Ultrasound measurements on acromio-humeral distance and supraspinatus tendon thickness: Test–retest reliability and correlations with shoulder rotational strengths

Factors determining the short-term clinical outcomes of conservative treatment in patients with supraspinatus tear

INTRODUCTION

To identify factors influencing the better and worse changes in the Western Ontario Rotator Cuff Index of patients undergoing conservative treatment for supraspinatus tendon tear.

METHODS

The study included 30 patients with supraspinatus tendon tear who underwent conservative treatment. The average duration of intervention was 35.4 days. The Western Ontario Rotator Cuff Index, shoulder range of motion, isometric muscle strength, supraspinatus tendon thickness, thickness of the supraspinatus, infraspinatus, and teres minor muscles, and acromiohumeral interval were assessed before and after the intervention. In the statistical analyses, change in the Western Ontario Rotator Cuff Index was the dependent variable, and the amount of change in each measurement variable before and after the intervention was the independent variable.

RESULTS

The average Western Ontario Rotator Cuff Index improved from 1067 at pre-treatment to 997 at post-treatment, but without a significant difference (p = 0.29). A multiple regression analysis revealed that supraspinatus tendon thickness and muscle strength in shoulder external rotation at 90° scaption had a significant effect on the change in the Western Ontario Rotator Cuff Index (R2 = 0.44, p < 0.01).

CONCLUSION

Supraspinatus tendon thickness and muscle strength in shoulder external rotation at 90° scaption were important factors for the Western Ontario Rotator Cuff Index score in the early stages of conservative treatment for patients with supraspinatus tendon tear.

Supraspinatus Muscle and Tendon Characteristics 1 Year After Surgical Rotator Cuff Repair Compared With Contralateral Shoulder: Data From the CUT-N-MOVE Trial

BACKGROUND

It is necessary to better understand the structural characteristics of the supraspinatus tendon and associated muscle after rotator cuff repair and in the event of retear.

PURPOSE

To study structural differences between the repaired and contralateral shoulders 1 year after rotator cuff repair in patients who received either progressive exercise therapy (PR) or usual care (UC) in a randomized controlled trial and to investigate whether there was interaction with tendon retear and limb dominance.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Patients with surgically repaired traumatic full-thickness rotator cuff tears involving the supraspinatus tendon were included. After surgery, they were randomized to PR or UC (active from postoperative week 2 or 6, respectively). The subacromial structures (acromiohumeral distance, supraspinatus tendon thickness, and vascularity) and the supraspinatus muscle thickness were examined with ultrasound at the 1-year follow-up.

RESULTS

A total of 79 patients were included. The characteristics of the 2 intervention groups (PR and UC) were comparable, including the Western Ontario Rotator Cuff Index score and number of retears. The authors found significantly thinner supraspinatus tendon (PR, P < .001; UC, P = .003) and reduced acromiohumeral distance (PR, P = .023; UC, P = .025) in the repaired versus the contralateral shoulders in both intervention groups. For neovascularization, there was no interlimb difference in either of the groups or between groups (PR vs UC). In patients with intact tendons, there was no interlimb difference in the muscle thickness, but in patients with tendon retear the muscle was significantly thinner on the repaired side (P = .024 and P < .001, respectively). When the dominant supraspinatus tendon was repaired (both groups), it was significantly thinner than the nondominant healthy tendon, but this difference was not seen when the nondominant supraspinatus tendon was repaired (P = .006).

CONCLUSION

One year after rotator cuff surgery, the repaired supraspinatus tendon was significantly thinner and the corresponding acromiohumeral distance was reduced. In patients with retear, the supraspinatus muscle was significantly thinner on the repaired side and early initiation of tendon-loading exercises did not affect these findings.

REGISTRATION

NCT02969135 (ClinicalTrials.gov identifier).

Does an Increase in Supraspinatus Tendon Thickness After Swimming Increase the Likelihood of Future Shoulder Pain?

BACKGROUND

Increase in supraspinatus tendon thickness (STT) resulting from swimming practice has been observed in those with a history of shoulder pain. The magnitude of change in STT after a swimming session and its rate of recovery may be an indicator of future shoulder pain incidence.

HYPOTHESIS

The supraspinatus tendons that demonstrate a greater increase in thickness as a result of swimming practice will have an increased likelihood of future shoulder pain in a cohort of competitive swimmers over a period of 6 months.

DESIGN

Descriptive epidemiology study.

LEVEL OF EVIDENCE

Level 2b, individual cohort studies.

METHODS

A cohort of 50 nationally qualified swimmers aged between 14 and 22 years, from 3 open National Swimming Programs in Victoria, Australia, were recruited for this study. Ultrasonographic measurements of swimmers' STT was obtained of both shoulders, before, immediately after, and 6 hours after a single swimming practice session. Data were recorded of any significant interfering shoulder pain at 3 and 6 months after the initial testing session.

RESULTS

Stepwise logistic regression models indicated that significant predictors of the likelihood of experiencing significant interfering pain were sex [significant at 6 months; odds ratio (OR) 4.2] and the extent of change in STT immediately (OR 2.3 and 1.3 per mm at 3 and 6 months, respectively) and 6 hours postpractice (OR 1.9 and 1.5 per mm at 3 and 6 months, respectively).

CONCLUSION

The current data suggest larger increases in tendon thickness after training are associated with an increased likelihood of future shoulder pain.

CLINICAL RELEVANCE

These data may be valuable for monitoring training load and identifying athletes who may have an increased likelihood of shoulder pain.

Novel Posterior Shoulder Stretching With Rapid Eccentric Contraction and Static Stretching in Patients With Subacromial Pain Syndrome: A Randomized Trial

BACKGROUND

In subacromial pain syndrome (SPS), it is unknown whether posterior shoulder stretching exercises (PSSE) with rapid eccentric contraction, a muscle energy technique, improve clinical and ultrasonographic outcomes more than no stretching or static PSSE.

HYPOTHESIS

PSSE with rapid eccentric contraction is superior to no stretching and static PSSE in improving clinical and ultrasonographic outcomes in SPS.

STUDY DESIGN

Randomized controlled trial.

LEVEL OF EVIDENCE

Level 1.

METHODS

Seventy patients with SPS and glenohumeral internal rotation deficit were randomized into the modified cross-body stretching with rapid eccentric contraction group (EMCBS; n = 24), static MCBS group (SMCBS; n = 23), or control group (CG; n = 23). In addition to 4-week physical therapy, EMCBS received PSSE with rapid eccentric contraction, SMCBS static PSSE, and CG no PSSE. The primary outcome was internal rotation range of motion (ROM). Secondary outcomes were posterior shoulder tightness, external rotation ROM (ERROM), pain, modified Constant-Murley score, short form of the disabilities of the arm, shoulder, and hand questionnaire (QuickDASH), rotator cuff strength, acromiohumeral distance (AHD), supraspinatus tendon thickness, and supraspinatus tendon occupation ratio (STOR).

RESULTS

Shoulder mobility, pain, function and disability, strength, AHD, and STOR improved in all groups (P < 0.05).

CONCLUSION

In patients with SPS, PSSE with rapid eccentric contraction and static PSSE were superior to no stretching in improving clinical and ultrasonographic outcomes. Stretching with rapid eccentric contraction was not superior to static stretching, but improved ERROM compared with no stretching.

CLINICAL RELEVANCE

In SPS, both PSSE with rapid eccentric contraction and static PSSE included in physical therapy program are beneficial to improve posterior shoulder mobility and other clinical and ultrasonographic outcomes. In the case of ERROM deficiency, rapid eccentric contraction might be preferred.

Diagnostic Implications of Ultrasound Evaluation in Patients With Shoulder Impingement Syndrome

OBJECTIVE

To evaluate the diagnostic value of musculoskeletal ultrasound measurements of subacromial bursa (SAB) thickness, supraspinatus tendon (SUP) thickness, acromiohumeral distance (AHD), and SUP-to-AHD ratio (AHD%) in patients with shoulder impingement syndrome (SIS).

METHODS

This was a prospective cross-sectional observational study. Thirty patients with SIS (60 shoulders) admitted between January 2019 and January 2020 were enrolled. The SUP thickness, SAB thickness, AHD, and AHD% (calculated as AHD% = [(SUP / AHD) × 100%]) were measured in 60 shoulders using musculoskeletal ultrasound.

RESULTS

The affected shoulder displayed thicker SUP and SAB (t = 7.838), narrower AHD (t = 2.324), and larger AHD% (t = 6.875) than the unaffected shoulder (P < .05). The SUP thickness showed a linear positive correlation with AHD (r = .503) and AHD% (r = .792) in the affected shoulder (P < .05). On receiver operating characteristic analysis, AHD*AHD% showed the best diagnostic performance in both measurements (area under the curve: 0.877).

CONCLUSION

This study revealed that SIS symptoms may be related to a larger AHD% with SUP thickening. As diagnostic criteria, the cut-off values of AHD% (65.6%) and AHD*AHD% (0.504) have good sensitivity and specificity and can help improve the differential diagnosis of patients with SIS.

