Mirror Therapy – Lower Extremity

Evidence Reviewed as of before: 01-11-2018
Author(s): Annabel McDermott, OT; Adam Kagan, B.Sc; Samuel Harvey-Vaillancourt, PT U3; Shahin Tavakol, PT U3; Dan Moldoveanu, PT U3; Phonesavanh Cheang, PT U3; Elissa Sitcoff, BA BSc; Nicol Korner-Bitensky, PhD OT
Table of contents

Introduction

Mirror therapy is a type of motor imagery whereby the patient moves his unaffected limb while watching the movement in a mirror; this in turn sends a visual stimulus to the brain to promote movement in the affected limb. Some of the effects of mirror therapy on the brain have already been demonstrated. A crossover study on healthy individuals by Garry, Loftus & Summers (2004) showed that viewing the mirror image of an individual’s active hand increased the excitability of neurons in the ipsilateral primary motor cortex significantly more than viewing the inactive hand directly (no mirror). The study also found a trend toward significance in favour of viewing a mirror image of the active hand compared to viewing the active hand directly (no mirror).

While numerous studies have investigated the use of mirror therapy on the upper extremity following stroke, there is a limited body of evidence regarding lower extremity mirror therapy. As more studies become available, the benefits and use of mirror therapy with the lower extremity can be better understood. In order to gain a clearer appreciation for the effect of mirror therapy on lower extremity outcomes, this review includes studies where mirror therapy is provided to the intervention group in isolation rather than as a combined treatment (e.g. mirror therapy with repetitive transcranial magnetic stimulation).

Please also see our Mirror Therapy – Upper Extremity module for studies that have investigated the use of mirror therapy with the upper limbs.

Clinician Information

Note: When reviewing the findings, it is important to note that they are always made according to randomized clinical trial (RCT) criteria – specifically as compared to a control group. To clarify, if a treatment is “effective” it implies that it is more effective than the control treatment to which it was compared. Non-randomized studies are no longer included when there is sufficient research to indicate strong evidence (level 1a) for an outcome.

Nine randomized trials (4 high quality RCTs, 4 fair quality RCTs and 1 poor quality RCT) have studied the use of lower extremity mirror therapy following stroke. Of these:

  • One fair quality study investigated the effect of mirror therapy on balance, mobility and motor function in the acute phase of stroke recovery;
  • Three high quality RCTs involved patients in the subacute phase of recovery and outcomes included functional ambulation, gait and mobility, functional independence, motor recovery, spasticity and range of motion;
  • One high quality RCT and one fair quality RCT involved patients in the chronic phase of recovery and included outcomes of gait and walking speed, motor function and motor recovery, range of motion and spasticity; and
  • The remaining 2 fair quality RCTs and 1 poor quality RCT included patients across the recovery continuum and outcomes included balance, gait and walking, motor function and motor recovery.

Comparison interventions included sham mirror therapy, conventional rehabilitation, electrical stimulation and facilitated movement/exercises.

Results Table

View results table

Outcomes

Acute Phase

Balance
Not Effective
2A

One fair quality RCT (Mohan et al., 2013) investigated the effect of lower extremity mirror therapy on balance in patients with acute stroke. This fair quality RCT randomized patients to receive lower extremity mirror therapy or sham mirror therapy; both groups also received conventional stroke rehabilitation. Balance was measured by the Brunnel Balance Assessment at post-treatment (2 weeks). No significant between-group difference was found.

Conclusion: There is limited evidence (Level 2a) from one fair quality RCT that lower extremity mirror therapy is not more effective than a comparison therapy (sham mirror therapy) for improving balance in patients with acute stroke.

Mobility
Effective
2A

One fair quality RCT (Mohan et al., 2013) investigated the effect of lower extremity mirror therapy on mobility in patients with acute stroke. This fair quality RCT randomized patients to receive lower extremity mirror therapy or sham mirror therapy; both groups also received conventional stroke rehabilitation. Mobility was measured by the Functional Ambulation Categories at post-treatment (2 weeks). A significant between-group difference was found, in favour of mirror therapy vs. sham therapy.

Conclusion: There is limited evidence (Level 2a) from one fair quality RCT that lower extremity mirror therapy is more effective than a comparison therapy (sham mirror therapy) for improving mobility in patients with acute stroke.

