Energy Consumption and Cardiorespiratory Load During Walking With and Without Robot-Assistance

Terminated

Phase N/A Results N/A

Trial Description

The primary objective of the study is to investigate the energy consumption, cardiorespiratory load and perceived exertion, and how these parameters change, during walking with robot-assistance compared to walking on a treadmill and walking overground in stroke patients.
A secondary objective is to investigate whether these changes or differences in energy consumption, cardiorespiratory load and perceived exertion during walking with and without robot-assistance in stroke patients are related to changes or differences spatiotemporal gait characteristics.

Detailed Description

Background. Impaired cardiorespiratory fitness, which is a major risk factor in the development of cardiorespiratory diseases, is frequently reported in stroke patients. The mean energy cost of walking, i.e. the amount of oxygen consumption in milliliter per kilogram of body-weight per meter, in stroke patients is almost twice as high compared to healthy subjects (resp. 0.27 ml/kg/m vs. 0.15 ml/kg/m). In the rehabilitation of stroke patients, the primary aim is to improve kinematic and functional gait-related parameters. However, due to the previously mentioned cardiorespiratory risks, it is important to be aware of the energy consumption and cardiorespiratory load of stroke patients during gait rehabilitation. In the past, gait training was mainly fulfilled by treadmill training, overground training and/or more conventional therapies, but in recent years, the implementation of robot-assistance in gait rehabilitation is increasing. However, what the influence is of robot-assistance on the cardiorespiratory load and energy consumption, and therefore also what potentially negative and/or positive side effects are for the cardiorespiratory system, is less investigated and unclear.
Up to now, short walking durations of robot-assisted gait (up to 7 minutes) seem less energy consuming and cardiorespiratory stressful than walking without robot-assistance. However, what the influences are of longer walking durations is not clear. In addition, it is also unclear why possible differences between robot-assisted gait and walking without robot-assistance might exist. One possible explanation might be that differences in spatiotemporal gait parameters are responsible for differences in energy consumption and cardiorespiratory load.
Patient recruitment. Stroke patients in the Rehabilitation Centre St. Ursula (Herk-de-Stad, Belgium) will receive verbal and written information on the aims and interventions of the study. Eligible stroke patients, who agree to participate in the study, will be recruited. Signed informed consent will be obtained from all participants.
Sample size. Sample size calculation is based on previous investigations indicating large effect sizes between the effect of robot-assisted gait compared to walking without robot-assistance on energy consumption and cardiorespiratory load (based on a systematic review submitted for peer-review). To detect a large effect size (f = 0.40) of robot-assisted gait compared to overground and treadmill gait on energy consumption, cardiorespiratory load and perceived fatigue, in a repeated measures within subjects design (3 walking conditions and 4 measurements), with a significance level of 5% and a power level of 80%, a sample size of 21 subjects is needed (G*Power 3.1 for Mac). Sample size is inflated up to 24 subjects, so each walking order will be performed the same number of times.
Intervention. Patients will be tested in 3 single walking sessions each on a separate day: walking in the Lokomat with 60% guidance force, walking on a treadmill and walking overground. Within subjects, all walking conditions will be performed at the same comfortable walking speed (CWS), with the same amount of body-weight support (BWS) (if necessary) during a total duration of maximum 30 minutes. The CWS (with a maximum of 3.2 kmph corresponding to the maximum Lokomat speed) and the amount of BWS (if necessary) will be individually determined on a separate day before the start of the study. Walking tests will be terminated early when relative or absolute indications are presented as reported by the American Heart Association or when patients are unable to continue walking. Patients will be asked to not consume food, alcohol, caffeine or nicotine at least 3 hours prior to the intervention, and not to perform additional strenuous activities at least 12 hours prior to the interventions. Walking sessions will be controlled for time of day. Before the start of the study, demographic and clinical characteristics will be collected and the CWS and the amount of BWS (if necessary) will be determined in a 10 minute walking test. At the start of each walking condition, a chest-carrying gas analysis system with mouth mask (Metamax 3B, Cortex, Germany), a heart rate belt (Polar H7) and 2 wearable foot sensors (Physiolog, Gait Up, Switzerland) will be applied. Patients will be seated for 5 minutes during which resting values (energy consumption, cardiorespiratory parameters and perceived fatigue) will be registered. After a resting period of 5 minutes, patients will walk for 30 minutes during which energy consumption, cardiorespiratory parameters, perceived fatigue and spatiotemporal parameters will be monitored continuously. Perceived fatigue will be registered every minute. Average values at rest, the beginning, middle and end of the walking sessions will be calculated offline.
Randomization and Concealment. Walking sessions will be performed in a random order at 3 separate days. An independent investigator will assign the 24 patients (in 2 series of 12) at random to one of the 6 possible walking orders using a random sequence generator. Allocation will be concealed for the investigators using an excel file with blind and locked sections, to which only the independent investigator has access to. The random walking order of the patient will therefore only be available when the patient has been recruited and his name is entered in the excel sheet. This method will assure that the investigator does not know the walking order of the next participant.
Dropout. In case subjects drop out, the subject will be replaced by a new participant who will perform all three trials in the same randomized order as the subject that dropped out. So, in case of drop out, additional patients will be tested until the data of 24 patients that participated in all three conditions are collected.
Statistical analysis. Statistics will be performed using SPSS (IBM, Chicago, IL). Descriptive statistics will be calculated for baseline demographic and clinical patient characteristics. Repeated measures analyses of variance (ANOVA) with Bonferroni correction for multiple comparisons will be used to analyze differences in primary and secondary outcomes within and between walking conditions. Regression analysis will be performed to evaluate whether (changes in) spatiotemporal parameters are predictive for (changes in) energy consumption. The significance level will be set at 5%.

