Figure 1.
Characteristics of the Intervention
| Study | Group | n | Age (Mean ± SD) | Sex (M/F) | Time post-stroke (years) | Hemiplegic Side (Left/Right) | Duration/frequency | Electrodes placement | Application Parameters |
|---|---|---|---|---|---|---|---|---|---|
| Shamay, 2007 | TENS | 19 | 56.4 ± 9.1 | 17/2 | 6.2 ± 4.1 | NR | 4W - 5D | Acupuncture points used; ST 36 (Zusanli), LV 3 (Taichong), GB 34 (Yanglinquan) and UB 60 (Kunlun) | TENS: 100 Hz, square pulses of 0.2 ms, 2 to 3 times sensory threshold for 60 minutes. |
| TENS/TRT | 21 | 58.4 ± 7.1 | 16/5 | 5.0 ± 3.0 | TENS: 100 Hz, square pulses of 0.2 ms, 2 to 3 times sensory threshold for 60 minutes + TRT: (4 loading exercises and steps with wooden blocks of 2.5 or 5 cm height) during 60 minutes of training. | ||||
| PBO TENS | 20 | 57.1 ± 7.8 | 17/3 | 4.7 ± 4.1 | Placebo from TENS devices with identical appearance, with the electrical circuit disconnected inside, for 60 minutes + TRT (4 loading exercises and steps with wooden blocks of 2.5 or 5 cm height) during 60 minutes. | ||||
| Control | 20 | 57.3 ± 8.6 | 17/3 | 5.2 ± 2.9 | Not treatment. | Not treatment. | |||
| Shamay, 2009 | TENS | 28 | 56.5 ± 8.2 | 24/4 | NR | 18/10 | 4 W - 5D (20 ss) | Acupuncture points used; ST 36 (Zusanli), LV 3 (Taichong), GB 34 (Yanglinquan) and UB 60 (Kunlun) | TENS: 100 Hz, square pulses of 0.2 ms, 2 times sensory threshold for 60 minutes. |
| TENS/EX | 27 | 57.8 ± 7.3 | 21/6 | 17/10 | TENS: 100 Hz, square pulses of 0.2 ms, 2 times sensory threshold for 60 minutes + Task-related exercises recommended for stroke rehabilitation for 60 minutes. | ||||
| PBO TENS | 25 | 56.9 ± 8.6 | 20/5 | 13/12 | Placebo: from devices with identical appearance but with disconnected circuit + Task-related exercises recommended for stroke rehabilitation. | ||||
| Control | 29 | 55.5 ± 8.0 | 20/9 | 20/9 | Not treatment. | Not treatment. | |||
| Park, 2014 | TENS/EX | 15 | 71.2 ± 3.46 | 12/3 | 1.5 ± 0.2 | NR | 6W - 5D | Quadriceps and gastrocnemius muscles | TENS: (5 cm2) dual-channel, with 100 Hz and a pulse width of 200 μs at double sensory threshold for 30 minutes + Exercise consisted of individual ROM exercise, functional exercise on mat, and walking exercise (10 minutes each). |
| PBO TENS | 14 | 71.14 ± 3.82 | 8/6 | 1.5 ± 0.145 | Placebo TENS + Exercise included individual ROM exercise, functional exercise on mat, and walking exercise (10 minutes each). | ||||
| Jung, 2020 | TENS | 20 | 53.1 ± 7.9 | 14/6 | 0.56 ± 0.2 | NR | 6 W | Common peroneal nerve | TENS: Frequency of 100 Hz with a pulse width of 200 μs applied for 30 minutes at double the sensory threshold + Heel raise and lower exercise where participants placed their forefeet on a block of sufficient height to allow heel contact with the ground. |
| PBO TENS | 20 | 52.7 ± 11.5 | 12/8 | 0.58 ± 0.21 | Placebo+ Heel raise and lower exercise where participants placed their forefeet on a block of sufficient height to allow heel contact with the ground. | ||||
| Sung, 2021 | TENS/Tape | 23 | 53.7 ± 9.6 | 15/8 | NR | 11/12 | 6W - 5D (30 ss) | Common peroneal nerve | TENS: Frequency of 100 Hz with pulse widths of 200 μs and at double the sensory threshold intensity for an application duration of 30 minutes + adhesive tape using the Karadag-Saygi method: on the feet, ankles, and shins |
