Abstract
Background Shoulder pain is a common musculoskeletal condition in the general population. Passive physical modalities are commonly used to treat shoulder pain. However, previous systematic reviews reported conflicting results.
Purpose The aim of this study was to evaluate the effectiveness of passive physical modalities for the management of soft tissue injuries of the shoulder.
Data Sources MEDLINE, EMBASE, CINAHL, PsycINFO, and the Cochrane Central Register of Controlled Trials were searched from January 1, 1990, to April 18, 2013.
Study Selection Randomized controlled trials (RCTs) and cohort and case-control studies were eligible. Random pairs of independent reviewers screened 1,470 of 1,760 retrieved articles after removing 290 duplicates. Twenty-two articles were eligible for critical appraisal. Eligible studies were critically appraised using the Scottish Intercollegiate Guidelines Network criteria. Of those, 11 studies had a low risk of bias.
Data Extraction The lead author extracted data from low risk of bias studies and built evidence tables. A second reviewer independently checked the extracted data.
Data Synthesis The findings of studies with a low risk of bias were synthesized according to principles of best evidence synthesis. Pretensioned tape, ultrasound, and interferential current were found to be noneffective for managing shoulder pain. However, diathermy and corticosteroid injections led to similar outcomes. Low-level laser therapy provided short-term pain reduction for subacromial impingement syndrome. Extracorporeal shock-wave therapy was not effective for subacromial impingement syndrome but provided benefits for persistent shoulder calcific tendinitis.
Limitations Non-English studies were excluded.
Conclusions Most passive physical modalities do not benefit patients with subacromial impingement syndrome. However, low-level laser therapy is more effective than placebo or ultrasound for subacromial impingement syndrome. Similarly, shock-wave therapy is more effective than sham therapy for persistent shoulder calcific tendinitis.
Shoulder pain is common in the general population, ranking fourth behind low back pain, knee pain, and neck pain as the most prevalent musculoskeletal conditions.1–3 One third of adults experience shoulder pain every year.2 Shoulder complaints place a significant burden on the health care system.4,5 In the United Kingdom, 2.4% of the population consult general practitioners for shoulder pain each year.6 In the United States, more than 500,000 rotator cuff surgical repairs and shoulder arthroscopies are performed annually.7 Moreover, shoulder injuries are associated with a substantial economic burden, costing an average of €326 per patient during a 6-month period in Sweden.8
Musculoskeletal conditions are commonly managed with passive physical modalities.9,10 Despite being commonly used, large insurers such as the Ontario Workplace Safety and Insurance Board (WSIB) do not recommend passive physical modalities for the management of shoulder pain.11 Such a recommendation is consistent with the results of several systematic reviews suggesting that ultrasound, interferential current therapy, and kinesiotaping are equal to placebo or other interventions for the management of shoulder disorders.12–15 In addition, evidence on the effectiveness of electromagnetic field therapy, low-level laser therapy (LLLT), and shock-wave therapy is conflicting.14,16–18 However, these reviews suffer from methodological limitations that may have biased their conclusions. Specifically, the reviews pooled quantitative results from heterogeneous studies13,14,16,17 and synthesized the evidence from studies with small sample sizes or a high risk of bias, or both.12–18
Therefore, an up-to-date systematic review was needed to evaluate the effectiveness of passive physical modalities in the treatment of soft tissue shoulder injuries. We aimed to address the limitations of previous reviews by assessing the homogeneity of samples across studies. Moreover, our review aimed to minimize bias by restricting our synthesis to high-quality evidence. The purpose of our review was to determine the effectiveness of passive physical modalities on self-rated recovery, functional recovery, pain intensity, health-related quality of life, psychological outcomes, and adverse events in patients with soft tissue injuries of the shoulder.
Method
Registration
We registered this review with the International Prospective Register of Systematic Reviews (PROSPERO) on June 14, 2013 (CRD42013004854).
Eligibility Criteria
Population.
