Electrical Stimulation of the Muscle Pumps of the Leg

Study Overview
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Brief Summary
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The most efficient way of electrically stimulating the calf muscles has not been identified. The investigators aim to investigate this using a matrix of electrical parameters, and measuring the outcome with vascular ultrasound of the leg.

Detailed Description
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Blood is aided on its journey to the heart by the action of the muscles of the legs. Muscle contraction squeezes the deep veins of the leg and pushes blood upwards, back towards the heart. In immobilised patients, or those with blood vessel problems, the pumping process can be helped by machines that either squeeze or shock the muscles of the calf (e.g. intermittent pneumatic compression, electrical stimulating devices). Many are licensed for medical use, and some are common place in hospitals and outpatient departments.

Official Title
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Electrical Stimulation of the Muscle Pumps of the Leg

Conditions
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Haemodynamic Physiology

Intervention / Treatment
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* Device: Electrical stimulation (Digitimer)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18 years or older Current good health Exclusion Criteria: History of cardiovascular disease Ankle Brachial Pressure Index <0.9 Venous reflux>0.5s Pregnancy

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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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 1<br>Stimulation of muscle in this order: vastus medials, rectus femoris, vastus lateralis, tibialis anterior, peroneus longus, medial head gastrocnemius, lateral head gastrocnemius | Device: Electrical stimulation (Digitimer)<br>* Stimulation with Digitimer (DS7A HV, Digitimer Ltd, UK) over motor point of muscle in protocol. 1Hz, pulse duration 1ms, maximum compliance voltage 200V. Current set to twice motor threshold<br>|
| Experimental: 2<br>Stimulation of muscle in this order: rectus femoris, vastus lateralis, tibialis anterior, peroneus longus, medial head gastrocnemius, lateral head gastrocnemius, vastus medials | Device: Electrical stimulation (Digitimer)<br>* Stimulation with Digitimer (DS7A HV, Digitimer Ltd, UK) over motor point of muscle in protocol. 1Hz, pulse duration 1ms, maximum compliance voltage 200V. Current set to twice motor threshold<br>|
| Experimental: 3<br>Stimulation of muscle in this order: vastus lateralis, tibialis anterior, peroneus longus, medial head gastrocnemius, lateral head gastrocnemius, vastus medials, rectus femoris | Device: Electrical stimulation (Digitimer)<br>* Stimulation with Digitimer (DS7A HV, Digitimer Ltd, UK) over motor point of muscle in protocol. 1Hz, pulse duration 1ms, maximum compliance voltage 200V. Current set to twice motor threshold<br>|
| Experimental: 4<br>Stimulation of muscle in this order: tibialis anterior, peroneus longus, and the medial head gastrocnemius, lateral head gastrocnemius, vastus medials, rectus femoris, vastus lateralis | Device: Electrical stimulation (Digitimer)<br>* Stimulation with Digitimer (DS7A HV, Digitimer Ltd, UK) over motor point of muscle in protocol. 1Hz, pulse duration 1ms, maximum compliance voltage 200V. Current set to twice motor threshold<br>|
| Experimental: 5<br>Stimulation of muscle in this order: peroneus longus, medial head gastrocnemius, lateral head gastrocnemius, vastus medials, rectus femoris, vastus lateralis, tibialis anterior | Device: Electrical stimulation (Digitimer)<br>* Stimulation with Digitimer (DS7A HV, Digitimer Ltd, UK) over motor point of muscle in protocol. 1Hz, pulse duration 1ms, maximum compliance voltage 200V. Current set to twice motor threshold<br>|
| Experimental: 6<br>Stimulation of muscle in this order: medial head gastrocnemius, lateral head gastrocnemius, vastus medials, rectus femoris, vastus lateralis, tibialis anterior, peroneus longus | Device: Electrical stimulation (Digitimer)<br>* Stimulation with Digitimer (DS7A HV, Digitimer Ltd, UK) over motor point of muscle in protocol. 1Hz, pulse duration 1ms, maximum compliance voltage 200V. Current set to twice motor threshold<br>|
| Experimental: 7<br>Stimulation of muscle in this order: lateral head gastrocnemius, vastus medials, rectus femoris, vastus lateralis, tibialis anterior, peroneus longus, medial head gastrocnemius, | Device: Electrical stimulation (Digitimer)<br>* Stimulation with Digitimer (DS7A HV, Digitimer Ltd, UK) over motor point of muscle in protocol. 1Hz, pulse duration 1ms, maximum compliance voltage 200V. Current set to twice motor threshold<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Venous Haemodynamic Measurements (Volume Flow Rate) | Measurement by ultrasound, in right femoral vein. Flow rate (ml/min). | Baseline compared to that after 10-mins stimulation (2-mins to take measurements) | 
| Venous Haemodynamic Measurements (Time Averaged Maximum Velocity) | Measurement by ultrasound, in right femoral vein. Time averaged maximum velocity (cm/s). | Baseline compared to that after 10-mins stimulation (2-mins to take measurements) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain Grading on Stimulation | Visual analogue scale (0-minimum pain, to 100-maximum pain) | During stimulation (10-mins each muscle) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Haemodynamic physiology