Cardiovascular responses and postexercise hypotension after arm cycling exercise in subjects with spinal cord injury

OBJECTIVE: To examine postexercise hypotension and contributing factors in subjects with spinal cord injury (SCI). DESIGN: Prospective clinical research study. SETTING: Rehabilitation center. PARTICIPANTS: Subjects with chronic cervical-level (n=19) and thoracic-level (n=8) SCI. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Subjects underwent graded arm-cycling with electrocardiogram and oxygen uptake monitoring to exhaustion. Heart rates and blood pressures were measured before and after exercising. Injury to motor and sensory pathways was determined by American Spinal Injury Association grade, and to autonomic pathways by sympathetic skin responses (SSRs) (n=16). RESULTS: Resting blood pressures and heart rates were lower in cervical than thoracic SCI (mean arterial pressure [MAP]: cervical, 76.6+/-2 mmHg; thoracic, 93.5+/-3 mmHg; P<.001). Following exercise, heart rate responses were greater in thoracic than cervical SCI; MAP increased in thoracic SCI (8.4+/-5 mmHg) and markedly decreased in cervical SCI (-9.3+/-2 mmHg) (P<.001). No subject had significant electrocardiographic abnormalities at rest or during exercise. There were correlations between SSR and heart rate and blood pressure responses to exercise; the correlation between the SSR and blood pressure response was due to an interaction between the heart rate and blood pressure responses. CONCLUSIONS: Abnormal cardiovascular responses to exercise and transient postexercise hypotension were common in cervical, but not thoracic SCI. This may be partly related to loss of descending sympathetic nervous control of the heart and vasculature following high SCI.     

Increases in bone mineral density after functional electrical stimulation cycling exercises in spinal cord injured patients

Purpose.?To assess the change in bone mineral density (BMD) after spinal cord injury (SCI) and to evaluate whether BMD loss can be reversed with the intervention of functional electric stimulation cycling exercises (FESCE).

Methods.?Fifteen males with SCI were included. Fifteen able-bodied males were also tested to compare BMD. In the SCI group, the FESCE was performed for six months, and then was discontinued in the subsequent six months. BMD was performed before the FESCE, immediately after six months of the FESCE, and at the end of the subsequent six months.

Results.?Before the FESCE, the BMD of the SCI subjects in every site, except the lumbar spine, was lower than that of the able-bodied subjects. After six months of FESCE, BMD of the distal femur (DF) and proximal tibia (PT) increased significantly, and BMD of the calcaneus (heel) showed a trend of increase. However, the BMD in the DF, PT, and heel decreased significantly after the subsequent six months without FESCE. The BMD of the femoral neck (FN) decreased progressively throughout the programme.

Conclusions.?Our study showed site-specific BMD changes after FESCE. The BMD loss in the DF and PT was partially reversed after six months of FESCE, but the effect faded once the exercise was discontinued.     

Increases in bone mineral density after functional electrical stimulation cycling exercises in spinal cord injured patients

Purpose. To assess the change in bone mineral density (BMD) after spinal cord injury (SCI) and to evaluate whether BMD loss can be reversed with the intervention of functional electric stimulation cycling exercises (FESCE).

Methods. Fifteen males with SCI were included. Fifteen able-bodied males were also tested to compare BMD. In the SCI group, the FESCE was performed for six months, and then was discontinued in the subsequent six months. BMD was performed before the FESCE, immediately after six months of the FESCE, and at the end of the subsequent six months.

Results. Before the FESCE, the BMD of the SCI subjects in every site, except the lumbar spine, was lower than that of the able-bodied subjects. After six months of FESCE, BMD of the distal femur (DF) and proximal tibia (PT) increased significantly, and BMD of the calcaneus (heel) showed a trend of increase. However, the BMD in the DF, PT, and heel decreased significantly after the subsequent six months without FESCE. The BMD of the femoral neck (FN) decreased progressively throughout the programme.