Mid-term effects of two different Kinesio tape treatments in female patients with subacromial impingement syndrome: Randomized controlled ultrasonographic study

STUDY DESIGN

Randomized controlled study.

PURPOSE OF THE STUDY

To evaluate the effect of Kinesio Tape (KT) applied differently in patients diagnosed with Subacromial Impingement Syndrome (SIS) on acromiohumeral distance (AHD) and supraspinatus tendon (SsT) thickness using ultrasound (US) and its effect on pain, upper limb functional status and hand grip muscle strength in the short and mid-term.

METHODS

The 90 patients diagnosed with unilateral SIS by clinical examination were randomized into 3 groups. In addition to exercise therapy, the deltoid in group 1 and the supraspinatus muscle in group 2 were taped from insertion to origin. Group 3, which was the control group, was applied 9 sessions of sham taping for 3 weeks. Cases were evaluated for AHD and SsT thickness, pain was evaluated with the Visual Analog Scale (VAS), function with the Disabilities of the arm, shoulder and hand (DASH) and the Western Ontario Rotator Cuff Index (WORC), and hand grip strength (HGS) using a dynamometer before, and 3rd week and 3rd month after the KT application.

RESULTS

There was a significant improvement in all parameters in the short and mid-term intra group comparisons in Group 1 and 2 after taping (P < .05). In intergroup comparisons, significant improvement was achieved in all parameters in Group 1 and Group 2 in the mid and short term compared to the control group (P < .05). In comparison of Group 1 and Group 2, HGS in the short term (p: 0.07) and the SsT thickness in the short and mid-term (p: 0.36, p: 0.85) did not exhibit any difference. The improvement in all other parameters in group 1 was statistically significant.

CONCLUSION

The findings of our study provide definitive evidence for the effectiveness of KT treatment depending on the method of tape application employed.

Deep learning algorithm for predicting subacromial motion trajectory: Dynamic shoulder ultrasound analysis

Subacromial motion metrics can be extracted from dynamic shoulder ultrasonography, which is useful for identifying abnormal motion patterns in painful shoulders. However, frame-by-frame manual labeling of anatomical landmarks in ultrasound images is time consuming. The present study aims to investigate the feasibility of a deep learning algorithm for extracting subacromial motion metrics from dynamic ultrasonography. Dynamic ultrasound imaging was retrieved by asking 17 participants to perform cyclic shoulder abduction and adduction along the scapular plane, whereby the trajectory of the humeral greater tubercle (in relation to the lateral acromion) was depicted by the deep learning algorithm. Extraction of the subacromial motion metrics was conducted using a convolutional neural network (CNN) or a self-transfer learning-based (STL)-CNN with or without an autoencoder (AE). The mean absolute error (MAE) compared with the manually-labeled data (ground truth) served as the main outcome variable. Using eight-fold cross-validation, the average MAE was proven to be significantly higher in the group using CNN than in those using STL-CNN or STL-CNN+AE for the relative difference between the greater tubercle and lateral acromion on the horizontal axis. The MAE for the localization of the two aforementioned landmarks on the vertical axis also seemed to be enlarged in those using CNN compared with those using STL-CNN. In the testing dataset, the errors in relation to the ground truth for the minimal vertical acromiohumeral distance were 0.081-0.333 cm using CNN, compared with 0.002-0.007 cm using STL-CNN. We successfully demonstrated the feasibility of a deep learning algorithm for automatic detection of the greater tubercle and lateral acromion during dynamic shoulder ultrasonography. Our framework also demonstrated the capability of capturing the minimal vertical acromiohumeral distance, which is the most important indicator of subacromial motion metrics in daily clinical practice.

Subacromial Motion Metrics in Painful Shoulder Impingement: A Dynamic Quantitative Ultrasonography Analysis

OBJECTIVES

To explore the subacromial motion metrics in patients with and without subacromial impingement syndrome (SIS) and to investigate whether the abnormality was associated with rotator cuff pathologies.

DESIGN

This cross-sectional observational study used dynamic quantitative ultrasonography imaging for shoulder joint assessment.

SETTING

Outpatient rehabilitation clinic.

PARTICIPANTS

Individuals with SIS on at least 1 shoulder (n=32) and asymptomatic controls (n=32) (N=64).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Frame-by-frame, the humeral greater tuberosity against the lateral edge of the acromion was traced to obtain the minimal vertical acromiohumeral distance (AHD). The rotation angle and radius of the humerus were computed using the least-squares curve fitting method.

RESULTS

Approximately two-thirds of the shoulders with SIS did not have any sonographically identifiable rotator cuff pathologies. There was a consistent trend of nonsignificantly increased humeral rotation angles in painful shoulders. The generalized estimating equation demonstrated that the decreased minimal vertical AHD was associated with painful subacromial impingement (β coefficient: -0.123cm, 95% confidence interval [CI], -0.199 to -0.047). The area under the curve for the minimal vertical AHD to discriminate painful or impinged shoulders ranged from 0.624-0.676. The increased rotation angle (β coefficient: 10.516°; 95% CI, 3.103-17.929) and decreased rotation radius (β coefficient: -2.903cm; 95% CI, -5.693 to -0.111) were shown to be significantly related to the presence of supraspinatus tendinopathy.

CONCLUSIONS

Shoulders with SIS were characterized by a decreased minimal vertical AHD during dynamic examination. Abnormal subacromial metrics can develop in patients with mild (or no) rotator cuff pathologies. More prospective cohort studies are warranted to investigate the changes in subacromial motion metrics in populations at risk for painful or impinged shoulders.

Inter- and Intra-Rater Reliability of Ultrasound Measurements of Superficial and Deep Fasciae Thickness in Upper Limb

Ultrasound (US) imaging is increasingly the most used tool to measure the thickness of superficial and deep fasciae, but there are still some doubts about its reliability in this type of measurement. The current study sets out to assess the inter-rater and intra-rater reliability of US measurements of superficial and deep fasciae thicknesses in the arm and forearm. The study involved two raters: the first (R1) is an expert in skeletal–muscle US imaging and, in particular, the US assessment of fasciae; the second (R2) is a radiologist resident with 1 year’s experience in skeletal–muscle US imaging. R2, not having specific competence in the US imaging of fasciae, was trained by R1. R1 took US images following the protocol by Pirri et al. 2021, and the US-recorded images were analyzed separately by the two raters in different sessions. Each rater measured both types of fasciae at different regions and levels of the arm and forearm. Intra- and inter-rater reliability was excellent for the deep fascia and good and excellent for the superficial fascia according to the different regions/levels (for example for the anterior region of the arm: deep fascia: Ant 1: ICC_2,2 = 0.95; 95% CI = 0.81–0.98; superficial fascia: Ant 1: ICC_2,2 = 0.85, 95% CI = 0.79–0.88). These findings confirm that US imaging is a reliable and cost-effective tool for evaluating both fasciae, superficial and deep.

Reliability of point-of-care shoulder ultrasound measurements for subacromial impingement in asymptomatic participants

Background

Rehabilitation is the key to management of patients with subacromial impingement syndrome to prevent disability and loss of function. While point-of-care musculoskeletal ultrasound aids clinical diagnosis of subacromial impingement syndrome, many patients do not demonstrate the classic findings of dynamic supraspinatus tendon impingement beneath the acromion on ultrasound. The objective of this study was to establish the most reliable shoulder ultrasound measurements for subacromial impingement, by evaluating the intra-rater and inter-rater reliability of measurements in asymptomatic participants.

Methods

Eighteen participants (9 women, 9 men, mean ± standard deviation: 34.6 ± 7.9 years of age) underwent bilateral shoulder ultrasound evaluations with measurements for subacromial impingement (acromiohumeral distance, acromion-greater tuberosity distance, supraspinatus tendon, subacromial-subdeltoid bursa, and subacromial-subdeltoid bursal fluid thickness) performed by two sports medicine physicians. Intra-class coefficients were calculated to determine the intra- and inter-rater reliability of shoulder ultrasound images and measurements.

Results

Intra-rater reliability for acromiohumeral distance (0.76–0.79), supraspinatus tendon (0.91–0.95), subacromial-subdeltoid bursa (0.76–0.84), and subacromial-subdeltoid bursal fluid thickness (0.75–0.81) was found to be good to excellent, whereas inter-rater reliability ranged from poor to moderate.

Conclusions

Acromiohumeral distance in neutral position and short axis ultrasound measurements of supraspinatus tendon, subacromial-subdeltoid bursa, and subacromial-subdeltoid bursal fluid thickness in the modified Crass position were the most reliable for subacromial impingement in asymptomatic participants. We recommend validation of these measurements in a symptomatic population to aid diagnosis and direct rehabilitation of patients with suspected subacromial impingement, and to increase point-of-care ultrasound uptake, availability, and training among rehabilitation professionals across health systems.

