Improving upper limb function is a core element of stroke rehabilitation needed to reach independency.
Different therapy approaches can support your recovery after stroke.

The theory behind mirror therapy

Based on the knowledge of the motor neuron system, mirror therapy uses visual stimulation. In reflecting the non-paretic side, it tricks the brain into seeing normal movements of the paretic limb. Because of neuroplasticity, restructuring and rewiring neurons by activating certain parts of the brain, is possible. The concept of mirror therapy was originally used by Ramachandran (1994) to treat ‘‘phantom limb’’ pain in amputees. The idea of creating an illusion to improve movement on the impaired limb was introduced later on. (1,2,3)

Background and how it works

Mirror therapy builds upon the findings of Dr. Ramachandran, that the efference- afference loop has been interrupted and can be restored. (1,4)

The efference- afference loop is everything that goes into and comes out of our brain to our body.  This means, by losing the loop we have to fall back to visual control, for example, to control our hand.
Observation of movements and performance of the observed action share similar areas in your brain. Movement-mirroring leads to additional activation in these areas. Findings like these are the basis for visual feedback and mirror therapy. (2)

During mirror therapy, a mirror is placed perpendicular out in front of you. The non-paretic limb should be on the reflecting side of the mirror. For example, looking into the mirror, you should be able to see the reflection of your left arm giving the illusion of watching your right arm. One of the biggest advantages of mirror therapy is the relatively easy setup and the possibility for self-administered home therapy. Especially for people with severe motor deficits, mirror therapy is a simple method for home therapy. (2)

Mirror therapy setting

Mirror therapy can also be included in all stages of recovery. Especially in the early stages, it can give you the chance to mentally practice a task before being physically able. (5)

It is very little you need for mirror therapy.

  • a mirror, or mirror box
  • concentration
  • a little bit of time and patience

Observation of a limb

Being able to create an illusion and concentrate on the limb in the mirror is the first step.
Sometimes that can be hard and it needs time to get used to. Focusing on the motionless limb in the mirror for 30 seconds can feel like forever at the beginning. Repeating this observation can help you to start your daily home therapy.

Observation of movement

By slowly moving the non-paretic arm and tracing the moving arm in the mirror, the brain can be tricked. Start without objects, just track a slow and simple movement repeatedly and you can learn how to include mirror therapy into your daily routine.
As you progress there are ways to include complex movements and objects into mirror therapy.

Left/Right Discrimination

Left-right discrimination in the rewellio app

Left/right discrimination, also known as left/right judgment tasks, is the mechanism of recognizing one side of the body as differ from the other. In addition, it also includes being able to detect movements in certain directions such as rotation. (6)

By looking at a picture of a hand or arm and thinking about its alignment we have to imagine the position and movement in our head.
In addition to mirror therapy early left/right discrimination and motor imagery can be used in addition to and as preparation for focusing on mirror therapy.

The data behind it

Here are some systematic reviews to read up:

Studies over the last 20 years show additional areas were mirror therapy is or could be effective.

  • Pain
    Clinical studies reported the effects of mirror therapy on pain reduction in arm amputees or CRPS-type I. (2)
  • Gait
    Studies indicate that mirror therapy for the lower limb may have a positive effect after stroke by improving gait speed. Also, mobility and motor recovery can be affected by mirror therapy. (8,9)

Other Studies show promising results concerning walking ability and balance by combining mirror therapy with conventional therapy. (10)

New ways of mirror therapy and visual stimulation

A Cochrane review, 2018 includes studies with new ways of movement observation and visual stimulation using video or computer graphics. By producing “mirror-like” images the same effect as in mirror therapy should occur. Virtual Rehabilitation devices using Augmented Reflection Technology show potential for stroke rehabilitation. (2, 11)

Research shows that virtual reality in stroke rehabilitation cannot replace therapy, but assist as an additional therapeutic approach in the rehabilitation process. (12)

How I include mirror therapy into my therapy routine

For me as an OT in an early phase rehab setting, mirror therapy presents itself as one of the first hands-off techniques that are available.
Having a mirror available in the clinic as well as in my therapy practice, I can evaluate the usability in each setting.
Especially for patients with high motoric and mild to moderate cognitive deficits, mirror therapy is something that I always try out.
Although mirror therapy should not be proclaimed as THE technique, a lot of my patients are able to add it into their individual training sessions.
Overall starting mirror therapy without supervision can often be very hard and frustrating. Having someone to guide at the beginning can ease the start. Even putting mirror therapy in a play-like context can help with your motivation.