Conclusions. Our study showed site-specific BMD changes after FESCE. The BMD loss in the DF and PT was partially reversed after six months of FESCE, but the effect faded once the exercise was discontinued.     

Increasing muscle mass in spinal cord injured persons with a functional electrical stimulation exercise program

OBJECTIVE: To determine the magnitude of changes in muscle mass and lower extremity body composition that could be induced with a regular regimen of functional electrical stimulation (FES)-induced lower-extremity cycling, as well as the distribution of changes in muscle mass among the thigh muscles in persons with spinal cord injury (SCI). STUDY DESIGN: Thirteen men with neurologically complete motor sensory SCI underwent a 3-phase, FES-induced, ergometry exercise program: phase 1, quadriceps strengthening: phase 2, progressive sequential stimulation to achieve a rhythmic pedaling motion (surface electrodes placed over the quadriceps, hamstrings, and gluteal muscles); phase 3, FES-induced cycling for 30 minutes. Participants moved from one phase to the next when they met the objectives for the current phase. MEASURES: Computed tomography of legs to assess muscle cross-sectional area and proportion of muscle and adipose tissue. Scans were done at baseline (before subjects started the program), at first follow-up, typically after 65.4+/-5.6 (SD) weekly sessions, and at second follow-up, typically after 98.1+/-9.1 sessions. RESULTS: Increases in cross-sectional areas were found in the following muscles: rectus femoris (31%, p<.001). sartorius (22%, p<.025), adductor magnus-hamstrings (26%, p<.001), vastus lateralis (39%, p = .001), vastus medialis-intermedius (31%, p = .025). Cross-sectional area of adductor longus and gracilis muscles did not change. The ratio of muscle to adipose tissue increased significantly in thighs and calves. There was no correlation among the total number of exercise sessions and the magnitude of muscle hypertrophy. CONCLUSIONS: Muscle cross-sectional area and the muscle to adipose tissue ratio of the lower extremities increased during a regular regimen of 2.3 FES-induced lower extremity cycling sessions weekly. The distribution of changes was related to the proximity of muscles to the stimulating electrodes.     

Effects of four-month handbike training under free-living conditions on physical fitness and health in wheelchair users

Purpose: Recognizing the encouraging effect of challenging events, the HandbikeBattle (HBB) was created to promote exercise among wheelchair users. The purpose of this study was to reveal the effects on physical fitness and health outcomes of four-month handbike training under free-living conditions in preparation for the event.

Methods: In this prospective cohort study, 59 relatively inexperienced handyclists participated in the HBB of 2013 or 2014. Incremental exercise tests were conducted, respiratory function was tested and anthropometrics were measured before and after the preparation period. Main outcome measures were peak power output (POpeak), peak oxygen uptake (VO2peak) and waist circumference, of which the changes were tested using repeated measures ANOVA. To detect possible determinants of changes in physical fitness, a linear regression analysis was conducted with personal characteristics, executed training volume and upper-extremity complaints during the training period as independent variables.

Results: POpeak, VO2peak and waist circumference improved significantly with 17%, 7% and 4.1%, respectively. None of the included variables were significant determinants for the changes in POpeak found as a result of the training.

Conclusion: A challenging event such as the HBB provokes training regimes among participants of sufficient load to realize substantial improvements in physical fitness and health outcomes.

• Implications for Rehabilitation

• Due to the often impaired muscle function in the lower-limbs and an inactive lifestyle, wheelchair users generally show considerably lower levels of fitness compared to able-bodied individuals.

• This prospective cohort study showed that four months of handbike training under free-living conditions in preparation for this event resulted in substantial improvements in physical fitness and health outcomes in wheelchair users.

• The creation of a challenging event such as the HandbikeBattle as part of a follow-up rehabilitation practice can therefore be a useful tool to help wheelchair users initiate or keep training to improve their physical fitness and health.

     

Salbutamol effect in spinal cord injured individuals undergoing functional electrical stimulation training.