Motor function
Not Effective
2A

One fair quality RCT (Mohan et al., 2013) investigated the effect of lower extremity mirror therapy on motor function in patients with acute stroke. This fair quality RCT randomized patients to receive lower extremity mirror therapy or sham mirror therapy; both groups also received conventional stroke rehabilitation. Lower extremity motor function was measured by the Fugl-Meyer Assessment (Lower Extremity score) at post-treatment (2 weeks). No significant between-group difference was found.

Conclusion: There is limited evidence (Level 2a) from one fair quality RCT that lower extremity mirror therapy is not more effective than a comparison therapy (sham therapy) for improving lower extremity motor function in patients with acute stroke.

Subacute Phase

Functional ambulation
Not Effective
1B

One high quality RCT (Sutbeyaz et al., 2007) investigated the effect of lower extremity mirror therapy on functional ambulation in patients with subacute stroke. This high quality RCT randomized patients to receive lower extremity mirror therapy or sham mirror therapy; both groups received conventional rehabilitation. Functional ambulation was measured by the Functional Ambulation Categories at post-treatment (4 weeks) and follow-up (6 months). No significant between-group difference was found at follow-up.
Note: Post-treatment results were not reported.

Conclusion: There is moderate evidence (Level 1b) from one high quality RCT that lower extremity mirror therapy is not more effective than a comparison intervention (sham mirror therapy) for improving functional ambulation in patients with subacute stroke.

Functional independence
Effective
1B

One high quality RCTs (Sutbeyaz et al., 2007) investigated the effect of lower extremity mirror therapy on functional independence in patients with subacute stroke. This high quality RCT randomized patients to receive lower extremity mirror therapy or sham mirror therapy; both groups received conventional rehabilitation. Functional independence was measured by the Functional Independence Measure (Motor score) at post-treatment (4 weeks) and follow-up (6 months). A significant difference was seen at follow-up, in favour of mirror therapy vs. sham mirror therapy.
Note: Post-treatment results were not reported.

Conclusion: There is moderate evidence (Level 1b) from one high quality RCT that lower extremity mirror therapy is more effective than a comparison intervention (sham mirror therapy) for improving functional independence in patients with subacute stroke.

Gait
Effective
1B

One high quality RCT (Ji & Kim, 2014) investigated the effect of lower extremity mirror therapy on gait in patients with subacute stroke. This high quality RCT randomized patients to receive lower extremity mirror therapy or sham mirror therapy; both groups received conventional rehabilitation. Temporospatial gait characteristics (single stance, step length, stance phase, swing phase, velocity, cadence, stride length, step width) were measured by a motion analysis device at post-treatment (4 weeks). Significant between-group differences were found in 3 measures (single stance, step length, stride length), in favour of mirror therapy vs. sham mirror therapy.

Conclusion: There is moderate evidence (Level 1b) from one high quality RCT that lower extremity mirror therapy is more effective than a comparison intervention (sham mirror therapy) for improving some gait measures in patients with subacute stroke.

Mobility
Effective
1B

One high quality RCT (Xu et al., 2017) investigated the effect of lower extremity mirror therapy on mobility in patients with subacute stroke. This high quality RCT randomized patients with foot drop to receive lower extremity mirror therapy, mirror therapy and neuromuscular electrical stimulation (NMES), or sham mirror therapy. Mobility was measured by the 10 meter Walk Test at post-treatment (4 weeks). Significant between-group difference was found, in favour of lower extremity mirror therapy vs. sham mirror therapy.

Note: Significant between-group differences were also found in favour of mirror therapy + NMES vs. lower extremity mirror therapy and vs. sham mirror therapy.

Conclusion: There is moderate evidence (Level 1b) from one high quality RCT that lower extremity mirror therapy is more effective than a comparison intervention (sham mirror therapy) for improving mobility in patients with subacute stroke.

Motor recovery
Effective
1A

Two high quality RCTs (Sutbeyaz et al., 2007; Xu et al., 2017) investigated the effect of lower extremity mirror therapy on lower extremity motor recovery in patients with subacute stroke.

