Passive Leg Cycling Research Articles

The interaction of breath holding and muscle mechanoreflex on cardiovascular responses in breath-hold divers and non-breath-hold divers

Cardiovascular responses to diving are characterized by two opposing responses: tachycardia resulting from exercise and bradycardia resulting from the apnea. The convergence of bradycardia and tachycardia may determine the cardiovascular responses to diving. The purpose of this study was to investigate the interaction of breath holding and muscle mechanoreflex on cardiovascular responses in breath-hold divers (BHDs) and non-BHDs. We compared the cardiovascular responses to combined apnea and the mechanoreflex in BHDs and non-BHDs. All participants undertook three trials—apnea, passive leg cycling (PLC), and combined trials—for 30 s after rest. Cardiovascular variables were measured continuously. Nine BHD (male:female, 4:5; [means ± SD] age, 35 ± 6 years; height, 168.6 ± 4.6 cm; body mass, 58.4 ± 5.9 kg) and eight non-BHD (male:female, 4:4; [means ± SD] age, 35 ± 7 years; height, 163.9 ± 9.1 cm; body mass, 55.6 ± 7.2 kg) participants were included. Compared to the resting baseline, heart rate (HR) and cardiac output (CO) significantly decreased during the combined trial in the BHD group, while they significantly increased during the combined trials in the non-BHD group (P < 0.05). Changes in the HR and CO were significantly lower in the BHD group than in the non-BHD group in the combined trial (P < 0.05). These results suggest that bradycardia with apnea in BHDs is prioritized over tachycardia with the mechanoreflex, whereas that in non-BHDs is not. This finding implies that diving training changes the interaction between apnea and the mechanoreflex in cardiovascular control.

Clinical effects of passive leg cycling after chronic thoracic spinal cord injury

Introducción: el pedaleo pasivo (PP) es considerado una herramienta en la rehabilitación de personas con lesión medular (LM). Objetivo: revisar la evidencia científica sobre los efectos clínicos producidos por intervenciones que emplean PP en personas con lesión medular torácica crónica. Metodología: revisión narrativa. Se realizó una búsqueda en las bases de información científica MEDLINE, CINAHL, LILACS, PEDro y Clinicalkey de artículos en inglés y español, con términos como “spinal cord injury”, “thoracic injuries”, “passive pedaling”, “cycling passive” y “protocol”, entre otros. Resultados: se obtuvieron 14 artículos que describen efectos limitados a nivel de los sistemas cardiovascular, neuromuscular y musculoesquelético; se encontró heterogeneidad clínica en los sujetos del estudio, así como diferencias en los parámetros de realización del pedaleo. Conclusiones: los estudios del PP en personas con LM torácica crónica evalúan en su mayoría el efecto de una única sesión. Los cambios cardiovasculares son estudiados con mayor frecuencia, aunque se requieren más investigaciones.

Passive leg cycling increases activity of the cardiorespiratory system in people with tetraplegia.

Individuals with cervical spinal cord injury (SCI) are at an increased risk for cardiovascular disease. Exercise is well-established for preventing cardiovascular disease; however, there are limited straightforward and safe exercise approaches for increasing the activity of the cardiorespiratory system after cervical SCI. The objective of this study was to investigate the cardiorespiratory response to passive leg cycling in people with cervical SCI. Beat-by-beat blood pressure, heart rate, and cerebral blood flow were measured before and throughout 10minutes of cycling in 11 people with SCI. Femoral artery flow-mediated dilation was also assessed before and immediately after passive cycling. Safety was monitored throughout all study visits. Passive cycling elevated systolic blood pressure (5± 2mm Hg), mean arterial pressure (5± 3mm Hg), stroke volume (2.4± 0.8mL), heart rate (2± 1beats/min) and cardiac output (0.3± 0.07L/min; all p< 0.05). Minute ventilation (0.67± 0.23L/min), tidal volume (70± 30mL) and end-tidal PO2 (2.6± 1.23mm Hg) also increased (all p< 0.05). Endothelial function was improved immediately after exercise (1.62± 0.13%, p< 0.01). Passive cycling resulted in an incidence of autonomic dysreflexia. Therefore, passive leg cycling increased the activity of the cardiorespiratory system and improved endothelial function, indicating it may be a beneficial exercise intervention for the cardiovascular and respiratory systems in people with cervical SCI. Novelty: Passive leg cycling increases the activity of the cardiorespiratory system and improves markers of cardiovascular health in cervical SCI. Passive leg cycling exercise is an effective, low-cost, practical, alternative exercise modality for people with cervical SCI.

