Is there a relationship between subacromial ...

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BJSM Online First, published on October 30, 2013 as 10.1136/bjsports-2013-092389 Original article

Is there a relationship between subacromial impingement syndrome and scapular orientation? A systematic review Elizabeth Ratcliffe,1 Sharon Pickering,2 Sionnadh McLean,3 Jeremy Lewis4,5,6 ▸ Additional material is published online only. To view please visit the journal online (http://dx.doi.org/10.1136/ bjsports-2013-092389). 1

Department of Therapies, Chelsea & Westminster Hospital, London, UK 2 Deakin University, Geelong, Victoria, Australia 3 Department of Allied Health Professions, Sheffield Hallam University, Sheffield, UK 4 Department of Allied Health Professions and Midwifery, University of Hertfordshire, Hertfordshire, UK 5 Central London Community Healthcare NHS Trust, London, UK 6 St George’s NHS Healthcare Trust, London, UK Correspondence to Elizabeth Ratcliffe, Department of Therapies, Chelsea and Westminster Hospital, 369 Fulham Road, London SW10 9NH, UK; [email protected] Received 11 April 2013 Revised 13 September 2013 Accepted 24 September 2013

To cite: Ratcliffe E, Pickering S, McLean S, et al. Br J Sports Med Published Online First: [ please include Day Month Year] doi:10.1136/bjsports-2013092389

ABSTRACT Background Alterations in scapular orientation and dynamic control, specifically involving increased anterior tilt and downward rotation, are considered to play a substantial role in contributing to a subacromial impingement syndrome (SIS). Non-surgical intervention aims at restoring normal scapular posture. The research evidence supporting this practice is equivocal. Objective The aim of this study was to systematically review the relevant literature to examine whether a difference exists in scapular orientation between people without shoulder symptoms and those with SIS. Data sources MEDLINE, AMED, EMBASE, CINAHL, PEDro and SPORTDiscus databases were searched using relevant search terms up to August 2013. Additional studies were identified by hand-searching the reference lists of pertinent articles. Review methods Of the 7445 abstracts identified, 18 were selected for further analysis. Two reviewers independently assessed the studies for inclusion, data extraction and quality, using a modified Downs and Black quality assessment tool. Results 10 trials were included in the review. Scapular position was determined through two-dimensional radiological measurements, 360° inclinometers and threedimensional motion and tracking devices. The findings were inconsistent. Some studies reported patterns of reduced upward rotation, increased anterior tilting and medial rotation of the scapula. In contrast, others reported the opposite, and some identified no difference in motion when compared to asymptomatic controls. Conclusions The underlying aetiology of SIS is still debated. The results of this review demonstrated a lack of consistency of study methodologies and results. Currently, there is insufficient evidence to support a clinical belief that the scapula adopts a common and consistent posture in SIS. This may reflect the complex, multifactorial nature of the syndrome. Additionally, it may be due to the methodological variations and shortfalls in the available research. It also raises the possibility that deviation from a ‘normal’ scapular position may not be contributory to SIS but part of normal variations. Further research is required to establish whether a common pattern exists in scapular kinematics in SIS patients or whether subgroups of patients with common patterns can be identified to guide management options. Non-surgical treatment involving rehabilitation of the scapula to an idealised normal posture is currently not supported by the available literature.

INTRODUCTION Shoulder pain is associated with substantial morbidity. The reported point prevalence ranges between 7% and 27% in the general population and it is

Ratcliffe E, et al. Br Article J Sports Med 2013;0:1–7. Copyright author (ordoi:10.1136/bjsports-2013-092389 their employer) 2013.