Our review targeted studies of adults and children with soft tissue injuries of the shoulder. We included grade I to II sprains and strains, nonspecific diffuse shoulder pain, shoulder tendinitis, impingement syndromes, bursitis, and other soft tissue injuries of the shoulder.19–22 We excluded studies of shoulder pain due to pathology (eg, fractures, dislocations, infections, neoplasms, frozen shoulder, systemic disease). The principles outlined in the Declaration of Helsinki were followed.
Interventions.
We restricted our review to studies on the effectiveness of passive physical modalities. Passive physical modalities include physical modalities or devices that do not require the active participation of patients (including rest). We divided passive physical modalities into 2 categories: physicochemical and structural.9,10 Physicochemical modalities use thermal or electromagnetic effect, such as cold, heat, or light application at the skin level, or light, ultrasonic, or electromagnetic radiation, affecting structures beneath the skin. Structural modalities include nonfunctional assistive devices that encourage rest in anatomic positions (eg, pillows, seat cushions) or actively inhibit or prevent movement (eg, collars, corsets, casts, slings, rest splints) and functional assistive devices that align, support, or indirectly facilitate function in the affected region (eg, tenodesis splints, taping, assistive braces).
Comparison groups.
We included studies that compared passive physical modalities with other types of conservative care, waiting list, sham/placebo, or no intervention.
Outcomes.
We aimed to capture both specific and generic health outcomes. Eligible studies had to include one of the following outcomes: (1) self-rated recovery (eg, self-reported on a Likert scale); (2) functional recovery (eg, range of motion [ROM] measured with a goniometer; function measured with the Constant-Murley Scale [CMS]; disability measured with the Shoulder Pain and Disability Index [SPADI]; self-reported return to activities, work, or school); (3) pain intensity (eg, measured with a visual analog scale [VAS] or numerical rating scale); (4) health-related quality of life (eg, measured with EuroQol EQ-5D or the 36-Item Short-Form Health Survey [SF-36]); (5) psychological outcomes (eg, depression measured with the Center for Epidemiologic Depression Scale [CES-D] or Beck Depression Inventory); or (6) adverse events.
Study characteristics.
Eligible studies met the following criteria: (1) English language; (2) published between January 1, 1990, and April 18, 2013; (3) randomized controlled trials (RCTs), cohort studies, or case-control studies; and (4) included an inception cohort of a minimum of 30 participants per treatment arm with a soft tissue shoulder injury in RCTs or 100 participants per group with the specified condition in cohort studies or case-control studies. We excluded studies with the following characteristics: (1) letters, editorials, commentaries, unpublished manuscripts, dissertations, government reports, books and book chapters, conference proceedings, meeting abstracts, lectures and addresses, consensus development statements, and guideline statements; (2) pilot studies, cross-sectional studies, case reports, case series, qualitative studies, narrative reviews, systematic reviews, clinical practice guidelines, biomechanical studies, and laboratory studies; and (3) cadaveric or animal studies.
Data Sources and Searches
We developed our search strategy with a health sciences librarian (Appendix). A second librarian reviewed the search strategy for completeness and accuracy using the Peer Review of Electronic Search Strategies (PRESS) Checklist.23,24 We searched MEDLINE, EMBASE, CINAHL, PsycINFO, and the Cochrane Central Register of Controlled Trials from January 1, 1990, to April 18, 2013.
We developed the search strategy in MEDLINE, which was subsequently adapted to the other bibliographic databases. The search terms included subject headings specific to each database (eg, MeSH in MEDLINE) and free text words relevant to passive physical modalities and soft tissue injuries of the shoulder. We downloaded the search results into a database created using EndNote x6 (Thomson Reuters Corp, New York, New York, http://endnote.com/support/online-user-manual/x6).