Shoulder pain and ultrasound findings: A comparison study of wheelchair athletes, nonathletic wheelchair users, and nonwheelchair users

BACKGROUND

Shoulder pain is one of the most common musculoskeletal concerns in manual wheelchair users including among athletes. However, there is a paucity of research characterizing both shoulder pain and shoulder pathology in this population.

OBJECTIVE

To characterize and compare the prevalence of current shoulder pain and ultrasound metrics of shoulder pathology between wheelchair athletes, nonathletic wheelchair users, and nonwheelchair users.

DESIGN

Cross-sectional.

SETTING

Chicago-area adaptive sport teams/programs and musculoskeletal clinics.

PARTICIPANTS

Thirty-four wheelchair athletes, six nonathletic wheelchair users, and 12 nonwheelchair users.

METHODS

Self-reported shoulder pain was assessed by questionnaire and Wheelchair User Shoulder Pain Index (WUSPI). Shoulder physiology and pathology were assessed by physical and ultrasound evaluation of both shoulders by a sports medicine physician.

MAIN OUTCOME MEASURES

Questionnaire outcomes: Prevalence of current shoulder pain, total WUSPI score. Physical examination outcomes: total Physical Examination of Shoulder Scale (PESS) score. Sonographic outcomes: Acromiohumeral distance (AHD) and presence of shoulder pathology.

RESULTS

The majority of wheelchair athletes (68%) and nonathletic wheelchair users (67%) experienced shoulder pain since using a manual wheelchair. Wheelchair basketball players had a mean WUPSI score of 17.2 (SD = 21.8), and athletes participating in handcycling, sled hockey, and quad rugby had mean scores of 4.91 (SD = 8.32), 7.76 (SD = 13.1), and 4.29 (SD = 7.75), respectively. Shoulder pathology was observed in 14 of 31 (45%) wheelchair athletes and 4 of 6 (67%) nonathletic wheelchair users (p = .41).

CONCLUSIONS

Although wheelchair use is a risk factor for shoulder pain, participation in amateur wheelchair sports may not be associated with increased risk of shoulder pain. It is possible that overhead sports such as wheelchair basketball may define a unique high-risk group. Further study is needed to examine this relationship and to determine whether there are differences between specific wheelchair sports.

Effect of Fatiguing Wheelchair Propulsion and Weight Relief Lifts on Subacromial Space in Wheelchair Users

Objective

This study aimed to identify targets of intervention for reducing shoulder pain in wheelchair users with spinal cord injury (SCI) by (1) examining changes in subacromial space [acromiohumeral distance (AHD) and occupation ratio (OccRatio)] with fatiguing wheelchair propulsion, and different loading conditions [unloaded position vs. weight relief lifts (WRL)]; (2) associating these changes with wheelchair user capacity, as well as (3) identifying subject characteristics associated with subacromial space, such as sex, lesion level, time since injury, body mass index and impaired shoulder range of motion.

Methods

Fifty manual wheelchair users with SCI [11 females, age = 50.5 (9.7) years, time since injury = 26.2 (11.4) years] participated in this quasi-experimental one-group pretest-posttest study. Ultrasound images were used to define AHD during an unloaded position, and during personal and instructed WRL before and after fatiguing wheelchair propulsion. Furthermore, supraspinatus and biceps thickness defined from ultrasound images were used to calculate OccRatios. Wheelchair user capacity was quantified as functional strength (maximum resultant force reached during maximum isometric forward push) and anaerobic work capacity (highest power output reached during 15-m sprint test). Multilevel mixed-effects linear regression analyses controlling for between subject variability and covariables were performed to address the research questions.

Results

AHD was significantly smaller during personal WRL (p &lt; 0.001) and instructed WRL (p = 0.009, AHD both 11.5 mm) compared to the unloaded position (11.9 mm). A higher wheelchair user capacity (higher anaerobic work capacity) reduced the impact of WRL on AHD decrease. The fatiguing wheelchair propulsion had no effect on AHD (p = 0.570) and on OccRatio of supraspinatus (p = 0.404) and biceps (p = 0.448). Subject characteristics related to a larger subacromial space were lower lesion level, shorter time since injury, impaired external rotation, a lower body mass index and a higher anaerobic work capacity.

Conclusion

This study showed a significant reduction in AHD during WRL with no effect of fatiguing wheelchair propulsion on the subacromial space in wheelchair users with SCI. A higher anaerobic work capacity was beneficial in stabilizing the shoulder during WRL. Our findings may assist clinicians in designing a shoulder injury prevention program.

Supraspinatus tendon thickness and subacromial impingement characteristics in younger and older adults

Background

Subacromial impingement (SAI) may be a cause of age-related rotator cuff abnormalities; therefore, the purpose of this study was to compare SAI characteristics between younger and older adults. In addition to the fact that thickened supraspinatus tendon (SST) indicates tendon abnormalities, SAI characteristics have been recognized as follows: greater SST thickness, reduced acromiohumeral distance (AHD), greater reduction of AHD (∆AHD) with arm elevation, and a higher percentage of SST within AHD (i.e., occupation ratio: OcAHD). Furthermore, we investigated the relationships between SST thickness and AHD, as well as SST thickness and ∆AHD to clarify the effect of SAI on rotator cuff abnormalities.

Methods

Healthy younger (n = 18, 21–24-year-old) and older (n = 27, 45–80-year-old) adults without any shoulder symptoms participated in this study. We measured their SST thickness and AHD at rest and at arm elevation (30° and 60°) in the scapular plane using ultrasound, and calculated ∆AHD as the relative change expressed as a percentage of the baseline. OcAHD was expressed as the ratio of SST thickness at rest to AHD at rest and in elevated positions.

Results

The older subjects had approximately one mm thicker SST (P = 0.003, 95% Confidence interval [CI] = 0.410 to 1.895) and approximately 1.0 to 1.3 mm greater AHD than the younger subjects (P = 0.011, 95%CI = 0.284 to 2.068 at rest; P = 0.037, 95%CI = 0.082 to 2.609 for 30° of arm elevation; P = 0.032, 95%CI = 0.120 to 2.458 for 60° of arm elevation). However, there were no differences in ΔAHD and OcAHD between the groups.

Conclusion

This study demonstrated that, compared with the younger subjects, the older subjects showed thicker supraspinatus tendon but no other SAI characteristics including decreases in AHD and increases in OcAHD. Thus, this study suggests that older subjects showed age-related SST abnormalities without SAI, although the magnitude of the differences in SST thickness is notably small and the clinical significance of this difference is unclear.

Development of shoulder pain with job-related repetitive load: mechanisms of tendon pathology and anxiety

BACKGROUND

The paucity of longitudinal clinical studies limits our understanding of the development of shoulder pain with repetitive shoulder tasks, and its association with underlying mind and body mechanisms. Tendon thickening characterizes painful shoulder supraspinatus tendinopathy, and the perception of pain can be affected by the presence of psychological factors such as anxiety and depression. This study determined the incidence of shoulder pain in novice individuals exposed to repetitive shoulder tasks, and the associated change in outcomes of supraspinatus tendon morphology and measures of anxiety and depression.

METHODS

We recruited dental hygiene (DH) students (n = 45, novice and exposed to shoulder repetitive tasks) and occupational therapy (OT) students (n = 52, novice, but not exposed to shoulder repetitive tasks), following them over their first year of training. We measured shoulder pain, supraspinatus morphology via ultrasonography, and psychosocial distress via the Hospital Anxiety and Depression Scale. We compared the incidence of shoulder pain (defined as a change of visual analog scale for pain score greater than the minimal clinically important difference) between DH and OT students using Fisher exact test. We used mixed effects models to longitudinally compare the change in outcomes between 3 groups: DH students who develop and did not develop shoulder pain, and OT students.

RESULTS

The incidence of shoulder pain is higher in DH students (relative risk = 4.0, 95% confidence interval [CI] 1.4, 11.4). After 1 year, DH students with pain had the greatest thickening of the supraspinatus (0.7 mm, 95% CI 0.4, 0.9). The change in supraspinatus thickness of DH students with pain was greater than both DH students with no pain (0.4 mm, 95% CI 0.1, 0.8) and OT students (0.9 mm, 95% CI 0.5, 1.2). Anxiety score increased 3.8 points (95% CI 1.6, 5.1) in DH students with pain, and 43% of DH students with pain had abnormal anxiety score at 1 year (relative risk = 2.9, 95% CI 1.0, 8.6).

CONCLUSION

Our results provide support for the theoretical model of repetitive load as a mechanism of tendinopathy. The supraspinatus tendon thickens in the presence of repetitive tasks, and it thickens the most in those who develop shoulder pain. Concurrently, anxiety develops with shoulder pain, indicating a potential maladaptive central mechanism that may impact the perception of pain.

Acromiohumeral distance and supraspinatus tendon thickness in people with shoulder impingement syndrome compared to asymptomatic age and gender-matched participants: a case control study

Background

Shoulder impingement syndrome (SIS) is the most common form of shoulder pain. Conservative and surgical treatments for SIS are often not effective. One such surgical intervention is subacromial decompression, aimed at widening the subacromial space (SAS). A better understanding of the changes in the SAS may help explain the relative ineffectiveness of current interventions.

