Module 2: Therapeutic Modalities

Introduction

Acute and Chronic Pain

Thermotherapy and Cryotherapy

Ultrasounds

Mechanotransduction

Tissue Types

Articular Cartilage

Muscle

Tendon

Bone

Bone stimulation

TENS (Transcutaneous Electrical Nerve Stimulation)

sources of Acute Soft Tissue Pain

pain can arise from:

Overstretch injury

Heavy eccentric loading

Direct insult to the tissue

Muscle strains

DOMS

How does muscle damage produce pain and weakness

The pathway from damage to pain

DOMS is still not entirely understood

The following is observed post-exercise

cellular osmolarity increases

capillary permeability increases, which increases the likelihood of edema

inflammatory mediators are released

inorganic phosphate, H+ and lactic build up as a result of anaerobic metabolism

produces muscle fatigue

resulting edema can cause compression of the capillaries which can inhibit blood flow

results in reduced o2 delivery and impaired waste removal

Exercise can also induce oxidative stress from the increased energy turnover and elevated temperature

this oxidative stress can affect excitation-contraction coupling and modify Ca2+ levels

elevates calcium and inflammation can inhibit protein synthesis and impaire force generation

some heavy exercise types can cause direct damage to the muscle cell (sarcolemma and CT)

if there isn't proper post-exercise recovery, the inflammation can continue and cause secondary muscle damage

Acute pain not treated adequately can become chronic pain

Nerve cells start to remodel

Inhibitory interneurons are lost

Peripheral nociceptors become overactivated

This process leads to long-term sensitization of second-order spinal neurons: chronic pain

Acute pain management

Pharmacotherapies

Nonpharmacological

Relaxants

Corticosteroids

Acetaminophen

Opiods

NSAIDS

Cold

Therapeutic ultrasound

Heat

TENS

commonly used modality for both acute and chronic pain


Both come in a wide array of types

Cryotherapy

Thermotherapy

used in managing:

DOMS

Inflammation

Muscle spasm

Edema

Chronic pain

Acute trauma

Effectiveness varies by the modality's ability to lower temperature - wetted ice is more effective than cubed at lower skin/muscle temp

Intended Effects

To reduce inflammation to an affected area by slowing the delivery of leukocytes and other inflammatory mediators

To reduce metabolic demand of an affected area in order to prevent secondary hypoxic damage

To reduce blood flow to an affected area via a sympathetic vasoconstrictive reflex

To produce an analgesic/anesthetic effect (cold-induced neuropraxia) by lowering activation threshold of nociceptors and the slowing the velocity of nerve signals carrying pain messages

To reduce muscle spasm via inhibition of the spinal cord reflex loop

Cold Sprays

Produces a cooling sensation superficially, which causes analgesia by activating ion channels in peripheral neurons

While it may have an analgesic effect, it does not actually lower tissue temperature or produce decreases in metabolism or blood flow

Do not act by lowering tissue temperature

Specific Uses

Ankle Sprain

DOMS

High-quality studies examining the use of cryotherapy for ankle sprains are scarce

Some studies suggest a marginal benefit, some suggest improvements in pain, function and RTP; some are inconclusive or show no superior effect over compression alone

Many have small sample sizes and are of a structurally low quality

Ice baths have demonstrated some ability to reduce post-exercise soreness

Not immediately, but within the DOMS time frame

The evidence is conflicting, however

Contraindications or Special Considerations

Should be used with caution or not used in individuals with:

cold hypersensitivity

Raynaud's disease

Decreased sensitization

Vascular compromise

hypertension

serious cognitive impairement

Superficial heat includes

Deep heat therapies

wraps

hot stone therapy

heating pads

hot towels

hot water bottles

sauna, paraffin wax

Moist heat

ultrasound

short wave and microwave diathermy

effectiveness is based on the modality's ability to raise tissue temperature

heat produces a therapeutic effect by:

Increasing blood flow (vasodilation), with the intention of increasing the supply of blood, oxygen and nutrients to the affected tissue, as well as tissue metabolism

Increasing elasticity of connective tissue, with the goal of improved ROM through increases in viscoelastic properties of collagen fibers

Relieving pain through mediation of neural transduction through descending
antinociceptive pathways

Specific use

LBP

DOMS

Heat does demonstrate the ability to improve pain symptoms and ROM in pxs with low back pain

Heat can also serve as a successful adjunct to exercise therapy for LBP

Heat demonstrated the ability to reduce symptoms of DOMS when used preventatively and post-exercise

special consideration

should be used with caution or not used in individuals with:

