Wheelchair Ergometry Research Articles

Effect of work rate increment on peak oxygen uptake during wheelchair ergometry in men with quadriplegia : Lasko-McCarthey, P and Davis, J ASur J Appl Physiol Occup Physiol Vol 63 No 5 (1991) pp 49–353 (21 refs)

Effect of work rate increment on peak oxygen uptake during wheelchair ergometry in men with quadriplegia : Lasko-McCarthey, P and Davis, J ASur J Appl Physiol Occup Physiol Vol 63 No 5 (1991) pp 49–353 (21 refs)

Anaerobic threshold in wheelchair athletes with cerebral palsy: validity and reliability.

This study examined the validity and reliability of the anaerobic threshold (AT) using blood lactate (ATLa) and respiratory gas exchange (ATg) criteria during cycle ergometry (CE) and wheelchair ergometry (WE) in athletes with spastic cerebral palsy (CP). Eleven subjects attempted a discontinuous incremental test protocol, two minutes work interspersed with one minute rest, twice each on the CE and WE. Only five out of the 11 subjects were able to complete the CE tests, whereas all the subjects were able to complete the WE test. Inadequate hip flexion due to muscle spasticity was the primary limiting factor during the CE tests. Although the maximal aerobic power using this protocol was reliable during WE (r = 0.89, p < .05), the validity and reliability of the AT identified by two independent evaluators using these two techniques was questionable. Evaluator 1 was able to identify ATLa and ATg in seven out of the 11 cases, whereas evaluator 2 was successful in five and seven cases, respectively. It is unclear from these results whether the poor validity and reliability of the AT was due to the discontinuous test protocol used, or whether it was due to inconsistencies in the rate of lactate diffusion from the muscle into the blood due to variations in muscle spasticity during the test.

Multidisciplinary data acquisition and analysis of wheelchair ergometry

Multidisciplinary data acquisition and analysis of wheelchair ergometry

Maximal aerobic power in cerebral palsied wheelchair athletes: validity and reliability.

This study examined the validity and reliability of maximal aerobic power (VO2max) during wheelchair ergometry (WE) in wheelchair athletes with cerebral palsy. Six class 3 and class 4 male athletes with cerebral palsy completed two graded exercise tests to volitional fatigue on a wheelchair ergometer mounted on frictionless rollers. Four athletes were also able to complete two tests of bicycle ergometry (BE). Although the reliability coefficients for the VO2max during the two exercise modes were high (.89 and .93 for the WE and BE tests, respectively), the validity coefficients for this variable (ie, the correlations between WE and BE) were poor (.31 and -.24 for trials 1 and 2, respectively). Examination of the individual data indicated that athletes who used wheelchairs as their primary mode of ambulation had higher VO2max values during WE; whereas, those who used canes or no aids for daily ambulation had higher values on BE. Because of the specificity of the, VO2max response, it is recommended that the primary mode of ambulation be considered when deciding on the testing mode for evaluating the cardiorespiratory fitness of athletes with cerebral palsy.

Effect of work rate increment on peak oxygen uptake during wheelchair ergometry in men with quadriplegia