Objective: To measure the acromiohumeral distance (AHD) and supraspinatus tendon thickness (STT) in people with SIS using a case control study.

Methods

The AHD and STT of 39 participants with SIS ≥3 months and 39 age, gender and dominant arm matched controls were measured using ultrasound imaging. Between-group differences for AHD and STT were compared using t-tests. A linear regression was used to determine if there was a relationship between AHD and STT measures, with group as a covariate.

Results

Compared to controls (mean age 55.7 years, SD 10.6), individuals with SIS (mean age 57.1 years, SD 11.1) had a significantly larger AHD (mean difference 2.14 mm, 95% CI 1.21, 3.07, p < 0.001) and STT (mean difference 1.25 mm, 95% CI 0.60, 1.90, p < 0.001). The linear regression model indicated an association between AHD and STT (β = 0.59, 95% CI 0.29, 0.89, p < 0.01, R² = 0.35, n = 78), suggesting that as STT increases in size, so does the AHD.

Conclusion

Individuals with SIS had a larger AHD and greater STT than controls. These results suggest the SAS is already wider in people with SIS and that the symptoms associated with SIS may be more related to an increased STT than a smaller SAS.

Temporo-spatial parameters, shoulder kinematics and acute tendon changes in four different stroke patterns in men wheelchair users with spinal cord injury

BACKGROUND

Manual wheelchair propulsion causes the shoulder tendon pathologies in wheelchair users with spinal cord injury due to its repetitive nature. Four different wheelchair stroke patterns can cause varying amounts of acute changes in the shoulder tendons.

OBJECTIVE

To evaluate and compare acute changes in the supraspinatus and biceps tendons and acromio-humeral distance (AHD) after propulsion between different stroke patterns in individuals with spinal cord injury. Additionally, to associate tendon changes with demographic and biomechanical characteristics.

DESIGN

Prospective and comparative study between four groups.

SETTING

Tertiary rehabilitation hospital.

PATIENTS

Men wheelchair users with spinal cord injury.

INTERVENTIONS

Participants were divided into 4 groups according to stroke pattern (arcing, semicirculer (SC), single-loop (SL) and double-loop (DL)), in which they used their wheelchair on a motorized treadmill at a speed of 1 m/s. A sample of 40 people was created, 10 in each group. All participants performed a propulsion test.

MAIN OUTCOME MEASURES

Temporo-spatial variables and shoulder kinematics were analyzed. Supraspinatus tendon thickness (SSTT), long head of biceps tendon thickness (LHBTT) and AHD were measured before and after the propulsion test.

RESULTS

SC pattern had lower cadance and larger contact angle. A reduction in SSTT and LHBTT in arcing pattern, LHBTT and AHD in SC pattern and, LHBTT in DL pattern was observed (all P < 0.05). However, SL pattern did not differ significantly in all ultrasonographic measurements (all P > 0.05). Body mass index was associated with a decrease in SSTT. Age and number of daily push-up were associated with a decrease in AHD.

CONCLUSIONS

Less tendon changes after the propulsion in the SL pattern suggested that the supraspinatus and biceps tendons were preserved in this pattern. The SL pattern may be a better choice for men wheelchair users with supraspinatus and biceps tendon pathologies. This article is protected by copyright. All rights reserved.

Significance of the acromiohumeral distance on stress radiography for predicting healing and function after arthroscopic repair of massive rotator cuff tears

BACKGROUND

A decreased acromiohumeral distance (AHD) is commonly detected in patients with massive rotator cuff tears (mRCTs). Most studies evaluating fixed humeral elevation have used preoperative or postoperative standardized radiography and not stress radiography. This study aimed to evaluate the predictive role of the preoperative AHD measured using stress radiography (AHD_stress) in rotator cuff healing and function after arthroscopic repair of mRCTs.

METHODS

The data of 113 patients who underwent arthroscopic repair of mRCTs were analyzed. Postoperative cuff integrity was evaluated using magnetic resonance imaging at 1 year, and shoulder function was evaluated at a mean of 34.9 ± 17.8 months (range, 24-92 months) postoperatively. Forty-seven patients showed healing failure. Propensity score matching (1-1) was performed between the healed group and healing failure group. Thirty-eight patients in each group were matched in the final analysis. The AHD and AHD_stress were defined as the shortest distances from the inferior acromion to the superior humerus on standard anteroposterior radiography and stress radiography (5.4-kg weight applied inferiorly in a neutral position), respectively. The AHD difference (AHD_diff) was defined as the difference between the AHD and AHD_stress values. Receiver operating characteristic curve analysis was performed to determine cutoff values for significant variables.

RESULTS

No difference in the mean preoperative AHD was found between the healed group (7.5 ± 2.0 mm) and healing failure group (6.9 ± 2.2 mm, P = .234). The AHD_diff value was significantly higher in the healed group (4.4 ± 2.1 mm) than in the healing failure group (3.0 ± 2.0 mm, P = .002; cutoff, 3.2 mm). Patients with an AHD_diff value ≥ 3.2 mm showed a lower healing failure rate (28.9% vs. 71.1%, P < .001) and higher functional scores than patients with an AHD_diff value < 3.2 mm. The AHD_diff value was higher in patients with an American Shoulder and Elbow Surgeons (ASES) score ≥ 80 (4.9 ± 1.9 mm) than in those with an ASES score < 80 (3.1 ± 2.1 mm, P = .024). Among patients with healing failure, only the postoperative AHD showed a significant difference between those with an ASES score ≥ 80 (7.0 ± 2.5 mm) and those with an ASES score < 80 (4.8 ± 2.1 mm, P = .009; cutoff, 4.8 mm).

CONCLUSION

A reducible AHD, which increased by ≥ 3.2 mm under stress radiography, can be a favorable predictor of rotator cuff healing and function after arthroscopic repair of mRCTs. Our findings suggest that this new and simple radiologic parameter should be considered preoperatively and would be helpful to determine appropriate treatment strategies.

The association between gird and overhead throwing biomechanics in cricket

The development of GIRD is a well-documented adaptation associated with repetitive overhead throwing in numerous sports. In occurrence with total rotational range of motion deficit, GIRD is considered pathological and increases shoulder injury risk. While cricketers demonstrate these deficits in rotational range; the association between GIRD and overhead throwing has yet to be explored. Therefore, the aim of this study was to determine the relationship between GIRD and overhead throwing biomechanics in cricketers. Passive shoulder rotational range of motion was measured in 15 cricketers (elite = 8, amateur = 7). Kinetic and kinematic data were obtained during overhead throws from a stationary and run-up approach. Linear regression was used to determine potential relationships between GIRD and discrete shoulder kinetics for both throwing approaches. One-dimensional statistical parametric mapping regression was conducted to assess relationships between GIRD and throwing kinematics. When throwing overhead from a stationary position, GIRD was associated with reduced hip abduction during the preparatory arc (p = 0.002); superior shoulder (p = 0.003) and elbow compressive (p = 0.009) forces, at cocking. In addition, GIRD was associated with increased posterior shoulder force during arm deceleration for both stationary (p = 0.013) and run-up approaches (p = 0.03) to overhead throwing. Cricketers with GIRD utilise a shorter stride, creating early pelvic rotation and a slow throwing arm with an associated reduction in forces about the shoulder and elbow at cocking, when throwing from a stationary position. Further, overload of the posterior shoulder occurs during arm deceleration, irrespective of throwing approach. These findings highlight potential shoulder injury risk.

Examining Muscle Activity Differences During Single and Dual Vector Elastic Resistance Exercises

BACKGROUND

Elastic resistance exercise is a common part of rehabilitation programs. While these exercises are highly prevalent, little information exists on how adding an additional resistance vector with a different direction from the primary vector alters muscle activity of the upper extremity.

PURPOSE

The purpose of this study was to examine the effects of dual vector exercises on torso and upper extremity muscle activity in comparison to traditional single vector techniques.

STUDY DESIGN

Repeated measures design.

METHODS

Sixteen healthy university-aged males completed four common shoulder exercises against elastic resistance (abduction, flexion, internal rotation, external rotation) while using a single or dual elastic vector at a fixed cadence and standardized elastic elongation. Surface electromyography was collected from 16 muscles of the right upper extremity. Mean, peak and integrated activity were extracted from linear enveloped and normalized data and a 2-way repeated measures ANOVA examined differences between conditions.

RESULTS

All independent variables differentially influenced activation. Interactions between single/dual vectors and exercise type affected mean activation in 11/16 muscles, while interactions in peak activation existed in 7/16 muscles. Adding a secondary vector increased activation predominantly in flexion or abduction exercises; little changes existed when adding a second vector in internal and external rotation exercises. The dual vector exercise in abduction significantly increased mean activation in lower trapezius by 25.6 ± 8.11 %MVC and peak activation in supraspinatus by 29.4 ± 5.94 %MVC (p<0.01). Interactions between single/dual vectors and exercise type affected integrated electromyography for most muscles; the majority of these muscles had the highest integrated electromyography in the dual vector abduction condition.