Effect of Functional Electrical Stimulation Cycling Exercise on Lower Limb Strength Asymmetry in Persons With Multiple Sclerosis.

Lower limb strength asymmetry (ie, significant difference between contralateral limbs) has been associated with mobility impairment in persons with multiple sclerosis (MS). However, whether an adaptive exercise modality can be used to modify lower limb strength and potentially improve mobility is unclear. The effect of functional electrical stimulation (FES) cycling on lower limb strength asymmetry in persons with MS with mobility impairment was assessed, and the association between change in lower limb strength asymmetries and changes in functional and self-reported mobility outcomes was explored. Eight adults with MS (Expanded Disability Status Scale scores, 5.5-6.5) were included. Outcomes included knee extensor and knee flexor strength asymmetry, Timed 25-Foot Walk (T25FW) test, 2-Minute Walk Test (2MWT), Timed Up and Go (TUG) test, and 12-item Multiple Sclerosis Walking Scale (MSWS-12). Participants received 24 weeks (3 times per week) of FES cycling or passive leg cycling. The FES condition demonstrated a small decrease in knee extensor (d = -0.33) and knee flexor (d = -0.23) strength asymmetry compared with passive leg cycling. With both groups combined, weak-to-strong associations were observed between change in knee extensor asymmetry and change in T25FW test time (rs = -0.43), 2MWT time (rs = -0.24), TUG test time (rs = 0.55), and MSWS-12 score (rs = 0.43). Moderate correlations were observed between change in knee flexor asymmetry and change in T25FW test time (rs = -0.31), TUG test time (rs = 0.33), and MSWS-12 score (rs = 0.35). FES cycling may be an efficacious exercise modality for reducing lower limb strength asymmetry and improving mobility in persons with MS.

Passive bilateral leg cycling with concomitant regional circulatory occlusion for testing mechanoreflex\u2013metaboreflex interactions in humans

PurposeThe exercise pressor reflex (EPR) plays a fundamental role in physiological reactions to exercise in humans and in the pathophysiology of cardiovascular disorders. There is no “gold standard” method for EPR assessment; therefore, we propose a new protocol for testing interactions between the muscle mechanoreflex and metaboreflex (major components of EPR).MethodsThirty-four healthy subjects (mean age [± standard deviation] 24 ± 4 years, 22 men) were enrolled in the study. During the study, the hemodynamic and ventilatory parameters of these subjects were continuously monitored using our proposed assessment method. This assessment method consists of an initial 5-min rest period (baseline) followed by 5 min of passive cycling (PC) on an automated cycle ergometer (mechanoreceptor stimulation), after which tourniquet cuffs located bilaterally on the upper thighs are inflated for 3 min to evoke venous and arterial regional circulatory occlusion (CO) during PC (metaboreceptor stimulation). Deflation of the tourniquet cuffs is followed by a second 5 min of PC and finally by a 5-min recovery time. The control test comprises a 5-min rest period, followed by 3 min of CO only and a final 5-min recovery.ResultsMean arterial pressure (MAP) and minute ventilation (MV) increased significantly during PC (MAP: from 90 ± 9.3 to 95 ± 9.7 mmHg; MV: from 11.5 ± 2.5 to 13.5 ± 2.9 L/min; both p < 0.05) and again when CO was applied (MAP: from 95 ± 9.7 to 101 ± 11.0 mmHg; MV: from 13.5 ± 2.9 to 14.8 ± 3.8 L/min; both p < 0.05). In the control test there was a slight increase in MAP during CO (from 92 ± 10.5 to 94 ± 10.0 mmHg; p < 0.05) and no changes in the ventilatory parameters.ConclusionBilateral leg passive cycling with concomitant circulatory occlusion is a new, simple and effective method for testing interactions between the mechanoreflex and metaboreflex in humans.

