transport.

Performance of the CYBERLEGs motorized lower limb prosthetic device during simulated daily activities

2021 ◽  
Vol 2 ◽  
Author(s):  
Jo Ghillebert ◽  
Joost Geeroms ◽  
Louis Flynn ◽  
Sander De Bock ◽  
Renée Govaerts ◽  
...  
Keyword(s):  
Lower Limb ◽  
Stride Length ◽  
Cognitive Effort ◽  
Stair Climbing ◽  
Daily Activities ◽  
Human Gait ◽  
Limb Amputation ◽  
Future Research ◽  
Experimental Session ◽  
Adaptation Period

Abstract Background The CYBERLEGs-gamma (CLs-ɣ) prosthesis has been developed to investigate the possibilities of powerful active prosthetics in restoring human gait capabilities after lower limb amputation. Objective The objective of this study was to determine the performance of the CLs-ɣ prosthesis during simulated daily activities. Methods Eight participants with a transfemoral amputation (age: 55 ± 15 years, K-level 3, registered under: NCT03376919) performed a familiarization session, an experimental session with their current prosthesis, three training sessions with the CLs-ɣ prosthesis and another experimental session with the CLs-ɣ prosthesis. Participants completed a stair-climbing-test, a timed-up-and-go-test, a sit-to stand-test, a 2-min dual-task and a 6-min treadmill walk test. Results Comparisons between the two experimental sessions showed that stride length significantly increased during walking with the CLs-ɣ prosthesis (p = .012) due to a greater step length of the amputated leg (p = .035). Although a training period with the prototype was included, preferred walking speed was significantly slower (p = .018), the metabolic cost of transport was significantly higher (p = .028) and reaction times significantly worsened (p = .012) when walking with the CLs-ɣ compared to the current prosthesis. Conclusions It can be stated that a higher physical and cognitive effort were required when wearing the CLs-ɣ prosthesis. Positive outcomes were observed regarding stride length and stair ambulation. Future prosthetics development should minimize the weight of the device and integrate customized control systems. A recommendation for future research is to include several shorter training periods or a prolonged adaptation period.

scholarly journals Running Stride Length And Rate Are Changed And Mechanical Efficiency Is Preserved After Cycling In Middle-Level Triathletes

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Rodrigo Gomes da Rosa ◽  
Henrique Bianchi de Oliveira ◽  
Luca Paolo Ardigò ◽  
Natalia Andrea Gomeñuka ◽  
Gabriela Fischer ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Maximal Oxygen Uptake ◽  
Stride Length ◽  
Metabolic Cost ◽  
Mechanical Efficiency ◽  
Middle Level ◽  
Moderate Intensity ◽  
Cost Of Transport ◽  
Spatiotemporal Parameters ◽  
The Cost

AbstractAlthough cycling impairs the subsequent metabolic cost and performance of running in some triathletes, the consequences on mechanical efficiency (Eff) and kinetic and potential energy fluctuations of the body center of mass are still unknown. The aim of this study was to investigate the effects of previous cycling on the cost-of-transport, Eff, mechanical energy fluctuations (Wtot), spring stiffness (Kleg and Kvert) and spatiotemporal parameters. Fourteen middle-level triathletes (mean ± SD: maximal oxygen uptake, $$\dot{{\rm{V}}}$$V̇O2max = 65.3 ± 2.7 ml.kg−1.min−1, age = 30 ± 5 years, practice time = 6.8 ± 3.0 years) performed four tests. Two maximal oxygen uptake tests on a cycle ergometer and treadmill, and two submaximal 20-minute running tests (14 km.h−1) with (prior-cycling) and without (control) a previous submaximal 30-minute cycling test. No differences were observed between the control and post-cycling groups in Eff or Wtot. The Eff remains unchanged between conditions. On the other hand, the Kvert (20.2 vs 24.4 kN.m−1) and Kleg (7.1 vs 8.2 kN.m−1, p < 0.05) were lower and the cost-of-transport was higher (p = 0.018, 3.71 vs 3.31 J.kg−1.m−1) when running was preceded by cycling. Significantly higher stride frequency (p < 0.05, 1.46 vs 1.43 Hz) and lower stride length (p < 0.05, 2.60 vs 2.65 m) were observed in the running after cycling condition in comparison with control condition. Mechanical adjustments were needed to maintain the Eff, even resulting in an impaired metabolic cost after cycling performed at moderate intensity. These findings are compatible with the concept that specific adjustments in spatiotemporal parameters preserve the Eff when running is preceded by cycling in middle-level triathletes, though the cost-of-transport increased.