The first high quality RCT (Sutbeyaz et al., 2007) randomized patients to receive lower extremity mirror therapy or sham mirror therapy; both groups received conventional rehabilitation. Lower extremity motor recovery was measured by Brunnstrom stages of motor recovery (Lower extremity score) at post-treatment (4 weeks) and follow-up (6 months). A significant between-group difference was found at follow-up, in favour of mirror therapy vs. sham mirror therapy.

Note: post-treatment results were not reported.

The second high quality RCT (Xu et al., 2017) randomized patients with foot drop to receive lower extremity mirror therapy, mirror therapy and neuromuscular electrical stimulation (NMES), or sham mirror therapy. Lower extremity motor recovery was measured by Brunnstrom stages of motor recovery (Lower extremity score) at post-treatment (4 weeks). A significant between-group difference was found, in favour of lower extremity mirror therapy vs. sham mirror therapy.

Note: A significant between-group difference was found in favour of mirror therapy + NMES vs. sham mirror therapy. There were no significant differences between lower extremity mirror therapy vs. mirror therapy + NMES.

Conclusion: There is strong evidence (Level 1a) from two high quality RCTs that lower extremity mirror therapy is more effective than a comparison intervention (sham mirror therapy) for improving lower extremity motor recovery in patients with subacute stroke.

Range of motion
Effective
1B

One high quality RCT (Xu et al., 2017) investigated the effect of lower extremity mirror therapy on range of motion in patients with subacute stroke . This high quality RCT randomized patients with foot drop to receive lower extremity mirror therapy, mirror therapy and neuromuscular electrical stimulation (NMES), or sham mirror therapy. Passive range of motion on ankle dorsiflexion was measured by a goniometer at post-treatment (4 weeks). A significant between-group difference was found, in favour of lower extremity mirror therapy vs. sham mirror therapy.

Note: A significant between-group difference was found in favour of mirror therapy + NMES vs. sham mirror therapy. There were no significant differences between lower extremity mirror therapy vs. mirror therapy + NMES.

Conclusion: There is moderate evidence (Level 1b) from one high quality RCT that lower extremity mirror therapy is more effective than a comparison intervention (sham mirror therapy) for improving range of motion (ankle dorsiflexion) in patients with subacute stroke.

Spasticity
Not Effective
1A

Two high quality RCTs (Sutbeyaz et al., 2007; Xu et al., 2017) investigated the effect of lower extremity mirror therapy lower extremity spasticity in patients with subacute stroke.

The first high quality RCT (Sutbeyaz et al., 2007) randomized patients to receive lower extremity mirror therapy or sham mirror therapy; both groups received conventional rehabilitation. Lower extremity spasticity was measured by the Modified Ashworth Scale at post-treatment (4 weeks) and follow-up (6 months). No significant between-group difference was found at follow-up.
Note: Post-treatment results were not reported.

The second high quality RCT (Xu et al., 2017) randomized patients with foot drop to receive lower extremity mirror therapy, mirror therapy and neuromuscular electrical stimulation (NMES), or sham mirror therapy. Lower extremity spasticity was measured by the Modified Ashworth Scale (plantar flexion) at post-treatment (4 weeks). No significant between-group difference was found when comparing lower extremity mirror therapy vs. sham mirror therapy.
Note: Significant between-group difference was found in favour of mirror therapy + NMES vs. sham mirror therapy. There were no significant differences between lower extremity mirror therapy vs. mirror therapy + NMES.

Conclusion: There is strong evidence (Level 1a) from two high quality RCTs that mirror therapy is not more effective than a comparison intervention (sham mirror therapy) for reducing lower extremity spasticity in patients with subacute stroke.

Chronic Phase

Gait
Effective
1b

One high quality RCT (Arya, Pandian & Kumar, 2017) investigated the effect of lower extremity mirror therapy on gait in patients with chronic stroke. This high quality RCT randomized patients to receive lower extremity mirror therapy or time-matched conventional rehabilitation. Gait was measured by the Rivermead visual gait assessment at post-treatment (3 months). A significant between-group difference was found, in favour of mirror therapy vs. conventional rehabilitation.

Conclusion: There is moderate evidence (Level 1b) from one high quality RCT that lower extremity mirror therapy is more effective than a comparison intervention (conventional rehabilitation) for improving gait in patients with chronic stroke.

