Energy Consumption and Cardiorespiratory Load During Overground Gait Training With a Wearable Exoskeleton After Stroke

Study Overview
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Brief Summary
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To investigate acute metabolic and cardiorespiratory responses during overground gait training with a wearable exoskeleton in persons after stroke

Detailed Description
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RESEARCH AIMS: To investigate the effect of the level of swing assistance on the acute metabolic and cardiorespiratory responses during overground gait training with a wearable exoskeleton in persons after stroke To investigate if there is an interaction-effect between the level of swing assistance and the duration of walking To compare the exercise intensity to aerobic training recommendations STUDY DESIGN: An experimental, 1-group trial with randomized crossover design. PATIENT RECRUITMENT: Participants will be recruited at the AZ Herentals (Herentals, Belgium). LOCATION: The trial will be conducted at the REVAlution Center (Herentals, Belgium). ELIGIBILITY CRITERIA: See section Eligibility PROCEDURES: Before the start of the study, informed consent and baseline patient characteristics will be collected. Next, participants will be measured during three training sessions with the Ekso GT SmartAssist: 20-minute training with high swing assistance 20-minute training with neutral swing assistance 20-minute training with high swing resistance Trainings will be performed on a separate day in a randomized order (within one week and controlled for time of day). Following settings will be used in all three conditions: sitting program (Min lean); standing program (Auto lean); step initiation program (ProStep+), training mode (Off), SmartAssist option (2Free); and stance support (Low). The level of stance support and swing assistance will be set symmetrically for the affected and non-affected side. During training, participants will walk back and forth at a self-selected walking speed in a 30m hall way using a cane at the non-affected side. Prior to the experimental conditions, participants will have had three training sessions in the Ekso GT. RESTRICTIONS & PROHIBITIONS: Participants will be instructed to not consume food, alcohol, caffeine or nicotine at least 3h prior to the intervention. Usual medication intake will be allowed with small amounts of water. MATERIALS: The Ekso GT robotic exoskeleton with SmartAssist (Ekso Bionics Inc., USA) will be used during the overground training sessions. A flexible facemask (adult facemask, small/medium, Cortex, Germany), lightweight chest carrying gas analysis system (Metamax 3B, Cortex, Germany) and Bluetooth heart rate belt (Polar H7, Polar Electro, Finland) will be used to measure metabolic and cardiorespiratory parameters. At the start of each measurement, gas (room air and reference gas (17.4% O2 and 5.1% CO2)) and volume (3L syringe) calibrations of the breath-by-breath gas analysis system will be performed in accordance with the manufacturer's instructions. OUTCOMES: See section Outcome Measures DATA-ANALYSES: Descriptive statistics will be calculated for baseline patient characteristics. To investigate the effect of level of swing assistance and duration, a repeated measures ANOVA (within factor duration and within factor assistance level) will be conducted (interaction-effect time x duration, main effect assistance level and main effect duration). In case of significant differences, posthoc analyses will be interpreted. The walking speed will be considered as a covariate in the ANOVA analysis (in case significant different between conditions). Significance level will be set at 5%.

Official Title
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Energy Consumption and Cardiorespiratory Load During Overground Gait Training With a Wearable Exoskeleton After Stroke: the Effect of the Level of Swing Assistance

Conditions
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Stroke

Intervention / Treatment
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* Other: Ekso GT gait training with high swing assistance
* Other: Ekso GT gait training with neutral swing assistance
* Other: Ekso GT gait training with high swing resistance


