Evidence of Physiotherapy Interventions for Patients with Chronic Neck Pain: A Systematic Review of Randomised Controlled Trials

Table 4

Electrotherapy—patients with chronic nonspecific neck pain.

Author	Participants	Interventions	Main outcome measures	Study results on effect* of intervention on pain
Altan et al. [62]	Patients with chronic cervical myofascial pain syndrome (>3 mths), having tender points (𝑁=53)	(1) Laser treatment (𝑛=23), applied over four trigger points bilat., frequency 1000 Hz for 2 min over each point. Laser parameters: infrared 27 GaAs diode, 904 nm, frequency range 5–7000 Hz, max power of 27 W, 50 W, or 27 × 4 W was used; (2) Placebo, sham laser treatment (𝑛=25); All: treatment once a day for 10 days during a period of 14 days, instructed to perform isometric exercises and stretching at home	VAS, algometric measurements, ROM	There were no significant differences between groups immediately after (wk 2) and at 12 wks followup
Chiu et al. [63]	Patients with chronic intermittent neck pain (>3 mths), age 20–70 (𝑁=218)	(1) TENS group (𝑛=73): infrared radiation, advice on neck care, TENS to the neck region for 30 min. TENS parameters: dual-channel TENS unit (130 Z), continuous 150 𝜇s square pulses at 80 Hz, four surface electrodes, intensity of TENS was adjusted to produce a tingling sensation; (2) Exercise group (𝑛=67): infrared radiation, advice on neck care, intensive neck exercise programme.; (3) Control group (𝑛=78): infrared radiation, advice on neck care.; All: two sessions a wk for six wks	VNPS, NPQ, NPI, strength	There were no statistically significant differences between the three groups on VNPS pain after 6 wk and at 6 mths followup, but the TENS group and the exercise group had a significantly better improvement in NPQ than that of the control group (𝑃=0.034 and 𝑃=0.02, resp.) after 6 wks and at 6 mths followup
Chow et al. [64]	Patients with chronic neck pain (>3 mths), age > 18 (𝑁=90)	(1) Laser treatment (𝑛=45), applied to tender points for 30 s per point with up to 50 points being treated. Laser parameters: class 3B, diolase devices, wavelength 830 nm, power of 300 mW in continuous wave mode at a power density of 0.67 W/cm^2; (2) Sham laser treatment (𝑛=45); All: 14 treatments over 7 wks	VAS	The improvement in raw VAS was statistically significantly greater in the laser-treatment group than in the sham laser treatment group (−2.7 compared with +0.3, 𝑃<0.001). at 12 wk followup
Dundar et al. [65]	Patients with chronic cervical myofascial pain, having spot tenderness along taut band, age 20–60 (𝑁=64)	(1) Laser treatment (𝑛=32), applied over three trigger points bilat., frequency 1,000 Hz for 2 min over each point, power output 58 mW/cm^2 by 1,000 Hz. Dose per point 7 J, total per treatment 42 J. Laser parameters: infrared Ga-As-Al diode, wavelength 830 nm, max power output of 450 mW; (2) Placebo, sham laser (𝑛=32); All: once a day for 15 days during 3 wks, instructed in daily isometric exercise and stretching exercise	VAS, ROM, NDI	There were no statistically significant differences between groups after 4 wks
Esenyel et al. [66]	Patients with chronic myofascial trigger points (duration 6 months to 7 yrs) in one side of the upper trapezius muscles (𝑁=102)	(1) Ultrasound therapy (𝑛=36), dose 1.5 W/cm^2, 6 min, 10 sessions; (2) Trigger point injections (1% lidocaine) (𝑛=36); (3) Control (𝑛=30); All: neck-stretching exercises	VAS, PPT, ROM	Statistically significant and equal reduction in VAS pain from ultrasound and injection groups compared with controls (𝑃<0.001) after treatment and at 3 mth followup. There were no statistically significant differences in outcome measures between groups 1 and 2
Gam et al. [67]	Patients with chronic trigger points in the neck and with an intensity disturbing normal daily activity, age 18–60 (𝑁=67)	(1) Ultrasound, massage, exercise (𝑛=18), dose 100 Hz, pulse = 2 : 8, 3 W/cm^2, 3 min; (2) Sham ultrasound, massage, exercise (𝑛=22); (3) Control group (𝑛=18); Groups 1 and 2 were treated 2 sessions per wk in 4 wks	VAS, measure of trigger points	There were no significant differences between groups post treatment and at 6 mth followup
