Ergonomic effects of load carriage on the upper and lower back on metabolic energy cost of walking

Abstract Background The human ankle joint has an influential role in the regulation of the mechanics and energetics of gait. The human ankle can modulate its joint ‘quasi-stiffness’ (ratio of plantarflexion moment to dorsiflexion displacement) in response to various locomotor tasks (e.g., load carriage). However, the direct effect of ankle stiffness on metabolic energy cost during various tasks is not fully understood. The purpose of this study was to determine how net metabolic energy cost was affected by ankle stiffness while walking under different force demands (i.e., with and without additional load). Methods Individuals simulated an amputation by using an immobilizer boot with a robotic ankle-foot prosthesis emulator. The prosthetic emulator was controlled to follow five ankle stiffness conditions, based on literature values of human ankle quasi-stiffness. Individuals walked with these five ankle stiffness settings, with and without carrying additional load of approximately 30% of body mass (i.e., ten total trials). Results Within the range of stiffness we tested, the highest stiffness minimized metabolic cost for both load conditions, including a ~ 3% decrease in metabolic cost for an increase in stiffness of about 0.0480 Nm/deg/kg during normal (no load) walking. Furthermore, the highest stiffness produced the least amount of prosthetic ankle-foot positive work, with a difference of ~ 0.04 J/kg from the highest to lowest stiffness condition. Ipsilateral hip positive work did not significantly change across the no load condition but was minimized at the highest stiffness for the additional load conditions. For the additional load conditions, the hip work followed a similar trend as the metabolic cost, suggesting that reducing positive hip work can lower metabolic cost. Conclusion While ankle stiffness affected the metabolic cost for both load conditions, we found no significant interaction effect between stiffness and load. This may suggest that the importance of the human ankle’s ability to change stiffness during different load carrying tasks may not be driven to minimize metabolic cost. A prosthetic design that can modulate ankle stiffness when transitioning from one locomotor task to another could be valuable, but its importance likely involves factors beyond optimizing metabolic cost.

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A feedback-controlled treadmill (treadmill-on-demand) and the spontaneous speed of walking and running in humans

Journal of Applied Physiology ◽

10.1152/japplphysiol.00128.2003 ◽

2003 ◽

Vol 95 (2) ◽

pp. 838-843 ◽

Cited By ~ 78

Author(s):

Alberto E. Minetti ◽

Lorenzo Boldrini ◽

Laura Brusamolin ◽

Paola Zamparo ◽

Tom McKee

Keyword(s):

Energy Cost ◽

The Self ◽

Metabolic Energy ◽

Stride Frequency ◽

Range Finder ◽

On Demand ◽

Speed Range ◽

Potential Applications ◽

The Subject ◽

Energy Cost Of Walking

A novel apparatus, composed by a controllable treadmill, a computer, and an ultrasonic range finder, is here proposed to help investigation of many aspects of spontaneous locomotion. The acceleration or deceleration of the subject, detected by the sensor and processed by the computer, is used to accelerate or decelerate the treadmill in real time. The system has been used to assess, in eight subjects, the self-selected speed of walking and running, the maximum “reasonable” speed of walking, and the minimum reasonable speed of running at different gradients (from level up to +25%). This evidenced the speed range at which humans neither walk nor run, from 7.2 ± 0.6 to 8.4 ± 1.1 km/h for level locomotion, slightly narrowing at steeper slopes. These data confirm previous results, obtained indirectly from stride frequency recordings. The self-selected speed of walking decreases with increasing gradient (from 5.0 ± 0.8 km/h at 0% to 3.0 ± 0.9 km/h at +25%) and seems to be ∼30% higher than the speed that minimizes the metabolic energy cost of walking, obtained from the literature, at all the investigated gradients. The advantages, limitations, and potential applications of the newly proposed methodology in physiology, biomechanics, and pathology of locomotion are discussed in this paper.

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Effects of load carriage, load position, and walking speed on energy cost of walking

Applied Ergonomics ◽

10.1016/j.apergo.2004.03.008 ◽

2004 ◽

Vol 35 (4) ◽

pp. 329-335 ◽

Cited By ~ 81

Author(s):

Daijiro Abe ◽

Kazumasa Yanagawa ◽

Shigemitsu Niihata

Keyword(s):

Energy Cost ◽

Walking Speed ◽

Load Carriage ◽

Energy Cost Of Walking

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A Single Assistive Profile Applied by a Passive Hip Flexion Device Can Reduce the Energy Cost of Walking in Older Adults

Applied Sciences ◽

10.3390/app11062851 ◽

2021 ◽

Vol 11 (6) ◽

pp. 2851

Author(s):

Fausto Antonio Panizzolo ◽

Eugenio Annese ◽

Antonio Paoli ◽

Giuseppe Marcolin

Keyword(s):