The purpose of this study was to determine the effect of work rate increment on peak oxygen uptake (VO2 peak) during wheelchair ergometry (WCE) in men with quadriplegia due to cervical spinal cord injuries (CSCI). Twenty-two non-ambulatory subjects (aged 20-38 years) with CSCI were divided into two groups based on wheelchair sports classification (n = 12 for IA group and n = 10 for IB/IC group). Subjects underwent three different, continuous graded exercise tests (spaced at least 1 week apart) on an electronically braked wheelchair ergometer. Following a 3-min warmup, the work rate was increased 2, 4, or 6 W.min-1 for the IA group and 4, 6, or 8 W.min-1 for the IB/IC group. Ventilation and gas exchange were measured breath-by-breath with a computerized system. Repeated-measures ANOVA showed no significant difference among the three protocols for VO2 peak in the IA group (P greater than 0.05). The mean (SD) VO2 peak values (ml.kg-1.min-1) were 9.3 (2.4), 9.4 (3.2), and 8.4 (2.6) for the 2, 4, and 6 W.min-1 protocols, respectively. In contrast, the IB/IC group showed a significant difference among the protocols for VO2 peak (P less than 0.05). The mean (SD) VO2 peak values (ml.kg-1,min-1) were 15.1 (4.0), 14.1 (4.4), and 12.7 (4.0) for the 4, 6, and 8 W.min-1 protocols, respectively. Post hoc analysis revealed a difference between the 4 and 8 W.min-1 protocols. Our results suggest that graded exercise testing of men with quadriplegia due to CSCI, using WCE, should employ work rate increments between 2 and 6 W.min-1 and that work rate increments of 8 W.min-1 or greater will result in an underestimate of VO2 peak.

Reliability of peak physiological responses during wheelchair ergometry in persons with spinal cord injury.

This study examined the test-retest reliability of peak physiological responses during wheelchair ergometry (WE) in individuals with spinal cord injury (SCI). Seven wheelchair dependent subjects, two with paraplegia (T10-11 and T11-12 lesions) and five with quadriplegia (all with C6-7 lesions), were given two incremental exercise tests to volitional fatigue on separate occasions within a one-week period. Each subject wheeled his or her personal wheelchair, which was mounted on a set of frictionless rollers with side-mounted flywheels. Metabolic and cardiorespiratory responses were continuously monitored by means of an automated metabolic measurement cart interfaced with an electrocardiograph. Statistical analysis revealed no significant differences (p greater than .05) between the mean values of the two test trials for six peak values. Reliability coefficients (p less than .01) were: oxygen uptake (0.98), heart rate (0.97), ventilation volume (0.96), respiratory exchange ratio (0.91), oxygen pulse (0.96), and ventilatory equivalent for oxygen (0.88). The investigators concluded that these six physiological responses in subjects with SCI undergoing WE are highly reliable, and that these variables can be used in the objective prescription, monitoring, and evaluation of exercise rehabilitation programs for individuals with SCI.

Physiological and biomechanical differences between wheelchair-dependent and able-bodied subjects during wheelchair ergometry : Brown, D.D., Knowlton, R.G., Hamill, J., Schneider, T.L., and Hetzler, R.K.Euro J Appl Physiol and Occupat Physiol, 1990, 60.3, 179–182, 14 refs

Physiological and biomechanical differences between wheelchair-dependent and able-bodied subjects during wheelchair ergometry : Brown, D.D., Knowlton, R.G., Hamill, J., Schneider, T.L., and Hetzler, R.K.Euro J Appl Physiol and Occupat Physiol, 1990, 60.3, 179–182, 14 refs

Perspectives on Cardiovascular Fitness and SCI

The purpose of these papers is to review and discuss the fundamental concepts and problems underlying cardiovascular fitness and spinal cord injury. Particular attention is paid to several modes of exercise available to individuals with spinal cord injury (SCI)--voluntary arm-crank and wheelchair ergometry, electrical stimulation leg cycle ergometry, and combined voluntary arm-cranking and electrical stimulation leg (hybrid) exercise. The effects of level of injury, active muscle mass, and sympathetic dysfunction upon acute central hemodynamic adjustments during exercise testing and chronic training adaptations are discussed for both quadriplegics and paraplegics. Several topics for future research are suggested.