Trial Stopped: Difficulties patient recruitment

Conditions

Interventions

  • Lokomat Device
    Intervention Desc: A single walking trial in which the patient walks in the Lokomat with 60% guidance force for 30 minutes at comfortable walking speed (body-weight supported if necessary)
    ARM 1: Kind: Experimental
    Label: Lokomat - Treadmill - Overground
    Description: Walking order: lokomat walking, treadmill walking, overground walking
    ARM 2: Kind: Experimental
    Label: Lokomat - Overground - Treadmill
    Description: Walking order: lokomat walking, overground walking, treadmill walking
    ARM 3: Kind: Experimental
    Label: Treadmill - Lokomat - Overground
    Description: Walking order: treadmill walking, lokomat walking, overground walking
    ARM 4: Kind: Experimental
    Label: Treadmill - Overground - Lokomat
    Description: Walking order: treadmill walking, overground walking, lokomat walking
    ARM 5: Kind: Experimental
    Label: Overground - Lokomat - Treadmill
    Description: Walking order: overground walking, lokomat walking, treadmill walking
    ARM 6: Kind: Experimental
    Label: Overground - Treadmill - Lokomat
    Description: Walking order: overground walking, treadmill walking, lokomat walking
  • Treadmill Device
    Intervention Desc: A single walking trial in which the patient walks on a treadmill for 30 minutes at comfortable walking speed (body-weight supported if necessary)
    ARM 1: Kind: Experimental
    Label: Lokomat - Treadmill - Overground
    Description: Walking order: lokomat walking, treadmill walking, overground walking
    ARM 2: Kind: Experimental
    Label: Lokomat - Overground - Treadmill
    Description: Walking order: lokomat walking, overground walking, treadmill walking
    ARM 3: Kind: Experimental
    Label: Treadmill - Lokomat - Overground
    Description: Walking order: treadmill walking, lokomat walking, overground walking
    ARM 4: Kind: Experimental
    Label: Treadmill - Overground - Lokomat
    Description: Walking order: treadmill walking, overground walking, lokomat walking
    ARM 5: Kind: Experimental
    Label: Overground - Lokomat - Treadmill
    Description: Walking order: overground walking, lokomat walking, treadmill walking
    ARM 6: Kind: Experimental
    Label: Overground - Treadmill - Lokomat
    Description: Walking order: overground walking, treadmill walking, lokomat walking
  • Overground Other
    Intervention Desc: A single walking trial in which the patient walks overground for 30 minutes at comfortable walking speed (body-weight supported if necessary)
    ARM 1: Kind: Experimental
    Label: Lokomat - Treadmill - Overground
    Description: Walking order: lokomat walking, treadmill walking, overground walking
    ARM 2: Kind: Experimental
    Label: Lokomat - Overground - Treadmill
    Description: Walking order: lokomat walking, overground walking, treadmill walking
    ARM 3: Kind: Experimental
    Label: Treadmill - Lokomat - Overground
    Description: Walking order: treadmill walking, lokomat walking, overground walking
    ARM 4: Kind: Experimental
    Label: Treadmill - Overground - Lokomat
    Description: Walking order: treadmill walking, overground walking, lokomat walking
    ARM 5: Kind: Experimental
    Label: Overground - Lokomat - Treadmill
    Description: Walking order: overground walking, lokomat walking, treadmill walking
    ARM 6: Kind: Experimental
    Label: Overground - Treadmill - Lokomat
    Description: Walking order: overground walking, treadmill walking, lokomat walking