Study Selection
We used a 2-phase screening process. In phase 1, random pairs of independent trained reviewers (from a pool of 8 reviewers) screened citation titles and abstracts to determine eligibility and classified citations as relevant, possibly relevant, or irrelevant. In phase 2, the same pairs of reviewers independently reviewed possibly relevant manuscripts to make a final determination. Reviewers met to resolve disagreements. If consensus could not be reached, a third reviewer was used.
Quality Assessment and Data Extraction
Eligible studies were critically appraised by random pairs of independent reviewers (from a pool of 10 reviewers). We assessed the internal validity of studies using the Scottish Intercollegiate Guidelines Network (SIGN) criteria (eTab. 1).25 The SIGN criteria were used to qualitatively evaluate the impact of selection bias, information bias, and confounding on study results. We did not use a quantitative score or a cutoff point to determine the internal validity of studies.26 Rather, the SIGN criteria were used to assist reviewers in making an informed judgment on the internal validity of studies.
Specifically, we critically appraised the following methodological aspects: (1) clarity of the research question; (2) randomization method; (3) concealment of treatment allocation; (4) blinding of treatment and outcomes; (5) similarity of baseline characteristics between treatment arms; (6) cointervention contamination; (7) validity and reliability of outcome measures; (8) follow-up rates; (9) analysis according to intention-to-treat principles; and (10) comparability of results across study sites (where applicable). All reviewers were trained to critically appraise studies using the SIGN criteria. Consensus between the reviewers in each pair was reached through discussion, with the involvement of an independent third reviewer where necessary. We contacted authors when we needed additional information for the critical appraisal to be accurate and valid. After critical appraisal, studies with a low risk of bias were included in our synthesis.27
The lead author extracted data from studies with a low risk of bias and built evidence tables (eTab. 2). A second reviewer independently checked the extracted data. Edits were made using the “Track Changes” feature of Microsoft Word (Microsoft Corporation, Redmond, Washington) by the second reviewer and incorporated by the lead author. Disagreements were resolved through discussion.
Data Synthesis and Analysis
We assessed the clinical homogeneity of studies by comparing the diagnoses, characteristics of the study samples, and parameters of the interventions. We considered conducting a meta-analysis if the studies were homogeneous. However, a qualitative best-evidence synthesis was performed if the studies were clinically heterogeneous.27 We used minimal clinically important differences (MCIDs) to determine the clinical significance of outcome measures. These MCIDs included a between-group difference of 1.4/10 cm on the VAS,28 18/100 on the SPADI,29 and 8/100 on the short form of the Disabilities of the Arm, Shoulder, and Hand questionnaire (QuickDASH).30 The MCIDs for ROM, the Simple Shoulder Test (SST), the CMS, and the University of California–Los Angeles (UCLA) scales have not been defined in the literature. We synthesized the evidence according to the outcome measures. Specifically, we report the effectiveness of interventions according to their impact on specific (eg, shoulder function) or generic (eg, health-related quality of life) outcomes. We stratified our results by shoulder diagnosis and duration (ie, recent [<3 months], persistent [≥3 months], or variable [all durations included]).
We computed reviewer agreement for the screening of titles and abstracts and reported kappa statistics with 95% confidence intervals (95% CIs).31 The percentage of agreement for critical appraisal of articles was calculated for the studies with high and low risk of bias. We calculated differences in mean change from baseline between groups with 95% CIs where data were available to quantify the effectiveness of interventions. We based the computation of the 95% CI on the assumption that the preintervention and postintervention outcomes were highly correlated (r=.8).32,33
Reporting
This systematic review complies with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.34
Role of the Funding Source
This study was funded by the Ontario Ministry of Finance and the Financial Services Commission of Ontario (RFP# No.: OSS_00267175). This research was undertaken, in part, thanks to funding from the Canada Research Chairs program (#950-228941).
