Extracorporeal Shockwave Therapy for Treating Chronic Low Back Pain: A Systematic Review and Meta-analysis of Randomized Controlled Trials

Table 1

Summary of findings of the systematic review of extracorporeal shock wave therapy (ESWT) for chronic low back pain (CLBP).

	Characteristics of the included studies (based on PICO structure) [33]
	Patients		Intervention	Comparison	Outcomes (ESWT vs. control)				Quality of evidence
Author	ESWT vs. control: randomized (completed); mean age (yrs); gender	Eligibility criteria	ESWT group: device; parameters; adjuvant therapies	Control group: comparator therapies	Pain results	Disability/functional/quality of life results	Adverse events	Author’s conclusions	Jaded score
Ahmed et al. 2018 [24]	: 15 (15) vs. 15 (15); Age: vs.; Gender (female): 15/15 vs. 15/15; BMI: vs.	Inclusion: multiparous women suffering from postpartum low back pain (3 mo after delivery); age, 25–35 yrs;  kg/m^2; parity, 2–3 children; delivery type, normal cesarean section; Exclusion: gynecological diseases; specific spinal diseases	ESWT; Device: Storz with 20 mm D-actor head; Parameters: 2 bar, 10 Hz, 2000 pulses, 0.18 mJ/mm^2, 5 min; Sessions: twice a wk for 4 wk; Physical exercise: abdominal strengthening exercise, postural correction exercises, and posterior pelvic tilting exercise (60 min); Sessions: twice a wk for 4 wk	Physical exercise: abdominal strengthening exercise, postural correction exercises, and posterior pelvic tilting exercise (60 min); Sessions: twice a wk for 4 wk	VAS; Baseline: vs.; 4-wk FU: vs.		ND	Shockwave therapy is an effective modality in alleviating postpartum low back pain	1
Çelik et al. 2020 [50]	: 25 (25) vs. 25 (20); Age: vs.; Gender (female): 10/25 vs. 12/20	Inclusion: 18 and 65 yrs old; months; history of physical therapy and/or spinal injection within the past 3 mo; Exclusion: Specific spinal disease; pregnancy; cardiac pacemaker; rheumatic diseases; structural anomaly; medical treatment such as pregabalin, gabapentin, and antidepressant for chronic pain treatment	ESWT; Device: EMD, E1000, C-ARMOR, 2011, Turkey; Parameters: 2.5 Hz, 1500 shocks, 0.12 mJ/mm^2, 20 min, twice a wk for 6 wk	Sham ESWT; Device: EMD, E1000, C-ARMOR, 2011, Turkey; Parameters: 2.5 Hz, 1500 shocks, 0.08 mJ/mm^2, 20 min, twice a wk for 6 wk	NRS; Baseline at rest: 5 (2–8) vs. 5 (3–8); Baseline at movement: 8 (4–10) vs. 8.5 (7–10); 6-wk FU at rest: vs.; 6-wk FU at movement: vs.; 12-wk FU at rest: vs.; 12-wk FU at movement: vs.	ODI; Baseline: 44 (11–74) vs. 46 (15–82); 6-wk FU: vs.; 12-wk FU: vs.	None of the patients left the study due to side effects of the treatment	ESWT showed a significant superiority over placebo in improving the parameters of pain, disability, depression, anxiety, and quality of life in the patients with CLBP	5
Eftekharsadat et al. 2020 [23]	: 27 (27) vs. 27 (27); Age: vs.; Gender (female): 20/27 vs. 17/27; BMI: vs.	Inclusion: CLBP months; quadratus lumborum muscle tenderness; palpable nodule/tout band; normal neurological examination; Exclusion: treatment in past 3 mo; SIJ problems; Bertolotti syndrome; hemorrhagic disorders; infection; allergy to corticosteroids; pregnancy; diabetes; dynamic listhesis;  kg/m^2	ESWT; Device: Zimmer enPulsPro Medizin system GmbH, Germany; Parameters: 10–16 Hz, 1500 pulses, 0.1 mJ/mm^2; Sessions: once a wk for 3 wk; Physical exercise: stretching exercises	TPI; Muscle injection of 40 mg triamcinolone +2 mL lidocaine 2%; one session; Physical exercise: stretching exercises	VAS; Baseline: vs.; 2-wk FU: vs.; 4-wk FU: vs.	ODI; Baseline: vs.; 2-wk FU: vs.; 4-wk FU: vs.; SF-36; Baseline: vs.; 2-wk FU: vs.; 4-wk FU: vs.	No clinically important adverse events, side effects, or severe complications requiring medical interference were mentioned in either of the groups	After 4 wk of treatment, ESWT was more efficacious than corticosteroid TPI in reducing pain and improving quality of life and disability outcomes	4
