ES FOR MUSCLE CONTRACTION: DENERVATED M.S

Denervation/Degeneration: Phase 1

Acute response to injury

Inc of cellular fraction

Denervation/Degeneration: Phase II

Lag bw injury and onset of Wallerian degeneration

Defense response (Inflamm & immune response)

Elevated expressions of cytokine, growth factor, chemokine, & hormone

Denervation/Degeneration: Phase III

Wallerian degeneration

Transition to homeostasis

Denervation classification: Seddon

Neuropraxia

Axonotmesis

Neurotmesis

Denervation classification: Seddon - Neuropraxia → Sunderland - __

1st degree

Denervation classification: Seddon - Axonotmesis → Sunderland - __

2nd degree

Denervation classification: Seddon - Neurotmesis → Sunderland - __

3rd, 4th, 5th degree

Injury to myelin sheath: degeneration __, regeneration __

conduction block

complete recovery

Injury to myelin & axon: degeneration __, regeneration __

Wallerian degeneration

Complete recovery

Injury to M + A + Endoneurium: degeneration __, regeneration __

Wallerian degeneration

Incomplete recovery

Injury to M + A + E + Perineurium: degeneration __, regeneration __

Wallerian degeneration

Incomplete recovery

Injury to M + A + E + P + Epineurium: degeneration __, regeneration __

Wallerian degeneration

Incomplete recovery

Physiology of denervation

Partial depolarization of the sacrolemma

Atrophy

Muscle degeneration

Partial depolarization: As early as __ following nerve transection, __ of sacrolemma __

3hrs; RMP; decreases

Physiology of denervation: Atrophy: To a greater extent, of __ muscle fibers

type II

Physiology of denervation: M. degeneration

Intramuscular venous stasis

Superimposed trauma

Physiology of denervation: Other changes

Hypersensitivity of Ach

Fibrillations

Membrane changes

Mechanical changes

Physiology of re-innervation: Total denervation rate of n growth

1-2mm/day

Physiology of re-innervation: Partial denervation

Collateral sprouting

Nodal

Terminal

Controversies for ES: FOR

• Can cause denervated m. to contract

• Limits edema & venous stasis → delays muscle fibrosis

• Recovery time is shortened

Controversies for ES: AGAINST

• May disrupt regenerating neuromuscular junctions

• Further traumatize nerves

• Not worth financial & time costs

Parameters: Waveform/Current type

Slowly rising exponentially progressive current (EPC)

• Saw tooth pulse

• Triangular

• Trapezoidal pulse

Monophasic PC

Parameters: Pulse freq

1-500 pps/Hz

Parameters: Pulse duration

≥ chronaxie

1-450 msec (less accurate)

Determination of pulse duration

Rheobase

Chronaxie

Pulse duration: Rheobase definition

Least amt of INTENSITY needed for visible m. contraction for an indefinite duration

Pulse duration: Rheobase value

5-35 volts/ 2-18 mA

Pulse duration: Chronaxie definition

Minimum TIME required to produce a muscle contraction c an intensity set at 2x the rheobase

Pulse duration: Chronaxie value

0.05-0.5 ms or <1ms

Strength duration curve: Innervated muscles

SD curve shifts to the left (for normal physiologic ms)

Strength duration curve: Dennervated ms

SD shifts tot he right (takes a longer time to stimulate c a higher rheobase intensity)

Parameters: Current amplitude

Maximum tolerated contraction

Parameters: Duration

≤ 20-30 mins

2-3x a day; 5-7 days per wk

Parameters: Electrode configuration

Cathode over most excitable part or muscle

Ideally smaller than anode

Parameters: ES for denervated m.s: Pulse duration

≥ Chronaxie (more accurate)

1-400 msec

Parameters: ES for denervated m.s: Amplitude

Visible m. twitches up to max tolerated contraction

Parameters: ES for denervated m.s: Ramp up/down

N/A

Parameters: ES for denervated m.s: Frequency

1-500 pps/Hz

Parameters: ES for denervated m.s: Duration

20-30 mins

Parameters: ES for denervated m.s: On time: Off time ratio

1:1

Evidence of ES fro denervated ms

ES combined c exercise = inc axonal regeneration p peripheral n. injury

Documentation

ES on <affected m> x <pulse freq> x <pulse duration> x <treatment duration> to <rationale>

Contraindications

(DOOM DAAP)

DVT / PVDs

Over carotid sinus/phrenic n

Over abdomen/pelvis of preggo

Malignant tumors (cancer)

Diathermy (within 3-5m)

Active hemorrhage (areas)

Arrythmias (unstable)

Pacemaker (demand-type)

Precautions

(I SEC)

Impaired mentation and sensation

Skin irritation or open wounds

Epilepsy or seizure disorders

Cardiac disease

Adverse effects

Burns (d/t inc current density)

Skin irritation