Cardiovascular and ventilatory responses to electrically induced cycling with complete epidural anaesthesia in humans

Kjær, Michael; Perko, G.; Secher, N. H.; Boushel, Robert; Beyer, Nina; Pollack, Susan F; Horn, Allan; Fernandes, A.; Mohr, Thomas; Lewis, Steven F.; Galbo, H.

doi:10.1111/j.1748-1716.1994.tb09738.x

Cited by 46 publications

(29 citation statements)

References 36 publications

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“…E ciency of electrically induced movements relative to that of voluntary exercise has been found to be 1 : 4, by use of epidural anaesthesia and electrically induced cycling in able-bodied subjects. 11 In line with these facts e ciency of electrically induced exercise in SCI individuals (calculated to approximately 4%) is very low compared to that of voluntary exercise. 29 It follows that unloaded exercise with an ergometer power output of zero on the equipment we used should not necessarily be considered useless from a training perspective.…”

Section: Total Work Outputmentioning

confidence: 76%

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Long term adaptation to electrically induced cycle training in severe spinal cord injured individuals

et al. 1997

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Spinal cord injured (SCI) individuals most often contract their injury at a young age and are deemed to a life of more or less physical inactivity. In addition to the primary implications of the SCI, severe SCI individuals are stigmatized by conditions related to their physically inactive lifestyle. It is unknown if these inactivity related conditions are potentially reversible and the aim of the present study was, therefore, to examine the e ect of exercise on SCI individuals. Ten such individuals (six with tetraplegia and four with paraplegia; age 27 ± 45 years; time since injury 3 ± 23 years) were exercise trained for 1 year using an electrically induced computerized feedback controlled cycle ergometer. They trained for up to three times a week (mean 2.3 times), 30 min on each occasion. The gluteal, hamstring and quadriceps muscles were stimulated via electrodes placed on the skin over their motor points. During the ®rst training bouts, a substantial variation in performance was seen between the subjects. A majority of them were capable of performing 30 min of exercise in the ®rst bout; however, two individuals were only able to perform a few minutes of exercise. After training for 1 year all of the subjects were able to perform 30 min of continuous training and the work output had increased from 4+1 (mean+SE) to 17+2 Kilo Joules per training bout (P50.05). The maximal oxygen uptake during electrically induced exercise increased from 1.20+0.08 litres per minute measured after a few weeks habituation to the exercise to 1.43+0.09 litres per minute after training for 1 year (P50.05).Magnetic resonance cross sectional images of the thigh were performed to estimate muscle mass and an increase of 12% (mean, P50.05) was seen in response to 1 year of training. In biopsies taken before exercise various degrees of atrophy were observed in the individual muscle ®bres, a phenomenon that was partially normalized in all subjects after training.The ®bre type distribution in skeletal muscles is known to shift towards type IIB ®bres (fast twitch, fast fatiguable, glycolytic ®bres) within the ®rst 2 years after the spinal cord injury. The muscle in the present investigation contained of 63% myosin heavy chain (MHC) isoform IIB, 33% MHC isoform IIA (fast twitch, fatigue resistant) and less than 5% MHC isoform I (slow twitch) before training. A shift towards more fatigue resistant contractile proteins was found after 1 year of training. The percentage of MHC isoform IIA increased to 61% of all contractile protein and a corresponding decrease to 32% was seen in the fast fatiguable MHC isoform IIB, whereas MHC isoform I only comprised 7% of the total amount of MHC. This shift was accompanied by a doubling of the enzymatic activity of citrate synthase, as an indicator of mitochondrial oxidative capacity.It is concluded that inactivity-associated changes in exercise performance capacity and skeletal muscle occurring in SCI individuals after injury are reversible, even up to over 20 years after the injury. It follows that electricall...

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Section: Total Work Outputmentioning

confidence: 76%

“…However, it has been shown that FES gives rise to higher increases in lactate than voluntary exercise in able-bodied individuals. 11 In healthy subjects the cardiac pump capacity limits VO 2 -max. If a small muscle mass is used, the maximal cardiac pump activity cannot be reached.…”

Section: Changes In Vo 2 -Maxmentioning

confidence: 99%

Long term adaptation to electrically induced cycle training in severe spinal cord injured individuals

et al. 1997

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“…The average workrate for this oxygen cost was found to be approximately 120 W during volitional cycling, but less than 40 W for FES-cycling. From data presented in the paper, [15], we estimate the net efficiencies for FES-cycling and for volitional cycling in this group to be 7% and 22%, respectively. This establishes that even in subjects where the underlying muscle condition is normal, FES-induced cycling is less efficient by a factor of approximately 3 than cycling achieved by volitional muscle control.…”

Section: Introductionmentioning

confidence: 99%

“…Kjaer et al [15] investigated the performance of eight healthy young males in both volitional and FES-induced cycling. The group performed volitional cycling at a workrate which elicited an average oxygen uptake of 1.9 l · min −1 .…”

Section: Introductionmentioning

confidence: 99%

Comparison of stimulation patterns for FES-cycling using measures of oxygen cost and stimulation cost

