Week 6 Flashcards
what is NMES?
-neuromuscular electrical stimulation
-activation of skeletal muscle for strengthening, reeducation or edema reduction
-the peripheral nerve depolarizes to create a muscle contraction
what is FES?
-functional electrical stimulation
-activation of skeletal muscle for reeducation or movement training for function use
-used on innervated or denervated muscle
what is EMS?
-electrical muscle stimulation
-implies stimulation of denervated muscle
what is the primary difference between NMES and EMS
the type of tissue stimulated
what are the goals of ES for strengthening and reeducation
-to prevent or treat muscular atrophy following disuse, immobilization or detraining
-increase or maintain ROM
-reeducation, retrain or facilitate muscle for movement or posture
how does NMES for increasing ROM in neurological conditions work?
-stimulation of antagonist to increase length of agonist
-parameters should induce 3+/5 contraction to stretch shortened muscle
-begin with shorter on time, longer off time (progress to 1:1 ratio (10 sec on/off))
what are the 3 theories for NMES for decreasing spasticity in neurological conditions?
-stimulate antagonist - reciprocal inhibition
-stimulate agonist - recurrent inhibition
-habituation (sensory level: continuous with lover amplitude to avoid a muscle contraction)
what is the correct placement of electrodes for NMES?
one electrode directly over the muscle to be stimulated and one over its motor point running parallel to the muscle fibers
what is the difference between voluntary and NMES muscle recruitment?
-voluntary = smaller to large motor units (smaller, slow twitch type 1 activated first)
-NMES = more random (small and large motor units recruited even with little force production; larges diameter nerve fibers, innervating the larger fast twitch type ii muscle 3fibers activated first)
what are some limitation of NMES compared to voluntary muscle recruitment?
-increased fatigability can account for greater muscle soreness, limit in amount of training
-increased DOMS
-limited number of muscle groups can be trained (only single joint activity)
Stimulation of denervated muscle requires different parameters what are these differences?
-longer pulse duration
-higher intensity
-different waveforms - typically direct current
what are the EMS parameters for denervated muscle?
-pulse duration: 1-450 msec
-frequency: 1-500 pps
-amplitude: high enough to obtain contractions but low enough to prevent burns
-ramp up/down time: not specified
-duty cycle: highly variable; on time 3-10 sec and off time 30-50 sec
-time and duration: 30min/8 hours/day; 5-7 day/week; 4 days to 4 years
