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ELECTRICAL CURRENT FOR MUSCLE CONTRACTION

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Page 1: ELECTRICAL CURRENT FOR MUSCLE CONTRACTIONcontents.kocw.net/KOCW/document/2014/cu/shinhwakyung/3.pdf · 2016. 9. 9. · ES에의한muscle strengthening기전 6 Overload principle 근육에

ELECTRICAL CURRENT FOR MUSCLE CONTRACTION

Page 2: ELECTRICAL CURRENT FOR MUSCLE CONTRACTIONcontents.kocw.net/KOCW/document/2014/cu/shinhwakyung/3.pdf · 2016. 9. 9. · ES에의한muscle strengthening기전 6 Overload principle 근육에

Innervated muscle

Muscle contraction

Page 3: ELECTRICAL CURRENT FOR MUSCLE CONTRACTIONcontents.kocw.net/KOCW/document/2014/cu/shinhwakyung/3.pdf · 2016. 9. 9. · ES에의한muscle strengthening기전 6 Overload principle 근육에

Electrically stimulated m.contraction & physiological initiated m. contraction

3

Electrically stimulated muscle contraction과 physiological initiated muscle contraction의 차이점 order of recruitment of motor unit

Electrically stimulated muscle contraction: fast twitch type II fiber → slow twitch type 1 fiber

( ∴disuse에 의한 muscle weakness에 효과적인 strengthening) physiological initiated muscle contraction

: smoothness of the onset of the contraction

Electrically stimulated muscle contractionRapid and jerky onset

physiological initiated muscle contractionSmooth onset (∵asynchronous recruitment of motor units )

※ Electrically stimulated muscle contractiona. disuse induced muscle의 strengthening에 특히 효과적

그러나 환자에게 전기자극과 생리적 수축 모두 적용하는 것이 좋다. b long resting time between contraction. Why?

Page 4: ELECTRICAL CURRENT FOR MUSCLE CONTRACTIONcontents.kocw.net/KOCW/document/2014/cu/shinhwakyung/3.pdf · 2016. 9. 9. · ES에의한muscle strengthening기전 6 Overload principle 근육에

Type II muscle fiber atrophy from disuse4

Page 5: ELECTRICAL CURRENT FOR MUSCLE CONTRACTIONcontents.kocw.net/KOCW/document/2014/cu/shinhwakyung/3.pdf · 2016. 9. 9. · ES에의한muscle strengthening기전 6 Overload principle 근육에

Longer off times → stronger contractions5

Figure 08-07. The effect of changing the on:off ratio on the force of contraction produced. Note that stronger contractions are produced when longer off times are used.

Page 6: ELECTRICAL CURRENT FOR MUSCLE CONTRACTIONcontents.kocw.net/KOCW/document/2014/cu/shinhwakyung/3.pdf · 2016. 9. 9. · ES에의한muscle strengthening기전 6 Overload principle 근육에

ES에 의한 muscle strengthening 기전6

Overload principle 근육에 적용되는 load ↑ force contraction ↑일 수록 strength gain ↑

physiological contraction : resistance (weight)를 증가시킴

electrical stimulated contraction : 환자의 인내력과 피로를 고려하여

total amount of current ↑

specificity ES는 type II muscle fiber에 더욱 효과적, limb muscle

: reduced muscle strength, specific muscle weakness after surgery 환자는tupe II muscle atrophy 발생

→ 재활 초기에 ES는 기능회복를 빠르게 하고 운동만 하는 것보다 근력 증가에 더 효과적이다.

ES는 endurance/strength, quality of motor recruitment, functional activity↑ strength gain : higher force contraction이 효과적

healthy muscle : at lest 50% of MVIC

injured muscle: 10% of the MVIC

Endurance gain : prolonged lower force contraction이 효과적

Page 7: ELECTRICAL CURRENT FOR MUSCLE CONTRACTIONcontents.kocw.net/KOCW/document/2014/cu/shinhwakyung/3.pdf · 2016. 9. 9. · ES에의한muscle strengthening기전 6 Overload principle 근육에

ES for innervated muscle 7

To increase strength and function in patient with the orthopedic problem and intact PNS and CNS

To improve control in patient with CNS damage

Page 8: ELECTRICAL CURRENT FOR MUSCLE CONTRACTIONcontents.kocw.net/KOCW/document/2014/cu/shinhwakyung/3.pdf · 2016. 9. 9. · ES에의한muscle strengthening기전 6 Overload principle 근육에

Patient with CNS damage (peripheral motor nerve intact) 8

Hemiplegia following stroke, CP

ex. Clinical application ?