Mood Responses to Passive and Active Motion Leg Cycling Exercise in Healthy Sedentary Young Adults.

Previous studies suggest that passive motion exercise (PME) may be useful for overcoming exercise limitations associated with a sedentary lifestyle, orthopedic disorders, and various other debilitating conditions. Negative mood response is one of the factors that limit a person's ability to exercise. Therefore, this study tests the hypothesis that the mood response associated with PME is not different than the mood response associated with active motion exercise (AME). Eight women and seven men participated in the study and were administrated the Profile of Mood States (POMS) during modes of PME and AME in a randomized order. Outcome of the POMS consisted of the total mood disturbance score [(feelings of tension + depression + fatigue + anger + confusion) − vigor]. ANOVA was used to determine significance of differences in total mood disturbance, oxygen uptake (V.O2), and middle cerebral blood flow velocity (MCAv) at baseline and immediately after 30-minute conditions of PME and AME. Postexercise total mood disturbance score was significantly decreased for both conditions (PME baseline 29.2 ± 5.2 vs. postexercise 16.4 ± 6.8, P < 0.05) and AME baseline 22.4 ± 4.4 vs. postexercise 13.1 ± 5.2, P < 0.05). These senses of changes in feelings were associated with significant physiological increases in V.O2 and MCAv during both PME and AME (P < 0.05). These results demonstrate that physiological and mood responses to passive and active motion cycling exercise are not different. Future studies should determine whether passive motion cycling exercise is a useful preventive medicine strategy for overcoming various disease-related exercise limitations and counteracting the adverse effects of sedentary lifestyles.

Functional Electrical Stimulation Cycling Exercise in People with Multiple Sclerosis: Secondary Effects on Cognition, Symptoms, and Quality of Life.

Functional electrical stimulation (FES) cycling is an advanced rehabilitation modality that involves systematic mild electrical stimulation of focal muscle groups to produce leg cycling movement against an adjustable work rate. The present study reports on the efficacy of an assessor-blinded, pilot randomized controlled trial of supervised FES cycling exercise in people with multiple sclerosis (MS) on secondary trial outcomes, including cognition, fatigue, pain, and health-related quality of life. Eleven adult participants with MS were randomized to receive FES cycling exercise (n = 6) or passive leg cycling (n = 5) for 24 weeks. Cognitive processing speed was assessed using the Symbol Digit Modalities Test. Symptoms of fatigue and pain were assessed using the Fatigue Severity Scale, the Modified Fatigue Impact Scale, and the short-form McGill Pain Questionnaire. Physical and psychological health-related quality of life were assessed using the 29-item Multiple Sclerosis Impact Scale. Eight participants (four, FES; four, passive leg cycling) completed the intervention and outcome assessments. The FES cycling exercise resulted in moderate-to-large improvements in cognitive processing speed (d = 0.53), fatigue severity (d = -0.92), fatigue impact (d = -0.45 to -0.68), and pain symptoms (d = -0.67). The effect of the intervention on cognitive performance resulted in a clinically meaningful change, based on established criteria. We provide preliminary evidence for the benefits of FES cycling exercise on cognition and symptoms of fatigue and pain. Appropriately powered randomized controlled trials of FES cycling exercise are necessary to determine its efficacy for people with MS.