| TENS | 23 | 54.4 ± 9.9 | 16/7 | 12/11 | TENS: Frequency of 100 Hz with pulse widths of 200 μs and at double the sensory threshold intensity for an application duration of 30 minutes |
Results of protocol interventions in muscle strength
| Study | Group | Measures | Initial Measure | Final Measure | Follow-up / Difference | p-value |
|---|---|---|---|---|---|---|
| Shamay, 2007 | TENS | Load cell method (kg) | 13.2 ± 8.0 | 19.8 ± 8.1 | 14.7 ± 7.4 | < 0.01 |
| TENS/TRT | 11.3 ± 4.8 | 16.9 ± 4.8 | 16.5 ± 5.1 | |||
| PBO TENS | 10.3 ± 5.8 | 14.7 ± 6.2 | 14.7 ± 6.5 | |||
| Control | 13.9 ± 8.9 | 15.2 ± 9.0 | 15.0 ± 9.2 | |||
| Jung, 2020 | TENS | Dynamometry (kg) | 12.0 ± 2.0 | 18.4 ± 3.5 | N/A | < 0.05 |
| PBO TENS | 11.6 ± 2.0 | 16.1 ± 1.9 | ||||
| Sung, 2021 | TENS/Tape | 12.0 ± 2.3 | 15.9 ± 2.6 | N/A | < 0.05 | |
| TENS | 12.4 ± 2.0 | 13.7 ± 1.8 |
Methodological quality assessment
| # | Study | 1* | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | Total Score |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Shamay, 2007 | - | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 8 |
| 2 | Shamay, 2009 | - | 1 | 0 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 7 |
| 3 | Park, 2014 | - | 1 | 0 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 7 |
| 4 | Jung, 2020 | - | 1 | 0 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 8 |
| 5 | Sung, 2021 | - | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 10 |
Results of protocol interventions in walking speed (cm/sec)
| Study | Group | Initial Measure | Final Measure | Follow-up / Difference | p-value |
|---|---|---|---|---|---|
| Shamay, 2007 | TENS | 54.8 ± 25.6 | 62.9 ± 28.4 | 58.8 ± 26.5 | < 0.01 |
| TENS/TRT | 50.6 ± 28.3 | 68.2 ± 34.5 | 72.2 ± 34.0 | ||
| PBO TENS | 48.7 ± 25.0 | 57.7 ± 29.8 | 58.3 ± 28.8 | ||
| Control | 62.6 ± 24.6 | 63.9 ± 24.1 | 64.5 ± 23.8 | ||
| Shamay, 2009 | TENS | 57.7 ± 26.3 | 60.9 ± 24.8 | 61.2 ± 27.3 | < 0.01 |
| TENS/EX | 47.9 ± 26.8 | 66.6 ± 32.5 | 70.2 ± 32.7 | ||
| PBO TENS | 50.7 ± 24.5 | 60.6 ± 29.7 | 61.3 ± 28.6 | ||
| Control | 58.9 ± 24.9 | 60.9 ± 24.8 | 61.2 ± 24.2 | ||
| Park, 2014 | TENS | 45.81 ± 15.22 | 52.89 ± 17.43 | 7.07 ± 4.58 | < 0.05 |
| PBO TENS | 46.85 ± 20.07 | 49.40 ± 20.50 | 2.55 ± 2.76 | ||
| Jung, 2020 | TENS | 24.7 ± 4.0 | 19.4 ± 3.3 | N/A | < 0.05 |
| PBO TENS | 25.2 ± 4.8 | 22.5 ± 5.0 | |||
| Sung, 2021 | TENS/Tape | 25.2 ± 4.2 | 20.1 ± 2.5 | N/A | < 0.05 |
| TENS | 25.9 ± 4.6 | 23.6 ± 4.0 |
Results of protocol interventions in other variables
| Study | Group | Measures | Initial Measure | Final Measure | Follow-up / Difference | p- value |
|---|---|---|---|---|---|---|
| Shamay, 2009 | TENS | Gait endurance (cm) | 202.6 ± 81.8 | 221.0 ± 90.6 | 219.3 ± 92.8 | < 0,01 |
| TENS/EX | 191.9 ± 89.4 | 242,0 ± 104,1 | 245.5 ± 99.7 | |||
| PBO TENS | 175.9 ± 81.9 | 206.7 ± 97.2 | 206.82 ± 85.8 | |||
| CONTROL | 195.6 ± 75.9 | 196.2 ± 70.7 | 197.9 ± 68.6 | |||
| TENS | Functional mobility (TUG score) | 22.7 ± 10.9 | 20.6 ± 10.4 | 21.0 ± 9.9 | ||
| TENS/EX | 25.5 ± 17.4 | 18.7 ± 9.7 | 18,8 ± 11.2 | |||
| PBO TENS | 29.4 ± 22.1 | 26.2 ± 21.7 | 25.3 ± 19.7 | |||
| CONTROL | 22.9 ± 13.5 | 22.9 ± 13.2 | 22.2 ± 12.5 | |||