OBJECTIVE: Preliminary study to investigate possible changes in skeletal muscle morphology and function, as well as hormonal and metabolic effects, after treatment with a selective beta2-adrenergic receptor agonist. DESIGN: Double-blind, placebo-controlled trial. PARTICIPANTS: Three individuals with spinal cord injury (SCI). INTERVENTION: Two-week treatment with salbutamol (2mg) or placebo (ascorbic acid, 50mg) twice a day. Program of functional electronic stimulation (FES) cycling for 30 minutes twice a week. MAIN OUTCOME MEASURES: Body weight, three measures of leg circumference (gluteal furrow, one third of subischial height up from tibial-femoral joint space, and minimum circumference above the knee), muscle fiber area, and total work output per session. RESULTS: There were increases in body weight (2.30 +/- .70kg), leg circumferences (gluteal furrow 1.70 +/- .27cm, one third subischial height 1.53 +/- 1.65cm, minimum circumference above the knee .43 +/- .04cm), and muscle (vastus lateralis) cross-sectional area (1,374 +/- 493 to 2,446 +/- 1,177microm2) after salbutamol treatment, whereas quadriceps muscle contractile function was not modified. Total work output during FES cycling sessions was increased more during salbutamol treatment (64%) compared with training alone (27%). Salbutamol treatment was associated with a large decrease in skeletal muscle beta-adrenergic receptor density. CONCLUSION: Although some side effects were noted, these results suggest that a short treatment with the beta2-adrenergic receptor agonist salbutamol during a training program with FES cycling could be beneficial in patients with SCI.     

Cardiovascular and metabolic responses during functional electric stimulation cycling at different cadences

Fornusek C, Davis GM. Cardiovascular and metabolic responses during functional electric stimulation cycling at different cadences.

Objective

To determine the influence of pedaling cadence on cardiorespiratory responses and muscle oxygenation during functional electric stimulation (FES) leg cycling.

Design

Repeated measures.

Setting

Laboratory.

Participants

Nine subjects with T4 through T10 spinal cord injury (SCI) (American Spinal Injury Association grade A).

Interventions

FES cycling was performed at pedaling cadences of 15, 30, and 50 revolutions per minute (rpm).

Main Outcome Measures

At each cadence, heart rate, oxygen uptake, and cardiac output were recorded during 35 minutes of cycling. Near infrared spectroscopy was used to quantify quadriceps muscle oxygenation.

Results

All pedaling cadences induced similar elevations in cardiorespiratory metabolism, compared with resting values. Higher average power output was produced at 30rpm (8.2±0.7W, P<.05) and 50rpm (7.9±0.5W, P<.05) compared with 15rpm (6.3±0.6W). Gross mechanical efficiency was significantly higher (P<.05) at 30 and 50rpm than at 15rpm. Quadriceps muscle oxygenation did not differ with pedaling cadences.

Conclusions

Cardiorespiratory responses and muscle metabolism adjustments during FES leg cycling were independent of pedal cadence. FES cycling at a cadence of 50rpm may not confer any advantages over 30 or 15rpm for cardiovascular fitness promotion in persons with SCI.     

Functional electrical stimulation leg cycle ergometer exercise: training effects on cardiorespiratory responses of spinal cord injured subjects at rest and during submaximal exercise.