thought to increase with age.1 Subacromial impingement syndrome (SIS) and rotator cuff tendinopathy are considered to be the most common causes of shoulder pain. Their point prevalence has been estimated to be between 2.4% and 14%.2 SIS has been shown to affect both manual and sedentary workers3 4 as well as sporting populations.5 The term SIS encompasses shoulder pain and pathology originating from the tendon or bursal tissue in the subacromial space, but its aetiology is still not fully understood. The symptoms experienced in SIS may be due to extrinsic,6 7 intrinsic8 or a mixed aetiology.9 10 The condition is typically diagnosed clinically using a combination of impingement or rotator cuff tests; however, the diagnostic accuracy of these tests has not been confirmed.11–13 One hypothesis is that scapular dyskinesia is involved in the pathogenesis of SIS by reducing the subacromial space creating mechanical impingement of the subacromial tissue, thus resulting in pain and dysfunction.14 15 The rehabilitation of scapula-stabilising muscles is commonly prescribed for the management of SIS.16 17 However, the findings of studies which have examined changes in the activation patterns of muscles of the shoulder complex and those controlling the scapula in people with SIS have been equivocal. A recent systematic review of nine electromyographic (EMG) studies of the shoulder complex in people with SIS concluded that a difference between the upper and lower trapezius EMG activity may exist when compared to people without symptoms, whereas evidence did not exist or was inconsistent for supraspinatus, teres minor, serratus anterior, deltoid and biceps.18 These variations in findings may represent the multifactorial aetiology of SIS or, alternatively, may be due to the small study sizes and methodological factors failing to detect change. An alternative method to investigate the relationship between SIS and posture is to explore the relationship between scapular orientation and symptoms. The literature has associated an anteriorly tilted, downwardly rotated scapular orientation with SIS.17 19 20 Early studies investigating scapular orientation analysed static measurements derived from bony landmarks on radiographs.21 22 These studies identified that differences existed between asymptomatic and symptomatic shoulders in scapular orientation at different points in arm elevation. With the development of measurement techniques, three-dimensional (3D) motion recording methods have enabled a more accurate

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Original article representation of multiplanar scapular motion.23 This investigation aims to systematically review the available research on scapular orientation in people with SIS when compared to those without symptoms, in order to establish whether a relationship between scapular position and SIS exists.

METHODS Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed when conducting this systematic review.24 25 To avoid a bias of predicting and directing the study towards a desired outcome, the methodology was formulated a priori.26

Literature search A search of the literature was performed using the following databases ▸ MEDLINE and In Process and Other Non-Indexed Citations and Ovid MEDLINE, from 1946 to 26 August 2013 ▸ Allied and Complementary Medicine Database (AMED), from 1985 to 26 August 2013 (through OVID) ▸ ExcerptaMedica Database (EMBASE), from 1980 to 26 August 2013 (through OVID) ▸ Citation Index for Nursing and Allied Health Literature with full text (CINAHL plus with full text) 1981 to 26 August 2013 (via the EBSCOhost) ▸ PEDro, 1929 to 26 August 2013 as per criteria for inclusion to database ▸ SPORTDiscus 1939 to 26 August 2013 (via the EBSCOhost) Subject headings and free text search terms were used to search for relevant articles. These included variations of the following: shoulder joint; shoulder; shoulder pain; scapula; shoulder impingement syndrome; SIS; rotator cuff; bursitis; orientation; biomechanics; imaging; movement; posture; and kinesiology. The full Medline search strategy is presented in the online supplementary appendix.

Study selection The following inclusion and exclusion criteria were applied to the articles. The titles and abstracts were screened by the first reviewer (ER), and papers were identified based on the relevance of the study in relation to the population, intervention and outcomes detailed in the title and abstract. Full text copies were obtained for the selected studies and for those where relevance was not clearly identifiable in the abstract and title. The electronic search was then supplemented by manual searches of the reference lists of these articles. The selected articles were further assessed in a non-blinded and standardised manner by the first and second reviewers for their eligibility (ER and SP). The inclusion and exclusion criteria (summarised in table 1) were applied. Disagreement was reconciled by a third reviewer ( JL/SM).

Quality assessment Studies meeting the above inclusion criteria were assessed for quality using the Downs and Black Checklist (1998).27 In its entirety, this appraisal tool is a 27-point checklist and is divided into five subscales comprising: assessment of adequate reporting (10 items); external validity (3 items); internal validity detailing measurement and outcome bias (7 items); confounding (6 items); and power (1 item). It has a maximum score of 32, with each item scoring 0 or 1, except for a 2 point score for fully describing the distribution of principal confounders, and a possible 5 point score for sufficient power calculation. Most of 2