기전

increased general excitability of the MN pool produced by motor level ES, enhancing descending control of muscle recruitment

motor neuron stimulation에 의한 sensory input은 환자가 움직임을 개시하고muscle group을 활성화시키도록 Que를 제공한다.

→ functional activity 개선 “FES”

※ patterned sensory level stimulation 이란?

Page 9: ELECTRICAL CURRENT FOR MUSCLE CONTRACTIONcontents.kocw.net/KOCW/document/2014/cu/shinhwakyung/3.pdf · 2016. 9. 9. · ES에의한muscle strengthening기전 6 Overload principle 근육에

Spasticity, swallowing difficulty, urinary incontinence9

Patient with spasticity - antagonist muscle을 자극하는 것에 초점. - 그러나 수축 사이에 brief rest period를 두고 agonist antagonist를 순서대로 수축시키는 것도 효과적일 수 있다. Why?

- ES를 적용한 근육은 보조기와 같은 역할을 하면서 joint positioning을 assist

patient with swallowing difficulty resultant stroke

Urinary incontinence associated pelvic floor dysfunction

ES에 의한 muscle contraction은 Healthy individual, patient with poor circulation에서 blow flow를 촉진 시킨다. → tissue healing개선※ sensory level ES 또한 건강성인이 아닌 단지 환자에서만 말초 혈액순환 증가시킴.

Page 10: ELECTRICAL CURRENT FOR MUSCLE CONTRACTIONcontents.kocw.net/KOCW/document/2014/cu/shinhwakyung/3.pdf · 2016. 9. 9. · ES에의한muscle strengthening기전 6 Overload principle 근육에

Denervated muscle10

신경손상으로 근육의 physiological contraction이 불가능할때 ES는 10ms 이상동안 전류를 통전할때 수축 가능함

: 흔히 단속 직류(interrupted DC) 사용 : EMS gradually increase to reach full amplitude over a number of seconds

그러나, 최근에는 denervated m.에 DC를 이용하는 수축을 자극하는 것은 권장되지않는다.

Page 11: ELECTRICAL CURRENT FOR MUSCLE CONTRACTIONcontents.kocw.net/KOCW/document/2014/cu/shinhwakyung/3.pdf · 2016. 9. 9. · ES에의한muscle strengthening기전 6 Overload principle 근육에

Parameter for ES of contraction in innervated muscles11

• Electrode placement

• Waveform

• Pulse duration

• Frequency

• On:off time

• Ramp up /Ramp down

• Current amplitude

• Treatment time

Page 12: ELECTRICAL CURRENT FOR MUSCLE CONTRACTIONcontents.kocw.net/KOCW/document/2014/cu/shinhwakyung/3.pdf · 2016. 9. 9. · ES에의한muscle strengthening기전 6 Overload principle 근육에

Placement of 2 electrode motor point

stimulated muscle

motor point motor nerve가 근육으로 들어가는 피부

위에 존재하며, 최소한의 전류로 최대수축을 유발할 수 있는 위치

일반적으로 middle of muscle belly 에 위치

2 electrode 는 muscle fiber의 방향과 parallel, 최소 2 inch 떨어지도록 부착

Electrode placement12

Page 13: ELECTRICAL CURRENT FOR MUSCLE CONTRACTIONcontents.kocw.net/KOCW/document/2014/cu/shinhwakyung/3.pdf · 2016. 9. 9. · ES에의한muscle strengthening기전 6 Overload principle 근육에

Waveform13

ES for muscle contraction Pulsed biphasic waveform : m. contraction을 위해 대부분의 장비에 사용 가능,

Russian protocol : greater and faster strength gain

신경지배근의 전기자극 FES

ICT

HVPC

Page 14: ELECTRICAL CURRENT FOR MUSCLE CONTRACTIONcontents.kocw.net/KOCW/document/2014/cu/shinhwakyung/3.pdf · 2016. 9. 9. · ES에의한muscle strengthening기전 6 Overload principle 근육에

Pulse duration 14

150 ~ 350 ㎲ to stimulate motor nerve (Fig 8-3)

. 대부분의 장비는 maximum duration을 300 ㎲ 주변으로 고정함.

