Energetics of Load Carriage by Bamboo Carrying Poles

Abstract Unlike western conventions of rigid body attachments (e.g. backpack), carriers in Asia prefer to use bamboo poles, an ancient, ingenious, elastically-suspended equipment, especially when carrying heavy loads. As an elastically-suspended equipment, bamboo pole might have some potential benefits including reducing peak shoulder forces as well as saving metabolic transport cost, but certain skills should be needed for loading. Experienced carriers routinely carry loads exceeding their own body mass (Mb) for a long distance, while novices might hurt themselves. However, no skillful bamboo pole carriers’ performance or loading with heavy load has not been reported as far as we know. We set out to determine the loads capability and distances carried by skillful carriers, measure their metabolic cost for carrying the loads, and observe whether their natural walking speed changed as a function of load. In this paper, we compared the skillful carriers’ energy expenditure on carrying loads in both normal bamboo pole on shoulder and typical backpacks with hip support. Both carrying postures were normal, just as what subjects used in their daily life. The O2 consumption and CO2 production were measured in 13 subjects while standing or walking with loads. All subjects were asked to carry loads ranging from 0 kg to their load capacity in two loading type, while walking on a 1-meter wide nearly circular level track at their preferred speed. These speeds were record by cameras placed beside the track. Experimental results show that bamboo pole perform better under heavy load: 1. Loading by bamboo pole helped carriers to load 16% body weight heavier than by backpack on average. 2. With the load increasing, the walking speed loading by backpack would decrease from 1.3m/s (0kg) to 1.1m/s (load capacity), however loading by bamboo pole would slightly increase. 3. The rate of energy consumptions both increase with load increasing. Bamboo pole require more metabolic consumption than backpack with same load. 4. Since natural walking speed by bamboo pole faster than by backpack, the cost of transport by bamboo pole would be more economic than by backpack while the load is 50kg or more.

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

Neurorehabilitation and Neural Repair ◽

10.1177/1545968316675428 ◽

2016 ◽

Vol 31 (2) ◽

pp. 168-177 ◽

Cited By ~ 17

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.

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Optimized hip-knee-ankle exoskeleton assistance reduces the metabolic cost of walking with worn loads

Journal of NeuroEngineering and Rehabilitation ◽

10.1186/s12984-021-00955-8 ◽

2021 ◽

Vol 18 (1) ◽

Author(s):

Gwendolyn M. Bryan ◽

Patrick W. Franks ◽

Seungmoon Song ◽

Ricardo Reyes ◽

Meghan P. O’Donovan ◽

...

Keyword(s):

Body Weight ◽

Muscle Activity ◽

Metabolic Cost ◽

Load Carriage ◽

Heavy Load ◽

Human In The Loop ◽

Light Load ◽

Wide Range ◽

Ankle Exoskeleton ◽

The Individual

Abstract Background Load carriage is common in a wide range of professions, but prolonged load carriage is associated with increased fatigue and overuse injuries. Exoskeletons could improve the quality of life of these professionals by reducing metabolic cost to combat fatigue and reducing muscle activity to prevent injuries. Current exoskeletons have reduced the metabolic cost of loaded walking by up to 22% relative to walking in the device with no assistance when assisting one or two joints. Greater metabolic reductions may be possible with optimized assistance of the entire leg. Methods We used human-in the-loop optimization to optimize hip-knee-ankle exoskeleton assistance with no additional load, a light load (15% of body weight), and a heavy load (30% of body weight) for three participants. All loads were applied through a weight vest with an attached waist belt. We measured metabolic cost, exoskeleton assistance, kinematics, and muscle activity. We performed Friedman’s tests to analyze trends across worn loads and paired t-tests to determine whether changes from the unassisted conditions to the assisted conditions were significant. Results Exoskeleton assistance reduced the metabolic cost of walking relative to walking in the device without assistance for all tested conditions. Exoskeleton assistance reduced the metabolic cost of walking by 48% with no load (p = 0.05), 41% with the light load (p = 0.01), and 43% with the heavy load (p = 0.04). The smaller metabolic reduction with the light load may be due to insufficient participant training or lack of optimizer convergence. The total applied positive power was similar for all tested conditions, and the positive knee power decreased slightly as load increased. Optimized torque timing parameters were consistent across participants and load conditions while optimized magnitude parameters varied. Conclusions Whole-leg exoskeleton assistance can reduce the metabolic cost of walking while carrying a range of loads. The consistent optimized timing parameters across participants and conditions suggest that metabolic cost reductions are sensitive to torque timing. The variable torque magnitude parameters could imply that torque magnitude should be customized to the individual, or that there is a range of useful torque magnitudes. Future work should test whether applying the load to the exoskeleton rather than the person’s torso results in larger benefits.