Results
Study Selection
We retrieved 1,760 articles, removed 290 duplicates, and screened 1,470 articles for eligibility (Figure). Twenty-two articles were eligible for critical appraisal.35–56 Of those, 11 studies (reported in 12 articles) had a low risk of bias and were included in our synthesis.35–46 Two of the articles with a low risk of bias reported outcomes from different follow-ups from one study.39,40 The interrater agreement for the screening of articles was κ=.94 (95% CI=.88, 1.00). The percentage of agreement for the critical appraisal of studies was 81.0% (17/21 studies). For the 4 studies where reviewers disagreed, consensus was reached through discussion.
Identification and selection of articles.
Study Characteristics
All 11 studies with a low risk of bias were RCTs conducted in adults.35–46 Of these, 6 RCTs addressed subacromial impingement syndrome,35,39,40,42–45 2 investigated nonspecific shoulder pain,36,46 and 3 addressed shoulder calcific tendinitis.37,38,41 Of the 11 RCTs, 5 investigated the effectiveness of shock-wave therapy,37–41,45 3 evaluated the effectiveness of ultrasound,36,44,46 and 2 examined the effectiveness of LLLT.35,44 The remaining studies compared the effectiveness of bipolar interferential current therapy,46 local microwave diathermy,43 and tape.42 The parameters of the passive physical modalities are described in the Table. The studies were clinically heterogeneous and could not be pooled in a meta-analysis.
Parameters of Passive Physical Modalities in Accepted Randomized Controlled Trialsa
Risk of Bias
We critically appraised 21 studies reported in 22 articles. Of these, 11 studies (52%)35–46 had a low risk of bias, and 10 were judged to have a high risk of bias.47–56 All 11 studies with a low risk of bias blinded data collection, used valid and reliable outcome measures, and performed an intention-to-treat analysis (eTab. 1).35–46 Eighty-two percent (9/11) of studies with a low risk of bias used appropriate randomization35,36,38–44,46 and allocation concealment procedures.35–41,43,44,46 Balance in baseline characteristics was reported in 10/11 studies.35–45 The remaining study statistically controlled for differences in baseline characteristics.46 The follow-up rate was greater than 70% in all studies, with most (8/11) achieving a follow-up rate of at least 80%.35,37–40,42–44,46
Of the 21 studies critically appraised, 10 had a high risk of bias and important limitations.47–56 These limitations related to the methods of randomization (6/10),47–50,52,53,55 concealment of treatment allocation (9/10),47–56 or blinding where possible (4/10).48,50,53,55 Baseline characteristics were not reported in 5/10 studies,48,49,53,54,56 and 3/10 trials reported clinically important differences between groups at baseline.50,51,55 Cointerventions were not described or accounted for in 8/10 studies.48–51,53–56 Outcomes were not measured by using a valid and reliable instrument in one study.47 Most studies (7/10) reported high attrition or differential attrition between treatment arms, or did not report attrition by groups.48–50,52,53,55,56 Intention-to-treat analyses were not conducted or could not be confirmed in all but one study (9/10).47
Summary of Evidence for Soft Tissue Injuries of the Shoulder
Subacromial impingement syndrome57 of variable duration.
Consistent evidence from 2 RCTs suggests that LLLT is effective in providing short-term pain reduction for subacromial impingement syndrome of variable duration. However, the long-term benefits of LLLT are unknown. Abrisham et al35 randomized participants with subacromial impingement syndrome (rotator cuff and biceps tendinitis) to 10 sessions over 2 weeks of: (1) LLLT (wavelength of 890 nm, pulsed mode) and exercise (strengthening, stretching, and mobilization exercises) or (2) placebo laser and the same exercise (eTab. 2). Participants in the LLLT group reported a clinically important reduction in shoulder pain immediately postintervention (between-group mean change from baseline: VAS=1.6 [95% CI=1.27, 1.93]). The LLLT group also showed greater improvement in active shoulder flexion (17.8°) and abduction (17.9°) immediately postintervention. However, the improvements of shoulder ROM are within the standard error of the measurement (flexion=25°, abduction=21°, as measured by goniometer).58 Similarly, Santamato et al44 randomized participants with subacromial impingement syndrome (≥4 weeks' duration) to 10 sessions over 2 weeks of: (1) high-intensity laser over the upper trapezius, deltoid, and pectoralis minor muscles or (2) continuous ultrasound over the superior and anterior periarticular regions of the glenohumeral joint and trigger points (eTab. 2). They reported a clinically important difference in shoulder pain favoring LLLT immediately postintervention (between-group mean change from baseline=VAS 1.69 [95% CI=1.12, 2.27]). They also reported significant differences in shoulder function (CMS) favoring LLLT; however, the clinical importance of these differences is unclear because there is no known MCID.