Table 1

Inclusion and exclusion criteria

Inclusion criteria

Exclusion criteria

▸ The study must have been published or ‘in press’ prior to 26 August 2013 ▸ Published research in English only ▸ Studies conducted on humans ▸ Studies conducted on adults (over 16 years of age) ▸ A clear diagnosis of SIS (including rotator cuff tendinopathy or tendon pathology in association with a diagnosis of SIS), defined by a painful arc and positive impingement tests, such as the Hawkins-Kennedy test, Neer’s test or Jobe’s test or following an acceptable clinical assessment performed by an experienced clinician ▸ The study must assess scapular orientation in subjects with symptomatic SIS compared to asymptomatic controls, that is, likely to be observational studies with a control group

▸ Duplicated publications ▸ Studies investigating the effect of changing scapula orientation in asymptomatic participants or participants with other conditions, such as osteoarthritis, instability or full thickness rotator cuff tears, without a clear diagnostic criterion for SIS ▸ Studies without a comparison group of asymptomatic controls ▸ Cadaveric or animal studies ▸ Single-subject case reports ▸ Unpublished research ▸ Studies without ethical approval ▸ Trials not detailing unique data, that is, secondary citations

SIS, subacromial impingement syndrome.

these items pertain to any type of study design, but three items (known confounders, main outcomes and sample size) are design specific and customised by raters.28 The Downs and Black Checklist has been shown to have moderate to good interrater reliability.27 28 For the purpose of this study, the tool was modified by eliminating two items relating to randomisation and allocation concealment,28 and also by changing the final item from a score of 0–5 to a scale of 0–1. There was a score of 1 if a power calculation or sample size calculation was provided, and 0 if there was no power calculation, sample size calculation or explanation whether the number of participants was appropriate.29 The total maximum score of the modified checklist used in this review was 26. Each included study was initially assessed by two independent reviewers and scored using the modified checklist. Subsequently, if required, a consensus score was reached after discussion. The Downs and Black Checklist itself does not provide bandings for levels of quality.27 Various quality rating categories have been suggested, such as using the median values of percentage scores,30 or assigning the following ordinal categories: low (≤33.3%), moderate (33.4–66.7%) and high (≥66.8%).28 The latter categorisation was chosen for this systematic review.

Data extraction and synthesis Data extraction was carried out by the first reviewer (ER) and checked by the second reviewer (SP), using predesigned and standardised forms.26 31 After data extraction, the final inclusion and exclusion decisions were made regarding the study, referenced against the predetermined criteria (table 1), and this decision was detailed on the data extraction forms. The information is detailed in table format to highlight the similarities and differences within the study designs, objective, subject population and control, measurement and outcome measure. Two tables detail this information. Online supplementary table S1 details the study characteristics and online supplementary table S2 details the outcomes. While the approach used to conduct this review was guided by the PRISMA statement, the heterogeneity in the studies did Ratcliffe E, et al. Br J Sports Med 2013;0:1–7. doi:10.1136/bjsports-2013-092389


Original article Table 2 Included studies Study

Authors

40

Ludewig, PM and CookTM (combined with 41 for quality assessment) Borstad JD and Ludewig PM. Endo K, Ikata T, Katoh S, Takeda Y. Finley MA, McQuade KJ, Rodgers MM. Hebert LJ, Moffet H, McFadyen BJ, Dionne CE. Lin J, Hsieh SC, Cheng WC, Chen WC, Lai Y. Lukasiewicz AC, McClure P, Michener L, Pratt N, Sennett B. McClure PW, Michener LA, Karduna AR. Su KP, Johnson MP, Gracely EJ, et al. Warner JJ, Micheli, LJ, Arslanian LE, et al.

41 45 48 46 42 47 44 43 49

not allow for a meta-analysis, and therefore a narrative review was performed.

Methodological quality The 10 selected investigations were scored using the modified quality assessment tool. Uncertainties were discussed and consensus was reached, resulting in incomplete consensus between raters. The results are shown in table 3. Articles relating to the same cohort40 41 had their scores combined to prevent bias. The quality scores ranged from 14/2642 to 19/26,43 with three studies40 41 43 being deemed to be of high quality and the remainder of moderate quality. All 10 articles were therefore considered in this review. The most common methodological flaws were: (1) not including an acknowledgement of whether or not there were any adverse effects on the measurement process (criterion 8, table 3); (2) poor description of the source population and recruitment process (criteria 11and12, table 3); (3) not describing the environment where the studies took place (criterion 13, table 3); and (3) not stating whether the rater was blinded to the study group during measurements (criterion 15, table 3). Only one study had a follow-up period,43 so applying criteria 9 and 12 had limited value for the remaining studies.