Small m. 에서는 short pulse duration이 comfortable 하다고 느낌.

: also small people, children

Large m.에서는 long pulse duration이 comfortable

Pulse duration이 짧아짐에 따라, long pulse duration에 의한 contraction 강도와 같게 하기 위해 더 큰 amplitude가 요구된다.

Page 15: ELECTRICAL CURRENT FOR MUSCLE CONTRACTIONcontents.kocw.net/KOCW/document/2014/cu/shinhwakyung/3.pdf · 2016. 9. 9. · ES에의한muscle strengthening기전 6 Overload principle 근육에

Frequency15

At lest 30 pps for stimulate motor nerve

: Frequency ↑ -> summation -> smooth tetanic contraction

50~80 pps : greater m. strength, but more rapid fatigue

임상에서는 30~50 pps 사용 권장, 최대 80pps 까지는 환자가 comfortable하게 느끼며 증가시킬 수 있음.

Page 16: ELECTRICAL CURRENT FOR MUSCLE CONTRACTIONcontents.kocw.net/KOCW/document/2014/cu/shinhwakyung/3.pdf · 2016. 9. 9. · ES에의한muscle strengthening기전 6 Overload principle 근육에

On:off time 16

Purpose of on-off time ES를 muscle contraction에 적용할때, on:off time은 수축, 이완을 위해 사용

fatigue 감소

초기 on:off ratio 1:5 On time 6~10 sec , off time 50~120 sec 권장

off time ↑ -> muscle fatigue ↓

환자가 피로에 강해짐에 따라 1:4. 1:3으로 진행

↓muscle spasm to produce muscle fatigue and relax the spasm

1:1 (on off 모두 2~5초 사이)

↓pumping-out for edema 목적일 때: 1:1 (on off 모두 2~5초 사이)

Page 17: ELECTRICAL CURRENT FOR MUSCLE CONTRACTIONcontents.kocw.net/KOCW/document/2014/cu/shinhwakyung/3.pdf · 2016. 9. 9. · ES에의한muscle strengthening기전 6 Overload principle 근육에

Ramp time 17

Muscle contraction 자극 시 off time ↔ on time으로 바뀔 때 갑작스러운 증가또는 감소보다는 점차적인 힘의 증가와 감소를 편안하게 느낌.

Clinical application 반복 운동를 촉진하고 on time이 6~10 sec일 때 ramp up/down 1~4 sec가 권장됨

gait training ?

stimulating contraction of the antagonist to a spastic muscle?

Page 18: ELECTRICAL CURRENT FOR MUSCLE CONTRACTIONcontents.kocw.net/KOCW/document/2014/cu/shinhwakyung/3.pdf · 2016. 9. 9. · ES에의한muscle strengthening기전 6 Overload principle 근육에

Current amplitude 18

Muscle strength People without injury : at least 50% of MVIC ButDuring recovery from injury or surgery:≥10 % of MVIC of uninjured limb

Motor re-education maximal strength를 요구하지 않으며 functional movement 유발이 치료 목적 최소한의 current amplitude는 functional movement를 일으키기에 충분함. strong motor level ES 후 환자가 voluntary control이 가능해지면

→ lower amplitude → sensory level ES

Reduction of muscle spasm visible contraction 가능한 정도면 충분함.

Page 19: ELECTRICAL CURRENT FOR MUSCLE CONTRACTIONcontents.kocw.net/KOCW/document/2014/cu/shinhwakyung/3.pdf · 2016. 9. 9. · ES에의한muscle strengthening기전 6 Overload principle 근육에

Treatment time 19

10~ 20 minute/session 치료

: 가정용 치료기기가 있다면 하루에 여러 번 반복할 수 있음.

Muscle reeducaton

: functional activity에 따라 치료 시간은 다양하나, session 당 20분을 초과해서는 안됨.