Impact of Passive Leg Cycling in Persons With Spinal Cord Injury: A Systematic Review.

Background: Passive leg cycling is an important clinical tool available for rehabilitation after spinal cord injury (SCI). Passive cycling can be used to derive exercise-related benefits in patients with poor motor control. There have been a number of studies examining the effects of passive cycling on a variety of outcomes. There is need for a systematic assessment of the cycling parameters and the associated clinical changes in cardiovascular, neuromuscular, and musculoskeletal outcomes after passive cycling. Objectives: To assess the effectiveness of passive leg cycling interventions on cardiovascular, neuromuscular, and musculoskeletal outcomes post SCI, and to describe intensity, duration, and type of passive leg cycling post SCI. Methods: PRISMA guided systematic review of literature based on searches in the following databases: PubMed/MEDLINE, PEDro, EMBASE, Cochrane Library, and Google Scholar. Peer-reviewed publications that were written in English were included if they described the effects of a single session or multiple sessions of passive leg cycling in persons post SCI. Results: Eleven papers were included: two were randomized controlled trials (RCTs), one was a crossover trial, and the rest were pre-post single-group designs. Three studies (including two RCTs) reported statistically significant benefits of multiple sessions of passive cycling on leg blood flow velocity, spasticity, reflex excitability and joint range of motion, and markers of muscle hypertrophy. About half of the single session studies showed statistically significant improvement in acute responses. Conclusion: Multiple sessions of passive leg cycling showed benefits in three categories - cardiovascular, musculoskeletal, and neurological - with medium to large effect sizes.

Pilot randomized controlled trial of functional electrical stimulation cycling exercise in people with multiple sclerosis with mobility disability

BackgroundExercise training has been shown to be beneficial for persons with multiple sclerosis (MS). Adapted exercise modalities are needed to accommodate those with severe mobility impairment (Expanded Disability Status Scale [EDSS] scores 5.5–6.5). Functional electrical stimulation (FES) cycling is one such exercise modality; however, few studies have examined the feasibility and potential benefits of FES cycling for people with MS with severe mobility impairment. ObjectiveDetermine the feasibility of FES cycling exercise for people with MS with severe mobility impairment, and the efficacy of FES cycling exercise for improving mobility and physiological fitness. Methods11 participants with MS with mobility impairment (EDSS = 5.5–6.5) were randomly allocated to FES cycling exercise (n = 6) or passive leg cycling (PLC; n = 5). Feasibility metrics included participant recruitment, retention, adherence, safety, and satisfaction. The primary mobility outcome was walking speed assessed by the Timed 25-Foot Walk (T25FW) test. The primary physiological fitness outcome was peak oxygen consumption (VO2peak), assessed using a cardiopulmonary exercise test. ResultsEight participants completed the intervention (FES n = 4; PLC n = 4) with an adherence rate ≥80%. Three participants (FES n = 2, PLC n = 1) withdrew due to a lack of time. Six Grade 1 (i.e., mild) adverse events were experienced by participants in the FES group. Participants in the FES cycling condition demonstrated small-to-moderate improvements on T25FW performance (Cohen's d = 0.40; 22.9%) and VO2peak (Cohen's d = 0.34; 13.8%) compared to participants in the PLC condition. ConclusionsWe provide evidence that FES cycling exercise is feasible for individuals with MS with severe mobility impairment, and might have positive effects on mobility and physiological decondition. These results will inform the design of future efficacy trials of FES cycling exercise for persons with MS with mobility disability.

Arm Cycling Combined with Passive Leg Cycling Enhances VO2peak in Persons with Spinal Cord Injury Above the Sixth Thoracic Vertebra.

