Research on IFT and TUS

Question 1

What could your overall conclusion on the evidence for use of TUS be?

Answer 1

• quality of evidence is very low, where it exists.
• Different systematic reviews have found current evidence doesn’t support use for LBP, hip or shoulder pain, or MSK disorders generally
• Larger, higher quality trials needed
• if we say it doesn’t target pain, how do we test whether it is doing it’s job of helping healing?
• Is it ethical to charge customers for treatment that despite many trials, hasn’t been shown to work?

Question 2

What are the 4 stages of healing?

Answer 2

bleeding, inflammation, proliferation, remodelling

Question 3

What effects might TUS have on inflammation stage?

Answer 3

• pro-inflammatory as it helps the inflammation stage work as well as possible
• Acoustic streaming may change platelet membrane permeability and encourage serotonin release
• TUS can interact with platelets, mast cells, macrophages and neutrophils to accelerate repair

Question 4

What effects might TUS have on proliferation stage?

Answer 4

• In vitro studies showed that TUS increased fibroblast motility
• TUS interacts with microphages to stimulate fibroblasts to proliferate
• Can increase angiogenesis (formation of new blood vessels)

Question 5

What effects might TUS have on remodelling stage?

Answer 5

• Low intensity TUS most effective at increasing collagen content (why we now mainly think about non-thermal effects of TUS, because low intensity is less heating)
• Mechanical properties and alignment of collagen improved with TUS
• Tensile strength and elasticity of scar higher than control groups the earlier the US was started post injury

Question 6

Why does IFT work?

Answer 6

• pain is reduced when you stimulate primary afferent neurons with low frequency currents
• it stimulates the muscles, which can pump/ flush fluid away and so reduce oedema
• side effect of stimulated muscles may be increased local blood flow

Question 7

How does opiate system work in IFT when stimulated with 1-5 or 2-4Hz?

Answer 7

The hypothalamus can request release of noradrenaline into the synaptic space to inhibit pain sensation

Reduces cortisol levels

Opiate mechanisms and any reduction in stress hormone will continue working after treatment finishes

Question 8

How does pain gate theory work in IFT when tissues stimulated with 90-150Hz?

Answer 8

At that frequency the tingling sensation from treatment is very pronounced and may lead to a temporary physiological block of nociceptive fibres

Takes pain away temporarily but will return once treatment ends

Question 9

How do pain gate and opiate overlap during IFT?

Answer 9

Opiate system helps people feel relaxed as well as helping with pain. So you might be using 90-150Hz for pain gate but athlete is releasing endorphins just from lying down having treatment

You could be using 2-4Hz to stimulate opiate system but beta fibres that relate to pain gate are being stimulated by sensation of sponges on their skin

Question 10

Research on IFT?

Answer 10

2 different systematic reviews found IFT:
- can be recommended for knee osteoarthritis because it helps short & long term pain and short term function
- probably better than placebo for LBP for pain and disability