Chronic Pain Free Tools

How left/right training works, and what the research says

The gist

  • Deciding whether a picture shows a left or right body part makes your brain briefly imagine moving your own body, without you actually moving.
  • People with long-lasting pain are often slower or less accurate at these judgements, especially for limbs and the face.7
  • Left/right training is the first step of graded motor imagery, which reduced pain in small clinical trials for complex regional pain syndrome (CRPS) and phantom limb pain.1,3
  • The evidence is promising but limited. Left/right training is best thought of as a gentle first step and a way to track how your brain is processing a body area.

Your brain’s map of your body

Your brain keeps a working map of your body — where each part is, how it is positioned and how it can move. You use it constantly to plan movements without thinking. When pain lasts a long time, researchers think this map can become less precise, and the brain can become more protective of the painful area. That protection can show up as stiffness, guarding, and movements that feel effortful or unsafe even when the tissues have healed.

What a left/right judgement does

When you see a photo of a hand, or a head turned to one side, and decide whether it is left or right, you usually do it by mentally matching your own body to the picture. This is called implicit motor imagery: your brain rehearses the movement at a planning level, without you moving or consciously imagining it.

Because the task is fast and simple, it is a useful window into the body map. Researchers measure two things: how accurate you are, and how long you take.

What studies have found in people with pain

In people with CRPS of one hand, recognising pictures of the painful hand took longer, and the delay was related to how long they had had symptoms and how much pain the pictured movement would cause.2

A 2019 review pooled 25 studies with 2,266 participants. It found consistent evidence that people with chronic pain in the limbs or face perform worse on left/right judgements, but less consistent evidence for the neck and back.7

The neck specifically

  • What’s typical: in 1,361 adults without pain, the average time to judge a neck turn was about 1.6 seconds, and the median accuracy was 92.5%. Age, gender, handedness and how much the image was rotated all affected performance, and right turns were judged more accurately than left turns.8
  • Chronic vs. recent neck pain: in an online study of about 1,400 people, those with chronic neck pain were less accurate than people without pain, while people with recent (acute) neck pain were not.9 An earlier, smaller study found the same for recurrent neck pain.10
  • Training: in a small randomised trial of 48 people with chronic neck pain, a session of neck left/right judgements improved some measures of neck range of motion and position sense straight afterwards, while the same task with foot pictures did not.11 This was a short-term result in one study, so it needs confirming.

Graded motor imagery

Graded motor imagery (GMI) is a rehabilitation approach with three stages, usually done in order and with a clinician’s guidance:

  1. Left/right judgements, like the exercise on this site.
  2. Imagined movements: deliberately picturing yourself moving the painful area.
  3. Mirror therapy: using a mirror so the brain sees the painful side moving normally.

The idea is to work the brain’s movement networks gradually, starting at a level that is unlikely to set off a protective pain response, then building up, much like graded exercise for the body.

In a 2004 randomised trial of 13 people with long-standing CRPS, a six-week GMI programme reduced pain and swelling, and the effect was repeated when the control group then received the programme.1 A 2006 trial of 51 people with CRPS or phantom limb pain found that GMI reduced pain and disability more than physiotherapy and usual medical care.3

The honest limits

  • Small studies. A 2013 systematic review found GMI reduced pain compared with usual physiotherapy, but this was based on only two small trials (63 people), and the overall quality of the research was low. Very few trials have tested left/right training on its own, and they did not find an effect on pain.5 That is a small amount of research, not proof that it can’t help.
  • Real-world results vary. When two UK clinics offered GMI to people with CRPS as part of everyday care, average pain did not improve, although left/right performance did.6 How often and how carefully the exercises are practised may matter a lot.
  • Imagining movement can hurt. In some people with chronic arm pain, imagining movements increased pain and swelling.4 This is one reason GMI starts with the gentler left/right stage and builds up slowly.
  • Most research is on limbs. The best evidence comes from CRPS and phantom limb pain. Evidence for the neck is newer and smaller.

A note from the person who made this site: left/right training has been a genuinely helpful part of my own rehabilitation. That is one person’s experience, not a clinical result, but studies can’t capture everyone, and it is why this site exists.

So this site does not promise pain relief. What it offers is a free, convenient way to practise a well-studied exercise, track your own performance, and take a first step that you can discuss with your clinician.

Please read: this site is for education and practice. It is not medical advice and does not replace care from a qualified clinician. If an exercise makes your pain or other symptoms worse, stop and rest, and talk to your clinician before trying again.

References

  1. Moseley GL. Graded motor imagery is effective for long-standing complex regional pain syndrome: a randomised controlled trial. Pain. 2004;108(1–2):192–198. Link
  2. Moseley GL. Why do people with complex regional pain syndrome take longer to recognize their affected hand? Neurology. 2004;62(12):2182–2186. Link
  3. Moseley GL. Graded motor imagery for pathologic pain: a randomized controlled trial. Neurology. 2006;67(12):2129–2134. Link
  4. Moseley GL, Zalucki N, Birklein F, Marinus J, van Hilten JJ, Luomajoki H. Thinking about movement hurts: the effect of motor imagery on pain and swelling in people with chronic arm pain. Arthritis Care & Research. 2008;59(5):623–631. Link
  5. Bowering KJ, O’Connell NE, Tabor A, Catley MJ, Leake HB, Moseley GL, Stanton TR. The effects of graded motor imagery and its components on chronic pain: a systematic review and meta-analysis. The Journal of Pain. 2013;14(1):3–13. Link
  6. Johnson S, Hall J, Barnett S, et al. Using graded motor imagery for complex regional pain syndrome in clinical practice: failure to improve pain. European Journal of Pain. 2012;16(4):550–561. Link
  7. Breckenridge JD, Ginn KA, Wallwork SB, McAuley JH. Do people with chronic musculoskeletal pain have impaired motor imagery? A meta-analytical systematic review of the left/right judgment task. The Journal of Pain. 2019;20(2):119–132. Link
  8. Wallwork SB, Butler DS, Fulton I, Stewart H, Darmawan I, Moseley GL. Left/right neck rotation judgments are affected by age, gender, handedness and image rotation. Manual Therapy. 2013;18(3):225–230. Link
  9. Wallwork SB, Leake HB, Peek AL, Moseley GL, Stanton TR. Implicit motor imagery performance is impaired in people with chronic, but not acute, neck pain. PeerJ. 2020;8:e8553. Link
  10. Elsig S, Luomajoki H, Sattelmayer M, Taeymans J, Tal-Akabi A, Hilfiker R. Sensorimotor tests, such as movement control and laterality judgment accuracy, in persons with recurrent neck pain and controls: a case-control study. Manual Therapy. 2014;19(6):555–561. Link
  11. León-Hernández JV, Marcos-Lorenzo D, Morales-Tejera D, Cuenca-Martínez F, La Touche R, Suso-Martí L. Effect of laterality discrimination on joint position sense and cervical range of motion in patients with chronic neck pain: a randomized single-blind clinical trial. Somatosensory & Motor Research. 2019;36(2):136–143. Link