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Optimized Hip-Knee-Ankle Exoskeleton Assistance Reduces the Metabolic Cost of Walking With Worn Loads

10.21203/rs.3.rs-544617/v1 ◽

2021 ◽

Author(s):

Gwendolyn M Bryan ◽

Patrick Franks ◽

Seungmoon Song ◽

Ricardo Reyes ◽

Meghan O’Donovan ◽

...

Keyword(s):

Body Weight ◽

Muscle Activity ◽

Metabolic Cost ◽

Load Carriage ◽

Heavy Load ◽

Human In The Loop ◽

Light Load ◽

Wide Range ◽

Ankle Exoskeleton ◽

Load Conditions

Abstract BackgroundLoad carriage is a typical activity in a wide range of professions, but prolonged load carriage is associated with increased fatigue and overuse injuries. Exoskeletons could improve the quality of life of these professionals by reducing metabolic cost to combat fatigue and reducing muscle activity to prevent injuries. Current exoskeletons have reduced the metabolic cost of loaded walking by up to 23% when assisting one or two joints. Greater metabolic reductions may be possible with optimized assistance of the entire leg. MethodsWe used human-in the-loop optimization to optimize hip-knee-ankle exoskeleton assistance with no additional load, a light load (15% of body weight), and a heavy load (30% of body weight) for three participants. All loads were applied through a weight vest with an attached waist belt. We measured metabolic cost, exoskeleton assistance, kinematics, and muscle activity. We performed one-tailed paired t-tests to determine significant reductions for metabolic cost and muscle activity, and we performed an analysis of variance (ANOVA) to determine significant changes across load conditions for metabolic cost and applied power. ResultsExoskeleton assistance reduced the metabolic cost of walking relative to walking in the device without assistance for all tested conditions. Exoskeleton assistance reduced the metabolic cost of walking by 47% with no load (p = 0.02), 35% with the light load (p = 0.03), and 43% with the heavy load (p = 0.02). The smaller metabolic reduction with the light load may be due to insufficient participant training or lack of optimizer convergence. The total applied positive power was similar for all tested conditions, and the positive knee power decreased slightly as load increased. Optimized torque timing parameters were consistent across participants and load conditions while optimized magnitude parameters varied. ConclusionsWhole-leg exoskeleton assistance can reduce the metabolic cost of walking while carrying a range of loads. The consistent optimized timing parameters suggest that metabolic cost reductions are sensitive to torque timing. The variable torque magnitude parameters could imply that torque magnitude should be customized to the individual, or that there is a range of useful torque magnitudes. Future work should test whether applying the load to the exoskeleton rather than the person's torso results in larger benefits.

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Quantifying Cause-Effect Relations Between Walking Speed, Propulsive Force, and Metabolic Cost

10.1101/2021.10.18.21265129 ◽

2021 ◽

Author(s):

Richard Pimentel ◽

Jordan N Feldman ◽

Michael D Lewek ◽

Jason R Franz

Keyword(s):

Young Adults ◽

Health Status ◽

Time Course ◽

Walking Speed ◽

Metabolic Cost ◽

Propulsive Force ◽

Metabolic Power ◽

Cost Of Transport ◽

Walking Speeds ◽

Variance Explained

Walking speed is a useful surrogate for health status across the population. Walking speed appears to be governed in part by propulsive force (FP) generated during push-off and simultaneously optimized to minimize metabolic cost. However, no study to our knowledge has established empirical cause-effect relations between FP, walking speed, and metabolic cost, even in young adults. To overcome the potential linkage between these factors, we used a self-paced treadmill controller and real-time biofeedback to independently prescribe walking speed or FP across a range of condition intensities. Walking with larger and smaller FP led to instinctively faster and slower walking speeds, respectively, with about 80% of variance explained between those outcomes. We also found that comparable changes in either FP or walking speed elicited predictable and relatively uniform changes in metabolic cost, each explaining about ~53% of the variance in net metabolic power and ~15% of the variance in cost of transport, respectively. These findings build confidence that interventions designed to increase FP will translate to improved walking speed. Repeating this protocol in other populations may identify additional cause-effect relations that could inform the time course of gait decline due to age and disease.