CONCLUSION

Muscle activity often increased with a second resistance vector added; however, the magnitude was exercise-dependent. The majority of these changes existed in the flexion and abduction exercises, with little differences in the internal or external rotation exercises.

LEVEL OF EVIDENCE

3b.

Acromio-Humeral Distance Is Associated with Shoulder External Strength in National Elite Badminton Players-A Preliminary Study

Purpose: To examine acromio-humeral distance (AHD) and shoulder isometric strength for external rotation (ER) and internal rotation (IR) in national elite badminton players. Methods: Seven elite badminton players with asymptomatic shoulders aged 24 ± 4 (mean ± SD) from the Danish national badminton team were investigated. Shoulder AHD, isometric strength in ER and IR were bilaterally assessed with ultrasonography and a hand-held dynamometer (HHD). Results: AHD was greater on the dominant vs. the nondominant side (p = 0.018). Moreover, IR strength was greater on the dominant side vs. the nondominant side (p = 0.041). Furthermore, AHD and ER strength were highly correlated on the dominant side (p = 0.007, r = 0.900). A correlation was also shown between AHD and the ER/IR strength ratio on the dominant side (p = 0.033, r = 0.793). Conclusion: This preliminary study demonstrates that shoulder ER strength is strongly associated with AHD size, largely reflecting supraspinatus tendon-muscle hypertrophy as a result of sport-specific adaptation in national elite badminton players with asymptomatic shoulders. These novel data also suggest that habitual loading of the shoulder improves the supraspinatus tendon size, which may lower the mechanical stress and potentially reduce the risk of injury. This warrants strengthening the shoulder external rotators as a potential strategy to reduce the risk of future shoulder injury.

Differences in supraspinatus occupation ratio between the symptomatic, the contralateral asymptomatic shoulder and control subjects: A cross-sectional study

ABSTRACT

The relationship between supraspinatus tendon thickness and the acromiohumeral distance (AHD) at both rest position and shoulder elevation is still to be explored in those with chronic shoulder pain. The aim is to compare supraspinatus occupation ratio (OR) at 0° and 60° of shoulder elevation measured by ultrasound imaging in the symptomatic shoulder, the contralateral asymptomatic shoulder and in healthy subjects. This was across-sectional, observational study. A sample of 56 participants with subacromial pain syndrome in their dominant arm was recruited in 3 different primary care centres. Forty participants without shoulder pain were also recruited. The AHD at 0° and 60° of active shoulder abduction as well as the supraspinatus tendon thickness were measured by ultrasound in these groups. Supraspinatus OR at 60° was significantly greater in symptomatic compared to asymptomatic shoulders (P = .04) and healthy shoulders (P = .008). The percentage of change in supraspinatus OR from rest position to 60° was also greater in symptomatic shoulders when comparing with asymptomatic (P = .01) and healthy shoulders (P = .03). No other statistically significant differences for the rest of comparisons were found. Supraspinatus OR may explain shoulder pain in chronic conditions. Further studies at acute and chronic conditions after a physiotherapy treatment are needed to explore its usefulness in clinical practice.

Does forward head posture change subacromial space in active or passive arm elevation?

Objectives: Forward head posture (FHP) is one of the most common musculoskeletal disorders that appears to affect the shoulder joint through the shared muscles between the head and neck area and the shoulder girdle. The present study compared the acromiohumeral distance between individuals with normal head and neck alignment and those with moderate and severe FHP in active and passive arm elevation.Methods: Based on the craniovertebral angle, 60 volunteers were selected and equally distributed among three groups, including group one with normal head and neck alignment, group two with moderate FHP and group three with severe FHP. The space between the humeral head and the acromion was measured in 10°, 45° and 60° of active and passive arm elevation as the acromiohumeral distance.Results: The acromiohumeral distance was only different between the three groups at 45° arm elevation angle, and this difference was significant between groups one and three. In active and passive arm elevation, increased arm elevation angle reduced the subacromial space significantly. Also, in each arm elevation angle, the subacromial space differed significantly between the active and passive arm elevations.Conclusions: The acromiohumeral distance was significantly lower in the severe FHP group than the group with normal head and neck alignment in the 45° active arm elevation angle, which could be due to the changed tension in tissues between active and passive arm elevation and also the maximum muscle activity in the 45° active arm elevation angle.

Is There a Decrease in the Acromiohumeral Distance Among Recreational Overhead Athletes With Rotator Cuff-Related Shoulder Pain?

CONTEXT

Recreational overhead athletes are exposed to high overload, which increases the risk of shoulder injuries. Reduction of the acromiohumeral distance (AHD) is often associated with rotator cuff-related shoulder pain (RCRSP) among the general population. However, the AHD of symptomatic shoulders of recreational athletes has not yet been compared with their asymptomatic shoulders.

OBJECTIVE

To compare the AHD of a symptomatic to asymptomatic shoulder at rest (0°) and 60° abduction. To establish the relationship between AHD, pain, and functional limitations of recreational athletes with RCRSP.

DESIGN

Cross-sectional study.

SETTING

University laboratory.

PARTICIPANTS

A total of 45 recreational overhead athletes with RCRSP were examined.

MAIN OUTCOME MEASURES

The AHD was measured by ultrasonography at 0° and 60° abduction (angles). Shoulder pain was assessed using a numeric pain scale, whereas functional limitations were assessed using the The Disabilities of the Arm, Shoulder, and Hand questionnaire. Differences in the between-shoulders condition (symptomatic and asymptomatic) were determined using 2-way analysis of variance for repeated measures. A Pearson correlation established the relationship between AHD, pain, and functional limitations.

RESULTS

No angles × shoulder condition interactions (P = .776) nor shoulder condition effects (P = .087) were detected, suggesting no significant differences (P > .05) between asymptomatic and symptomatic shoulders in the AHD at 0° or 60°. The AHD at 60° reduced significantly compared with 0° (3.05 [1.36] mm [2.77-3.33], angle effects: P < .001). The AHD at 0° and 60° was not correlated with pain or functional limitations (-.205 ≤ r ≤ .210, .167 ≤ P ≤ .585).

CONCLUSIONS

The AHD of recreational athletes is not decreased in symptomatic shoulders compared with asymptomatic shoulders. Reduction of the AHD in symptomatic shoulders is not associated with an increase in pain or functional limitations of recreational athletes with RCRSP.

Isokinetic Fatigue Ratio of Shoulder Rotators in Elite Softball Players With and Without Rotator Cuff Tendinopathy, and its Association With the Subacromial Space

CONTEXT

Fatigue of the shoulder rotators may cause reduction of the subacromial space (SAS) and contribute to rotator cuff tendinopathy.

OBJECTIVES

To compare the isokinetic peak torques and fatigue ratios of shoulder external rotators (ER) and internal rotators (IR) between elite softball athletes with and without rotator cuff tendinopathy and to investigate their associations with the SAS.

DESIGN

Cross-sectional study.

SETTING

University laboratory.

PARTICIPANTS

Twenty-five elite softball players and 31 asymptomatic sedentary controls participated in this study.

MAIN OUTCOME MEASURES

Isokinetic concentric IR and ER peak torque and fatigue ratio were measured at 60°/s and at 180°/s, respectively; and ultrasound measurement of the SAS was measured during 0° and 60° of shoulder abduction.

RESULTS

Athletes with rotator cuff tendinopathy demonstrated lower peak torque in shoulder concentric ER when compared with their healthy counterparts (37.8 [5.8%] vs 43.6 [8.5%]). No significant difference was found in the fatigue ratios of ER, IR, and ER/IR when compared between elite softball athletes with and without rotator cuff tendinopathy (all P > .24). In asymptomatic athletes, greater IR peak torque (r = .583, P = .03), lower ER/IR strength ratio (r = -.605, P = .02), and greater ER/IR fatigue ratio (r = .575, P = .03) were moderately associated with more reduction of the SAS during 0° and 60° of shoulder abduction.

CONCLUSIONS

Decreased strength ratio and fatigue ratio of ER/IR were related to reduction of the SAS.

Current advances and research in ultrasound imaging to the assessment and management of musculoskeletal disorders

Currently evidence-based practice has given scientific weight to the physical therapist profession; it is essential that all medical professional and physical therapists know the usefulness of new tools that optimize the effectiveness of their interventions and allow the growing of the scientific knowledge base. The use of ultrasound imaging (USI) by physiotherapists has evolved in recent years, consolidating as an increasingly standardized technique, low cost compared to other imaging techniques, quickly of execution, feasible and reliable tool. USI offers a wide range of opportunities in clinical practice as well as in different research areas. Therefore, ultrasound has been currently used as a diagnostic tool by physicians and in recent years there has been an expansion of the use of ultrasound equipment by non-physicians professionals such as physical therapist or physical trainers, who incorporates USI as a means of assessing musculoskeletal system architecture and composition, musculoskeletal changes in dysfunction, pain or injury conditions, as an interventional technique assisting echo-guided procedures or using the visual real-time information as a biofeedback in control motor approaches, as guiding tool in clinical decisions as well as to improve the understanding of tissue adaptations to exercise or movement. The purpose of this article is to review and provide an overview about the currently research of the USI applications and their benefits for the diagnosis and management in individuals with musculoskeletal conditions.