RESULTS The initial database searches identified 7445 abstracts, and of these 1106 were identified as duplicates and removed. Eighteen articles were deemed relevant based on their title, abstract or both. Two were removed as the main body of the study was not in English.32 33 Full text articles were retrieved for 16 studies, 10 of which satisfied the inclusion and exclusion criteria and were included in this review (table 2); 6 were rejected.34–39 Of the six articles, one had required arbitration and it was rejected from this study on the basis of the diagnostic criteria used for the subject sample.37 Of the ten studies, two shared the same participants and because of this, these studies were combined during analysis.40 41 The selection process is displayed in figure 1.

Study characteristics Of the 10 studies included in this review, the sample size ranged from 2142 to 90.44 In two studies,45 46 56 participants compared the symptomatic shoulder to the asymptomatic contralateral side, and therefore the total number of participants was 370. The age range of the participants with SIS was 17– 74 years, compared with 19–74 years in the control group. The duration of symptoms was noted in only four studies40 41 43 46 and ranged between 2 weeks and 8 years. Six of the studies considered the degree of pain and disability resulting from SIS, and this was measured by the: Shoulder Pain and Disability Index (SPADI);40 41 47 Wheelchair Users’ Shoulder Pain Index (WUSPI);48 Neer & Welsh Swimmers’ Shoulder Grading

Figure 1 Depicts the identification, screening, eligibility and inclusion phases of the study selection process in this systematic review. Ratcliffe E, et al. Br J Sports Med 2013;0:1–7. doi:10.1136/bjsports-2013-092389

3


Original article Table 3 Results of Downs and Black Checklist Application in the included studies Study criteria

40 and 41 (combined)

42

43

44

45

46

47

48

49

1 2 3 4 5 (/2) 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 removed 24 rmoved 25 26 27(/1) Total/26 Scores in percentage

1 1 1 1 2 1 1 0 1 0 UTD/0 1 UTD/0 0 UTD/0 1 1 1 1 1 1 0 X X 1 0 1 18 69

1 1 1 1 1 1 1 0 1 1 1 UTD/0 UTD/0 0 UTD/0 1 0 1 1 1 1 1 X X UTD/0 0 0 16 62

1 1 1 1 2 1 1 0 1 1 0 UTD 0 0 UTD/0 1 UTD/0 1 1 1 UTD/0 UTD/0 X X 1 UTD/0 0 15 58

1 1 1 1 2 1 1 0 1 0 0 UTD/0 UTD/0 0 UTD/0 1 UTD/0 1 1 1 1 UTD/0 X X UTD/0 UTD/0 0 14 54

1 1 1 1 2 1 1 0 1 1 0 0 0 0 0 1 UTD/0 1 1 1 UTD/0 UTD/0 X X UTD/0 UTD/0 0 14 54

1 1 1 1 2 1 1 0 1 0 UTD/0 0 UTD/0 0 UTD/0 1 1 1 1 1 0 1 X X 1 UTD/0 0 16 62

1 1 1 1 2 1 1 0 1 1 0 0 UTD/0 0 UTD/0 1 1 1 1 1 0 UTD/0 X X 1 UTD/0 0 16 62

1 1 1 1 1 1 1 0 1 1 0 UTD/0 1 0 1 1 1 1 1 1 1 1 X X 1 UTD/0 0 19 73

1 1 1 1 1 1 0 0 1 0 0 UTD/0 UTD/0 0 1 1 1 1 1 1 1 UTD/0 X X 0 UTD/0 0 14 54

1. Is the hypothesis/aim/objective of the study clearly described? 2. Are the main outcomes to be measured clearly described in the Introduction or Methods section? 3. Are the characteristics of the patients included in the study clearly described? 4. Are the interventions of interest clearly described? 5. Are the distributions of principal confounders in each group of subjects to be compared clearly described? 6. Are the main findings of the study clearly described? 7. Does the study provide estimates of the random variability in the data for the main outcomes? 8. Have all important adverse events that may be a consequence of the intervention been reported? 9. Have the characteristics of patients lost to follow-up been described? 10. Have the actual probability values been reported (eg, 0.035 rather than