Trial Design

  • Allocation: Randomized
  • Masking: Open Label
  • Purpose: Basic Science
  • Intervention: Crossover Assignment

Outcomes

Type Measure Time Frame Safety Issue
Primary Gross oxygen consumption (VO2) at rest Minute 5 of 5-minute resting period No
Primary Gross oxygen consumption (VO2) at begin of walking Minute 6 of 30-minute walking period No
Primary Gross oxygen consumption (VO2) at mid of walking Minute 18 of 30-minute walking period No
Primary Gross oxygen consumption (VO2) at end of walking Minute 30 of 30-minute walking period No
Primary Net oxygen consumption (VO2) Change between average VO2 at minute 5 of rest and minute 6 of walking, at minute 5 of rest and minute 18 of walking, at minute 5 of rest and minute 30 of walking No
Primary Gross minute ventilation (VE) at rest Minute 5 of 5-minute resting period No
Primary Gross minute ventilation (VE) at begin of walking Minute 6 of 30-minute walking period No
Primary Gross minute ventilation (VE) at mid of walking Minute 18 of 30-minute walking period No
Primary Gross minute ventilation (VE) at end of walking Minute 30 of 30-minute walking period No
Primary Net minute ventilation (VE) Change between average VE at minute 5 of rest and minute 6 of walking, at minute 5 of rest and minute 18 of walking, at minute 5 of rest and minute 30 of walking No
Primary Gross respiration rate (RR) at rest Minute 5 of 5-minute resting period No
Primary Gross respiration rate (RR) at begin of walking Minute 6 of 30-minute walking period No
Primary Gross respiration rate (RR) at mid of walking Minute 18 of 30-minute walking period No
Primary Gross respiration rate (RR) at end of walking Minute 30 of 30-minute walking period No
Primary Net respiration rate (RR) Change between average respiration rate at minute 5 of rest and minute 6 of walking, at minute 5 of rest and minute 18 of walking, at minute 5 of rest and minute 30 of walking No
Primary Gross heart rate (HR) at rest Minute 5 of 5-minute resting period No
Primary Gross heart rate (HR) at begin of walking Minute 6 of 30-minute walking period No
Primary Gross heart rate (HR) at mid of walking Minute 18 of 30-minute walking period No
Primary Gross heart rate (HR) at end of walking Minute 30 of 30-minute walking period No
Primary Net heart rate (HR) Change between average heart rate at minute 5 of rest and minute 6 of walking, at minute 5 of rest and minute 18 of walking, at minute 5 of rest and minute 30 of walking No
Primary Gross Respiratory Exchange Ratio (RER) at rest Minute 5 of 5-minute resting period No
Primary Gross Respiratory Exchange Ratio (RER) at begin of walking Minute 6 of 30-minute walking period No
Primary Gross Respiratory Exchange Ratio (RER) at mid of walking Minute 18 of 30-minute walking period No
Primary Gross Respiratory Exchange Ratio (RER) at end of walking Minute 30 of 30-minute walking period No
Primary Net Respiratory Exchange Ratio (RER) Change between average RER at minute 5 of rest and minute 6 of walking, at minute 5 of rest and minute 18 of walking, at minute 5 of rest and minute 30 of walking No
Primary Metabolic Equivalent of Task (MET) at begin of walking Minute 6 of 30-minute walking period No
Primary Metabolic Equivalent of Task (MET) at mid of walking Minute 18 of 30-minute walking period No
Primary Metabolic Equivalent of Task (MET) at end of walking Minute 30 of 30-minute walking period No
Secondary Gross perceived exertion (assessed by the 6-20 Borg scale) at rest Minute 5 of 5-minute resting period No
Secondary Gross perceived exertion (assessed by the 6-20 Borg scale) at begin of walking Minute 6 of 30-minute walking period No
Secondary Gross perceived exertion (assessed by the 6-20 Borg scale) at mid of walking Minute 18 of 30-minute walking period No
Secondary Gross perceived exertion (assessed by the 6-20 Borg scale) at end of walking Minute 30 of 30-minute walking period No
Secondary Net perceived exertion (assessed by the 6-20 Borg scale) Change between Borg score at minute 5 of rest and minute 6 of walking, at minute 5 of rest and minute 18 of walking, at minute 5 of rest and minute 30 of walking No
Secondary Total walking duration Begin till end of walking (up to 30 minutes) No

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