Red light therapy and physiotherapy: how they fit together

Heat packs, ice bricks, a TENS machine bought for a sore back, and now red light devices: plenty of households have at least one thing in the cupboard they reach for when something aches. If you're working with a physio, it's fair to wonder how red light therapy and physiotherapy fit together, and whether using something at home helps, gets in the way or makes no difference at all. Here's how passive therapies fit alongside active rehab, what the research does and doesn't say, and how to raise what you're using with your own physio.

Can you use red light therapy alongside physiotherapy?

It depends on you and what you're dealing with, so the person to ask is your own physio. In general terms, a passive therapy can sit alongside physio when your physio knows about it, it suits your situation, and it doesn't take the place of the work that actually changes how your body copes with load. Light, heat, ice and TENS are what physios call passive therapies: something is applied to you while you rest. At most, they play a supporting role.

That distinction matters because the parts of rehab that build capacity, such as graded exercise, strength work and getting back to your usual activities, all ask something of you. Passive therapies ask very little, which is exactly why they're appealing, and why it's easy to let them crowd out the harder, more useful work.

Active and passive care: what's the difference?

Active care is anything you do: exercises, walking, strength training, practising a movement that's become difficult, gradually returning to sport, gardening or play with the grandkids. Passive care is anything done to you or applied to you: massage, heat, ice, electrical stimulation, light.

Australia's Low Back Pain Clinical Care Standard puts this plainly. It asks clinicians to prioritise active strategies, to encourage people to stay active and return to their usual activities, and to use physical therapies such as heat wraps and massage only for a short time, as part of a package that includes physical activity. That standard was written for back pain, but the principle travels well to most everyday aches and strains: movement and load are where lasting change happens.

A useful test for any passive therapy is whether it makes the next bit of movement easier to start. If a heat pack loosens a stiff back enough that you go for your walk, it has earned its place. If it becomes the reason you skip the walk, it hasn't.

What does the evidence say about heat, ice, TENS and light?

The research on passive therapies has a common thread: they can offer short-term relief, and the effects are usually modest.

• Heat. An older (2006) Cochrane review of nine trials (1,117 participants) found moderate evidence that heat wraps reduced pain and disability in the short term for back pain of less than three months, with a small, short-lived effect. In one trial within the review, adding exercise to heat reduced pain further.
• Ice. The same review found too few good-quality studies to draw any conclusions about cold for back pain. Ice is still widely used for comfort after knocks and strains, but for back pain at least, there's little good research either way.
• TENS. A large 2022 review in BMJ Open included 381 randomised trials in adults and found pain was lower during or immediately after TENS than with a placebo, rating the evidence for that comparison as moderate certainty.
• Light. A 2009 review in The Lancet of 16 randomised trials (820 people) found low-level laser therapy reduced neck pain compared with placebo, immediately after treatment in people with recent neck pain, and for up to 22 weeks afterwards in people with longer-term neck pain. Those trials tested low-level lasers applied in a research setting, not LED devices used at home, so they don't tell us how a home device would perform.

None of this makes passive therapies a substitute for rehab. It does suggest some can offer modest, short-term relief, which is why it's worth thinking about when you use them.

Where passive therapies fit around your exercises

The same thinking applies whether it's a heat pack or red light therapy alongside physiotherapy: if you use something at home, it should fit around your exercises, not become the plan itself. In practice, that can look like this:

• Before exercise. Some people find warmth helps a stiff area feel ready to move. If that's you, use it shortly before your exercises, then do them.
• After exercise. Others prefer to settle things down after a session or a long day. That's fine too, as long as the exercises still happen.
• Keep the exercises non-negotiable. If you only have twenty minutes, spend them on the program your physio gave you rather than on a passive therapy.
• Follow the directions for use. More isn't better with heat, ice or light. Stick to the session length on the label, and never fall asleep on a heat pack or ice brick.
• Track what you notice. A quick note in your phone (what you used, when, and how your exercises felt afterwards) gives your physio something useful to work with.

How to talk to your physio about what you use at home

Physios generally want to know everything you're doing for a problem, including things you've bought yourself. It helps them interpret how you're progressing, and it means they can flag anything that doesn't suit your situation. Bring these details to your next appointment:

1. What it is. The product name and, for a light device, its wavelengths and whether it's included on the Australian Register of Therapeutic Goods. This guide to checking a device on the ARTG explains how to look it up, and this explainer on red and near-infrared wavelengths covers what the numbers mean.
2. How you use it. Where on your body, for how long, how often and at what time of day.
3. What you notice. Whether it changes your pain or stiffness, for how long, and whether your exercises feel easier or harder afterwards.
4. Your questions. Ask directly whether it fits your plan, whether there's any reason to avoid it for your particular problem, and whether the timing should change as you progress.

A good conversation here goes both ways. Your physio should be interested in what you're using, and you should feel free to ask anything, including whether to keep using it at all. What it shouldn't do is quietly become the whole plan. If you're ever unsure how much of your plan is active and how much is passive, it's a reasonable thing to ask.

When to get assessed instead of managing at home

Passive therapies suit everyday aches that are already understood. Get assessed rather than self-managing if:

• pain is severe, getting worse, or not settling the way you expected
• it started after a fall, accident or sudden injury
• you have numbness, pins and needles or weakness
• pain wakes you at night or comes with feeling generally unwell
• you're simply not sure what the problem is

In Australia you can generally see a physio without a GP referral, as Healthdirect explains, and you can search for one near you through the Australian Physiotherapy Association's Find a Physio directory. If symptoms are severe or you feel unwell, see your GP promptly.

The contents of this blog, such as text, content and graphics, are intended for educational purposes only. The content is not intended to substitute for professional medical advice, diagnosis or treatment. Always seek the advice of your healthcare provider. Consult your healthcare provider before use if you are pregnant, are sensitive to light, or are taking medications that may increase light sensitivity. Always read the label and follow the directions for use.