Does the Dog-Ear or Bird-Beak Deformity Remodel After Rotator Cuff Repair?

BACKGROUND

Dog-ear and bird-beak deformities are common after transosseous-equivalent repair (suture bridge technique). The natural course of deformities after rotator cuff (RC) repair using the suture bridge technique is unclear. The remodeling potential of these deformities has not been investigated.

PURPOSE

To evaluate remodeling and retear rates associated with deformities after RC repair.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Between November 2011 and February 2012, we studied 99 consecutive shoulders. All patients underwent arthroscopic RC repair via the suture bridge technique with or without additional sutures. Two groups were formed: no deformity (n= 46) and deformity (n = 53). Deformity was defined as marginal detachment and protrusion of the RC after repair, involving inappropriate compression of the suture limbs from the anchors. Tendon height was measured from the highest point of the most protruding portion of the cuff to the cortex on semi-coronal magnetic resonance imaging (MRI) scan. Change in tendon height was evaluated on MRI scan at 1 week and 6 months postoperatively. Clinical assessment at every patient visit included the American Shoulder and Elbow Surgeons (ASES) score, Constant shoulder score, and visual analog scale for pain (pVAS) score.

RESULTS

No significant differences were found in age, sex, symptom duration, tear size, and preoperative ASES, Constant, and pVAS scores (P > .05) between the 2 groups. The initial tendon height was 7.4 ± 1.5 mm in the no-deformity group and 9.3 ± 2.0 mm in the deformity group. Follow-up height was 6.3 ± 2.1 mm in the no-deformity group and 6.4 ± 1.6 mm in the deformity group. Mean postoperative tendon heights were 90.1% ± 23.8% of the initial height in the no-deformity group and 73.2% ± 15.1% in the deformity group. Clinical scores (ASES, Constant, and pVAS) were not significantly different between the groups at 6 months. There were 4 shoulders in each group that experienced retearing (types 4 and 5 according to the Sugaya classification) at 6 months postoperatively. There was no difference in retear rate (P > .999).

CONCLUSION

Most deformities after RC repair were remodeled with no effect on retears. Clinical outcomes were not affected by deformities.

Reliability of ultrasonographic measurement of the supraspinatus thickness at different angles of shoulder abduction in patients with stroke

[Purpose] The primary purpose of this study was to evaluate the usefulness of the intraclass correlation coefficient for evaluating the reliability of the measurement of the supraspinatus thickness on shoulder ultrasonography at different angles in a resting position in patients with stroke. [Participants and Methods] The study included 20 patients with stroke. The supraspinatus thickness was measured on both sides on ultrasonography, with the participants’ shoulders in abduction at 3 testing angles (0°, 30°, and 60° abduction). Each measurement was performed three times, and the average of the three measurements was recorded. The intraclass correlation coefficient was calculated, with the supraspinatus thickness measured twice at an interval of 24 hours as the factor. [Results] All intraclass correlation coefficients for the hemiplegic and normal sides were greater than 0.93 when the shoulders were at the three testing angles. [Conclusion] In this investigation, the reliability of measuring the supraspinatus thickness on shoulder ultrasonography at each angle for 3 times was evaluated and was found to be excellent.

Correlation between acromiohumeral distance and the severity of supraspinatus tendon tear by ultrasound imaging in a Chinese population

Background

The aim of this study was twofold: (i) to investigate the intrarater reliability of acromiohumeral distance measurement; (ii) to assess the level of association between acromiohumeral distance measured by ultrasonography, and the degree of supraspinatus tendon tear, in patients suffering from chronic shoulder pain.

Methods

A cross-sectional, case-control study was carried out. A convenience sample comprising 59 patients with a unilateral supraspinatus tendon tear was assessed. Both shoulders of each patient were scanned by ultrasound, with the contralateral asymptomatic shoulders serving as the control group for comparison. Acromiohumeral distances of each shoulder were measured and analysed.

Results

Intrarater reliability was excellent for the ultrasound method of acromiohumeral distance measurement. The acromiohumeral distance of shoulders with full-thickness supraspinatus tendon tear was significantly smaller than that of joints with partial-thickness supraspinatus tendon tear and an intact supraspinatus tendon. There was a significant positive correlation between reduced acromiohumeral distance and the severity of a supraspinatus tendon tear.

Conclusions

Ultrasound is a reliable tool to measure acromiohumeral distance. A positive relationship was found between a narrowed acromiohumeral distance and the severity grading of a supraspinatus tendon tear. Reduced acromiohumeral distance can be considered a predictive parameter for a full-thickness supraspinatus tendon tear.

Trial registration

The study was prospectively registered with the Chinese Clinical Trial Registry. Registration number: ChiCTR-ROC-17013550. Date of registry: 26 November 2017.

Intra- and Inter-Rater Reliability of Ultrasound Measurements of Supraspinatus Tendon Thickness, Acromiohumeral Distance, and Occupation Ratio in Patients With Shoulder Impingement Syndrome

Objectives

This study aims to evaluate the intra- and inter-rater reliability coefficients of the supraspinatus tendon thickness, acromiohumeral distance, and occupation ratio in patients with shoulder impingement syndrome.

Patients and methods

The study included 83 patients (21 males, 62 females; mean age 51.6±11.0 years; range, 26 to 70 years) with shoulder impingement syndrome. The supraspinatus tendon thickness, acromiohumeral distance, and occupation ratio values were obtained one week apart by two observers. The intraclass correlation coefficient (ICC), minimum detectable change, and standard error of measurement were calculated.

Results

The first observer had excellent intra-rater reliability in all measurements (ICC >0.90) with minimum detectable change of 0.740-0.047 mm and standard error of measurement of 0.017-0.26 mm. The second observer had excellent intra-rater reliability in supraspinatus tendon thickness and acromiohumeral distance measurements (ICC >0.90) with minimum detectable change of 0.498-0.770 mm and standard error of measurement of 0.18-0.28 mm and good intra-rater reliability in the occupation ratio measurement (ICC; 0.75-0.90) with minimum detectable change of 0.060 mm and standard error of measurement of 0.022 mm. Inter-rater reliability coefficients were 0.916 (95% confidence interval [CI]; 0.873-0.945) for supraspinatus tendon thickness, 0.943 (95% CI; 0.914-0.963) for acromiohumeral distance with minimum detectable change of 0.673 mm and standard error of measurement of 0.243 mm and 0.790 (%95 CI; 0.693-0.853) for occupation ratio with minimum detectable change of 0.077 mm and standard error of measurement of 0.028 mm.

Conclusion

These findings suggest that ultrasonographic measurements of the supraspinatus tendon thickness, acromiohumeral distance and occupation ratio can be reliable and consistent for clinical evaluation of patients with shoulder impingement syndrome in terms of supporting diagnosis and monitoring the treatment effect.

The effect of loop size on loop security and elongation of a knot

INTRODUCTION

While repairing a teared rotator cuff tendon with suture anchors and horizontal mattress suture configurations, knots should be secure at time zero while approximating the tendon to the bone, otherwise any failure in loop security may cause undesired clinical results. Optimum distance between suture limbs passed through the tendon, in other words the bite size, is still not clear in the literature. The aim of this study was to test the effect of loop size, which is directly related to the bite size, on loop security and elongation of a knot.

HYPOTHESIS

We hypothesized that a knot with a smaller loop size would be more secure. We asked if a knot with shorter circumference (1) would offer a better knot security; (2) would produce less elongation following repeated traction cycles.

MATERIAL AND METHODS

Two parallel metal rods in 3.0mm diameter were fixed to load cells of dynamic testing machine. Four groups, from A to D, had the initial rod to rod distances of 2-4-6-8mm respectively (n=10). Surgeon's knots were prepared with 2/0 Ultrabraid® sutures around the rods. A tension meter was used for tying each half hitch under equal tension. Crosshead distances were recorded after 7N pre-load and subsequent 1000 repetitive cyclic loads between 7-30N.

RESULTS

Elongations after a 7N preload for groups A to D were 0.107mm (±0.006), 0.143mm (±0.018), 0,16mm (±0.025), 0.185mm (±0.018) respectively. This increase was significant (p<0.05, power>0.95) between each group except between groups B and C. Maximum elongations after 1000^th cycle for groups A to D were 0.32mm (±0.124), 1.12mm (±0.333), 1.162mm (±0.211), 1.292mm (±0.241) respectively. Only samples in group A (0.732mm±0.124) elongated significantly less than others (p<0.05, power >0.95). No knots unravelled or ruptured.

