Mechanics and energetics of stilt walking

1981 ◽  
Vol 51 (2) ◽  
pp. 529-532 ◽  
Author(s):  
P. Vaida ◽  
B. Anton-Kuchly ◽  
P. Varene

Three subjects were studied walking on a sports track with and without 1-m-long stilts. They were asked to walk in different ways. Pace length, step rate, heart rate, and oxygen consumption were measured under both conditions at different speeds. The results show that walking speed is generally faster for stilt walking than for normal walking. The higher speed is achieved due to increased pace length in spite of a decrease in step rate. The relationship between energy expenditure and walking speed is approximately the same in both cases. This result may be explained by two opposing factors: increase of pace length and decrease of step rate decrease the energy requirements of stilt walking, but the foot loading presented by the stilt walking exaggerates these conditions and increases energy expenditure.

2017 ◽  
Vol 12 (4) ◽  
pp. 504-513 ◽  
Author(s):  
Charles-Mathieu Lachaume ◽  
François Trudeau ◽  
Jean Lemoyne

The purpose of this study was to investigate the energy expenditure and heart rate responses elicited in elite male midget ice hockey players during small-sided games. Nine players (aged 15.89 ± 0.33 years) participated in the study. Maximal progressive treadmill testing in the laboratory measured the relationship of oxygen consumption ([Formula: see text]) to heart rate before on-ice assessments of heart rate during six different small-sided games: 1v1, 2v2, 2v2 with support player, 3v3 with support player, 3v3 with transitions, and 4v4 with two support players. Heart rate was recorded continuously in each game. 3v3 T small-sided game was the most intense for all four intensity markers. All six small-sided games reached 89% HRmax or more with heart rate peaks in active effort repetition. These findings demonstrate that such small-sided games are considered as high intensity games and are an effective training method for ice hockey players.


1997 ◽  
Vol 21 (1) ◽  
pp. 9-16 ◽  
Author(s):  
R. S. Gailey ◽  
M. S. Nash ◽  
T. A. Atchley ◽  
R. M. Zilmer ◽  
G. R. Moline-Little ◽  
...  

The effect of prosthesis mass on the metabolic cost of steady-state walking was studied in ten male non-vascular trans-tibial amputees (TTAs) and ten non-amputee controls. The subjects underwent four trials of treadmill ambulation, with each trial performed for nine minutes at level grade and 76 m/min. Twenty minutes of seated rest followed each trial. During trials numbers one and two, TTAs ambulated without mass added to their prosthesis. During the third and fourth trials, either 454 or 907 grammes mass (1 or 2lbs mass respectively) were randomly assigned and added to eithier the prosthesis or the leg of the non-amputee control. Subjects were blinded to the amount of mass added to their limb. Within-group comparisons across the four trials showed significant differences in oxygen consumption (VO2) and heart rate (HR) between the two non “mass added” trials, but no effect for addition of mass. The VO2 of TTAs was only 0.6ml/kg/min (4.7 percent) greater during walking following the addition of 907 grammes to the prosthesis than without mass addition at all, while HR averaged only 1.4 beats/min. higher under the same testing condition. Pearson-product moment correlations echoed these findings, as moderate, but in all cases, negative correlations were observed for associations among the factors of subject age, stump length, and prosthesis-shoe weight, and both VO2 and HR. It was concluded that adding up to 907 grammes mass to a non-vascular TTA's prosthesis will not significantly increase the energy expenditure or HR at a normal walking speed, and that elevated energy cost of ambulation in repeated measures testing without mass added may reflect task familiarisation and not an added burden of prosthesis mass.


Author(s):  
Andrew N. Bosch ◽  
Kirsten C. Flanagan ◽  
Maaike M. Eken ◽  
Adrian Withers ◽  
Jana Burger ◽  
...  