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Understanding health-seeking and adherence to treatment by patients with esophageal cancer at the Uganda cancer Institute: a qualitative study

BMC Health Services Research ◽

10.1186/s12913-021-06163-3 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Nakimuli Esther ◽

Ssentongo Julius ◽

Mwaka Amos Deogratius

Keyword(s):

Esophageal Cancer ◽

Data Collection ◽

Qualitative Study ◽

Cancer Patients ◽

Healthcare Professionals ◽

Transport Cost ◽

Adherence To Treatment ◽

Health Seeking ◽

Long Distance ◽

Cancer Symptoms

Abstract Background In the low- and middle-income countries, most patients with esophageal cancer present with advanced stage disease and experience poor survival. There is inadequate understanding of the factors that influence decisions to and actual health-seeking, and adherence to treatment regimens among esophageal cancer patients in Uganda, yet this knowledge is critical in informing interventions to promote prompt health-seeking, diagnosis at early stage and access to appropriate cancer therapy to improve survival. We explored health-seeking experiences and adherence to treatment among esophageal cancer patients attending the Uganda Cancer Institute. Methods We conducted an interview based qualitative study at the Uganda Cancer Institute (UCI). Participants included patients with established histology diagnosis of esophageal cancer and healthcare professionals involved in the care of these patients. We used purposive sampling approach to select study participants. In-depth and key informant interviews were used in data collection. Data collection was conducted till point of data saturation was reached. Thematic content analysis approach was used in data analyses and interpretations. Themes and subthemes were identified deductively. Results Sixteen patients and 17 healthcare professionals were included in the study. Delayed health-seeking and poor adherence to treatment were related to (i) emotional and psychosocial factors including stress of cancer diagnosis, stigma related to esophageal cancer symptoms, and fear of loss of jobs and livelihood, (ii) limited knowledge and recognition of esophageal cancer symptoms by both patients and primary healthcare professionals, and (iii) limited access to specialized cancer care, mainly because of long distance to the facility and associated high transport cost. Patients were generally enthused with patient – provider relationships at the UCI. While inadequate communication and some degree of incivility were reported, majority of patients thought the healthcare professionals were empathetic and supportive. Conclusion Health system and individual patient factors influence health-seeking for symptoms of esophageal cancer and adherence to treatment schedule for the disease. Interventions to improve access to and acceptability of esophageal cancer services, as well as increase public awareness of esophageal cancer risk factors and symptoms could lead to earlier diagnosis and potentially better survival from the disease in Uganda.

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Simulating ideal assistive devices to reduce the metabolic cost of walking with heavy loads

PLoS ONE ◽

10.1371/journal.pone.0180320 ◽

2017 ◽

Vol 12 (7) ◽

pp. e0180320 ◽

Cited By ~ 39

Author(s):

Christopher L. Dembia ◽

Amy Silder ◽

Thomas K. Uchida ◽

Jennifer L. Hicks ◽

Scott L. Delp

Keyword(s):

Metabolic Cost ◽

Assistive Devices ◽

Heavy Loads

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Load carriage, human performance, and employment standards

Applied Physiology Nutrition and Metabolism ◽

10.1139/apnm-2015-0486 ◽

2016 ◽

Vol 41 (6 (Suppl. 2)) ◽

pp. S131-S147 ◽

Cited By ~ 26

Author(s):

Nigel A.S. Taylor ◽

Gregory E. Peoples ◽

Stewart R. Petersen

Keyword(s):

Work Performance ◽

Human Performance ◽

Performance Testing ◽

The Body ◽

Load Carriage ◽

Physical Endurance ◽

Physiological Strain ◽

Employment Standards ◽

Heavy Loads ◽

External Loads

The focus of this review is on the physiological considerations necessary for developing employment standards within occupations that have a heavy reliance on load carriage. Employees within military, fire fighting, law enforcement, and search and rescue occupations regularly work with heavy loads. For example, soldiers often carry loads >50 kg, whilst structural firefighters wear 20–25 kg of protective clothing and equipment, in addition to carrying external loads. It has long been known that heavy loads modify gait, mobility, metabolic rate, and efficiency, while concurrently elevating the risk of muscle fatigue and injury. In addition, load carriage often occurs within environmentally stressful conditions, with protective ensembles adding to the thermal burden of the workplace. Indeed, physiological strain relates not just to the mass and dimensions of carried objects, but to how those loads are positioned on and around the body. Yet heavy loads must be borne by men and women of varying body size, and with the expectation that operational capability will not be impinged. This presents a recruitment conundrum. How do employers identify capable and injury-resistant individuals while simultaneously avoiding discriminatory selection practices? In this communication, the relevant metabolic, cardiopulmonary, and thermoregulatory consequences of loaded work are reviewed, along with concomitant impediments to physical endurance and mobility. Also emphasised is the importance of including occupation-specific clothing, protective equipment, and loads during work-performance testing. Finally, recommendations are presented for how to address these issues when evaluating readiness for duty.