Older Adults ◽

Energy Cost ◽

Metabolic Cost ◽

Metabolic Energy ◽

Assistive Device ◽

Spatiotemporal Parameters ◽

Negative Effect ◽

Low Torque ◽

Hip Flexion ◽

Energy Cost Of Walking

Difficulty walking in older adults affects their independence and ability to execute daily tasks in an autonomous way, which can result in a negative effect to their health status and risk of morbidity. Very often, reduced walking speed in older adults is caused by an elevated metabolic energy cost. Passive exoskeletons have been shown to offer a promising solution for lowering the energy cost of walking, and their simplicity could favor their use in real world settings. The goal of this study was to assess if a constant and consistent low torque applied by means of a passive exoskeleton to the hip flexors during walking could provide higher and more consistent metabolic cost reduction than previously achieved. Eight older adults walked on a treadmill at a constant speed of 1.1 m/s with and without the hip assistive device. Metabolic power and spatiotemporal parameters were measured during walking in these two conditions of testing. The hip assistive device was able to apply a low torque which initiates its assistive effect at mid-stance. This reduced the metabolic cost of walking across all the participants with respect to free walking (−4.2 ± 1.9%; p = 0.002). There were no differences in the spatiotemporal parameters reported. This study strengthened the evidence that passive assistive devices can be a valuable tool to reduce metabolic cost of walking in older adults. These findings highlighted the importance of investigating torque profiles to improve the performance provided by a hip assistive device. The simplicity and usability of a system of this kind can make it a suitable candidate for improving older adults’ independence.

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Human-in-the-loop optimization of wearable robots to reduce the human metabolic energy cost in physical movements

Robotics and Autonomous Systems ◽

10.1016/j.robot.2020.103495 ◽

2020 ◽

Vol 127 ◽

pp. 103495

Author(s):

Jing Fang ◽

Yuan Yuan

Keyword(s):

Energy Cost ◽

Metabolic Energy ◽

Loop Optimization ◽

Human In The Loop ◽

Wearable Robots

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ENERGY COST OF WALKING AND OF WHEELCHAIR PROPULSION BY CHILDREN WITH MYELODYSPLASIA: COMPARISON WITH NORMAL CHILDREN

Developmental Medicine & Child Neurology ◽

10.1111/j.1469-8749.1983.tb13821.x ◽

2008 ◽

Vol 25 (5) ◽

pp. 617-624 ◽

Cited By ~ 21

Author(s):

Linda O. Williams ◽

Amy D. Anderson ◽

Joyce Campbell ◽

Lynn Thomas ◽

Earl Feiwell ◽

...

Keyword(s):

Energy Cost ◽

Wheelchair Propulsion ◽

Normal Children ◽

Energy Cost Of Walking

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Parawalker: Energy Cost of Walking

European Journal of Pediatric Surgery ◽

10.1055/s-2008-1042527 ◽

1991 ◽

Vol 1 (S 1) ◽

pp. 7-10 ◽

Cited By ~ 25

Author(s):

J. Banta ◽

K. Bell ◽

E. Muik ◽

J. Fezio

Keyword(s):

Energy Cost ◽

Energy Cost Of Walking

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Contraction duration affects metabolic energy cost and fatigue in skeletal muscle

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1998.274.3.e397 ◽

1998 ◽

Vol 274 (3) ◽

pp. E397-E402 ◽

Cited By ~ 31

Author(s):

Michael C. Hogan ◽

Erica Ingham ◽

S. Sadi Kurdak

Keyword(s):

Skeletal Muscle ◽

Short Duration ◽

Energy Cost ◽

Lactate Concentration ◽

Metabolic Energy ◽

Muscle Lactate ◽

Contracting Muscle ◽

Contraction Duration ◽

Long Duration ◽

The Difference

It has been suggested that during a skeletal muscle contraction the metabolic energy cost at the onset may be greater than the energy cost related to holding steady-state force. The purpose of the present study was to investigate the effect of contraction duration on the metabolic energy cost and fatigue process in fully perfused contracting muscle in situ. Canine gastrocnemius muscle ( n = 6) was isolated, and two contractile periods (3 min of isometric, tetanic contractions with 45-min rest between) were conducted by each muscle in a balanced order design. The two contractile periods had stimulation patterns that resulted in a 1:3 contraction-to-rest ratio, with the difference in the two contractile periods being in the duration of each contraction: short duration 0.25-s stimulation/0.75-s rest vs. long duration 1-s stimulation/3-s rest. These stimulation patterns resulted in the same total time of stimulation, number of stimulation pulses, and total time in contraction for each 3-min period. Muscle O2 uptake, the fall in developed force (fatigue), the O2 cost of developed force, and the estimated total energy cost (ATP utilization) of developed force were significantly greater ( P < 0.05) with contractions of short duration. Lactate efflux from the working muscle and muscle lactate concentration were significantly greater with contractions of short duration, such that the calculated energy derived from glycolysis was three times greater in this condition. These results demonstrate that contraction duration can significantly affect both the aerobic and anaerobic metabolic energy cost and fatigue in contracting muscle. In addition, it is likely that the greater rate of fatigue with more rapid contractions was a result of elevated glycolytic production of lactic acid.

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