Gur et al. [68]	Patients with chronic myofascial pain syndrome in the neck (>1 yr), affecting quality of life, with 1–10 tender points in shoulder girdle (𝑁=60)	(1) Laser treatment (𝑛=30), 2 J/cm^2 at each trigger point (max. 20 J/cm^2). Laser parameters: Ga-As laser, 20 W max output per pulse, 904 nm, 200 nanoseconds max duration pulse, 2,8 kHz pulse frequency, 11.2 mW average power, 1 cm^2 surface; (2) Placebo, sham laser treatment (𝑛=30); All: treatment 3 min at each triggerpoint, 5 times a wk for 2 wks, instructed in correct posture, ergonomics and to avoid activity exacerbated pain	NPDS, VAS	Statistically significant difference on pain in favour of laser treatment at 2nd wk and 3rd wk on pain VAS (2nd wk: VAS pain at rest 3.11 ± 2.29, 𝑃=0.01; VAS pain at movement 2.67 ± 2.58, 𝑃=0.01) and NPDS, and at 12 wk followup maintained at NPDS (41.14±28.34) (𝑃=0.01)
Özdemir et al. [69]	Patients with chronic neck pain related to osteoarthritis (𝑁=60)	(1) Low-level laser therapy (𝑛=30), applied to 12 points, 0.90 J for each 1 cm^2, each point for 15 s. Laser parameters: endolaser 476, Ga-As_Al, power output of 50 mW, wavelength 830 nm, diameter beam 1 mm., 0.90 J for each 1 cm^2; (2) Placebo, sham laser (𝑛=30); All: treatment in 10 consecutive days	VAS, physician assessment of pressure pain, angle of lordosis, ROM, NPDS	The authors did not report any data on statistically significant differences on pain between groups after treatment
Seidel and Uhlemann [70]	Patients with chronic cervical pain syndrome (>6 mths) (𝑁=51)	(1) Placebo, sham laser treatment (𝑛=13); (2) Laser treatment (𝑛=12), output 7 mW, stimulation to meridian points, 1 min per point, totally 15 points. Laser parameters: cw-IR-GaAIAs-Laser, 830 nm, Lasotronic, energy density 0 J/cm^2; 21 J/cm^2; 90 J/cm^2, irradiation area 0.02 cm^2, laser skin difference 8 mm; (3) Laser treatment (𝑛=13), output 30 mW, stimulation to meridian points, 1 min per point, totally 15 points. Laser parameters: cw-IR-GaAIAs-Laser, 830 nm, Lasotronic, energy density 0 J/cm^2; 21 J/cm^2; 90 J/cm^2, irradiation area 0.02 cm^2, laser skin difference 8 mm; (4) Needle acupuncture (𝑛=13); All: 8 treatments in 4 wk	VAS, PPT, ROM	The authors did not report any data on statistically significant differences on pain between groups after 4 wk
Smania et al. [71]	Patients with chronic myofascial pain syndrome of the superior trapezius muscle (and in no other muscle), age 18–80 (𝑁=53)	(1) Repetitive magnetic stimulation (rMS) (𝑛=17), stimulation to trigger points with figure-eight-shaped coil until coil temperature reached 40 degrees and then replaced by circular coil, pulsed magnetic stimuli (4000) each 20 min session in 5-second trains at 20 Hz separated by 25-second pause.; (2) Transcutaneous electrical stimulation (TENS) (𝑛=18), 100 Hz, pulse width 250 𝜇s, asymmetrical rectangular biphasic wave form, intensity set to patients comfort until significant local sensation; (3) Placebo (𝑛=18), sham-ultrasound therapy; All: treatment sessions, 2 times a wk for 2 wks	NPDVAS, VAS, PPT, ROM	The rMS group and the TENS group showed a statistically significant improvement in the NPDVAS compared to the placebo group: differences to placebo group in NPDVAS, rMS group: pre-post 𝑃<0.01; pre-1 mth 𝑃<0.001; pre-3 mths 𝑃=0.038. Differences to placebo group in NPDVAS, TENS group: pre-post 𝑃<0.01; no difference in pre-1 mths and pre-3 mths test. Difference in effect on NPDVAS between rMS and TNS in favour of rMS only in pre-1 mths test, 𝑃<0.001, and in pre-3 mths test, 𝑃<0.001
Thorsen et al. [72]	Female laboratory workers with chronic pain (>1 yr) from neck and shoulder girdle, pain affecting the quality of work or daily living, 1–10 tender points, age 18–65 yrs (𝑁=49)	Crossover study, 6 sessions over 2 wks followed by one wk pause before 6 new treatment sessions over 2 wks in other group.; (1) Laser treatment (𝑛=25) 0.9 J per treated point max 9 J per treatment. Laser parameters: endolaser 465 class no. B, 830 nm ± 0.5 nm, 30 mW,; Ga_AI_As diode, beam divergence 4 degrees, probehead 2.5 mm^2; (2) Placebo, sham laser treatment (𝑛=22); All: 6 sessions over a 2 wk period	VAS	There were no statistically significant differences between groups post treatment

^∗In order to show an effect of an intervention and hereby support the intervention, it requires showing statistical significant difference between groups.
VAS: visual analogue scale; NRS: numerical rating scale; VNPS: verbal numeric pain scale; NPQ: Northwick Park neck pain questionnaire; NDI: neck disability index; NPDI: neck pain and disability index; NPDS: neck pain and disability scale; NPDVAS: neck pain and disability visual analogue scale; PSFS: patient-specific functional scale; NPI: Northwick Park neck pain index; SF-36: short-form 36; PPT: pressure pain threshold; ROM: range of movement; RPE: rating of perceived exertion; EMG: electromyographic, HRQoL: health-related quality of life.