Objective: To test whether passive leg cycling (PLC) during arm cycling ergometry (ACE) affects peak oxygen uptake (VO2peak) differently in individuals with spinal cord injury (SCI) at/above the 6th thoracic vertebra (T6) and below T6. Methods: We conducted a cross-sectional study, analyzed by univariate and multivariate regression models. Between- and within-group differences were examined during (a) ACE only, (b) ACE combined with PLC (ACE-PLC), and (c) ACE combined with functional electrical stimulation cycling (FES hybrid). Fifteen SCI subjects were recruited and grouped according to injury level: at/above T6 (SCI-high, n = 8) or below T6 (SCI-low, n = 7). VO2peak tests during ACE only, ACE-PLC, and FES hybrid were performed in random order on separate days. Results: In the SCI-high group, mean (SD) VO2peak was 19% higher during ACE-PLC than during ACE only [21.0 (3.8) vs 17.7 (5.0) mL·kg-1·min-1; p = .002], while VO2peak during FES hybrid cycling was 16% higher than during ACE-PLC [24.4 (4.1) mL·kg-1·min-1; p = .001]. No significant differences among exercise modalities were found for the SCI-low group. Conclusion: Additional training modalities (eg, PLC) during ACE facilitate exercise in SCI-high individuals, but not to the level of the FES hybrid method. Conversely, additional training modalities may not increase training load in SCI-low individuals.

Impact of Passive Leg Cycling in Persons with Spinal Cord Injury

1) to describe intensity, duration and type of passive leg cycling interventions post-spinal cord injury (SCI), 2) to identify outcome measures used to evaluate the impact of passive leg cycling post-SCI, and 3) to assess the effectiveness of passive leg cycling interventions with or without functional electrical stimulation (FES) post-SCI.

Passive Leg Cycling Comprehensively Restores Cerebrovascular Health After Experimental High‐thoracic Spinal Cord Injury

Individuals living with chronic spinal cord injury exhibit a 3–4 fold increased risk of stroke. Reduced cerebral blood flow following is associated with cognitive decline, increased risk of stroke, and development of white matter irregularities. Previously, we have reported impairment in cerebrovascular health following experimental high‐thoracic spinal cord injury, including cerebrovascular reactivity declines, as well as inward remodelling and profibrosis of the middle cerebral artery. Passive hind‐limb exercise after spinal cord injury has been shown to restore systemic cardiovascular function, however it has never been explored for improving cerebrovascular health.ObjectiveTo preclinically investigate the effect of passive hind‐limb exercise in preventing cerebrovascular decline following high‐thoracic spinal cord injury.Design/MethodMale Wistar rats (n=45) were uninjured, T3‐level complete transected or T3‐transected with passive exercise. Six days after surgery, the hind‐limb passive cycling intervention was initiated and lasted for five weeks. Six weeks after surgery, Magnetic resonance imaging was performed to evaluate baseline cerebral blood flow. Middle cerebral arteries were then harvested for functional and structural assessments, including in vitro pressure myography and immunohistochemistry.ConclusionThere was a 44% reduction in global cerebral blood flow (p=0.001) after spinal cord injury, which was restored with passive exercise (Figure 1). Passive exercise also prevented the endothelial dysfunction seen after spinal cord injury (p=0.046). Profibrotic remodelling of middle cerebral arteries demonstrated by increased collagen (95%, p=0.004), was also reversed by passive exercise. As such, passive hind‐limb cycling is effective in restoring healthy brain blood flow, endothelial function, and preventing profibrosis in the cerebral vasculature. Clearly, passive exercise is a promising pre‐clinical therapy to restore cardiovascular health after spinal cord injury, and the present data extend these benefits even to the brain.Support or Funding InformationSupport: AAP: Killam Trust, Craig H. Neilsen Foundation Postdoctoral Fellowship 337427, Heart and Stroke Foundation of Canada Research Fellowship, Michael Smith Foundation for Health Research Postdoctoral Fellowship AVK: Canadian Institute of Health Research, Craig H. Neilsen Foundation.

