The Effects of WBV on Muscle Stiffness and Reflex Activity in Stroke.

Study Overview
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Brief Summary
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Spastic hypertonia is common after stroke. Whole-body vibration (WBV) is known to have modulatory effects of muscle reflex activity and blood flow in other populations and thus have potential applications in the management of spastic hypertonia post-stroke. This study aims to investigate the acute effect of WBV on leg muscle H-reflex, stiffness, and blood perfusion in people with chronic stroke.

Detailed Description
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Spastic hypertonia is common after stroke. Whole-body vibration (WBV) is known to have modulatory effects of muscle reflex activity and blood flow in other populations and thus have potential applications in management of spastic hypertonia post-stroke. However, the potential effects of WBV on leg muscle stiffness in stroke rehabilitation remains unknown. Scientific evidence is warranted to fill the knowledge gap. Purpose This study aims to investigate the acute effect of WBV on leg muscle H-reflex, stiffness and blood perfusion in people with chronic stroke. Methods Individuals with chronic stroke will be recruited from community self-help groups and existing patient database. Relevant information (e.g. demographic information, medical history) will be obtained from medical records and subject interviews. Each subject will have to fulfill the following inclusion criteria: (1) diagnosis of chronic stroke, (2) community-dwelling, (3) able to follow simple verbal instructions. Exclusion criteria are: (1) other diagnoses of neurological conditions, (2) significant musculoskeletal conditions (e.g. amputations), (3) metal implants in the lower extremity or spine, (4) recent fracture in the lower extremity, (5) diagnosis of osteoporosis, (6) vestibular disorders, (7) peripheral vascular disease, and (11) other serious illnesses or contraindications to exercise. This is a single-blinded randomized within-patient cross-over study. Each participant was evaluated for the soleus H-reflex, stiffness and blood perfusion of the medial gastrocnemius (MG) using ultrasound on both sides before and after either a 5-minute WBV intervention (30 Hertz, 1.5mm, knee flexed 60 degrees) or a no-WBV condition (5 minutes). The measurements were performed at baseline and every 1-min post-intervention up to 5 minutes. The outcomes generated included the soleus H/M ratio, shear modulus and vascular index (VI) of the MG muscle.

Official Title
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The Effects of Whole Body Vibration (WBV) on Muscle Stiffness and Reflex Activity in People After Stroke.

Conditions
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Stroke

Intervention / Treatment
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* Device: paretic leg-control
* Device: paretic leg-WBV
* Device: non-paretic leg-control
* Device: non-paretic leg-WBV


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult with a diagnosis of a hemispheric stroke >6 months, Medically stable, Able to stand independently for at least 1 minute and Mas score >1 measured at the ankle plantar flexors. Exclusion Criteria: Brainstem or cerebellar stroke, Other neurological condition, Serious musculoskeletal or cardiovascular disease, Severe contracture of the ankle that the cannot be put in the neutral position. Metal implants or recent fractures in the lower extremities or spine, Fresh skin wound in lower extremities, especially popliteal fossa Other severe illnesses or contraindication for exercise.