scholarly journals Limitations of Foot-Worn Sensors for Assessing Running Power

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 4952
Author(s):  
Tobias Baumgartner ◽  
Steffen Held ◽  
Stefanie Klatt ◽  
Lars Donath
Keyword(s):  
Time Use ◽  
Stride Length ◽  
Metabolic Cost ◽  
Running Economy ◽  
Accelerometer Data ◽  
Gait Characteristics ◽  
Significant Difference ◽  
Metabolic Costs ◽  
Ground Contact Time ◽  
Training Signal

Running power as measured by foot-worn sensors is considered to be associated with the metabolic cost of running. In this study, we show that running economy needs to be taken into account when deriving metabolic cost from accelerometer data. We administered an experiment in which 32 experienced participants (age = 28 ± 7 years, weekly running distance = 51 ± 24 km) ran at a constant speed with modified spatiotemporal gait characteristics (stride length, ground contact time, use of arms). We recorded both their metabolic costs of transportation, as well as running power, as measured by a Stryd sensor. Purposely varying the running style impacts the running economy and leads to significant differences in the metabolic cost of running (p < 0.01). At the same time, the expected rise in running power does not follow this change, and there is a significant difference in the relation between metabolic cost and power (p < 0.001). These results stand in contrast to the previously reported link between metabolic and mechanical running characteristics estimated by foot-worn sensors. This casts doubt on the feasibility of measuring running power in the field, as well as using it as a training signal.

scholarly journals Associations Between Foot Placement Asymmetries and Metabolic Cost of Transport in Hemiparetic Gait

2016 ◽  
Vol 31 (2) ◽  
pp. 168-177 ◽  
Author(s):  
James M. Finley ◽  
Amy J. Bastian
Keyword(s):  
Walking Speed ◽  
Metabolic Cost ◽  
Positive Association ◽  
Stroke Survivor ◽  
Gas Analysis ◽  
Stroke Survivors ◽  
Cost Of Transport ◽  
Foot Placement ◽  
Hemiparetic Gait ◽  
All Speeds

Stroke survivors often have a slow, asymmetric walking pattern. They also walk with a higher metabolic cost than healthy, age-matched controls. It is often assumed that spatial-temporal asymmetries contribute to the increased metabolic cost of walking poststroke. However, elucidating this relationship is made challenging because of the interdependence between spatial-temporal asymmetries, walking speed, and metabolic cost. Here, we address these potential confounds by measuring speed-dependent changes in metabolic cost and implementing a recently developed approach to dissociate spatial versus temporal contributions to asymmetry in a sample of stroke survivors. We used expired gas analysis to compute the metabolic cost of transport (CoT) for each participant at 4 different walking speeds: self-selected speed, 80% and 120% of their self-selected speed, and their fastest comfortable speed. We also computed CoT for a sample of age- and gender-matched control participants who walked at the same speeds as their matched stroke survivor. Kinematic data were used to compute the magnitude of a number of variables characterizing spatial-temporal asymmetries. Across all speeds, stroke survivors had a higher CoT than controls. We also found that our sample of stroke survivors did not choose a self-selected speed that minimized CoT, contrary to typical observations in healthy controls. Multiple regression analyses revealed negative associations between speed and CoT and a positive association between asymmetries in foot placement relative to the trunk and CoT. These findings suggest that interventions designed to increase self-selected walking speed and reduce foot-placement asymmetries may be ideal for improving walking economy poststroke.

Abstract TP12: Comparison of 3D Stent Retriever to Solitaire in Patients with Small Ischemic Cores: An Analysis of the Penumbra 3D Trial

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Adnan Siddiqui ◽  
Donald Frei ◽  
Albert J Yoo ◽  
Ghita Soulimani ◽  
Hope Buell ◽  
...  
Keyword(s):  
Functional Outcomes ◽  
Meta Analysis ◽  
Analysis Data ◽  
Functional Independence ◽  
Stent Retriever ◽  
The Novel ◽  
Inclusion Criteria ◽  
Aspiration System ◽  
Randomized Controlled ◽  
Scale 8