This study investigated the cardiorespiratory (CR) responses at rest and during submaximal (0-W) functional electrical stimulation (FES)-induced leg cycle ergometer (LCE) exercise prior to and following a progressive intensity FES-LCEa exercise training program in spinal cord injured (SCI) subjects. Seven quadriplegics and six paraplegics participated in FES-LCE training three sessions per week for approximately 12 weeks (36 sessions). Monitored CR responses, including oxygen uptake (VO2), pulmonary ventilation (VE), respiratory exchange ratio (RER), arteriovenous O2 difference (a-vO2), blood pressure (BP), heart rate (HR), stroke volume (SV), total peripheral resistance (TPR), and cardiac output (Q), were determined before and after training. Power output (PO) increased significantly (p < .05) over the duration of the training program, indicating increased in strength and endurance of the paralyzed muscles used. Respiratory responses were not significantly altered by training in both groups. FES-LCE training significantly increased resting HR and SBP in quadriplegics and lowered SBP, DBP, and MAP in paraplegics. In both groups, HR and BP during submaximal exercise significantly decreased and SV and Q significantly increased after completion of the training program. These results suggest that FES-LCE training improves peripheral muscular and central cardiovascular fitness in SCI subjects. Posttraining HR and BP may also be more stable in quadriplegics and alleviate hypotension. This therapeutic exercise may ultimately lead to improved rehabilitation outcome and reduced stress during activities of daily living, and possibly reduce the risks for secondary CR disabilities.     

Physiologic effects of electrical stimulation leg cycle exercise training in spinal cord injured persons.

The purpose of this study was to assess the physiologic training effects of functional electrical stimulation leg cycle ergometer (FES-LCE) exercise in persons with spinal cord injury (SCI) who were previously untrained in this activity. Ten persons with quadriplegia (C5 to C7) and eight with paraplegia (T4 to T11) performed FES-LCE training on an ERGYS I ergometer 10 to 30 minutes per day, 2 or 3 days per week for 12 to 16 weeks (36 total sessions). Training session power output (PO) ranged from 0.0W (no external resistance) to 30.6W. Each subject completed discontinuous graded FES-LCE and arm crank ergometer (ACE) tests before and after training for determinations of peak lower and upper extremity metabolic, pulmonary, and hemodynamic responses. Compared with pretraining, this SCI group exhibited significantly (p less than or equal to .05) higher posttraining peak PO (+45%), oxygen uptake ([O2], + 23%), pulmonary ventilation (+27%), heart rate (+11%), cardiac output ([Qt], + 13%) and significantly lower total peripheral resistance ([TPR], - 14%) during FES-LCE posttests. There were no significant changes in peak stroke volume (+6%), mean arterial pressure ([MAP], - 5%), or arteriovenous oxygen difference ([a-vO2diff], + 10%) during posttraining FES-LCE tests. In addition, no significant differences were noted for the peak level of any monitored variable during ACE posttests after FES-LCE training. The rise in total vascular conductance, implied by the significant decrease in posttraining TPR during FES-LCE tests, denotes that a peripheral circulatory adaptation developed in the persons with SCI during FES-LCE exercise training.(ABSTRACT TRUNCATED AT 250 WORDS)     

Knee kinetics during functional electrical stimulation induced cycling in subjects with spinal cord injury: a preliminary study

The purpose of this preliminary study was to describe pedal effectiveness parameters and knee-joint reaction forces generated by subjects with chronic spinal cord injury (SCI) during functional electrical stimulation (FES)-induced bicycling. Three male subjects (age 33-36 years old), who were post-traumatic SCI (ASIA-modified level A, level T4-C5) and enrolled in an FES rehabilitation program, signed informed consent forms and participated in this study. Kinematic data and pedal forces during bicycling were collected and effective force, knee-joint reaction forces, knee generalized muscle moments, and knee-joint power and work were calculated. There were three critical findings of this study: 1) pedaling effectiveness was severely compromised in this subject population as indicated by a lack of overall positive crank work; 2) knee-joint kinetics were similar in magnitude to data reported for unimpaired individuals pedaling at higher rates and workloads, suggesting excessive knee-joint loading for subjects with SCI; and 3) shear reaction forces and muscle moments were opposite in direction to data reported for unimpaired individuals, revealing an energetically unfavorable knee stabilizing mechanism. The critical findings of this study suggest that knee-joint kinetics may be large enough to produce a fracture in the compromised lower limbs of individuals with SCI.     

Functional electrical stimulation elliptical stepping versus cycling in spinal cord-injured individuals

Background

The cardiorespiratory responses and mechanical efficiencies of two modalities of functional electrical stimulation augmented leg exercises – isokinetic cycling and isokinetic elliptical stepping – were compared amongst individuals with spinal cord injury.