Spinal cord injury

diabetes mellitus

Poor Circulation

Rheumatoid arthritis

Multiple Sclerosis

Heat vs Cold

warm pool

Cold pool

elevated levels of muscle stress reaction markers

decreased muscle stress markers including skeletal troponin I, CK, and myoglobin

Used with transition coupling gel

US is used for a huge array of MSK conditions

used therapeutically between 1-3 MHz

Non-thermal effects

Thermal effects

Effectiveness

higher intensities are used for other clinical purposes like abortions

Sprained ligaments, inflamed tendons and tendon sheaths, lacerations and other soft tissue damage, scar tissue sensitivity and tension, strained and torn muscles, inflamed and damaged joint capsules, fasciitis, and delayed-onset muscle soreness

At certain frequencies, US can provide a thermal effect to target tissues

Any benefit here is derived through similar mechanisms of other modalities of thermotherapy

US also provides non-thermal effects via acoustic streaming and cavitation

US is purported to modulate membrane potentials, alter cellular proliferation, increase collagen synthesis and increase proteins associated with inflammation and injury healing

Cavitation

Acoustic streaming

the physical forces of the sound waves that provide a driving force capable of displacing ions and small molecules

the physical forces of the sound waves on microenvironmental gases within fluid

Cavitation causes pulsations in tiny gas bubbles which can alter metabolism of the cell

In vivo studies using US are difficult

effectiveness in treating certain types of MSK conditions

Many rials have been performed in animal models

some remaining mechanistic questions

“The process by which the body converts mechanical loading into cellular responses. These cellular responses, in turn, promote structural change.”

occurs in soft tissues and in bone tissue

  1. Cell to cell communication (the integration)
  1. Effector response (the response)
  1. Mechanocoupling (the stimulus)

Can be shear forces, compressive forces, or tensile forces

Results in chemical signals being released

The physical load that disrupts a tissue's cells

The cell/s receiving the stimulus pass along the message to distal cells through
chemical mediators

Signaling proteins include calcium and inositol triphosphate

So long as the load is within the beneficial range, effector cells will respond to the stimulus with growth, repair, or stimulation of the target tissue

Too heavy load can cause stress-induced degradation

Too little stimuli and tissues can atrophy or degrade

Both mechanoresponsive and dynamic tissue

Tendon shows an upregulation of IGF-1 and other growth factors in response to exercise stimulus

Chondrocytes (cartilage cells) are mechanosensitive

Exact pathways seem comparable to muscle pathways, but are still under investigation

Overload leads to immediate increase in mechanogrowth factor (MGF) – a relative of IGF-1

MGF leads to hyptertrophy via activation of satellite cells

when skeletal muscle is damaged:

Daughter cells differentiate into myoblasts (undifferentiated single-nucleus cells, that serve as a precursor to myocytes)

Satellite cell-mediated hypertrophy of damaged muscle

Satellite cells (undifferentiated stem cells) in the plasma membrane and basement membrane are activated and undergo mitotic proliferation

They detect tensile loads and transform that stress into a series of biochemical reactions

osteocytes are the mechanosensors in bone

Osteoclasts and osteoblasts are stimulated to cause bone formation

Nitric oxide (NO) and cAMP are secreted in response to mechanical stress in the
immediate early stage

The expression level of IGF-I is enhanced by other cellular mediators to respond to stress with growth

Electrical Stimulation

Suggested to impact cellular pathways, including growth factor synthesis, proteoglycan and collagen regulation, and cytokine production

These pathways may stimulate the calcium-calmodulin pathway to stimulate bone

Non-invasive therapy meant to stimulate bone healing

Effectiveness

Ultimately, there is insufficient evidence to make a conclusion about bone stimulators

cost should be a major consideration

Tolerance to TENS can be developed

There is some evidence to suggest the effectiveness of TENS

Functions to treat pain both peripherally and centrally

TENS can be used at different frequencies

Typically used with either a small portable unit and attached electrodes or a larger stationary unit and electrodes

Nonpharmacologica pain relief treatment for both acute and chronic pain

Central and Peripheral Functions

electrodes placed at the site of injury

Centrally, sites in the spinal cord and brainstem that utilize opioid, serotonin, and muscarinic receptors are activated by TENS

Peripherally, at the site of TENS application, opioid and α-2 noradrenergic receptors are involved in TENS-induced analgesia

GABA the primary inhibitor NT is also implicated

Motor levels will help to initiate muscle contraction (Russian stimulation)

Sensory levels will assist with pain management

Can be avoided pharmacologically or non-pharmacologically

Some studies are underpowered or not well-controlled

less force generation

Rhabdomyolysis

breaks muscle tissue

Byproduct impair kidney function resulting in urine colour changes

can't give it to yourself since you can usually tell where your own threshold is

for pain and inflammation

use great deal of caution

must look at many different factors when choosing a modality

event

sport

age

training