Functional Electrical Stimulation

ZAIN SULTAN EE-01083-020NAEEM HUSSAIN EE-01083-039

Functional Electrical Stimulation (FES)

Functional electrical stimulation (FES) is a treatment that uses the application of small electrical charges to improve mobility in a number of conditions. It was first used in 1961 in people following a stroke.

Who may benefit from FES?

As FES applies stimulation along the existing nerves, the nerve fibres between the spinal cord and the muscles they supply must be undamaged. In practice this means that the individual needs to be able to walk, even if only a few metres with a stick or crutch.

Are there any risks or side effects?

Electrical stimulation causes a tingling 'pins and needles' sensation on the skin.Although most people do not find this a problem, some people with MS(Multiple Sclerosis ) are quite sensitive to changes in sensory input and find the effect uncomfortable. A short period of stimulation at a low intensity usually overcomes this problem.

Stroke: Overview

“Brain Attack”Damage due to lack of oxygen or bloodTypes of Stroke– Hemorrhagic– Ischemic

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Stroke: Damage & Resulting Disability

Dependent upon location & extent of damageExamples– Inability to move parts of the body

• Paralysis (hemiplesia or total)– Weakness in parts of the body– Persistent gait deficits

• Swing phase• Midsupport phase• “Drop foot”

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Gait Deficits Post-Stroke:“Drop-Foot”

significant weakness of ankle and toe dorsiflexion muscles.These muscles:– help the leg clear the foot

during swing phase– control plantar flexion of

the foot on heel strike. Causes toes to catch on the ground during swing phase

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Figure from: (Kelly, 1981)

FES: Clinical Applications to Stroke Rehabilitation

Dropped-Foot rehabilitation (ODFS)Improve functional mobility (during walking)

Main Goals – Improve coordination the different phases of gait.– Restoration of motor control– Prevent debilitating falls

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Spinal Cord Injury (SCI): Overview

What is Spinal Cord Injury?– Damage to the spinal cord that results in a loss of function

Frequent Causes of SCI include:– Trauma: car accident, gunshot, falls– Disease: polio, spina bifida, ataxia

The spinal cord does not have to be severed for loss of function to occurThe higher in the spinal column injury occurs, the more dysfunction a person will experience

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Spinal Cord Injury (SCI): Overview

Two types of injuries– Complete injury means that there is no function below the

level of injury; no sensation and no voluntary movement• Both sides are equally affected

– Incomplete injury means that there is some functioning below the primary level of the injury• May be able to use one limb more than another, may feel parts of the

body that cannot be moved, or may have more function in one side of the body than the other

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SCICervical injuries usually result in quadriplegiaInjuries above C-4 may require a ventilatorInjuries at or below the thoracic level result in paraplegia

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How many people have SCI? Who are they?

Approximately 450,000 people live with SCI in the US. There are about 10,000 new SCI's every year; the majority of them (82%) involve males between the ages of 16-30. These injuries result from motor vehicle accidents (36%), violence (28.9%), or falls (21.2%).Quadriplegia is slightly more common than paraplegia.

Is there a cure? Currently there is no cure for SCI. There are

researchers attacking this problem, and there have been many advances in the lab (see research updates ). Many of the most exciting advances have resulted in a decrease in damage at the time of the injury. Steroid drugs such as methylprednisolone reduce swelling, which is a common cause of secondary damage at the time of injury.

Current Research on FES usage in Stroke Patients

Burridge, J.H. et al (1997)– Improvements shown in walking speed with FES

Yoichi, S. et al (2005)– Improvements shown in acceleration phase of

walking with acceleration sensor + FES

Christopher Reeves

Reeves’ recovery came 5-7 years after his injury– began an intense exercise program under Dr. John McDonald

Exercise program included:– Daily electric stimulation– FES bicycle– Spontaneous breathing training– Aqua therapy– Treadmill training

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FES Bicycle

Allows a person with little or no voluntary leg movement to pedal a stationary leg-cycle (ergo meter)Cost approximately $15,000Some health clinics have the bikesIncrease muscle mass and cardiopulmonary function

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Conclusions

Applications of FES seems to be an effective addition to stroke and SCI rehabilitation; however, further research is needed and encouraged, especially with intramuscular FES systems.