Elliptical trainers and steppers are proposed as useful exercise modalities in the rehabilitation of injured runners due to the reduced stress on muscles and joints when compared to running. This study compared the physiological responses to submaximal running (treadmill) with exercise on the elliptical trainer and stepper devices at three submaximal but identical workloads. Authors had 18 trained runners (male/female: N = 9/9, age: mean ± SD = 23 ± 3 years) complete randomized maximal oxygen consumption tests on all three modalities. Submaximal tests of 3 min were performed at 60%, 70%, and 80% of peak workload individually established for each modality. Breath-by-breath oxygen consumption, heart rate, fuel utilization, and energy expenditure were determined. The value of maximal oxygen consumption was not different between treadmill, elliptical, and stepper (49.3 ± 5.3, 48.0 ± 6.6, and 46.7 ± 6.2 ml·min−1·kg−1, respectively). Both physiological measures (oxygen consumption and heart rate) as well as carbohydrate and fat oxidation differed significantly between the different exercise intensities (60%, 70%, and 80%) but did not differ between the treadmill, elliptical trainer, and stepper. Therefore, the elliptical trainer and stepper are suitable substitutes for running during periods when a reduced running load is required, such as during rehabilitation from running-induced injury.


2020 ◽  
Vol 1 (1) ◽  
pp. 72-9
Author(s):  
Alfan Mahdi Nugroho ◽  
Yusmein Uyun ◽  
Annemarie Chrysantia Melati

Analgesia epidural telah diperkenalkan secara rutin sebagai salah satu modalitas analgesia pada proses persalinan sejak lama. Hubungan antara analgesia epidural persalinan dengan demam intrapartum pada maternal sudah disebutkan pada beberapa literatur. Demam didefinisikan sebagai peningkatan suhu tubuh lebih dari 38 oC yang didapat dari dua kali pemeriksaan. Beberapa teori yang disebutkan antara lain perubahan termoregulasi, infeksi pada ibu-janin dan inflamasi non-infeksi yang dimediasi oleh sitokin proinflamasi. Namun demikian berbagai mekanisme analgesia epidural dapat menyebabkan demam masih terus diteliti. Identifikasi demam pada ibu saat persalinan merupakan hal yang penting untuk dilakukan karena memiliki konsekuensi klinis pada ibu dan neonatus. Pada ibu ditemukan suhu yang meningkat dikaitkan dengan peningkatan denyut jantung ibu, curah jantung, konsumsi oksigen, dan produksi katekolamin. Sedangkan pada janin demam intrapartum dapat menyebabkan sepsis, perubahan skor APGAR, peningkatan kebutuhan bantuan napas dan kejadian kejang. Efek demam pada ibu dan janin masih terus dipelajari, sehingga suatu saat didapatkan cara pencegahan yang paling baik yang pada akhirnya menghindarkan keraguan untuk melakukan analgesia persalinan.   Fever during labour epidural analgesia Abstract Epidural analgesia has been routinely introduced as one of the analgesia modalities during labour. Literature has mentioned the relationship between epidural analgesia and intrapartum fever among mothers. Fever is defined as increased temperature above 38 oC in more than two measurements. Several theories have been proposed, inculing thermoregulation changes, mother-fetal infection, and non-infectious inflammation mediated by proinflammatory cytokines. However, these mechanisms have been continued to evolve. Fever identification in pregnant women is essential to recognize clinical consequences to both mothers and neonates. Increased temperature in mothers is associated with increased heart rate, cardiac output, oxygen consumption, and catecholamines production. Meanwhile, in neonates intrapartum fever is related to sepsis, APGAR score changes, the need of respiratory support and incidence of neonatal seizure. Therefore, these consequences are extensively studied in order to determine the appropriate prevention.


Author(s):  
Stefano Brunelli ◽  
Andrea Sancesario ◽  
Marco Iosa ◽  
Anna Sofia Delussu ◽  
Noemi Gentileschi ◽  
...  