Evidence from one placebo-controlled crossover RCT suggests that one application of pretensioned tape does not reduce pain over placebo tape immediately postintervention in patients with subacromial impingement syndrome of variable duration. Lewis et al42 randomized participants with subacromial impingement syndrome (≥1 week's duration) to one session of 20 to 30 minutes of: (1) pretensioned tape (3.8 cm wide) or (2) placebo (not pretensioned) tape (5 cm wide). A 1-hour washout period occurred between interventions (eTab. 2). Both interventions were applied bilaterally from T1 to T12 and from the center of the spine of the scapula to the T12 spinous process. No differences in pain between the 2 groups were reported immediately postintervention. Although the difference in ROM (measured by inclinometer) was statistically significant, we cannot comment on the clinical importance of these differences because there is no known MCID.
Persistent subacromial impingement syndrome.
Evidence from 2 RCTs suggests that shock-wave therapy is not effective for the management of persistent subacromial impingement syndrome. Speed et al45 randomized participants with shoulder pain (≥3 months) to 3 sessions (one session per month over 3 months) of: (1) extracorporeal shock-wave therapy (dose of 1,500 pulses/session, energy of 0.12 mJ/mm2) at the site of maximal tenderness or (2) placebo shock-wave therapy (eTab. 2). No differences in shoulder pain and disability were found between groups at 3 months. In another RCT, Engebretsen and colleagues39,40 randomized patients with subacromial shoulder pain (≥3 months) to: (1) radial extracorporeal shock-wave therapy (one session per week for 4–6 weeks) or (2) a multimodal program of care (supervised clinic and home-based posture and endurance exercises and soft tissue therapy) (2 sessions per week for 12 weeks) (eTab. 2). No differences in shoulder pain (at rest or during activity), function, or ROM were found between groups. However, participants receiving a multimodal program of care were more likely than participants receiving radial extracorporeal shock-wave therapy to report improvement in shoulder pain and disability (≥19.6 on the SPADI) (odds ratio [OR]=3.2 [95% CI=1.3, 7.8]) and to return to work (relative risk [RR]=1.46 [95% CI=1.06, 2.00]) at 18 weeks.
Evidence from one RCT suggests that local microwave diathermy and subacromial corticosteroid injections lead to similar outcomes in shoulder disability, pain, and function in adults with persistent subacromial impingement syndrome. Rabini et al43 randomized participants to: (1) local microwave diathermy (3 sessions per week over 4 weeks) or (2) 3 local posterolateral subacromial corticosteroid injections (1 injection every 2 weeks at baseline, 2, and 4 weeks) (eTab. 2). They reported no differences between groups for shoulder disability, pain, and function at 4, 12, or 24 weeks postintervention.
Nonspecific shoulder pain of variable duration.
Evidence from 2 RCTs suggests that ultrasound is not effective for the management of nonspecific shoulder pain of variable duration. Ainsworth et al36 compared ultrasound combined with education, exercises, and manual therapy with placebo ultrasound, education, exercises, and manual therapy for the management of unilateral nonspecific shoulder pain (including upper arm pain) aggravated by movement (eTab. 2). Education, exercises, and manual therapy were identical in both groups. There were no differences between groups for shoulder disability, average pain, global improvement, or quality of life up to 6 months' follow-up. Van der Heijden et al46 randomized participants with pain in the deltoid region or restricted glenohumeral ROM to a 6-week program of: (1) ultrasound plus exercise, (2) placebo ultrasound plus exercise, or (3) exercise alone (eTab. 2). The exercise program (active and passive ROM of the shoulder) was identical in all groups. There were no differences between groups in self-perceived recovery, pain, or functional capacity at short- and long-term follow-up.
