Table 1 Characteristics of the studies included and their participants

Number of participants

31

4

26

30

10

Sex (M,F)

11, 20

1, 3

10,16

12,18

7,3

Age

50.1 ± 11 (mean)

56.25 (mean)

54.3 (mean)

 > 50 YOA

64.9 (mean)

Duration of Symptoms

 > 8 weeks

8 years (mean)

N/A

N/A

2.1 years (mean)

Severity of Pain (before TENS)

8.5 ± 2.92

8.66

8.69 ± 1.123

8.9 ± 2.98

9 ± 1.333

Severity of Pain (after TENS)

2 ± 1.41

1 ± 0

1.23 ± 1.632

1.30 ± 1.14

0.3 ± 0.949

Mode of Intervention

Constant Mode (16), Burst Mode (15)

Tonic Mode (3), Burst Mode (1)

Continuous mode (26)

N/A

N/A

Duration of intervention (per session)

30 min/weekly

N/A

40 min/weekly

20 min/daily

60 min/NA

Duration of Intervention (total)

3 weeks

1 year

6 weeks

1 year

N/A

Pulse width of intervention

120 µ

1000 µsec

N/A

N/A

50–200 µs

Frequency of intervention

200 Hz

40 Hz

100 Hz

N/A

50–100 Hz

Remission

N/A

N/A

N/A

None

7.1 ± 2.47 at the 5-year follow-up

Complications

N/A

Paresthesia (3), None (1)

N/A

None

N/A

Follow-up

N/A

3 months, 6 months,12 months

3 months, 6 months, 12 months

1 month, 3 months

2 months, 3 months, 12 months, 3 years, 5 years

Quality assessment

Moderate

Moderate

Moderate

Moderate

Serious