Alternating Passive Leg Cycling and Functional Electrical Stimulation: A Novel Approach in Clinical Exercise Rehabilitation for Spinal Cord Injury

Passive leg cycling and functional electrical stimulation are interventions used to improve the cardiovascular function in persons with spinal cord injury. Although the volume of evidence in support of these techniques is relatively limited, current findings have demonstrated their capacity to improve arterial function in the patients living with spinal cord injury. We proposed that a novel strategy is to alternate the application of passive leg cycling and functional electrical stimulation, which may elicit a synergistic cardiorespiratory response to exercise, leading to marked enhancements in cardiovascular function. This approach has the potential to improve the quality and efficacy of clinical exercise rehabilitation for persons with spinal cord injury, improve their cardiovascular health, and reduce their risks associated with cardiovascular disease.

Very Early Passive Cycling Exercise in Mechanically Ventilated Critically Ill Patients: Physiological and Safety Aspects - A Case Series

IntroductionEarly mobilization can be performed in critically ill patients and improves outcomes. A daily cycling exercise started from day 5 after ICU admission is feasible and can enhance functional capacity after hospital discharge. In the present study we verified the physiological changes and safety of an earlier cycling intervention (< 72 hrs of mechanical ventilation) in critical ill patients.MethodsNineteen hemodynamically stable and deeply sedated patients within the first 72 hrs of mechanical ventilation were enrolled in a single 20 minute passive leg cycling exercise using an electric cycle ergometer. A minute-by-minute evaluation of hemodynamic, respiratory and metabolic variables was undertaken before, during and after the exercise. Analyzed variables included the following: cardiac output, systemic vascular resistance, central venous blood oxygen saturation, respiratory rate and tidal volume, oxygen consumption, carbon dioxide production and blood lactate levels.ResultsWe enrolled 19 patients (42% male, age 55±17 years, SOFA = 6 ± 3, SAPS3 score = 58 ± 13, PaO2/FIO2 = 223±75). The median time of mechanical ventilation was 1 day (02), and 68% (n=13) of our patients required norepinephrine (maximum concentration = 0.47 µg.kg -1.min-1). There were no clinically relevant changes in any of the analyzed variables during the exercise, and two minor adverse events unrelated to hemodynamic instability were observed.ConclusionsIn our study, this very early passive cycling exercise in sedated, critically ill, mechanically ventilated patients was considered safe and was not associated with significant alterations in hemodynamic, respiratory or metabolic variables even in those requiring vasoactive agents.

Stimulation of Shank Muscles During Functional Electrical Stimulation Cycling Increases Ankle Excursion in Individuals With Spinal Cord Injury

Fornusek C, Davis GM, Baek I. Stimulation of shank muscles during functional electrical stimulation cycling increases ankle excursion in individuals with spinal cord injury. ObjectiveTo investigate the effect of shank muscle stimulation on ankle joint excursion during passive and functional electrical stimulation (FES) leg cycling. DesignWithin-subject comparisons. SettingLaboratory setting. ParticipantsWell-trained FES cyclists (N=7) with chronic spinal cord injuries. InterventionsTwo experimental sessions were performed on an isokinetic FES cycle ergometer with a pedal boot that allowed the ankle to plantarflex and dorsiflex during cycling. During the first session, the optimal stimulation timings to induce plantarflexion and dorsiflexion were investigated by systematically altering the stimulation angles of the shank muscles (tibialis anterior [TA] and triceps surae [TS]). During the second session, TA and TS stimulation was included with standard FES cycling (quadriceps, hamstrings, and gluteals) for 6 subjects. Main Outcome MeasuresAnkle, knee, and hip movements were analyzed using 2-dimensional video. ResultsThe ankle excursions during passive cycling were 19°±6°. TA and TS stimulation increased ankle joint excursion up to 33°±10° and 27°±7°, respectively. Compared with passive cycling, ankle joint excursion was not significantly increased during standard FES cycling (24°±7°). TA and TS stimulation significantly increased the ankle excursion when applied during standard FES cycling (41°±4°). ConclusionsFreeing the ankle joint to rotate during FES cycling was found to be safe. The combination of shank muscle stimulation and repetitive ankle joint movement may be beneficial for improving ankle flexibility and leg conditioning. Further research is required to test and design ankle supports that might maximize the benefits of shank muscle activation.