Motor function
Effective
1B

One high quality RCT (Arya, Pandian & Kumar, 2017) investigated the effect of lower extremity mirror therapy on lower extremity motor function in patients with chronic stroke. This high quality RCT randomized patients to receive lower extremity mirror therapy or time-matched conventional rehabilitation. Lower extremity motor function was measured by the Fugl-Meyer Assessment (Lower extremity score) at post-treatment (3 months). A significant between-group difference was found, in favour of mirror therapy vs. conventional rehabilitation.

Conclusion: There is moderate evidence (Level 1b) from one high quality RCT that lower extremity mirror therapy is more effective than a comparison intervention (conventional rehabilitation) for improving lower extremity motor function in patients with chronic stroke.

Motor recovery
Not Effective
1B

One high quality RCT (Arya, Pandian & Kumar, 2017) and one fair quality RCT (Abo Salem & Huang, 2015) investigated the effect of lower extremity mirror therapy on motor recovery in patients with chronic stroke.

The high quality RCT (Arya, Pandian & Kumar, 2017) randomized patients to receive lower extremity mirror therapy or time-matched conventional rehabilitation. Lower extremity motor recovery was measured by the Brunnstrom stages of motor recovery (Lower extremity score) at post-treatment (3 months). No significant between-group difference was found.

The fair quality RCT (Abo Salem & Huang, 2015) randomized patients to receive lower extremity mirror therapy or sham mirror therapy; both groups received conventional rehabilitation. Lower extremity motor recovery was measured by the Brunnstrom stages of motor recovery (Lower extremity score) at post-treatment (4 weeks). A significant between-group difference was found, in favour of lower extremity mirror therapy vs. sham mirror therapy.

Conclusion: There is moderate evidence (Level 1b) from one high quality RCT that lower extremity mirror therapy is not more effective than a comparison intervention (conventional rehabilitation) for improving motor recovery in the chronic phase of stroke recovery.

Note: However, a fair quality RCT found that lower extremity mirror therapy was more effective than sham mirror therapy for improving motor recovery. The studies differed in the intensity and duration of intervention, as well as the type of mirror therapy and comparison intervention provided.

Range of motion
Effective
2a

One fair quality RCT (Abo Salem & Huang, 2015) investigated the effect of lower extremity mirror therapy on range of motion in patients with chronic stroke. This fair quality RCT randomized patients to receive lower extremity mirror therapy or sham mirror therapy; both groups received conventional rehabilitation. Passive range of motion on ankle dorsiflexion was measured by a goniometer at post-treatment (4 weeks). A significant between-group difference was found, in favour of lower extremity mirror therapy vs. sham mirror therapy.

Conclusion: There is limited evidence (Level 2a) from one fair quality RCT that lower extremity mirror therapy is more effective than a comparison intervention (sham mirror therapy) for improving range of motion (ankle dorsiflexion) in patients with chronic stroke.

Spasticity
Not Effective
2A

One fair quality RCT (Abo Salem & Huang, 2015) investigated the effect of lower extremity mirror therapy on spasticity in patients with chronic stroke. This fair quality RCT randomized patients to receive lower extremity mirror therapy or sham mirror therapy; both groups received conventional rehabilitation. Spasticity (ankle plantarflexion) was measured by the Modified Ashworth Scale at post-treatment (4 weeks). No significant between-group difference was found.

Conclusion: There is limited evidence (Level 2a) from one fair quality RCT that lower extremity mirror therapy is not more effective than a comparison intervention (sham mirror therapy) for reducing spasticity (ankle plantarflexion) in patients with chronic stroke.

Walking speed
Not Effective
1B

One high quality RCT (Arya, Pandian & Kumar, 2017) and one fair quality RCT (Abo Salem & Huang, 2015) investigated the effect of lower extremity mirror therapy on walking speed in patients with chronic stroke.

The high quality RCT (Arya, Pandian & Kumar, 2017) randomized patients to receive mirror therapy or time-matched conventional rehabilitation. Walking speed was measured by the 10 Meter Walk Test (10MWT -Comfortable speed, Maximum speed) at post-treatment (3 months). No significant between-group differences were found.

The fair quality RCT (Abo Salem & Huang, 2015) randomized patients to receive lower extremity mirror therapy or sham mirror therapy; both groups received conventional rehabilitation. Walking speed was measured by the 10MWT at post-treatment (4 weeks). A significant between-group difference was found, in favour of lower extremity mirror therapy vs. sham mirror therapy.