BACKGROUND: Physiological Cost Index (PCI) is a simple method used to estimate energy expenditure during walking. It is based on a ratio between heart rate and self-selected walking speed. Previous studies reported that PCI is reliable in individuals with lower limb amputation but only if there is an important walking impairment. No previous studies have investigated the correlation of PCI with the Energy Cost Walking (ECW) in active individuals with traumatic unilateral trans-tibial amputation, considering that this particular category of amputees has an ECW quite similar to healthy individual without lower limb amputation. Moreover, it is important to determine if PCI is also correlated to ECW in the treadmill test so as to have an alternative to over-ground test. OBJECTIVES: The aim of this study was to evaluate the correlation between PCI and ECW in active individuals with traumatic trans-tibial amputation in different walking conditions. The secondary aim was to evaluate if this correlation permits to determine ECW from PCI values. METHODOLOGY: Ninety traumatic amputees were enrolled. Metabolic data, heart rate and walking speed for the calculation of ECW and for PCI were computed over-ground and on a treadmill with 0% and 12% slopes during a 6-minute walking test. FINDINGS: There is a significant correlation between ECW and PCI walking over-ground (p=0.003; R2=0.10) and on treadmill with 12% slopes (p=0.001; R2=0.11) but there is only a poor to moderate correlation around the trendline. No significant correlation was found walking on treadmill with 0% slope. The Bland-Altman plot analysis suggests that is not possible to evaluate ECW directly from PCI. CONCLUSIONS: PCI is a reliable alternative measure of energy expenditure during walking in active individuals with trans-tibial amputation when performing over-ground or at high intensity effort on treadmill. PCI is therefore useful only for monitoring a within subject assessment. LAYMAN’S ABSTRACT The knowledge of the energy cost of walking in disabled people is important to improve strategies of rehabilitation or fitness training and to develop new prosthetic and orthotic components. The “gold standard” for the evaluation of the energy cost of walking is the oxygen consumption measurement with a metabolimeter, but the testing procedure is expensive and time consuming, hardly practicable in many rehabilitation centers. The Physiological Cost Index (PCI) is an indirect tool that evaluates the oxygen consumption during walking. PCI considers heart rate during walking, in relation to the speed, as an indicator of energy expenditure. The formula is “walking heart rate – resting heart rate /speed”. PCI is widely used in literature but there is not a solid evidence of a direct correlation between PCI and energy cost of walking. In particular, for individuals with unilateral trans-tibial amputation without comorbidities, no previous studies have been conducted about this correlation. It has to be noticed that individuals with unilateral trans-tibial amputation have an energy cost of walking quite similar to healthy people. Previous studies reported that in healthy people such correlation does not exist. For this reason, the aim of this study was to evaluate if and in which walking condition a linear correlation exists between PCI and Energy Cost Walking in individuals with unilateral trans-tibial amputation. Oxygen consumption measurement with a metabolimeter and PCI were computed over-ground and on a treadmill with 0% and 12% slopes during a 6-minute walking test in 90 participants. We have found that PCI is an alternative measure of energy cost of walking when performing over-ground or with high intensity effort on treadmill (12% slope). These findings could be useful when PCI is used for monitoring a fitness training or for evaluation tests. Article PDF Link: https://jps.library.utoronto.ca/index.php/cpoj/article/view/32953/25717 How to Cite: Brunelli S, Sancesario A, Iosa M, Delussu A.S, Gentileschi N, Bonanni C, Foti C, Traballesi M. Which is the best way to perform the Physiological Cost Index in active individuals with unilateral trans-tibial amputation? Canadian Prosthetics & Orthotics Journal. Volume2, Issue1, No.5, 2019. https://doi.org/10.33137/cpoj.v2i1.32953. CORRESPONDING AUTHOR: Dr. Stefano Brunelli,Fondazione Santa Lucia, IRCCS, Via Ardeatina 306, 00179 Rome, Italy.ORCID: https://orcid.org/0000-0002-5986-1564Tel. +39 0651501844; Fax +39 0651501919E-MAIL: [email protected]


1968 ◽  
Vol 49 (3) ◽  
pp. 565-582
Author(s):  
G. M. HUGHES ◽  
SHUN-ICHI UMEZAWA

1. The usefulness of a bottom-living fish, the dragonet (Callionymus lyra), in experiments on fish respiration is described. The position and nature of its opercular opening made it possible to determine directly the volume of water pumped over the gills and the PO2 of the mixed expired water. The normal ventilation volume for a 100 g. fish was about 30 c.c./min. 2. The relationship between cardiac and respiratory rhythms was investigated and showed a variety of ratios. The heart usually beats more than once during each respiratory cycle. Individual variations in the coupling between these rhythms was common and close couplings were observed in the absence of anaesthetic and at normal PO2s. 3. Changes in minute volume produced by altering the hydrostatic pressure across the respiratory system did not affect the heart rate. Percentage utilization fell at higher flow rates. Changes in flow per cm. of water pressure gradient was less with negative gradients than when the static pressure on the mouth side exceeded that in the opercular collecting chamber. 4. Oxygen consumption of the fish is directly related to the ambient PO2 over a wide range (30-120 mm. Hg). Sudden lowering of the PO2 in the inspired water leads to compensatory responses in which the minute volume is maintained or increased as a result of a rise in stroke volume and lowered respiratory frequency: there is also a marked bradycardia. During recovery the increased oxygen consumption of the fish resulted from a rise in utilization rather than a change in the respiratory rate or ventilation volume. 5. Analysis of the time course of the changes in heart rate and ventilation volume in experiments in which PO2 was changed supports the view that the receptors mediating bradycardia occur on the gills and respond directly to the change in PO2 rather than to the secondary increase in flow produced by the hypoxia.