Evidence from one RCT suggests that bipolar interferential current is not effective for the management of nonspecific shoulder pain of variable duration. Van der Heijden et al46 randomized participants with pain in the deltoid region or restricted glenohumeral ROM to a 6-week program of: (1) bipolar interferential current plus exercise (active and passive ROM of the shoulder), (2) placebo bipolar interferential current plus exercise, or (3) exercise alone (eTab. 2). The exercise program was standardized across treatment groups. There were no differences in self-perceived recovery, pain, or functional capacity between groups at short- and long-term follow-up.
Persistent shoulder pain with calcific tendinitis.
Evidence from 3 RCTs suggests that shock-wave therapy is effective for reducing shoulder pain and disability in adults with persistent calcific tendinitis. Cacchio et al38 randomized participants with calcific tendinitis and shoulder pain lasting at least 6 months to 4 sessions over 4 weeks of: (1) radial shock-wave therapy or (2) sham shock-wave therapy (eTab. 2). Clinically important differences in shoulder pain favored the radial shock-wave therapy (between-group mean change from baseline postintervention: VAS=5.19 [95% CI=4.7, 5.68] and at 6 months: VAS=6.13 [95% CI=5.60, 6.66]). Participants in the radial shock-wave therapy group showed larger reductions in calcification size postintervention. The authors reported statistically significant differences in shoulder function (UCLA) favoring the radial shock-wave therapy, but their clinical importance is unclear because there is no known MCID.
Two other trials support the results of Cacchio et al.38 In one study, Albert et al37 evaluated the effectiveness of varied energy levels of shock-wave therapy for the management of calcific tendinitis with shoulder discomfort (≥3 months) (eTab. 2). Participants were randomized to 2 sessions with a 14-day interval of: (1) high-energy extracorporeal shock-wave therapy or (2) low-energy extracorporeal shock-wave therapy. Participants receiving high-energy shock-wave were more likely to report decreased pain and improved function of the shoulder (≥15 points on the CMS) (RR=2.5 [95% CI=1.3, 5.0]) and to perceive treatment efficacy (RR=2.45 [95% CI=1.42, 4.24]) 3 months postintervention. There was no difference between groups for shoulder pain 3 months postintervention. In the other study, Gerdesmeyer et al41 evaluated the effectiveness of high-energy, low-energy, and sham extracorporeal shock-wave therapy for the management of calcific tendinitis with shoulder pain (≥6 months). Participants were randomized to two 1-hour sessions with a 12- to 16-day interval of: (1) high-energy, (2) low-energy, or (3) sham extracorporeal shock-wave therapy. All groups received 10 sessions of physical therapy following the interventions (active and passive exercise, mobilization, massage, and manual therapy) and pain medication as needed. Clinically important differences in pain reduction favored high-energy over low-energy shock-wave therapy in the short term and long term (between-group mean change from baseline in VAS: 2.3 [95% CI=0.5, 1.3] at 3 months, 3.1 [95% CI=2.5, 4.3] at 6 months, and 3.0 [95% CI=2.3, 3.7] at 12 months). There also were reductions in the size of calcifications favoring high-energy over low-energy shock-wave therapy in the short term and long term. There was no difference in shoulder pain between low-energy and sham extracorporeal shock-wave therapy. There were statistically significant differences in shoulder function (CMS) among 3 groups; however, the clinical importance of these differences is unclear because there is no known MCID.
Adverse events.