Methods

Five subjects performed seated isokinetic evoked cycling and elliptical stepping leg exercise at 10, 20 and 30 rev·min^− 1 pedal cadences. 3-D motion analysis and force transducers attached onto the foot pedals quantified the external forces and power outputs developed by each lower extremity. Hip, knee and ankle joints power were derived via inverse dynamics analysis. The subjects' cardiorespiratory responses during exercise were measured by respiratory gas analysis.

Findings

Ensemble-averaged oxygen uptakes across pedal cadences were higher during stepping (448 (75) ml·min^− 1) compared to cycling (422 (54) ml·min^− 1). External power outputs and metabolic efficiencies during stepping (9.9 (8.3) W, 2.9 (3.2) %) were double those observed during cycling (5.3 (6.3) W, 1.6 (1.9) %). Cumulative internal and external leg joint powers during stepping were twice higher than cycling, but the stepping mechanical efficiencies derived from inverse dynamics analysis were comparable to cycling (76.3 (21.2) % and 63.6 (12.3) % respectively). Heart rate responses were similar between cycling and stepping, while carbon dioxide production and expired ventilation were slightly higher during elliptical stepping.

Interpretation

Both exercise modalities could deliver appropriate training stimuli for improving the aerobic fitness and leg pedalling strength of spinal cord-injured individuals. However electrical stimulation-enhanced elliptical stepping might provide greater exercise dose-potency for leg muscle strengthening than electrically-enhanced cycling due to the higher power outputs observed.     

Autonomic cardiovascular control and sports classification in Paralympic athletes with spinal cord injury

Purpose To investigate the relationship between the classification systems used in wheelchair sports and cardiovascular function in Paralympic athletes with spinal cord injury (SCI). Methods 26 wheelchair rugby (C3–C8) and 14 wheelchair basketball (T3‐L1) were assessed for their International Wheelchair Rugby and Basketball Federation sports classification. Next, athletes were assessed for resting and reflex cardiovascular and autonomic function via the change (delta) in systolic blood pressure (SBP) and heart rate (HR) in response to sit-up, and sympathetic skin responses (SSRs), respectively. Results There were no differences in supine, seated, or delta SBP and HR between different sport classes in rugby or basketball (all p?>?0.23). Athletes with autonomically complete injuries (SSR score 0‐1) exhibited a lower supine SBP, seated SBP and delta SBP compared to those with autonomically incomplete injuries (SSR score?>1; all p?2?=^?1.63, p?=?0.20). Conclusion We provide definitive evidence that sports specific classification is not related to the degree of remaining autonomic cardiovascular control in Paralympic athletes with SCI. We suggest that testing for remaining autonomic function, which is closely related to the degree of cardiovascular control, should be incorporated into sporting classification.

• Implications for Rehabilitation

• Spinal cord injury is a debilitating condition that affects the function of almost every physiological system.

• It is becoming increasingly apparent that spinal cord injury induced changes in autonomic and cardiovascular function are important determinants of sports performance in athletes with spinal cord injury.

• This study shows that the current sports classification systems used in wheelchair rugby and basketball do not accurately reflect autonomic and cardiovascular function and thus are placing some athletes at a distinct disadvantage/advantage within their respective sport.

     

Mechanomyography responses characterize altered muscle function during electrical stimulation-evoked cycling in individuals with spinal cord injury