1993 ◽  
Vol 17 (2) ◽  
pp. 95-100 ◽  
Author(s):  
R. S. Gailey ◽  
D. Lawrence ◽  
C. Burditt ◽  
P. Spyropoulos ◽  
C. Newell ◽  
...  

Twenty unilateral trans-femoral amputees fitted with either the Contoured Adducted Trochanteric-Controlled Alignment Method (CAT-CAM) socket (n=10) or the quadrilateral (QUAD) socket (n=10), and a “non-amputee” control group (n=10) participated in the study. Subjects meeting the following criteria were studied: healthy males between the ages of 18 and 55 years, amputation due to non-vascular pathology, an unaffected sound limb, at least six months use of the test prosthesis, and a minimal stump length of 15 cm. Subjects ambulated in two randomized trials separated by 20 minutes of rest at 2 assigned speeds: a pace reflecting normal walking speed (97 m/min=2.5 mph) or a slower speed (48.5 m/min=1.25 mph). Heart rate (HR) and Oxygen uptake (VO2) measured during steady state walking were analyzed via two-way ANOVA. Differences among means were further analyzed using Tukey post hoc and simple effects tests. Significant differences were observed between the control group and CAT-CAM subjects with respect to VO2 (p < 0.05) and HR (p < 0.01) at the slower speed. The control group and subjects using the QUAD socket also differed with respect to VO2 (p < 0.01) and HR (p < 0.01) at the slower pace. Faster pace required more energy expenditure (p < 0.01) and produced higher HR (p < 0.01) than slower speeds. At faster pace, a significantly higher energy expenditure in the QUAD than the CAT-CAM group was observed (p<0.01). It is concluded that ambulating at normal pace using the CAT-CAM socket design uses less energy than when using a QUAD socket design.


1996 ◽  
Vol 81 (4) ◽  
pp. 1754-1761 ◽  
Author(s):  
Jon K. Moon ◽  
Nancy F. Butte

Moon, Jon K., and Nancy F. Butte. Combined heart rate and activity improve estimates of oxygen consumption and carbon dioxide production rates. J. Appl. Physiol.81(4): 1754–1761, 1996.—Oxygen consumption (V˙o 2) and carbon dioxide production (V˙co 2) rates were measured by electronically recording heart rate (HR) and physical activity (PA). Mean daily V˙o 2 andV˙co 2 measurements by HR and PA were validated in adults ( n = 10 women and 10 men) with room calorimeters. Thirteen linear and nonlinear functions of HR alone and HR combined with PA were tested as models of 24-h V˙o 2 andV˙co 2. Mean sleepV˙o 2 andV˙co 2 were similar to basal metabolic rates and were accurately estimated from HR alone [respective mean errors were −0.2 ± 0.8 (SD) and −0.4 ± 0.6%]. The range of prediction errors for 24-h V˙o 2 andV˙co 2 was smallest for a model that used PA to assign HR for each minute to separate active and inactive curves (V˙o 2, −3.3 ± 3.5%; V˙co 2, −4.6 ± 3%). There were no significant correlations betweenV˙o 2 orV˙co 2 errors and subject age, weight, fat mass, ratio of daily to basal energy expenditure rate, or fitness. V˙o 2,V˙co 2, and energy expenditure recorded for 3 free-living days were 5.6 ± 0.9 ml ⋅ min−1 ⋅ kg−1, 4.7 ± 0.8 ml ⋅ min−1 ⋅ kg−1, and 7.8 ± 1.6 kJ/min, respectively. Combined HR and PA measured 24-h V˙o 2 andV˙co 2 with a precision similar to alternative methods.


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