Hunt

Ferrario

Grant

et al. 2006

Medical Engineering & Physics

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Aim: The energy efficiency of FES-cycling in spinal cord injured subjects is very much lower than that of normal cycling, and efficiency is dependent upon the parameters of muscle stimulation. We investigated measures which can be used to evaluate the effect on cycling performance of changes in stimulation parameters, and which might therefore be used to optimise them. We aimed to determine whether oxygen-cost and stimulation-cost measurements are sensitive enough to allow discrimination between the efficacy of different activation ranges for stimulation of each muscle group during constant-power cycling. Methods:We employed a custom FES-cycling ergometer system, with accurate control of cadence and stimulated exercise workrate. Two sets of muscle activation angles ("stimulation patterns"), denoted "P1" and "P2", were applied repeatedly (eight times each) during constant-power cycling, in a repeated measures design with a single paraplegic subject. Pulmonary oxygen uptake was measured in real time and used to determine the oxygen cost of the exercise. A new measure of stimulation cost of the exercise is proposed, which represents the total rate of stimulation charge applied to the stimulated muscle groups during cycling. A number of energy-efficiency measures were also estimated.Results: Average oxygen cost and stimulation cost of P1 were found to be significantly lower than those for P2 (paired t-test, p<0.05): oxygen costs were 0.56 ± 0.03 l · min −1 and 0.61 ± 0.04 l · min −1 (mean ± sd), respectively; stimulation costs were 74.91 ± 12.15 mC · min −1 and 100.30 ± 14.78 mC · min −1 (mean ± sd), respectively. Correspondingly, all efficiency estimates for P1 were greater than those for P2. Conclusion:Oxygen-and stimulation-cost measures both allow discrimination between the efficacy of different muscle activation patterns during constant-power FES-cycling. However, stimulation cost is more easily determined in real time, and responds more rapidly and with greatly improved signal-to-noise properties than the ventilatory oxygen uptake measurements required for estimation of oxygen cost. These measures may find utility in the adjustment of stimulation patterns for achievement of optimal cycling performance.

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“…Both reduced exercise tolerance on a treadmill walking test 6 and reduced cardiorespiratory fitness (maximal oxygen consumption [VO 2 max]) on a cycle ergometer 7 compared with able-bodied control subjects have been shown in adolescent renal transplant recipients. Reductions in VO 2 max compared with agematched healthy individuals 8 and limitations in daily functioning were noted in adult LT recipients. [9][10][11] To the best of our knowledge, no research has been conducted on the assessment of fitness levels in pediatric LT recipients.…”

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confidence: 96%

Fitness testing of pediatric liver transplant recipients

Unnithan

Veehof

Rosenthal³

et al. 2001

Liver Transpl

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Liver transplantation is accepted as the standard management for end-stage liver disease in children. Pediatric heart and heart-lung transplant recipients have shown significantly diminished exercise capacities compared with age-matched, able-bodied, control subjects. The primary aim of this study is to compare the fitness levels of a group of pediatric liver transplant (LT) recipients (LT group, 20 boys, 9 girls; age, 8.9 ؎ 4.8 years; 56 ؎ 35 months posttransplantation) with a group of able-bodied control subjects ( T ransplantation is the accepted therapy for endstage organ failure. Thirty five thousand individuals received organ transplants in 1998, and this number is growing. One of the major reasons for this increase over previous years is the better long-term prognosis for these individuals. 1 Common to all adult liver transplant (LT) candidates is an impaired physical performance level before transplantation. [2][3][4] It is expected that impaired exercise capacity affects the performance of adults in their daily recreational activities and inhibits the accomplishment of simple physical tasks. Although improved physical functioning is assumed after transplantation, limited information exists regarding the physical functioning of adult and pediatric transplant recipients. 2 The limited cross-sectional data that exist in pediatric heart, heart-lung, and lung transplant recipients showed significant (43% to 64%) reductions in physical work capacity compared with able-bodied control subjects. 5 The limitations to exercise performance more likely stem from central limitations in heart and heartlung transplant recipients and pretransplantation exercise intolerance. Both reduced exercise tolerance on a treadmill walking test 6 and reduced cardiorespiratory fitness (maximal oxygen consumption [VO 2 max]) on a cycle ergometer 7 compared with able-bodied control subjects have been shown in adolescent renal transplant recipients. Reductions in VO 2 max compared with agematched healthy individuals 8 and limitations in daily functioning were noted in adult LT recipients. [9][10][11] To the best of our knowledge, no research has been conducted on the assessment of fitness levels in pediatric LT recipients. The purpose of this study is to use simple field tests of the basic components of physical fitness (cardiorespiratory fitness and muscular endurance, specifically abdominal and flexibility) to (1) compare the fitness level of pediatric LT recipients with able-bodied control subjects and (2) assess the proportion of pediatric LT recipients capable of achieving able-bodied pediatric criterion fitness standards.

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Cardiovascular and ventilatory responses to electrically induced cycling with complete epidural anaesthesia in humans

Cited by 46 publications

References 36 publications

Long term adaptation to electrically induced cycle training in severe spinal cord injured individuals

Long term adaptation to electrically induced cycle training in severe spinal cord injured individuals

Comparison of stimulation patterns for FES-cycling using measures of oxygen cost and stimulation cost

Fitness testing of pediatric liver transplant recipients

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