Participation Criteria
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Eligibility Criteria
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Included will be persons who Had a stroke Cannot walk independently or can walk independently on level ground, but still require help on stairs, slopes or uneven surfaces (FAC 0 - 4) Excluded will be persons who Can walk independently on level ground, stairs, slopes and uneven surfaces (FAC 5) Have musculoskeletal problems (other than stroke) affecting the ability to walk Have concurrent pulmonary diseases (e.g. asthma) Have unstable cardiovascular conditions Have concurrent neurological diseases (e.g. Parkinson's Disease) Have communicative and/or cognitive problems affecting the ability to understand or follow instructions Present contra-indications for using the Ekso GT (according to manufacturer's instructions) Severe concurrent medical diseases (infections, circulatory, heart or lung, pressure sores) Severe spasticity (Ashworth 4) Range of motion restrictions that would prevent a patient from achieving normal, reciprocal gait pattern, or would restrict a patient from completing normal sit-to-stand or stand-to-sit transitions Bilateral hip flexion < 110° Knee flexion contracture > 12° Inability to achieve 0° neutral angle dorsiflexion with knee flexion ≤ 12° Weight ≥ 100 kg Hip width < 35.8 cm or > 45.6 cm Upper leg length < 51 cm or > 61.4 cm Lower leg length < 48 cm or > 63.4 cm Upper leg length discrepancy > 0.5 inch (1.3 cm) Lower leg length discrepancy > 0.75 inch (1.9 cm) Unstable spine, unhealed limbs or pelvic fractures Unhealthy bone density Heterotopic ossification Significant contractures Elbows and shoulders are unable to support crutches, walker or cane Psychiatric or cognitive situations that may interfere with proper operation of the device