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: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Control<br>This group will stand with knee flexion 60 degrees on the same vibration platform for 60 seconds for 5 times with 60-seconds rest interval, but no vibration will be given. | Device: paretic leg-control<br>* standing on the vibration platform, with no vibration signals delivered.<br>Device: non-paretic leg-control<br>* standing on the vibration platform, with no vibration signals delivered.<br>|
| Active Comparator: High intensity whole body vibration<br>This group will stand with knee flexion 60 degrees on the same vibration platform for 60 seconds for 5 times with 60-seconds rest interval. The whole body vibration platform will be set with frequency at 30Hz and amplitude at 1.5mm. | Device: paretic leg-WBV<br>* standing on the vibration platform, with WBV at 30Hz, 1.5mm.<br>Device: non-paretic leg-WBV<br>* standing on the vibration platform, with WBV at 30Hz, 1.5mm.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| H-reflex of paretic soleus muscle | To measure the efficacy of synaptic transmission | Immediately before the intervention | 
| H-reflex of paretic soleus muscle | To measure the efficacy of synaptic transmission | 1st minute after the intervention | 
| H-reflex of paretic soleus muscle | To measure the efficacy of synaptic transmission | 2nd minute after the intervention | 
| H-reflex of paretic soleus muscle | To measure the efficacy of synaptic transmission | 3rd minute after the intervention | 
| H-reflex of paretic soleus muscle | To measure the efficacy of synaptic transmission | 4th minute after the intervention | 
| H-reflex of paretic soleus muscle | To measure the efficacy of synaptic transmission | 5th minute after the intervention | 
| Muscle stiffness of paretic medial gastrocnemius | Measured by Supersonic elastography with ankle in neutral position | Immediately before the intervention | 
| Muscle stiffness of paretic medial gastrocnemius | Measured by Supersonic elastography with ankle in neutral position | 1st minute after the intervention | 
| Muscle stiffness of paretic medial gastrocnemius | Measured by Supersonic elastography with ankle in neutral position | 2nd minute after the intervention | 
| Muscle stiffness of paretic medial gastrocnemius | Measured by Supersonic elastography with ankle in neutral position | 3rd minute after the intervention | 
| Muscle stiffness of paretic medial gastrocnemius | Measured by Supersonic elastography with ankle in neutral position | 4th minute after the intervention | 
| Muscle stiffness of paretic medial gastrocnemius | Measured by Supersonic elastography with ankle in neutral position | 5th minute after the intervention | 
| H-reflex of non-paretic soleus muscle | To measure the efficacy of synaptic transmission | Immediately before the intervention | 
| H-reflex of non-paretic soleus muscle | To measure the efficacy of synaptic transmission | 1st minute after the intervention | 
| H-reflex of non-paretic soleus muscle | To measure the efficacy of synaptic transmission | 2nd minute after the intervention | 
| H-reflex of non-paretic soleus muscle | To measure the efficacy of synaptic transmission | 3rd minute after the intervention | 
| H-reflex of non-paretic soleus muscle | To measure the efficacy of synaptic transmission | 4th minute after the intervention | 
| H-reflex of non-paretic soleus muscle | To measure the efficacy of synaptic transmission | 5th minute after the intervention | 
| Muscle stiffness of non-paretic medial gastrocnemius | Measured by Supersonic elastography with ankle in neutral position | Immediately before the intervention | 
| Muscle stiffness of non-paretic medial gastrocnemius | Measured by Supersonic elastography with ankle in neutral position | 1st minute after the intervention | 
| Muscle stiffness of non-paretic medial gastrocnemius | Measured by Supersonic elastography with ankle in neutral position | 2nd minute after the intervention | 
| Muscle stiffness of non-paretic medial gastrocnemius | Measured by Supersonic elastography with ankle in neutral position | 3th minute after the intervention | 
| Muscle stiffness of non-paretic medial gastrocnemius | Measured by Supersonic elastography with ankle in neutral position | 4th minute after the intervention | 
| Muscle stiffness of non-paretic medial gastrocnemius | Measured by Supersonic elastography with ankle in neutral position | 5th minute after the intervention | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Intramuscular blood perfusion of paretic medial gastrocnemius muscle | Measured by power Doppler ultrasound | Immediately before the intervention | 
| Intramuscular blood perfusion of paretic medial gastrocnemius muscle | Measured by power Doppler ultrasound | 1 minute after the intervention | 
| Intramuscular blood perfusion of paretic medial gastrocnemius muscle | Measured by power Doppler ultrasound | 2nd minute after the intervention | 
| Intramuscular blood perfusion of paretic medial gastrocnemius muscle | Measured by power Doppler ultrasound | 3rd minute after the intervention | 
| Intramuscular blood perfusion of paretic medial gastrocnemius muscle | Measured by power Doppler ultrasound | 4th minute after the intervention | 
| Intramuscular blood perfusion of paretic medial gastrocnemius muscle | Measured by power Doppler ultrasound | 5th minute after the intervention | 
| Intramuscular blood perfusion of non-paretic medial gastrocnemius muscle | Measured by power Doppler ultrasound | Immediately before the intervention | 
| Intramuscular blood perfusion of non-paretic medial gastrocnemius muscle | Measured by power Doppler ultrasound | 1th minute after the intervention | 
| Intramuscular blood perfusion of non-paretic medial gastrocnemius muscle | Measured by power Doppler ultrasound | 2nd minute after the intervention | 
| Intramuscular blood perfusion of non-paretic medial gastrocnemius muscle | Measured by power Doppler ultrasound | 3rd minute after the intervention | 
| MoviIntramuscular blood perfusion of non-paretic medial gastrocnemius muscle | Measured by power Doppler ultrasound | 4th minute after the intervention | 
| Intramuscular blood perfusion of non-paretic medial gastrocnemius muscle | Measured by power Doppler ultrasound | 5th minute after the intervention | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Muscle Stiffness, Ultrasound elastography, H-reflex, Whole body vibration, blood perfusion