Acute Effects of Passive Leg Cycling on Upper Extremity Tremor and Bradykinesia in Parkinson's Disease

Background: Previous studies have shown that single bouts of high-rate active cycling (> 80 rpm) improve upper extremity motor function in individuals with Parkinson's disease (PD). It is unknown if passive leg cycling produces a similar effect on upper extremity function. This article examines whether passive leg cycling can promote immediate changes in upper tremor and bradykinesia in PD and if pedaling rates have variable effects. Methods: Twenty individuals with mild-to-moderate idiopathic PD completed 4 sessions, with each session taking place 1 week apart. In the second to fourth sessions, a motorized bicycle was set to passively rotate the subjects' legs at rates of 60, 70, or 80 rpm for 30 minutes. Quantitative upper extremity motor assessments were completed immediately before and after each session. Results: Passive leg cycling was shown to reduce tremor and bradykinesia in PD. However, the rate of passive cycling did not affect the degree of improvement in bradykinesia or tremor. Conclusion: These findings suggest that lower extremity passive cycling can promote changes in upper extremity motor function in individuals with PD.

Changes in Executive Function After Acute Bouts of Passive Cycling in Parkinson’s Disease

Individuals with Parkinson's disease (PD) often experience cognitive declines. Although pharmacologic therapies are helpful in treating motor deficits in PD, they do not appear to be effective for cognitive complications. Acute bouts of moderate aerobic exercise have been shown to improve cognitive function in healthy adults. However, individuals with PD often have difficulty with exercise. This study examined the effects of passive leg cycling on executive function in PD. Executive function was assessed with Trail-Making Test (TMT) A and B before and after passive leg cycling. Significant improvements on the TMT-B test occurred after passive leg cycling. Furthermore, the difference between times to complete the TMT-B and TMT-A significantly decreased from precycling to postcycling. Improved executive function after passive cycling may be a result of increases in cerebral blood flow. These findings suggest that passive exercise could be a concurrent therapy for cognitive decline in PD.

Acute Bouts of Passive Leg Cycling Can Improve Cognitive Function in Parkinson's Patients

Parkinson's disease (PD) often leads to a deficit in cognitive function. Pharmacological therapies are effective in treating motor symptoms in PD, but do not slow the progression of cognitive decline. A number of studies have reported that intensive exercise can improve cognitive function. However, individuals with PD often have difficulties participating in high-intensity exercise. PURPOSE: The purpose of this study is to determine if acute bouts of passive leg cycling can improve cognitive function in PD, and if different rates of pedaling have variable effects on cognitive function. METHODS: Nineteen, mild to moderate idiopathic PD patients (12 men, 7 women, age- 63.2 ± 8.6), reported to the exercise science laboratory on four separate occasions, separated by one week. On the first visit, PD patients completed a YMCA cycling test (Excalibur 1300 W cycle ergometer) to estimate maximal oxygen consumption and a computer based psychomotor tests consisting of Trail Making Test (TMT) A and B while 'on' anti-Parkinson's medication. For the next three visits PD patients participated in passive leg cycling (MOTOmed viva2) at 60, 70 and 80 revolutions per minute (rpm) while 'off' anti-Parkinson's medications. Cycling rates were randomly administered. The TMT A and B were administered prior to and immediately after each cycling session. RESULTS: Data were analyzed using a 3 (trial) by 2 (time) analysis of variance (ANOVA) with repeated measures on both variables. TMT A scores did not differ between trials (p=0.569) or across time (p=0.207). In addition, no trial by time interaction was observed for TMT A Scores (p=0.555). TMT B scores improved across time (70.3 ± 3.7 vs. 62.4 ± 2.6 sec, p=0.003) with no difference between trials (p=0.919) or trial by time interactions observed (p=0.841). The difference in scores between TMT B and A showed a main effect of time (pre: 37.6 ± 2.6, post: 31.0 ± 1.9 sec, p=0.006). CONCLUSION: These data suggest that passive leg cycling can improve executive function in PD patients, as measured by the TMT B. Lack of improvement in the TMT A suggests that TMT B improvement is due to changes in visual search and motor speed alone. However, there is no association between cognitive improvement and passive cycling rate. Future studies will compare these results with active-assisted cycling at variable rates.