Elgendy et al. 2020 [51]	: 15 (15) vs. 15 (15); Age: vs.; Gender (female): 5/15 vs. 5/15; BMI: vs.	Inclusion: 20–30 yrs old; normal BMI; CLBP  mo; Exclusion: specific spinal disease; pregnancy	ESWT; Device: Elettronica Paganis medical devices with 17 mm head; Parameters: 5 Hz, 2000 pulses, 0.10 mJ/mm^2; Sessions: twice a wk for 6 wk; Physical therapy: manual passive stretching exercises, progressive strengthening exercises for abdominal and back muscles, anterior and posterior pelvic tilt; physical therapy program was applied twice per wk for 6 wk	Physical therapy: manual passive stretching exercises, progressive strengthening exercises for abdominal and back muscles, anterior and posterior pelvic tilt; physical therapy program was applied twice per wk for 6 wk	VAS: Baseline: vs.; 6-wk FU: vs.		ND	ESWT can effectively improve trunk muscle activity and reduce pain level in patients with nonspecific CLBP	3
Guo et al. 2020 [52]	: 47 (47) vs. 48 (44); Age: vs.; Gender (female): 22/47 vs. 25/48; BMI: vs.	Inclusion: 18–80 yrs old; CLBP; Exclusion: specific spinal disease, history of spine surgery, mental illness, uncontrolled systemic diseases	ESWT; Device: Swiss DolorClast device (Electro Medical Systems, Nyon, Switzerland) and EvoBlue handpiece; Parameters: 15 Hz, 4000 pulses; Sessions: once a wk for 4 wk	Medication; Celecoxib ( mg per day for moderate pain (NRS score 4–6), or  mg per day (NRS score 7–10)) and eperisone ( mg per day) for 4 wk	NRS; Baseline: vs.; 4-wk FU: vs.; 12-wk FU: vs.	PSEQ; Baseline: vs.; 4-wk FU: vs.	No severe adverse events were observed during the study	rESWT may be superior to medication in reducing pain in subjects with CLBP	5
Kang 2015 [35]	: 22 vs. 21; Age: 43.1; BMI: 21.33	Inclusion: CLBP  mo; diagnosis of myofascial pain syndrome; Exclusion: specific spinal disease, history of spine surgery, mental illness	ESWT; Device: Evotron, Switech Medical, Switzerland; Parameters: 4 Hz, 1000 pulses, 0.10–0.15 mJ/mm^2; Sessions: once a wk for 8 wk; Conservative treatment: resting, medication, heat therapy, TENS, and therapeutic exercise; Exercise was applied 3/wk for 8 wk	Conservative treatment: resting, medication, heat therapy, TENS, and therapeutic exercise; Exercise was applied 3/wk for 8 wk	VAS: Baseline: vs.; 8-wk FU: vs.	ODI: Baseline: vs.; 8-wk FU: vs.; SF-36; Baseline: vs.; 8-wk FU: vs.	Pain during ESWT was observed in some patients	ESWT together with the conservative rehabilitation therapy has a great influence on the myofascial pain syndrome	1
Schneider et al. 2017 [20]	: 15 (15) vs. 15 (15); Age: 43.2 (range: 23–65); Gender (female): 18/30	Inclusion: CLBP  mo; legal age; Exclusion: major disease; drug addiction; mental illness; pregnancy	ESWT; Device: Cellconnect Impulse; Parameters: 15–42 Hz; Sessions: twice a wk for 3 wk; Myofascial trigger therapy: palpation of the target musculature, identification of the trigger points, and provocation of the taut muscle fasciae for 30 min; Sessions: twice a wk for 3 wk	Myofascial trigger therapy: palpation of the target musculature, identification of the trigger points, and provocation of the taut muscle fasciae for 30 min; Sessions: twice a wk for 3 wk	7-point-Likert scale: ESWT + MT vs. MT; Baseline: vs.; 3-wk FU: vs.		All 30 patients completed the trial, and none complained about adverse effects	Combining MT with ESWT enhances the physiotherapeutic effectiveness of treating chronic back pain	3