Introduction: A recent meta-analysis of four randomized controlled trials (RCTs) concluded that mechanical thrombectomy using Solitaire for large vessel ischemic stroke was effective with significantly reduced disability. Hypothesis: Our hypothesis was that treatment with the Penumbra Aspiration System and the novel 3D Stent Retriever would demonstrate similar angiographic and functional outcomes compared to use of Solitaire. Methods: The 3D trial was a RCT to compare the safety and effectiveness of the 3D Stent Retriever when used with the Penumbra Aspiration System (3D/PS) compared to the PS alone. Inclusion criteria for the 3D RCT included presentation with NIH Stroke Scale ≥ 8 and refractory to or not eligible for IV rtPA. Analysis compared reperfusion to mTICI 2b or 3 and functional independence (mRS 0-2 at 90 days) in a 3D Trial cohort with ASPECTS 8-10 vs the meta-analysis data reported by Campbell et al ( Stroke 2016). Results: One hundred four (104) of 198 patients met analysis criteria. Baseline ASPECTS (median [IQR]) were similar between the 3D Trial ASPECTS 8-10 cohort (3D/PS, PS, combined: 9 [8,10]) and Campbell group (9 [7,10]). Substantial reperfusion (mTICI 2b or 3) was experienced in 84.6% (44/52) of 3D/PS and 75.0% (39/52) of PS alone cases, similar to the Campbell group (76.6%). When both arms were pooled, results (79.8%) were also similar to Campbell. With regards to functional independence, both 3D cohorts and pooled trial results showed similar rates compared with Campbell (Figure). Conclusions: The novel 3D Stent Retriever + Penumbra System and the Penumbra Aspiration System alone showed similar reperfusion and functional outcomes compared to Solitaire.

scholarly journals Factors affecting metabolic cost of transport during a multi-stage running race

2013 ◽  
Vol 217 (5) ◽  
pp. 787-795 ◽  
Author(s):  
S. Lazzer ◽  
P. Taboga ◽  
D. Salvadego ◽  
E. Rejc ◽  
B. Simunic ◽  
...  
Keyword(s):  
Metabolic Cost ◽  
Cost Of Transport ◽  
Factors Affecting ◽  
Multi Stage

Reduced prosthetic stiffness lowers the metabolic cost of running for athletes with bilateral transtibial amputations

2017 ◽  
Vol 122 (4) ◽  
pp. 976-984 ◽  
Author(s):  
Owen N. Beck ◽  
Paolo Taboga ◽  
Alena M. Grabowski
Keyword(s):  
Lower Limb ◽  
Metabolic Cost ◽  
Ground Reaction Forces ◽  
Metabolic Rates ◽  
Distance Running ◽  
Cost Of Transport ◽  
Leg Stiffness ◽  
Metabolic Costs ◽  
In Series ◽  
Reaction Forces

Inspired by the springlike action of biological legs, running-specific prostheses are designed to enable athletes with lower-limb amputations to run. However, manufacturer’s recommendations for prosthetic stiffness and height may not optimize running performance. Therefore, we investigated the effects of using different prosthetic configurations on the metabolic cost and biomechanics of running. Five athletes with bilateral transtibial amputations each performed 15 trials on a force-measuring treadmill at 2.5 or 3.0 m/s. Athletes ran using each of 3 different prosthetic models (Freedom Innovations Catapult FX6, Össur Flex-Run, and Ottobock 1E90 Sprinter) with 5 combinations of stiffness categories (manufacturer’s recommended and ± 1) and heights (International Paralympic Committee’s maximum competition height and ± 2 cm) while we measured metabolic rates and ground reaction forces. Overall, prosthetic stiffness [fixed effect (β) = 0.036; P = 0.008] but not height ( P ≥ 0.089) affected the net metabolic cost of transport; less stiff prostheses reduced metabolic cost. While controlling for prosthetic stiffness (in kilonewtons per meter), using the Flex-Run (β = −0.139; P = 0.044) and 1E90 Sprinter prostheses (β = −0.176; P = 0.009) reduced net metabolic costs by 4.3–4.9% compared with using the Catapult prostheses. The metabolic cost of running improved when athletes used prosthetic configurations that decreased peak horizontal braking ground reaction forces (β = 2.786; P = 0.001), stride frequencies (β = 0.911; P < 0.001), and leg stiffness values (β = 0.053; P = 0.009). Remarkably, athletes did not maintain overall leg stiffness across prosthetic stiffness conditions. Rather, the in-series prosthetic stiffness governed overall leg stiffness. The metabolic cost of running in athletes with bilateral transtibial amputations is influenced by prosthetic model and stiffness but not height. NEW & NOTEWORTHY We measured the metabolic rates and biomechanics of five athletes with bilateral transtibial amputations while running with different prosthetic configurations. The metabolic cost of running for these athletes is minimized by using an optimal prosthetic model and reducing prosthetic stiffness. The metabolic cost of running was independent of prosthetic height, suggesting that longer legs are not advantageous for distance running. Moreover, the in-series prosthetic stiffness governs the leg stiffness of athletes with bilateral leg amputations.