BackgroundInvestigation of muscle fatigue during functional electrical stimulation (FES)-evoked exercise in individuals with spinal cord injury using dynamometry has limited capability to characterize the fatigue state of individual muscles. Mechanomyography has the potential to represent the state of muscle function at the muscle level. This study sought to investigate surface mechanomyographic responses evoked from quadriceps muscles during FES-cycling, and to quantify its changes between pre- and post-fatiguing conditions in individuals with spinal cord injury.MethodsSix individuals with chronic motor-complete spinal cord injury performed 30-min of sustained FES-leg cycling exercise on two days to induce muscle fatigue. Each participant performed maximum FES-evoked isometric knee extensions before and after the 30-min cycling to determine pre- and post- extension peak torque concomitant with mechanomyography changes.FindingsSimilar to extension peak torque, normalized root mean squared (RMS) and mean power frequency (MPF) of the mechanomyography signal significantly differed in muscle activities between pre- and post-FES-cycling for each quadriceps muscle (extension peak torque up to 69%; RMS up to 80%, and MPF up to 19%). Mechanomyographic-RMS showed significant reduction during cycling with acceptable between-days consistency (intra-class correlation coefficients, ICC = 0.51–0.91). The normalized MPF showed a weak association with FES-cycling duration (ICC = 0.08–0.23). During FES-cycling, the mechanomyographic-RMS revealed greater fatigue rate for rectus femoris and greater fatigue resistance for vastus medialis in spinal cord injured individuals.InterpretationMechanomyographic-RMS may be a useful tool for examining real time muscle function of specific muscles during FES-evoked cycling in individuals with spinal cord injury.     

Arm crank ergometry and shoulder pain in persons with spinal cord injury

Dyson-Hudson TA, Sisto SA, Bond Q, Emmons R, Kirshblum SC. Arm crank ergometry and shoulder pain in persons with spinal cord injury.

Objective

To determine whether a primary fitness program utilizing arm crank ergometry would cause increased shoulder pain in persons with spinal cord injury (SCI).

Design

Cohort study.

Setting

Clinical research center.

Participants

People (N=23) with chronic SCI (>1y) who were participating in a weight loss study to compare the effectiveness of diet only (1000kcal/d for 12wk) versus diet with arm crank ergometry (1000kcal/d and arm crank ergometry 3 times a week for 12wk).

Intervention

Arm crank ergometry.

Main Outcome Measure

Changes in shoulder pain intensity using the Wheelchair User’s Shoulder Pain Index (WUSPI).

Results

After adjusting for baseline scores, there was no significant difference between the 2 groups on postintervention WUSPI scores (F_1,20=.85, P=.37, partial η²=.04). The strength of the relationship between group assignment (diet only vs diet and arm crank ergometry) and final WUSPI score was weak, as assessed by a partial η², with group assignment accounting for 4% of the variance on the WUSPI. The adjusted means were lower in the diet and arm crank ergometry group (mean, 7.84) than in the diet only group (mean, 12.22); however, these differences did not appear to be clinically significant.

Conclusions

A primary fitness program using arm crank ergometry does not increase shoulder pain in people with SCI who use wheelchairs. Further investigation with a larger group and what constitutes clinically significant changes on the WUSPI is warranted to confirm our results.     

Muscle changes following cycling and/or electrical stimulation in pediatric spinal cord injury

Johnston TE, Modlesky CM, Betz RR, Lauer RT. Muscle changes following cycling and/or electrical stimulation in pediatric spinal cord injury.

Objective

To determine the effect of cycling, electrical stimulation, or both, on thigh muscle volume and stimulated muscle strength in children with spinal cord injury (SCI).

Design

Randomized controlled trial.

Setting

Children's hospital specializing in pediatric SCI.

Participants

Children (N=30; ages, 5–13y) with chronic SCI.

Interventions

Children were randomly assigned to 1 of 3 interventions: functional electrical stimulation cycling (FESC), passive cycling (PC), and noncycling, electrically stimulated exercise (ES). Each group exercised for 1 hour, 3 times per week for 6 months at home.

Main Outcome Measures

Preintervention and postintervention, children underwent magnetic resonance imaging to assess muscle volume, and electrically stimulated isometric muscle strength testing with the use of a computerized dynamometer. Data were analyzed via analyses of covariance (ANCOVA) with baseline measures as covariates. Within-group changes were assessed via paired t tests.