The Spinal Injured Athlete

Physiological variables identified as important factors in athletic performance are discussed in relation to the spinal cord injured (SCI) athlete. These include body composition, pulmonary function, cardiorespiratory efficiency, muscular strength and endurance, and anaerobic power. SCI athletes are less fat and have a larger lean body mass than nonathletes, and male SCI are less fat than female SCI. Static lung volumes are usually below normal values in SCI subjects, but athletic SCI subjects tend to have higher values than sedentary SCI. Sedentary SCI subjects have lower aerobic power (O2max) than the general able-bodied (AB) sedentary population on tests of arm cranking or wheelchair ergometry. Low-lesion paraplegics generally achieve O2max values comparable to AB subjects. O2max is inversely related to level of injury, that is, the higher the SCI, the lower the O2max. However, elite SCI athletes are capable of achieving very high levels of O2max during arm exercise. SCI subjects respond well to strength and muscular endurance training. Paraplegic subjects achieve higher anaerobic power scores than quadriplegic subjects. Increases in O2max occur at about the same magnitude as in AB subjects. The required intensity level appears to be about 70–80% of maximal heart rate reserve.

Physiological and biomechanical differences between wheelchair-dependent and able-bodied subjects during wheelchair ergometry

The purpose of this study was to compare the physiological and biomechanical responses of wheelchair-dependent persons (WCD) to able-bodied persons (AB) during manual wheelchair ergometry. Five WCD and five AB performed a discontinuous wheelchair ergometer test starting at 12.8 W at 30 rev.min-1 (57 m.min-1) with increments of 7.0 W at 6-min intervals. Biomechanical data were collected 3.5 min into each stage followed by the collection of physiological data. After the fifth stage, peak oxygen consumption was determined by having the subject work against a resistance of 14.7-19.6 N at 30 rev.min-1. The WCD had significantly higher net mechanical efficiency at 26.7, 33.6 and 40.6 W in comparison to the AB. The WCD had significantly greater shoulder extension at the point of initial wheel contact as measured by the shoulder angle, while the AB had significantly greater shoulder range of motion at all work rates in comparison to the WCD. The results demonstrate that a significant physiological difference exists in the manner by which WCD and AB accomplish wheelchair ergometry. The biomechanical differences between AB and WCD were found to be a prominent factor contributing to the higher mechanical efficiency of WCD over AB. It was concluded that basic physiological and biomechanical differences exist between WCD and AB in manual wheelchair locomotion and that these differences are important considerations to the interpretation of data in wheelchair ergometry studies.

Effects of low - and moderate-intensity training in spinal cord-injured persons

This study examined the applicability of exercise prescription guidelines established for the able-bodied to spinal cord-injured (SCI) persons. Two SCI groups performed wheelchair ergometry (WCE) 20 min three times per week for 8 wk. Low-intensity (LI, N = 6) and moderate-intensity (MI, N = 5) groups trained at 50-60% and 70-80% maximal heart rate reserve (HRR), respectively. The subjects completed an incremental discontinuous maximal WCE test to exhaustion pre- and post-training. A submaximal WCE test consisting of 4-min exercise stages at power outputs of 5, 10, and 15 W was also performed pre- and post-training. Blood samples were collected before and after training and analyzed for total cholesterol (TC), triglycerides (TG), high-density lipoprotein-cholesterol (HDL-C), and low-density lipoprotein-cholesterol (LDL-C). The TC/HDL-C ratio was calculated. Both groups exhibited no significant changes (P greater than 0.10) in VO2max, HRmax, POmax, lactate (La)max, and VO2 at 4 mmol [La]. No pre- to post-training differences were recorded in the LI group for submaximal VO2, HR, VE, La, and ratings of perceived exertion (RPE). The MI group had significantly lower (P less than or equal to 0.10) post-training submaximal HR, La, and RPE and no changes in VO2 or VE. Blood lipid levels remained unaltered in the LI group, while the MI group exhibited significant increases in HDL-C and decreases in TG, LDL-C, and the TC/HDL-C ratio. The maximal test data revealed that 8 wk of LI and MI wheelchair ergometry training did not improve VO2max in SCI persons.(ABSTRACT TRUNCATED AT 250 WORDS)

The effects of arm crank training on the physiological responses to submaximal wheelchair ergometry.