Conclusion: There is moderate evidence (Level 1b) from one high quality RCT that lower extremity mirror therapy is not more effective than a comparison intervention (conventional rehabilitation) for improving walking speed in patients with chronic stroke.

Note: However, a fair quality RCT found that lower extremity mirror therapy was more effective than sham mirror therapy for improving walking speed. The studies differed in the intensity and duration of intervention, as well as the type of mirror therapy and comparison intervention provided.

Phase of stroke recovery not specific to one period

Balance
Not Effective
2A

One fair quality RCT (Wang et al., 2017) investigated the effect of lower extremity mirror therapy on balance in patients with stroke. This fair quality RCT randomized patients with acute/subacute stroke to receive lower extremity mirror therapy or sham mirror therapy; both groups received conventional rehabilitation. Balance was measured by the Berg Balance Scale at post-treatment (6 weeks). No significant between-group difference was found.

Conclusion: There is limited evidence (Level 2a) from one fair quality RCT that lower extremity mirror therapy is not more effective than a comparison intervention (sham mirror therapy) for improving balance in patients with stroke.

Gait
Not Effective
2A

One fair quality RCT (Ji et al., 2014) investigated the effect of lower extremity mirror therapy on gait in patients with stroke. This fair quality RCT randomized patients with subacute / chronic stroke to receive lower extremity mirror therapy, lower extremity mirror therapy + functional electrical stimulation (FES), or sham mirror therapy; all participants received additional rehabilitation. Gait was measured by a three-dimensional motion capture system (velocity, cadence, step length and stride length) at post-treatment (6 weeks). A significant between-group difference in one measure (velocity) was found, in favour of lower extremity mirror therapy vs. sham mirror therapy.
Note: There were significant between-group differences in three measures of gait (velocity, step length, stride length), in favour of mirror therapy + FES vs. sham mirror therapy. There were no significant differences between lower extremity mirror therapy vs. mirror therapy + FES.

Conclusion: There is limited evidence (Level 2a) from one fair quality RCT that lower extremity mirror therapy is not more effective than a comparison intervention (sham mirror therapy) for improving gait in patients with stroke.

Note: Mirror therapy with FES was more effective than sham mirror therapy for improving gait following stroke.

Motor function
Not Effective
2B

One poor quality RCT (Kawakami et al., 2015) investigated the effect of mirror therapy on lower extremity motor function in patients with stroke. This poor quality RCT randomized patients with acute/subacute stroke to receive (i) lower extremity mirror therapy, (ii) integrated volitional-control electrical stimulation, (iii) therapeutic electrical stimulation, (iv) repetitive facilitative exercises, or (v) facilitated movement. Lower extremity motor function was measured by the Stroke Impairment Assessment Set (Hip flexion test, Knee extension test, Foot pad test) at post-treatment (4 weeks). No significant between-group differences were found.

Conclusion: There is limited evidence (Level 2b) from one poor quality RCT that mirror therapy is not more effective than comparison interventions (integrated volitional-control electrical stimulation, therapeutic electrical stimulation, repetitive facilitative exercises, facilitated movement) for improving lower extremity motor function in patients with stroke.

Motor recovery
Effective
2A

One fair quality RCT (Wang et al., 2017) investigated the effect of lower extremity mirror therapy on motor recovery in patients with stroke. This fair quality RCT randomized patients with acute/subacute stroke to receive lower extremity mirror therapy or lower extremity sham mirror therapy; both groups received conventional rehabilitation. Motor recovery was measured by the Brunnstrom stages of motor recovery at post-treatment (6 weeks). A significant between-group difference was found, in favour of mirror therapy vs. sham mirror therapy.

Conclusion: There is limited evidence (Level 2a) from one fair quality RCT that lower extremity mirror therapy is more effective than a comparison intervention (sham mirror therapy) for improving lower extremity motor recovery in patients with stroke.

Walking
Effective
2A

One fair quality RCT (Wang et al., 2017) investigated the effect of lower extremity mirror therapy on walking in patients with stroke. This fair quality RCT randomized patients with acute/subacute stroke to receive lower extremity mirror therapy or lower extremity sham mirror therapy; both groups received conventional rehabilitation. Walking was measured by the Functional Ambulation Categories and the Functional Independence Measure (Locomotion subtest) at post-treatment (6 weeks). Significant between-group differences were found on both measures, in favour of mirror therapy vs. sham mirror therapy.