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Ekso GT gait training<br>Participants will be measured during three Ekso GT gait trainings: 20-minute Ekso GT gait training with high swing assistance 20-minute Ekso GT gait training with neutral swing assistance 20-minute Ekso GT gait training with high swing resistance. Each training will be performed on a separate day in a randomized order (within one week and controlled for time of day). | Other: Ekso GT gait training with high swing assistance<br>* Participant will walk for 20-minutes in the Ekso GT SmartAssist with the swing assistance set at high assistance<br>Other: Ekso GT gait training with neutral swing assistance<br>* Participant will walk for 20-minutes in the Ekso GT SmartAssist with the swing assistance set at neutral<br>Other: Ekso GT gait training with high swing resistance<br>* Participant will walk for 20-minutes in the Ekso GT SmartAssist with the swing assistance set at high resistance<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Net oxygen cost (OC, ml/kg/m) at minute 5 of walking | Net oxygen consumption (oxygen consumption (ml/kg/min) during walking minus during rest) divided by the walking speed (m/min) | Minute 5 of 20-minute walking period | 
| Net oxygen cost (OC, ml/kg/m) at minute 10 of walking | Net oxygen consumption (oxygen consumption (ml/kg/min) during walking minus during rest) divided by the walking speed (m/min) | Minute 10 of 20-minute walking period | 
| Net oxygen cost (OC, ml/kg/m) at minute 15 of walking | Net oxygen consumption (oxygen consumption (ml/kg/min) during walking minus during rest) divided by the walking speed (m/min) | Minute 15 of 20-minute walking period | 
| Net oxygen cost (OC, ml/kg/m) at minute 20 of walking | Net oxygen consumption (oxygen consumption (ml/kg/min) during walking minus during rest) divided by the walking speed (m/min) | Minute 20 of 20-minute walking period | 
| Net heart rate (HR, beats/min) at minute 5 of walking | Heart rate during walking (beats/min) minus resting heart rate | Minute 5 of 20-minute walking period | 
| Net heart rate (HR, beats/min) at minute 10 of walking | Heart rate during walking (beats/min) minus resting heart rate | Minute 10 of 20-minute walking period | 
| Net heart rate (HR, beats/min) at minute 15 of walking | Heart rate during walking (beats/min) minus resting heart rate | Minute 15 of 20-minute walking period | 
| Net heart rate (HR, beats/min) at minute 20 of walking | Heart rate during walking (beats/min) minus resting heart rate | Minute 20 of 20-minute walking period | 
| Net minute ventilation (VE, L/min) at minute 5 of walking | The amount of air in- or exhaled per minute (L/min) during walking minus during rest | Minute 5 of 20-minute walking period | 
| Net minute ventilation (VE, L/min) at minute 10 of walking | The amount of air in- or exhaled per minute (L/min) during walking minus during rest | Minute 10 of 20-minute walking period | 
| Net minute ventilation (VE, L/min) at minute 15 of walking | The amount of air in- or exhaled per minute (L/min) during walking minus during rest | Minute 15 of 20-minute walking period | 
| Net minute ventilation (VE, L/min) at minute 20 of walking | The amount of air in- or exhaled per minute (L/min) during walking minus during rest | Minute 20 of 20-minute walking period | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Net Rating of Perceived Exertion (RPE, 6-20) at minute 5 of walking | Rating of perceived effort, strain and/or fatigue during walking, pointed on a 15-point Borg scale (6-20) during walking minus during rest | Minute 5 of 20-minute walking period | 
| Net Rating of Perceived Exertion (RPE, 6-20) at minute 10 of walking | Rating of perceived effort, strain and/or fatigue during walking, pointed on a 15-point Borg scale (6-20) during walking minus during rest | Minute 10 of 20-minute walking period | 
| Net Rating of Perceived Exertion (RPE, 6-20) at minute 15 of walking | Rating of perceived effort, strain and/or fatigue during walking, pointed on a 15-point Borg scale (6-20) during walking minus during rest | Minute 15 of 20-minute walking period | 
| Net Rating of Perceived Exertion (RPE, 6-20) at minute 20 of walking | Rating of perceived effort, strain and/or fatigue during walking, pointed on a 15-point Borg scale (6-20) during walking minus during rest | Minute 20 of 20-minute walking period | 
| Percentage maximal heart rate (%HRmax) at minute 5 of walking | Heart rate divided by predicted maximum heart rate. | Minute 5 of 20-minute walking period | 
| Percentage maximal heart rate (%HRmax) at minute 10 of walking | Heart rate divided by predicted maximum heart rate. | Minute 10 of 20-minute walking period | 
| Percentage maximal heart rate (%HRmax) at minute 15 of walking | Heart rate divided by predicted maximum heart rate. | Minute 15 of 20-minute walking period | 
| Percentage maximal heart rate (%HRmax) at minute 20 of walking | Heart rate divided by predicted maximum heart rate. | Minute 20 of 20-minute walking period | 
| Percentage heart rate reserve (%HRR) at minute 5 of walking | Heart rate during walking minus during rest divided by predicted heart rate reserve (i.e. predicted maximum heart rate minus resting heart rate) | Minute 5 of 20-minute walking period | 
| Percentage heart rate reserve (%HRR) at minute 10 of walking | Heart rate during walking minus during rest divided by predicted heart rate reserve (i.e. predicted maximum heart rate minus resting heart rate) | Minute 10 of 20-minute walking period | 
| Percentage heart rate reserve (%HRR) at minute 15 of walking | Heart rate during walking minus during rest divided by predicted heart rate reserve (i.e. predicted maximum heart rate minus resting heart rate) | Minute 15 of 20-minute walking period | 
| Percentage heart rate reserve (%HRR) at minute 20 of walking | Heart rate during walking minus during rest divided by predicted heart rate reserve (i.e. predicted maximum heart rate minus resting heart rate) | Minute 20 of 20-minute walking period | 
| Metabolic Equivalent of Task (MET) at minute 5 of walking | Expression of the intensity of walking defined as the oxygen consumption (ml/kg/min) during walking divided by the oxygen consumption (ml/kg/min) in rest | Minute 5 of 20-minute walking period | 
| Metabolic Equivalent of Task (MET) at minute 10 of walking | Expression of the intensity of walking defined as the oxygen consumption (ml/kg/min) during walking divided by the oxygen consumption (ml/kg/min) in rest | Minute 10 of 20-minute walking period | 
| Metabolic Equivalent of Task (MET) at minute 15 of walking | Expression of the intensity of walking defined as the oxygen consumption (ml/kg/min) during walking divided by the oxygen consumption (ml/kg/min) in rest | Minute 15 of 20-minute walking period | 
| Metabolic Equivalent of Task (MET) at minute 20 of walking | Expression of the intensity of walking defined as the oxygen consumption (ml/kg/min) during walking divided by the oxygen consumption (ml/kg/min) in rest | Minute 20 of 20-minute walking period | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Wearable Exoskeleton, Stroke, Energy Consumption, Cardiorespiratory Load