Results

All 30 children completed the training. Muscle volume data were complete for 24 children (8 FESC, 8 PC, 8 ES) and stimulated strength data for 27 children (9 per group). Per ANCOVA, there were differences between groups (P<.05) for quadriceps muscle volume and stimulated strength, with the ES group having greater changes in volume and the FESC group having greater changes in strength. Within-group analyses showed increased quadriceps volume and strength for the FESC group and increased quadriceps volume for the ES group.

Conclusions

Children receiving either electrically stimulated exercise experienced changes in muscle size, stimulated strength, or both. These changes may decrease their risk of cardiovascular disease, insulin resistance, glucose intolerance, and type 2 diabetes.

Clinical Trials Registration Number

NCT00245726.     

Cardiorespiratory demand and rate of perceived exertion during overground walking with a robotic exoskeleton in long-term manual wheelchair users with chronic spinal cord injury: A cross-sectional study

Background

Many wheelchair users adopt a sedentary lifestyle, which results in progressive physical deconditioning with increased risk of musculoskeletal, cardiovascular and endocrine/metabolic morbidity and mortality. Engaging in a walking program with an overground robotic exoskeleton may be an effective strategy for mitigating these potential negative health consequences and optimizing fitness in this population. However, additional research is warranted to inform the development of adapted physical activity programs incorporating this technology.

Effects of hand cycle training on wheelchair capacity during clinical rehabilitation in persons with a spinal cord injury

Purpose.?To evaluate the effects of a structured hand cycle training programme on physical capacity in subjects with spinal cord injury (SCI) during clinical rehabilitation.

Method.?Twenty subjects with SCI who followed hand cycle training were compared with matched control subjects from a Dutch longitudinal cohort study, who received usual care.

Primary outcomes of physical capacity were peak power output (PO_peak), peak oxygen uptake (VO_2peak) and oxygen pulse during a hand rim wheelchair test. Secondary outcome measures were isometric peak muscle strength of the upper extremities and pulmonary function. Hand cycle capacity (PO_peak and VO_2peak) was evaluated in the training group only.

Results.?Strong tendencies for improvement were found in wheelchair capacity, reflected by PO_peak and oxygen pulse after additional hand cycle training. Significant effects on shoulder exo- and endo-rotation and unilateral elbow flexion strength were found but no improvements on pulmonary function.

Conclusions.?Additional hand cycle training during clinical rehabilitation seems to show similar or slightly favourable results on wheelchair capacity and muscle strength compared with regular care. The heterogeneous subject group and large variation in training period may explain the limited effects of additional hand cycle training on wheelchair capacity.     

Reliability and validity of the six-minute arm test for the evaluation of cardiovascular fitness in people with spinal cord injury

OBJECTIVES: To design a submaximal arm ergometry test (six-minute arm test [6-MAT]), for persons with spinal cord injury (SCI) and to determine the test-retest reliability and concurrent validity of this test. DESIGN: Prospective, exploratory, methodologic study. To determine test-retest reliability, subjects completed the 6-MAT on 2 days, separated by 1 week. Validity was determined by comparing 6-MAT results with peak oxygen consumption (VO2peak). SETTING: Tertiary rehabilitation center. PARTICIPANTS: Thirty subjects with SCI (mean age, 36.3y; 83% male). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Subjects were evaluated on the 6-MAT and a VO2peak test. RESULTS: All subjects were able to complete the 6-MAT. Test-retest reliability of steady-state oxygen consumption (VO2) and heart rate during the 6-MAT were excellent (intraclass correlation coefficient [ICC], .81; 95% confidence interval [CI], .58-.92; ICC=.90; 95% CI, .75-.96, respectively). The correlation between VO2peak and 6-MAT VO2 was excellent (r=.92) and the correlations between VO2peak and 6-MAT heart rate (r=.63) and VO2peak and 6-MAT power output (r=.73) were good. CONCLUSIONS: This study showed that the 6-MAT has acceptable values for test-retest reliability and validity. The 6-MAT should be further tested for responsiveness to enhance its use as a clinical tool.