Taheri et al. 2021 [53]	: 19 (17) vs. 19 (15); Age: vs.; Gender (female): 11/17 vs. 6/15; BMI: vs.	Inclusion:  yrs; CLBP  mo; Exclusion: undergoing treatment or surgery; pregnancy; cognitive problems; specific spinal diseases; medical condition; uncontrolled systemic diseases	ESWT; Device: DUOLITH SD1, Storz Medical, Tägerwilen, Switzerland; Parameters: 4 Hz, 1500 pulses, 0.15 mJ/mm^2; Sessions: once a wk for 4 w; Oral medications and exercise program: oral medications (tizanidine hydrochloride and meloxicam); exercise program: stretching exercises	Sham ESWT: method of sham treatment: treatment with same sound but no energy; Oral medications and exercise program: oral medications (tizanidine hydrochloride and meloxicam). Exercise program: stretching exercises	VAS; ESWT vs. control; Baseline: vs.; 4-wk FU: vs.; 12-wk FU: vs.	ODI; ESWT vs. control; Baseline: vs.; 4-wk FU: vs.; 12-wk FU: vs.	ND	ESWT, along with oral medication and exercise therapy, appears to be a safe and effective method in the short-term treatment of CLBP patients	4
Walewicz et al. 2019 [19]	: 20 (20) vs. 20 (17); Age: vs.; Gender (female): 14/20 vs. 15/20; BMI: 29.0	Inclusion: CLBP of L5-S1 discopathy; CLBP  mo; Exclusion: acute spinal pain; discopathy on a different level of the spine; lack of pain and reduced mobility in the lumbar and sacral regions; specific spinal diseases; pregnancy; pacemaker; cardiovascular diseases; blood coagulation disorders; metal implants; mental disorders; cancer; psoriasis; scleroderma; viral and bacterial infections; history of spinal surgery or drug therapy	ESWT; Device: Cosmogamma, Indonesia; Parameters: 2.5 bars, 5 Hz, 2000 pulses, 0.1 mJ/mm^2, 7 min; Sessions: twice a wk for 5 wk; Stability training: physical improvement in the form of functional training (45 min, once a day, 5 days a wk)	Sham ESWT: special polyethylene applicator cap with the same sound signals during the procedure of the pneumatic head and the same technical parameters as in the real procedures; Stability training: physical improvement in the form of functional training (45 mins, once a day, 5 days a wk)	VAS; Baseline: vs.; 5-wk FU: vs.; 9-wk FU: vs.; 17-wk FU: vs.; LPS; Baseline: vs.; 5-wk FU: vs.; 9-wk FU: vs.; 17-wk FU: vs.	ODI; Baseline: vs.; 5-wk FU: vs.; 9-wk FU: vs.; 17-wk FU: vs.	ND	ESWT had a significant effect on the reduction of pain and the improvement of functional condition compared with the conventional physiotherapy program in patients with LBP	5
Zheng et al. 2013 [22]	: 33 (32) vs. 33 (31); Age: vs.; Gender (female): 14/32 vs. 6/31	Inclusion: age 18–60 yrs; LBP >12 wk without treatment; Exclusion: specific spinal diseases; serious systemic diseases	ESWT; Device: SHOCKMASTER-500, Gymna, Belgium; Parameters: 1.6–3.0 bar, 8–12 Hz, 2000 pulses; Sessions: twice a wk for 2 wk	Thermomagnetic therapy; Sessions: 40°C, 15 min; Sessions: once a day for 14 days	VAS: Baseline: vs.; 2-wk FU: vs.	FFD: Baseline: vs.; 2-wk FU: vs.	ND	The pneumatically ballistic extracorporeal shockwave is more effective for chronic nonspecific low back pain than hot magnet	3

ESWT: extracorporeal shockwave therapy; FFD: finger foot distance; FU: follow-up; LPS: Laitinen Pain Scale; ND: not described; NRS: Numeric Rating Scale; ODI: Oswestry Disability Index; PLC: Profil der Lebensqualität chronisch Kranker; SIJ: sacroiliac joint; TPI: trigger point injection; VAS: Visual Analogue Scale; TENS: transcutaneous electrical nerve stimulation; PSEQ: Pain Self-Efficacy Questionnaire. Specific spinal diseases include discopathy with or without radiculopathy/cauda equina syndrome, spondylosis, spondylolisthesis, spinal malignancies, spinal fractures, spinal infections, and spinal trauma. One month equaled 4 weeks in this research.