Eight of the 11 RCTs with a low risk of bias reported adverse events.35,37–41,43,45,46 The rate of nonserious adverse events ranged from 3% for extracorporeal shock-wave therapy (energy=0.12 mJ/mm2)45 to 75% for high-energy extracorporeal shock-wave (energy =0.32 mJ/mm2).41 Nonserious events included pain, erythema, bleeding (petechiae), hematoma, and aggravation of presenting pain. No studies reported serious adverse events.
Discussion
Summary of Evidence
We examined the effectiveness of passive physical modalities for the management of soft tissue injuries of the shoulder. We found that pretensioned tape and shock-wave therapy are not more effective than placebo treatment for the management of subacromial impingement syndrome. Local microwave diathermy and subacromial corticosteroid injections lead to similar outcomes for the management of persistent subacromial impingement syndrome. Moreover, ultrasound and interferential current therapy are not more effective than placebo treatment for nonspecific shoulder pain of variable duration. However, we found that LLLT is more effective than placebo treatment or ultrasound in providing short-term (2-week) pain reduction for subacromial impingement syndrome of variable duration. The long-term benefits of LLLT have not been investigated. Finally, we found that shock-wave therapy is more effective than sham treatment in reducing short- and long-term (over a 1-year period) shoulder pain and disability for the treatment of persistent calcific tendinitis. Furthermore, individuals receiving high-energy shock-wave therapy reported more adverse events.
Our review provides insight into the effective range of parameters of passive physical modalities (Table). For laser, the reported parameters include wavelengths of 890 and 1,064 nm, power of 2–4 J/cm2 and 0.76 J/cm2, and irradiation time of 120 s/point.35,44 These parameters overlap with the effective range of 820 to 830 nm, 0.8 to 9.0 J/cm2, and 15 to 180 second or 904 nm, 0.8 to 4.2 J/cm2, and 100 to 600 seconds proposed by Chow et al.59 For shock-wave therapy, the range is 0.08 to 0.28 mJ/mm2 for radial medium energy60 and 0.28 mJ/mm2 to 0.60 mJ/mm2 for focused high-energy60 for the effective management of persistent calcific tendinitis.37,38,41 For ultrasound, diathermy, and tape, we cannot comment on their effective parameters based on the comparison interventions used, limited information of parameters, and study designs. More research is needed to validate the effective range of parameters.
Previous Systematic Reviews
We did not identify systematic reviews that comprehensively investigated the effectiveness of passive physical modalities for soft tissue injuries of the shoulder. However, many systematic reviews focused on individual passive physical modalities.12–18,61–65
Our results agree with 2 reviews that ultrasound is not effective for the management of soft tissue shoulder injuries.12,14 Our review strengthens these conclusions with the inclusion of a recent RCT.44 Our conclusion that LLLT is effective for short-term relief of subacromial impingement syndrome is consistent with the findings of von der Heyde18 but not with those of Kromer et al.14 This conclusion may be explained by the method used by Kromer et al, who performed a meta-analysis of heterogeneous studies.14 We found that extracorporeal shock-wave therapy is effective for the management of persistent calcific shoulder tendinitis. Our conclusion supports the review by Ioppolo et al16 but contradicts the findings of Lee et al,17 which were based on a meta-analysis of outdated heterogeneous studies. Our conclusion agrees with Fuentes et al13 that interferential current alone is not better than placebo or other therapies. Our review supports the conclusions of Morris et al,15 who reported that taping is not more effective than sham or usual care.
Generalizability of Passive Physical Modalities in Body Regions
Our review highlights that the effectiveness of passive physical modalities may be modality and condition specific. For example, previous reviews suggest that LLLT may be effective for the management of neck pain but not for persistent low back pain.59,66–69 In our reviews, we found evidence that LLLT is effective for the management of subacromial impingement syndrome. Furthermore, one review showed that shock-wave therapy is not effective for treating low back pain.70 This conclusion agrees with our finding that it is not effective for the management of subacromial impingement syndrome. However, we found that shock-wave therapy is effective for shoulder calcific tendinitis. Therefore, broad generalizations about the effectiveness of passive physical modalities cannot be made.