DISCUSSION

This study basically reports that a knot with a shorter loop circumference has superior properties regarding loop security and resistance to elongation. From the perspective of clinical importance, shorter distance between suture limbs of mattress configuration may provide a more secure fixation of the rotator cuff tendon to the bone.

LEVEL OF EVIDENCE

II.

Effects of pectoralis minor length on strength improvement and pain reduction during scapular reposition test

[Purpose] This study aimed to compare pain and shoulder elevation strength when scapular reposition test is applied to subclinical individuals with a short or long pectoralis minor. [Participants and Methods] Subclinical participants (n=34) with a positive impingement result on at least one of three tests were assigned to short (n=18) or long (n=16) pectoralis minor groups. Impingement tests were repeated with and without scapular reposition test. Visual analog scale was used to measure pain intensities under both conditions. Isometric shoulder elevation strength was measured by dynamometry. Two-way analyzes of variance and paired t-test were used to evaluate the effects of scapular reposition test in the two groups. [Results] The effects of pectoralis minor length on the frequencies of meaningful strength, pain reduction, and positive scapular reposition test result were evaluated. Repositioning reduced pain in both groups. In the short pectoralis minor group, shoulder elevation strength was significantly improved by scapular reposition test. A meaningful strength improvement and positive scapular reposition test result were reported more frequently in the short pectoralis minor group. [Conclusion] Consideration of pectoralis minor length and scapular reposition test results could aid the identification of factors contributing to scapular dyskinesis and related shoulder injuries, thereby enabling the selection of appropriate interventions.

Ultrasonographic and Myotonometric Evaluation of the Shoulder Girdle After an Isokinetic Muscle Fatigue Protocol

OBJECTIVES

The aim of the study was to investigate supraspinatus tendon thickness, acromiohumeral distance (AHD), and stiffness/creep measures of the shoulder girdle in overhead asymptomatic athletes in muscle fatigue conditions.

DESIGN

Observational, case series study.

SETTING

Biomechanics and motion analysis lab.

PARTICIPANTS

Twenty-four male overhead volleyball (n = 8), handball (n = 8), and tennis (n = 8) athletes. All subjects were without shoulder injury history.

MAIN OUTCOME MEASURE

The subjects were tested for supraspinatus tendon thickness (in short and long axis), AHD using ultrasound scans and stiffness/creep of upper trapezius, infraspinatus, anterior and posterior deltoid, and pectoralis major using the myotonometer device before and immediately after a fatigue protocol.

INTERVENTION

The fatigue protocol consisted of 3 sets of 32 maximum isokinetic concentric contractions performing shoulder internal and external rotation at isokinetic speed of 120°/s.

RESULTS

A significant increase in supraspinatus tendon thickness (both in short and long axis) (P = .045 and P = .01, respectively) and a reduction in AHD (P = .01) were found after an isokinetic protocol. The stiffness increased significantly in upper trapezius (P ≤ .01), infraspinatus (P = .003), posterior deltoid (P = .047), and pectoralis major (P = .01), whereas the creep showed a significant decrement for upper trapezius (P = .001) and infraspinatus (P = .003).

CONCLUSION

The present study has demonstrated the postexercise fatigue in overhead athletes. The increase of stiffness (reduction of muscle creep) and tendon thickness (simultaneous to the reduction of AHD) may indicate rotator cuff overloading as a primary intrinsic tendon pathology process.

In Vivo Evaluation of Subacromial and Internal Impingement Risk in Asymptomatic Individuals

OBJECTIVE

The study aim was to evaluate subacromial and internal impingement risk between shoulders (dominant/nondominant) during dynamic motion using subject-specific anatomy and precise in vivo kinematics.

DESIGN

In a prospective cross-sectional study, nine subjects underwent bilateral magnetic resonance (N = 18 shoulders) and fluoroscopic imaging during elevation and external rotation at 90 degrees of abduction. Subject-specific bone models were created and distances from footprint to (a) acromion and (b) glenoid were measured to evaluate risk.

RESULTS

Throughout elevation, subacromial impingement risk was greater in the dominant shoulder (P = 0.0178). Regardless of side, high subacromial impingement risk occurred at 30% (78 degrees), 50% (101 degrees), and 70% (57 degrees) of the elevation cycle (P < 0.0001). High subacromial impingement risk also occurred at 30% (94 degrees), 50% (120 degrees), and 70% (63 degrees) of the external rotation motion cycle (P < 0.0001). Throughout both motions, internal impingement risk was not observed; however, the footprint and glenoid were closest at 50% of the elevation (101 degrees) and external rotation (120 degrees) cycles (P < 0.0001).

CONCLUSIONS

During elevation, subacromial impingement risk is greatest at lower arm positions (30% cycle, 78 degrees) and is greater in the dominant shoulder. High subacromial impingement risk also occurs with external rotation (63-120 degrees). Internal impingement risk does not occur with maximal elevation (101 degrees) or external rotation at 90-degree abduction but is more closely approached with elevation.

Quantifying acromiohumeral distance in elite male field hockey players compared to a non-athletic population

BACKGROUND

Shoulders of elite field hockey players are loaded continuously during play. Frequent high shoulder loading is known to influence certain shoulder variables, such as acromiohumeral distance. However, the influence of elite field hockey play on acromiohumeral distance is not examined yet.

OBJECTIVE

To examine the acromiohumeral distance in elite male field hockey players compared to a non-athletic control group.

DESIGN

Cross-sectional study.

METHODS

Fifty male participants were included; 25 elite field hockey players (age: 24.0±2.72 years; weight: 77.2±5.29kg; height; 180.5±5.37cm) and 25 age- and gender matched non-athletes (23.0±2.29 years; weight: 75.7±9.53kg; height: 181.8±5.52cm). A Telemed-Colormaster-128 EXT-IZ device was used to bilaterally obtain ultrasound acromiohumeral distance images at 3 different angles of shoulder abduction in the frontal plane.

RESULTS

Field hockey players showed a bilateral larger acromiohumeral distance at 45° (mean difference: 1.46mm [95% CI 0.46; 2.46]; p=0.005) and 60° (mean difference: 1.07mm [95% CI 0.21; 1.93]; p=0.016) compared to controls. In both groups, a significant but clinically less relevant, side difference was established for the acromiohumeral distance at 60° (mean difference: 0.79mm [95% CI 0.21; 1.34]; p=0.009).

CONCLUSION

With active shoulder abduction, elite field hockey players show a larger acromiohumeral distance in comparison to non-athletic participants. This may be a protective sport-specific adaptation, to better guard the shoulder from injury. Thus, acromiohumeral distance measurement may help physical therapists/coaches decide which athletes could benefit from specific, additional exercises aimed at enlarging the subacromial space.

Non-traumatic chronic shoulder pain is not associated with changes in rotator cuff interval tendon thickness

OBJECTIVE

To determine whether the thickness of the rotator interval tendons is different when comparing both symptomatic and non-symptomatic sides in people with chronic shoulder pain, and to those free of pain. Furthermore, to calculate the level of association between the rotator interval tendon thicknesses and perceived shoulder pain-function.

DESIGN

A cross-sectional, observational study.

METHOD

The supraspinatus, subscapularis and biceps brachii tendon thickness of sixty two patients with chronic shoulder pain were determined from standardized ultrasonography measures performed on both shoulders, whereas only the dominant arm was measured for the control subjects.

FINDINGS

Supraspinatus, subscapularis and biceps brachii tendon thickness was comparable between sides in the symptomatic group and was also comparable between the symptomatic and asymptomatic participants. In addition, the correlation between the tendon thickness and shoulder pain-function was non-significant.

INTERPRETATIONS

Tendon thickness was unaltered in people with chronic shoulder pain. These findings do not rule out the possibility that other changes in the tendon are present such as changes in the elastic properties and cell population and this should be explored in future studies.

The Effects of Rigid Scapular Taping on the Subacromial Space in Athletes With and Without Rotator Cuff Tendinopathy: A Randomized Controlled Study

CONTEXT

Reduction of the subacromial space (SAS) during arm elevation may contribute to rotator cuff (RC) tendinopathy. The effects of scapular taping on the SAS in athletes with and without RC tendinopathy are unknown.

OBJECTIVE

To investigate the immediate effects of scapular taping on the SAS in athletes with and without RC tendinopathy.

DESIGN

Randomized controlled study with repeated measures.

SETTING

University laboratory.

PARTICIPANTS

A total of 43 male volleyball players (17 asymptomatic and 26 with RC tendinopathy, mean age = 22.9 [3.5] y) participated in the study.

INTERVENTION

Three scapular taping protocols-no taping (control), taping with tension (therapeutic taping), and taping without tension (sham taping).

MAIN OUTCOME MEASURES

Ultrasound measurements of the SAS with the arm at 0° and 60° of shoulder abduction, and the change in the SAS between 0° and 60° of shoulder abduction (SAS_0°-60°) were calculated.