| Park, 2014 | TENS/EX | Dynamic balance (TUG) | 26.16 ± 11.71 | 21.84 ± 9.28 | −4.32 ± 3.50 | < 0,05 |
| PBO TENS | 25.70 ± 12.41 | 24.61 ± 11.61 | −1.09 ± 1.83 | |||
| TENS/EX | Static balance (mm/sec) | 11.33 ± 5.67 | 5.52 ± 2.40 | −5.81 ± 4.42 | ||
| PBO TENS | 8.19 ± 4.61 | 7.79 ± 3.92 | −0.40 ± 0.97 |
Results of protocol interventions in spasticity
| Study | Group | Measures | Initial Measure | Final Measure | Follow-up / Difference | p-value |
|---|---|---|---|---|---|---|
| Shamay, 2007 | TENS | CSS | 12.2 ± 1.7 | 11.0 ± 1.7 | 11.5 ± 1.7 | < 0.01 |
| TENS/TRT | 12.1 ± 1.7 | 11.0 ± 1.4 | 11.2 ± 1.5 | |||
| PBO TENS | 12.2 ± 1.5 | 11.2 ± 1.7 | 11.4 ± 1.5 | |||
| Control | 11.8 ± 1.7 | 11.6 ± 1.6 | 11.7 ± 1.6 | |||
| Park, 2014 | TENS/EX | 2.60 ± 0.63 | 1.80 ±.41 | −0.80 ± 0.56 | < 0.05 | |
| PBO TENS | MAS | 2.50 ± 0.76 | 2.36 ± 0.74 | −0.14 ± 0.36 | ||
| Jung, 2020 | TENS | CSS | 11.5 ± 1.6 | 9.5 ± 1.9 | N/A | < 0.05 |
| PBO TENS | 11.9 ± 2.1 | 11.5 ± 2.3 | ||||
| Sung, 2021 | TENS/Tape | CSS | 12.1 ± 2.1 | 8.7 ± 1.9 | N/A | < 0.05 |
| TENS | 12.4 ± 2.5 | 11.1 ± 2.0 |
Characteristics of the included studies
| Study (Settings) | Objective | Variables | Main findings |
|---|---|---|---|
| Shamay, 2007 (HK) | To compare the effectiveness of three home-based active treatment programs versus no active treatment on spasticity, muscle strength, and functional capacity in patients with chronic stroke. |
| The combination of TENS with TRT was shown to be superior to other interventions for improving motor functions in subjects with chronic stroke. Twenty sessions could improve lower limb motor function in patients who suffered a stroke at least one year ago. |
| Shamay, 2009 (HK) | Determining whether such stimulation could also improve functional gait performance (gait speed, walking endurance, and functional mobility), which is more clinically significant for the stroke population with spastic plantar flexors. |
| Surface electrical stimulation combined with a structured home exercise program was generally more effective in improving gait speed, walking endurance, and functional mobility in hemiparetic patients compared to administering either treatment alone or no treatment at all. |
| Park, 2014 (KR) | The effects of a TENS exercise program on spasticity, balance, and gait in patients with chronic stroke to determine if TENS exercise enhances physical function in patients. |
| Combination of TENS and exercise improves spasticity, balance, and gait in patients with chronic stroke. |
| Jung, 2020 (KR) | Investigate the effect of heel raise and lower exercise on spasticity, strength, and gait speed after 30 minutes of transcutaneous electrical nerve stimulation in stroke patients. |
| Heel raise and lower exercise after TENS application was beneficial for treating spasticity, muscle strength, and gait function in stroke patients with spasticity in the ankle plantar flexor muscles. |
| Sung, 2021 (KR) | The effects of TENS combined with adhesive tape on spasticity, muscle strength, and gait capacity in stroke patients. |
| Transcutaneous electrical nerve stimulation reduced spasticity and improved muscle strength and gait capacity, with additional adhesive tape application significantly enhancing these effects. |