The purpose of this investigation was to examine the cardiovascular and metabolic effects of a 5 wk arm crank (AC) training program on submaximal wheelchair (WC) ergometry in able-bodied women. The 6 subjects in the training group (TG) and 4 in the control group (CG) performed a 10 min WC exercise prior to and following the training period at a power output (PO) that elicited 70% of the pre-training peak oxygen uptake (VO2). Steady state VO2, heart rate (HR), cardiac output (Qc) and stroke volume (Vs) were measured. Resting and post-exercise blood lactate concentrations (LA) were measured, the difference was recorded as net LA. The TG exercised on the AC 3 d.wk-1 at a PO that elicited 85% of each subject's recorded peak HR. Each session consisted of four 4 min exercise bouts preceded by a 2 min warm-up and interspersed with 2 min rest periods. After training, the TG had a significantly (p less than 0.05) lower HR, larger Vs and lower LA in response to the WC exercise. Qc and VO2 were not significantly altered. The results demonstrate that the AC exercise program used in this study produced a physiological training effect which was observed during submaximal WC exercise of an intensity frequently encountered during daily WC ambulation. It appears that short-term, moderate intensity AC training offers an adequate stimulus to reduce the stress imposed by wheelchair locomotion.

Metabolic responses of women to exercise attributable to long term use of a manual wheelchair.

The purpose of this study was to determine the effects of long term use of a manual wheelchair by wheelchair-confined women (means = 14.6 years) on physiological responses to wheelchair ergometry. Six experimental subjects were compared to six able bodied women during maximal exercise as well as submaximal wheelchair ergometry at 50 and 80% of peak VO2. The wheelchair dependent women achieved higher power outputs, greater efficiency at the higher submaximal workload, less metabolic acidosis during submaximal exercise as well as less ventilatory stress. There was no significant difference in peak VO2 between the two groups of women. Because these were not athletically trained women, it was concluded that the long term use of a manual wheelchair leads to physiological adaptations favourable to the daily requirements of wheelchair locomotion.

Arm cranking and wheelchair ergometry in elite spinal cord-injured athletes

ABSTRACTWe investigated the cardiorespiratory responses to progressive incremental arm cranking (AC) and wheelchair ergometry (WCE) and upper limb strength in 72 elite male (N=61) and female (N=11) physically disabled athletes. Peak Vo2 in the two tests increased progressively in athletes categorize

Metabolic and cardiopulmonary responses to wheelchair and bicycle ergometry

To evaluate wheelchair activity in reference to a more familiar mode of locomotion, metabolic and cardiopulmonary responses to wheelchair ergometer (WERG) and bicycle ergometer (BERG) exercise were compared. Eighteen able-bodies subjects were tested on a combination wheelchair-bicycle ergometer. Oxygen uptake (VO2), respiratory exchange ratio (R), pulmonary ventilation (VE), ventilatory equivalent (VE/VO2), percent net mechanical efficiency (ME), and heart rate (HR) were determined at power output (PO) levels of 30, 90, and 150 kpm/min on each ergometer. For WERG and BERG exercise, VO2, VE, and HR increased linearly with PO. Generally, VO2, R, VE, VE/VO2, and HR responses were higher (P less than 0.05) during WERG than BERG exercise at each PO. Blood lactate was determined after 150 kpm/min, and found to be higher (P less than 0.05) during WERG than BERG exercise. ME increased with PO and was lower (P less than 0.05) for WERG than BERG exercise at each PO level. The greater metabolic and cardiopulmonary responses observed during WERG exercise may be due to inefficient biomechanics and the relatively small upper body musculature used for propulsion.

The use of multistage exercise testing with wheelchair ergometry and arm cranking in subjects with spinal cord lesions

The primary aim of this investigation was to compare maximum wheelchair performance with arm cranking using a multistage progressive work load protocol. In five subjects with a wide range of neurological disability and two normal males the differences observed in maximum oxygen uptake, heart rate and ventilation during two forms of upper limbs exercise, were not significant.