If you like to know how rewellio is using this knowledge look at the box below.

Bibliography

    1. Garry, M. I., Loftus, A., & Summers, J. J. (2005). Mirror, mirror on the wall: Viewing a mirror reflection of unilateral hand movements facilitates ipsilateral M1 excitability. Experimental Brain Research, 163(1), 118–122. https://doi.org/10.1007/s00221-005-2226-9
    2. Thieme, H., Morkisch, N., Mehrholz, J., Pohl, M., Behrens, J., Borgetto, B., & Dohle, C. (2018). Mirror therapy for improving motor function after stroke. Cochrane Database of Systematic Reviews, 50(2), 2018–2019.  https://doi.org/10.1002/14651858.CD008449.pub3
    3. Zhang, J. J. Q., Fong, K. N. K., Welage, N., & Liu, K. P. Y. (2018). The Activation of the Mirror Neuron System during Action Observation and Action Execution with Mirror Visual Feedback in Stroke: A Systematic Review. Neural Plasticity, 2018, 1–14. https://doi.org/10.1155/2018/2321045
    4. Deconinck, F. J. A., Smorenburg, A. R. P., Benham, A., Ledebt, A., Feltham, M. G., & Savelsbergh, G. J. P. (2015). Reflections on Mirror Therapy. Neurorehabilitation and Neural Repair, 29(4), 349–361. https://doi.org/10.1177/1545968314546134
    5. Zimmermann-Schlatter, A., Schuster, C., Puhan, M. A., Siekierka, E., & Steurer, J. (2008). Efficacy of motor imagery in post-stroke rehabilitation: a systematic review. Journal of NeuroEngineering and Rehabilitation, 5(1), 8. https://doi.org/10.1186/1743-0003-5-8
    6. Berneiser, J., Jahn, G., Grothe, M., & Lotze, M. (2018). From visual to motor strategies: Training in mental rotation of hands. NeuroImage, 167, 247–255. https://doi.org/10.1016/j.neuroimage.2016.06.014
    7. Pérez-Cruzado, D., Merchán-Baeza, J. A., González-Sánchez, M., & Cuesta-Vargas, A. I. (2017). Systematic review of mirror therapy compared with conventional rehabilitation in upper extremity function in stroke survivors. Australian Occupational Therapy Journal, 64(2), 91–112. https://doi.org/10.1111/1440-1630.12342
    8. Louie, D. R., Lim, S. B., & Eng, J. J. (2019). The Efficacy of Lower Extremity Mirror Therapy for Improving Balance, Gait, and Motor Function Poststroke: A Systematic Review and Meta-Analysis. Journal of Stroke and Cerebrovascular Diseases, 28(1), 107–120. https://doi.org/10.1016/j.jstrokecerebrovasdis.2018.09.017
    9. Broderick, P., Horgan, F., Blake, C., Ehrensberger, M., Simpson, D., & Monaghan, K. (2018). Mirror therapy for improving lower limb motor function and mobility after stroke: A systematic review and meta-analysis. Gait & Posture, 63, 208–220. https://doi.org/10.1016/j.gaitpost.2018.05.017
    10. Li, Y., Wei, Q., Gou, W., & He, C. (2018). Effects of mirror therapy on walking ability, balance and lower limb motor recovery after stroke: a systematic review and meta-analysis of randomized controlled trials. Clinical Rehabilitation, 32(8), 1007–1021. https://doi.org/10.1177/0269215518766642
    11. Hoermann, S., Ferreira dos Santos, L., Morkisch, N., Jettkowski, K., Sillis, M., Devan, H., … Cutfield, N. J. (2017). Computerised mirror therapy with Augmented Reflection Technology for early stroke rehabilitation: clinical feasibility and integration as an adjunct therapy. Disability and Rehabilitation, 39(15), 1503–1514. https://doi.org/10.1080/09638288.2017.1291765
    12. Laver, K. E., Lange, B., George, S., Deutsch, J. E., Saposnik, G., & Crotty, M. (2017). Virtual reality for stroke rehabilitation. Cochrane Database of Systematic Reviews, 80(4 SUPPL. 1), 57–62. https://doi.org/10.1002/14651858.CD008349.pub4