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efficiency. By measurements of total odour strength in a treatment plant the ED values pointed out the sludge press and dewatering process as the predominant odour sources of the plant. In the venting air from this position extremely high ED values were recorded. This air was led through a carbon filter for odour reduction. Olfactometric measurements at the filter revealed poor odour reducing efficiency. It was observed that odour compounds were not destroyed in the filter. They only restrained until the carbon became saturated, and thereafter evaporated into the outlet air contributing to the odour strength. The filter capacity was obviously too small for the heavy load. Attempts to reduce the odour strength before the filter did not succeed, until the air was led through a container filled with saturated lime slurry (pH = 12-14). The slurry was part of a precipitation process in the plant. Dispersion in the alkaline slurry extensively reduced the odour strength of the air, resulting in sufficient capacity of the carbon filter also when handling heavy loads of sewage sludge. Since then the carbon filter has worked well, within the limitation of such filters in general. Neither is it observed signs indicating reduced precipitation properties of the lime slurry. Measurements of total odour strength in combustion processes imply sampling challenges. Beside the chemical scrubber process, combustion of odorous air is the best odour reducing method. The disadvantage of this process is the high energy costs. Treatment at apropriate conditions, however, will destroy the odorous compounds extensively. Temperatures about 850 C and contact time up to 3 seconds are reported (2,3). Olfactometric measurements in combustion processes involve certain sampling problems caused by the temperature difference between inlet and outlet. The humidity of outlet air must also be taken into consideration. Problems may occur when hot outlet air is sampled at low temperatures. In most such cases sampling is impossible without special arrangements. Such conditions are present during odour measurements in fish meal plants with combustion as the odour reducing method. The largest problem turned out to be the temperature differences between outlet air (85-220 C) and outdoor temperatures (0-15 C), causing condensation. The dew point of the outlet air was calculated, and experiments were carried out with dilution of the outlet air to prevent condensation in the sampling bags. Condensation was prevented by diluting the outlet air 5-150 times with dry, purified N gas. Comparison of N -diluted and undiluted samples revealed large differences in ED value. In samples demanding a high degree of dilution to prevent condensation, the measured odour strength was up to 5 times higher than in the undiluted corresponding samples. Samples demanding less dilution showed less deviating results. 4. CONCLUSIONS In the attempt to minimize odour emission, olfactometric measurements of total odour strength give useful informations about the odour reducing efficiency of different processes as a function of parameters like dosage of chemicals in scrubbers, humidity and temperature in packed filters, flow rates, etc. Olfactometric measurements also point out the main odour sources of the plant. From a set of olfactometric data combined with other essential

Odour Prevention and Control of Organic Sludge and Livestock Farming ◽

10.1201/9781482286311-34 ◽

1986 ◽

pp. 98-98

Keyword(s):

Treatment Plant ◽

High Energy ◽

Dew Point ◽

Precipitation Process ◽

Heavy Load ◽

Heavy Loads ◽

Combustion Processes ◽

Sampling Problems ◽

High Degree ◽

Carbon Filter

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CONSTRAINTS EXPERIENCED BY MUSHROOM GROWERS IN ADOPTING IMPROVED MUSHROOM PRODUCTION PRACTICES IN PUSA, BIHAR

International Journal of Advances in Agricultural Science and Technology ◽

10.47856/ijaast.2021.v08i7.011 ◽

2021 ◽

Vol 8 (7) ◽

pp. 97-106

Author(s):

Saloni Sarraf ◽

Dipak Kumar Bose ◽

Jahanara Jahanara ◽

Amit Kumar

Keyword(s):

Transport Cost ◽

Primary Data ◽

Mushroom Cultivation ◽

Short Time Period ◽

Long Distance ◽

Mushroom Production ◽

Time Period ◽

Production Practices ◽

Short Time ◽

Technical Guidance

Mushrooms (vegetarian meat/vegetable beef stick) is becoming fast popular because of its short time period between cultivation and harvesting; less initial investment and can be grown with locally available resources. Though more technology is available for boosting mushroom production, the yield so far achieved is not high. Hence, an attempt is made to find out the constraints faced by mushroom growers in adoption of improved mushroom production practices. Samastipur district of Bihar was purposively selected for the study because, Dr. Rajendra Prasad Central Agricultural University, a pioneer in mushroom production technology is located in the study area. 120 respondents from six villages of Pusa, Samastipur, Bihar forms the respondents of the present study. Primary data was collected from the mushroom growers and the responses were subjected to statistical analysis. The results indicated that unavailability of quality spawn, unavailability of skilled labor, absence of technical guidance, high transport cost, unavailability of storage facilities, high cost of spawn and long distance market were the most problematic constraints faced by the mushroom growers. Thus, it can be concluded that adequate extension service should be made available to make mushroom cultivation popular, market and marketing of the products.

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