This is probably one of the most important things to understand.

When we're talking about therapeutic red and near-infrared light in the context of photobiomodulation (PBM), the proposed effects aren't simply because we're warming an area up.

We're interested in how particular wavelengths of light may interact with cells and influence biological processes.

Think of it less as “heating the muscle” and more as “delivering light energy to tissue.”

That's where it starts getting interesting.

Meet the mitochondria!

Don't worry, we're not turning this into an anatomy exam.

But you might remember mitochondria from your anatomy and physiology studies. They're often described as the little powerhouses of our cells because they're involved in producing ATP, the usable energy cells need to function.

One of the principal proposed mechanisms of photobiomodulation involves light being absorbed by molecules within cells, particularly within the mitochondrial respiratory system.

This interaction is thought to influence cellular signalling and energy-related processes.

And from there, researchers have investigated possible downstream effects involving inflammatory signalling, circulation, tissue recovery and pain modulation.

That's a lot happening from something that, from the outside, simply looks like a red light!

This is where terminology can become confusing.

A therapeutic device may use red light, near-infrared light or a combination of wavelengths.

Visible red light generally uses shorter wavelengths than near-infrared light. Near-infrared wavelengths are invisible to the human eye and are of particular interest because of their ability to penetrate biological tissue differently.

So here's something worth remembering:

The brightest-looking red device isn't automatically the most therapeutically impressive one.

Some of the light being delivered may actually be invisible.

This is one reason why looking beyond appearance and understanding the specification of the equipment becomes important.

And then we add… a horse!

This is where laboratory science meets the real world.
Horses aren't hairless laboratory models.
They have coats.
Different coat colours.
Different skin pigmentation.
Different tissue depths.
Different amounts of muscle and fat.

And we're potentially trying to influence structures sitting at very different depths beneath the skin.

Research in horses has demonstrated that factors including wavelength, device characteristics and skin pigmentation can influence the transmission of light through equine tissues.

So when somebody asks:

“How long should I use red light for?”

The answer isn't necessarily as simple as giving them a number of minutes.

We first need to know what device we're talking about, what wavelengths it produces, how it is designed to be applied, what area we're targeting and what the manufacturer recommends.

That is why good-quality manufacturer guidance matters.

For me, this is probably the most interesting part.

Imagine you're working through a horse's longissimus dorsi.

Your hands tell you that one area feels different.

Perhaps the tissue feels less yielding.

Perhaps the horse gives you a different response.

Perhaps you've noticed something through movement assessment beforehand.

As a massage therapist, your first job isn't to grab a machine.

It's to think.

What am I feeling?

Does this make sense alongside what I observed?

Is it within my professional scope?

Does anything concern me enough to stop and recommend veterinary assessment?

And, if appropriate, could another modality complement what I'm already doing?

That's the point at which equipment becomes useful rather than simply impressive.

Red light doesn't replace good hands

I keep coming back to this because I think it is so important.

At Wolds Equine Rehabilitation & Training, we spend a huge amount of time teaching students to actually feel.

Feel normal tissue.
Feel differences.
Compare left with right.
Watch the horse.
Notice the tiny reactions rather than waiting for a dramatic one.
A red light device can't replace that skill.

But a therapist who has excellent hands and understands the science and practical application of additional modalities has another string to their bow.

And that's where I think our industry is heading.

Not hands or technology.

Hands plus knowledge plus appropriate technology.

Before we finish, let's have some fun with a few common assumptions.

“If it's glowing red, it's doing red light therapy.”

Not necessarily. Therapeutic devices are designed around particular wavelengths and treatment parameters. A red-coloured light alone doesn't tell us what is actually being delivered.

“The brighter it looks, the stronger the treatment.”

Again, not necessarily! Near-infrared wavelengths aren't visible to us, so our eyes aren't particularly useful for judging what a device is delivering.

“If ten minutes is good, twenty must be twice as good.”

No. Therapeutic dose doesn't necessarily work like that. Follow the protocol appropriate to the equipment rather than simply assuming more is better.

“I don't need to understand it because the machine does the work.”

Definitely not one we're teaching at Wolds!

Understanding why you're using something should always come before switching it on.

You don't need to become a physicist.

You don't need to memorise every wavelength ever studied.

And you certainly don't need to buy every new piece of equipment that appears on your social media feed!

What I do want you to develop is curiosity.

When somebody tells you that a modality does something, ask:

How?

Why?

What evidence supports that?

Is this particular device capable of delivering what we're talking about?

And is it appropriate for the horse standing in front of me?

That mindset will take you much further as a therapist than simply learning a list of supposed benefits.

Now we understand a little more about what we're trying to achieve with the light itself, our next blog can get even more practical.

We're going to look at what makes one red light device different from another.

We'll talk wavelengths, LEDs, power, treatment area, manufacturer protocols and some of the terminology you are likely to encounter when looking at equine red light equipment.

Because two machines can both glow red…

…but that doesn't necessarily mean they're doing exactly the same thing.

And with some exciting developments coming at Wolds Equine Rehabilitation & Training, this is definitely a subject we're going to be talking much more about.

Watch this space!

Over the next couple of blogs, we are going to take a much closer look at red and near-infrared light therapy.

We'll break down what those different wavelengths actually mean, why some light penetrates further than others, what happens when light reaches tissue and why the specifications of a therapeutic device are important.

We will also be looking at other modalities that can potentially sit alongside massage and rehabilitation.

This ties beautifully into the direction of our upcoming Wolds Equine CPD, because I want our CPD to keep evolving with the industry.

There are some really exciting developments happening within equine therapy and rehabilitation, and there is now some fantastic technology becoming much more accessible to everyday therapists and horse owners.

So rather than simply seeing a red light being used on a horse and wondering “What does that actually do?”, over the next few weeks we're going to start answering that question.

And I think it's going to be a really interesting subject.