Conclusion: There is limited evidence (Level 2a) from one fair quality RCT that lower extremity mirror therapy is more effective than a comparison intervention (sham mirror therapy) for improving walking in patients with stroke.

References

Abo Salem, H.M. & Huang, X. (2015). The effects of mirror therapy on clinical improvement in hemiplegic lower extremity rehabilitation in subjects with chronic stroke. International Journal of Biomedical and Biological Engineering, 9(2), 163-6. DOI: 10.1177/0269215518766642

Arya, K.N., Pandian, S., & Kumar, S.P. (2017, September 26). Effect of activity-based mirror therapy on lower limb motor-recovery and gait in stroke: a randomised controlled trial. Neuropsychological Rehabilitation, DOI: 10.1080/09602011.2017.1377087.

Ji, S.G., Cha, H.-G., Kim, M.-K., & Lee, C.-R. (2014). The effect of mirror therapy integrating functional electrical stimulation on the gait of stroke patients. Journal of Physical Therapy Science, 26(4), 497-9. DOI: 10.1589/jpts.26.497

Ji, S.G. & Kim, M.K. (2014). The effects of mirror therapy on the gait of subacute stroke patients: a randomized controlled trial. Clinical Rehabilitation, 29(4), 348-54. DOI: 10.1177/0269215514542356.

Kawakami, K., Miyasaka, H., Nonoyama, S., Hayashi, K., Tonogai, Y., Tanino, G., Wada, Y., Narukawa, A., Okuyama, Y., Tomita, Y., & Sonoda, S. (2015). Randomized controlled comparative study on effect of training to improve lower limb motor paralysis in convalescent patients with post-stroke hemiplegia. Journal of Physical Therapy Science, 27(9), 2947-50. DOI: 10.1589/jpts.27.2947

Mohan, U., Babu, S.K., Kumar, K.V., Suresh, B.V., Misri, Z.K., Chakrapani, M. (2013). Effectiveness of mirror therapy on lower extremity motor recovery, balance and mobility in patients with acute stroke: a randomized sham-controlled pilot trial. Annals of Indian Academy of Neurology, 16(4), 634-9. DOI: 10.4103/0972-2327.120496

Sütbeyaz S., Yavuzer G., Sezer N., Koseoglu B. F. (2007). Mirror Therapy Enhances Lower-Extremity Motor Recovery and Motor Functioning After Stroke: A Randomized Controlled Trial. Archives of Physical Medicine and Rehabilitation, 88, 555-559. DOI: 10.1016/j.apmr.2007.02.034

Wang, H., Zhao, Z., Jiang, P., Li, X., Lin, Q., & Wu, Q. (2017). Effect and mechanism of mirror therapy on rehabilitation of lower limb motor function in patients with stroke hemiplegia. Biomedical Research, 28(22), 10165-70.

Xu, Q., Guo, F., Salem, H.M.A., Chen, H., & Huang, X. (2017). Effects of mirror therapy combined with neuromuscular electrical stimulation on motor recovery of lower limbs and walking ability of patients with stroke: a randomized controlled study. Clinical Rehabilitation, 31(12), 1583-91. DOI: 10.1177/0269215517705689

Excluded Studies

Cha, H.-G. & Kim, M.K. (2015). Therapeutic efficacy of low frequency transcranial magnetic stimulation in conjunction with mirror therapy for sub-acute stroke patients. Journal of Magnetics, 20(1), 52-6.

Reason for exclusion: study compared mirror therapy + rTMS vs. sham mirror therapy + sham rTMS, limiting the ability to compare mirror therapy vs. sham mirror therapy alone.

Cha, H.G. & Oh, D.W. (2016). Effects of mirror therapy integrated with task-oriented exercise on the balance function of patients with poststroke hemiparesis: a randomized-controlled pilot trial. International Journal of Rehabilitation Research, 39(1), 70-6. DOI: 10.1097/MRR.0000000000000148

Reason for exclusion: participants performed movements in front of mirrors with full view of both sides of the body simultaneously.

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