A Randomized Controlled Trial on the Effects of Cycling With and Without Electrical Stimulation on Cardiorespiratory and Vascular Health in Children With Spinal Cord Injury

Johnston TE, Smith BT, Mulcahey MJ, Betz RR, Lauer RT. A randomized controlled trial on the effects of cycling with and without electrical stimulation on cardiorespiratory and vascular health in children with spinal cord injury. Objective To examine the cardiorespiratory/vascular effects of cycling with and without functional electrical stimulation (FES) in children with spinal cord injury (SCI). Design Randomized controlled trial. Setting Pediatric referral hospital. Participants Children with SCI (N=30), ages 5 to 13 years, with injury levels from C4 to T11, and American Spinal Injury Association grades A, B, or C. Interventions Children were randomly assigned to 1 of 3 groups: FES leg cycling exercise, passive leg cycling, or noncycling control group receiving electrical stimulation therapy. After receiving instruction on the use of the equipment, children exercised for 1 hour 3 times per week for 6 months at home with parental supervision. Main Outcome Measures Oxygen uptake (V̇ o 2) during an incremental arm ergometry test, resting heart rate, forced vital capacity, and a fasting lipid profile. Results There were no differences ( P>.05) between groups after 6 months of exercise when comparing pre- and postvalues. However, there were differences between groups for some variables when examining percent change. The FES cycling group showed an improvement ( P=.035) in V̇ o 2 (16.2%±25.0%) as compared with the passive cycling group (–28.7%±29.1%). For lipid levels, the electrical stimulation–only group showed declines ( P=.032) in cholesterol levels (–17.1%±8.5%) as compared with the FES cycling group (4.4%±20.4%). Conclusions Cycling with FES led to gains in V̇ o 2, whereas electrical stimulation alone led to improvements in cholesterol.

Peripheral Vascular Changes After Home-Based Passive Leg Cycle Exercise Training in People With Paraplegia: A Pilot Study

Ballaz L, Fusco N, Crétual A, Langella B, Brissot R. Peripheral vascular changes after home-based passive leg cycle exercise training in people with paraplegia: a pilot study. Objective To determine the hemodynamic adaptations after home-based passive leg cycle exercise training in person with paraplegia. Design A randomized controlled trial (small cohort). Setting University department of physical medicine and rehabilitation. Participants A volunteer sample of people with paraplegia (N=17). Intervention Subjects within the experimental group performed 36 passive cycling sessions at home. Main Outcome Measures Before and after training, we measured heart rate and maximal and minimal femoral artery blood flow velocity at rest and immediately after a 10-minute session of passive cycling by using a quantitative duplex Doppler ultrasound. For each condition, we calculated the mean blood flow velocity and velocity index (VI), used as an indicator of peripheral resistance. Results At rest, after training, mean blood flow velocity ( P=.08) and VI did not differ significantly in the experimental group compared with the pretraining values (nonparametric analysis). However, in this group, the postexercise mean blood flow velocity and VI are respectively increased and decreased after training ( P<.05) compared with the pretraining values. No changes were noted in the control group. Conclusions Six weeks of home-based passive cycling training have no significant effect on the rest hemodynamic values but increase the hemodynamic response to acute passive cycling exercise.