Strengths and Limitations
Our review has several strengths. First, we developed a comprehensive search strategy that was reviewed by a second independent librarian to minimize errors. Second, we defined an explicit set of inclusion and exclusion criteria to identify all possibly relevant literature. Third, we used 2 independent reviewers for screening and critical appraisal in order to minimize error and bias. Our methodology was standardized, and all reviewers were trained in critical appraisal prior to commencing the systematic review. Fourth, we used a well-accepted and valid set of criteria (SIGN) for critical appraisal. Fifth, we performed a best evidence synthesis by including studies with a low risk of bias to minimize bias. Finally, we assessed the clinical homogeneity of included studies.
Our review has limitations. First, we restricted our search to studies published in the English language. However, this is an unlikely source of bias because most large-scale RCTs are published in English.71 Also, previous reviews showed that the restriction of systematic reviews to English-language studies does not lead to bias.72–75 Second, our search may have missed potentially relevant studies. This limitation may have been due to inconsistently indexed terms of passive physical modalities. Third, critical appraisal requires scientific judgment. However, we trained reviewers to use a standardized critical appraisal tool and used a consensus to reach decisions regarding the quality of studies. Finally, we did not include qualitative studies that explored the lived experience of patients treated with passive physical modalities.
In conclusion, we found evidence that LLLT is more effective than placebo or ultrasound for the treatment of subacromial impingement syndrome at 2 weeks' follow-up. We also found that shock-wave therapy is more effective than sham therapy for treatment of persistent calcific tendinitis over a 1-year follow-up. However, pretensioned tape and shock-wave therapy are not more effective than placebo therapy for subacromial impingement syndrome. Similarly, ultrasound and interferential current therapy are not more effective than placebo therapy for nonspecific shoulder pain. Our review challenges the role of several passive physical modalities for the management of shoulder pain. Clinicians should select interventions with demonstrated effectiveness.
Appendix.
MEDLINE Through Ovid Search Strategy
Footnotes
Dr Yu, Dr Côté, Dr Shearer, Dr Wong, Ms Sutton, Ms Randhawa, Ms Varatharajan, Dr Southerst, Dr Mior, Dr Ameis, Dr Stupar, Dr Nordin, Dr van der Velde, Dr Carroll, and Dr Jacobs provided concept/idea/research design. Dr Yu, Dr Côté, Dr Wong, and Ms Sutton provided writing. Dr Yu, Dr Côté, Dr Shearer, Dr Wong, Ms Sutton, Ms Randhawa, Ms Varatharajan, Dr Southerst, Dr Mior, Dr van der Velde, Ms Taylor-Vaisey, Dr Abdulla, and Dr Shergill provided data collection. Dr Yu, Dr Côté, and Dr Stupar provided data analysis. Dr Yu, Dr Côté, Dr Shearer, and Dr Jacobs provided project management. Dr Côté provided fund procurement, facilities/equipment, and institutional liaisons. Dr Yu provided administrative support. Dr Côté, Dr Shearer, Dr Wong, Ms Sutton, Ms Randhawa, Ms Varatharajan, Dr Southerst, Dr Mior, Dr Ameis, Dr Stupar, Dr Nordin, Dr van der Velde, Dr Carroll, Dr Jacobs, Ms Taylor-Vaisey, Dr Abdulla, and Dr Shergill provided consultation (including review of manuscript before submission).
This study was funded by the Ontario Ministry of Finance and the Financial Services Commission of Ontario (RFP# No.: OSS_00267175). This research was undertaken, in part, thanks to funding from the Canada Research Chairs program (#950-228941).
Systematic Review Registration Number: CRD42013004854.
- Received August 25, 2014.
- Accepted November 3, 2014.
- © 2015 American Physical Therapy Association
References
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