scholarly journals Contributions of metabolic and temporal costs to human gait selection

2018 ◽  
Vol 15 (143) ◽  
pp. 20180197 ◽  
Author(s):  
Erik M. Summerside ◽  
Rodger Kram ◽  
Alaa A. Ahmed
Keyword(s):  
Movement Time ◽  
Metabolic Cost ◽  
Metabolic Energy ◽  
Human Gait ◽  
Cost Of Transport ◽  
Relative Value ◽  
Weighted Combination

Humans naturally select several parameters within a gait that correspond with minimizing metabolic cost. Much less is understood about the role of metabolic cost in selecting between gaits. Here, we asked participants to decide between walking or running out and back to different gait specific markers. The distance of the walking marker was adjusted after each decision to identify relative distances where individuals switched gait preferences. We found that neither minimizing solely metabolic energy nor minimizing solely movement time could predict how the group decided between gaits. Of our twenty participants, six behaved in a way that tended towards minimizing metabolic energy, while eight favoured strategies that tended more towards minimizing movement time. The remaining six participants could not be explained by minimizing a single cost. We provide evidence that humans consider not just a single movement cost, but instead a weighted combination of these conflicting costs with their relative contributions varying across participants. Individuals who placed a higher relative value on time ran faster than individuals who placed a higher relative value on metabolic energy. Sensitivity to temporal costs also explained variability in an individual's preferred velocity as a function of increasing running distance. Interestingly, these differences in velocity both within and across participants were absent in walking, possibly due to a steeper metabolic cost of transport curve. We conclude that metabolic cost plays an essential, but not exclusive role in gait decisions.

The Relationship between Knee Extension Strength and Activities of Daily Living in Patients with Dementia

2011 ◽  
pp. 244-256
Author(s):  
Makoto Suzuki ◽  
Hikari Kirimoto ◽  
Atsushi Inamura ◽  
Yoshitsugu Omori ◽  
Sumio Yamada
Keyword(s):  
Lower Extremity ◽  
Activities Of Daily Living ◽  
Daily Living ◽  
Functional Independence Measure ◽  
Knee Extensor ◽  
Functional Independence ◽  
Knee Extension ◽  
Daily Activities ◽  
Lower Body ◽  
Knee Extensor Strength

The purpose of this study was to examine the test-retest reliability of hand-held dynamometer measurements in patients with dementia and determine if predictions about a patient’s ability to perform daily activities can be made from knee extension strength measurements. This study was composed of two rounds of data collection. Sixty patients with dementia were enrolled in the first round to assess the reliability of hand-held dynamometer measurements, and 54 patients with dementia were enrolled in the second round for predicting their ability to perform daily activities. Knee extensor strength was measured twice, separated by a three minute interval, with hand-held dynamometer. The authors also assessed daily activities related to the patient’s lower extremities, including dressing the lower body, using the toile, transferring to the bed/toilet/shower, and walking. Lower extremity activities of the Functional Independence Measure were assessed by the nursing home caregiver that had the most regular contact with each subject. When the Functional Independence Measure score of each lower extremity function was =6 points, the subject was considered to be independent. The intraclass correlation coefficient was 0.97. Bland-Altman plots showed the 95% difference value to be within 2 SDs of the mean. The curves of negative and positive predictive values revealed the following threshold levels: 0.8 Nm/kg was the best predictor for dressing the lower body and using the toilet; 1.2 Nm/kg was the best predictor for transferring to the bed/toilet/shower; and 0.6 Nm/kg was the best predictor for gait performance. Strength measurements taken with a hand-held dynamometer were reliable in patients with dementia, and normalized knee extensor strength was found to be a predictor of the ability to perform activities of daily living.

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