W9 Functional Electrical Stimulation

Question 1

What is FES?

Answer 1

“…a means of producing useful movement in paralysed muscles. Electrical impulses are applied using either skin surface or implanted electrodes and cause muscles to contract in a controlled manner.”

– Salisbury Stroke/FES Centre website

Question 2

At the cellulal level, how does FES work? (outline)

Answer 2

Electrical control conducted by motor neruon via path of action potential down axon to muscle fibre neuromuscular junction –> excitation-contraction coupling –> calcium release -triggers–> thick-thin filament interaction –> muscle fibre contraction -leads to–> tension production

Question 3

Compare Type I with Type II motorunits in terms of size, fatigability, speed and force.

Answer 3

See image

Question 4

What are the three Basic Stimulation Parameters?

Answer 4

Pulse Amplitude

Pulse Width

Pulse Frequency

(see image)

Question 5

Aside:

In order of recruitment of motor units from slow to fast force…

Answer 5

Slow twitches come in first

Paralysed muscle is fast twitch

(??)

Question 6

True or False?

Stimulation activates sensory fibres as well

Answer 6

True

Populations with sensation might not tolerate much stimulation…

(? stimulates fast twitch preferentially ?)