RESULTS

Athletes with RC tendinopathy demonstrated larger SAS with therapeutic taping at 60° of shoulder abduction (6.9 [1.9] mm vs 5.8 [1.7] mm, mean difference = 1.1 mm, 95% confidence interval, -1.80 to -0.39, P = .002) when compared with the no taping condition. The tendinopathy group also showed less reduction in the SAS with therapeutic taping during SAS_0°-60° (2.0 [1.4] mm vs 2.8 [1.4] mm, P = .02) when compared with the no taping condition. When tape was applied to the scapula in asymptomatic athletes, our results showed a relatively small increase in the SAS with therapeutic taping during arm resting at 0° of abduction when compared with the no taping condition (8.7 [0.9] mm vs 8.3 [0.8] mm, mean difference = 0.4 mm, 95% confidence interval, -0.71 to -0.11, P = .01).

CONCLUSIONS

Athletes with RC tendinopathy demonstrated less reduction of the SAS with rigid scapular taping during early arm abduction. Such observation was not evidenced in asymptomatic athletes.

Shoulder tendon characteristics in disabled swimmers in high functional classes - Preliminary report

OBJECTIVE

To characterize disabled swimmers in comparison to an able-bodied swimmers for (1) supraspinatus tendon thickness, (2) subacromial space and (3) occupation ratio.

DESIGN

Cross-Sectional Study.

SETTING

Research laboratory.

PARTICIPANTS

Disabled swimmers with upper (DSw-Upper) (n = 8) and lower (DSw-Lower) (n = 7) extremity disorders. The DSw-Upper were classified in sports class S7-S8, while DSw-Lower in S9-S10. The control group had 15 able-bodied swimmers.

MAIN OUTCOME MEASURES

Ultrasound images of (1) supraspinatus tendon in short axis and long axis, (2) subacromial space, and (3) occupation ratio.

RESULTS

A thicker supraspinatus tendon in short axis was observed in DSw-Upper versus C-Sw (p = 0.012) and DSw-Upper versus DSw-Lower (p = 0.018); and in long axis for DSw-Upper versus CSw (p = 0.0001), and DSw-Upper versus DSw-Lower (p = 0.002). There was a greater occupation ratio in DSw-Upper versus DSw-Lower in short axis (p = 0.013) and long axis (p = 0.035).

CONCLUSIONS

The present study showed a thicker supraspinatus tendon and greater occupation ratio with the tendon occupying more of the subacromial space that may predispose upper extremity disabled swimmers to tendon disorders such as subacromial impingement syndrome. Ultrasound examination can be used to assess shoulder tendon characteristics and the relationship to the subacromial space, to determine potential for injury and training load monitoring.

What is the reliability of clinical measurement tests for humeral head position? A systematic review

STUDY DESIGN

Systematic review.

INTRODUCTION

Physiotherapists routinely assess the position of the humeral head (HH) in patients with shoulder pain.

PURPOSE OF THE STUDY

To conduct a systematic review to determine the quality and content of studies that evaluated the reliability of clinical measurement methods for assessing the HH position.

METHODS

Five databases and gray literature were searched for studies fitting the eligibility criteria. After abstract and full-text review, the included studies were appraised using the Quality Appraisal of Reliability Studies checklist. Articles were considered of high quality if 8 was achieved on the checklist, and the overall quality of evidence was classified using prespecified criteria. Multiple raters extracted and performed quality ratings; a consensus process was used to finalize the reliability data that were synthesized and presented in a narrative synthesis. Reliability was classified as excellent if the intracorrelation coefficients or intercorrelation coefficients (ICCs) reported exceeded 0.75.

RESULTS

Fifteen studies on the reliability of ultrasound (US) and 3 studies on palpation were included. The methodologic quality was moderate in 17 of 18 studies. The intrarater reliability for all studies was excellent (ICC, 0.76-0.99) with the exception of the 90° abduction in internal rotation position (ICC, 0.48) for palpation. The inter-rater reliability tended to be lower (ICC, 0.48-0.68) for palpation and higher (ICC, 0.66-0.99) for US. Physiotherapists demonstrated excellent intrarater reliability across different levels of training in ultrasonography.

DISCUSSION

Our study found a moderate overall level of evidence to support the use of US for assessing HH position in symptomatic or asymptomatic subjects.

CONCLUSION

A moderate overall level of evidence exists for the use of US to reliably assess the HH position. Limited research supports the methods used for palpation within a clinical setting.

LEVEL OF EVIDENCE

2a.

The Diagnostic Reproducibility of Tomosynthesis for the Correlation between Acromiohumeral Distance and Rotator Cuff Size or Type

Objective

To correlate the acromiohumeral distance (AHD) using tomosynthesis and rotator cuff (RC) pathology and various anatomical indices and to assess the diagnostic reproducibility of tomosynthesis for the evaluation of subacromial impingement.

Materials and Methods

A retrospective review of 63 patients with clinically suspected subacromial impingement was conducted. Two musculoskeletal radiologists independently measured the following quantitative data: the AHD on plain radiographs and the AHD at three compartments (anterior, middle, and posterior) using tomosynthesis, computed tomography (CT) arthrography, or magnetic resonance (MR) arthrography. To investigate the association between the AHD and RC pathology and various anatomical indices, we reviewed the arthroscopic operation record as the referenced standard.

Results

The size of rotator cuff tear (RCT) in full-thickness tears displayed a significant inverse correlation with the middle and the posterior tomosynthetic AHDs (p < 0.05). The results of an ANOVA revealed that the middle tomosynthetic AHD retained a significant association with the type of RCT (p = 0.042), and the posterior tomosynthetic AHD retained significance for the size of RCT in a full-thickness tear (p = 0.024). The inter-modality correlation exhibited significant agreement especially among the plain radiography, tomosynthesis, and CT or MR arthrography (p < 0.05). The intraobserver and interobserver correlation coefficients (ICCs) displayed excellent agreement (ICC = 0.896–0.983). The humeral head diameter and glenoid height were significantly correlated with patient height and weight.

Conclusion

Acromiohumeral distance measurement using tomosynthesis is reproducible compared with other modalities.

Supraspinatus tendon micromorphology in individuals with subacromial pain syndrome

STUDY DESIGN

Cross-sectional cohort.

INTRODUCTION

Tendon collagen organization can be estimated by peak spatial frequency radius (PSFR) on ultrasound images. Characterizing PSFR can define the contribution of collagen disruption to shoulder symptoms.

PURPOSE OF THE STUDY

The purpose of this was to characterize the (1) supraspinatus tendon PSFR in participants with subacromial pain syndrome (SPS) and healthy controls; (2) PSFR between participants grouped on a tendon visual quality score; and (3) relationship between PSFR with patient-reported pain, function, and shoulder strength.

METHODS

Participants with SPS (n = 20) and age, sex, and arm-dominance-matched healthy controls (n = 20) completed strength testing in scaption and external rotation, and patient-reported pain, and functional outcomes. Supraspinatus tendon ultrasound images were acquired, and PSFR was calculated for a region of interest 15 mm medial to the supraspinatus footprint. PSFR was compared between groups using an independent t-test and an analysis of variance to compare between 3 groups for visually qualitatively rated tendon abnormalities. Relationships between PSFR with pain, function, and strength were assessed using Pearson correlation coefficient.

RESULTS

Supraspinatus tendon PSFR was not different between groups (P = .190) or tendon qualitative ratings (P = .556). No relationship was found between PSFR and pain, functional loss, and strength (P > .05).

CONCLUSIONS

Collagen disruption (PSFR) measured via ultrasound images of the supraspinatus tendon was not different between participants with SPS or in those with visually rated tendon defects. PSFR is not related to shoulder pain, function, and strength, suggesting that supraspinatus tendon collagen disorganization may not be a contributing factor to shoulder SPS. However, collagen disruption may not be isolated to a single region of interest.

LEVEL OF EVIDENCE

3b: case-control study.

Changes in shoulder girdle strength in 3 consecutive years in elite adolescent swimmers: a longitudinal cohort study

BACKGROUND

The shoulder complex is highly loaded during swimming. No studies were found analyzing the changes in shoulder girdle strength in young swimmers, through the years.

OBJECTIVE

To analyze the changes in strength of internal rotators and external rotators of the arm, lower trapezius and supraspinatus and in the external rotators/internal rotators ratio in young elite swimmers through 3 years.

METHODS

31 adolescent elite swimmers (14-18 years, of both sexes) participated in the study. Isometric strength of the shoulder girdle muscles was performed using a handheld dynamometer during 3 years.

RESULTS

For boys absolute data, internal rotators increased from the first to the second (p=0.0001; mean difference 45.6N; 95%CI 26.7-65.0) and third years (p=0.01; mean difference: 32.4; 95%CI: 9.3-55.5). Considering the weight-normalized data, internal rotators increased from the first to the second year (p<0.0001; mean difference: 0.52; 95%CI: 0.26-0.78), external rotators decreased from the first to the third year (p=0.003; mean difference: -0.33; 95%CI: -0.53 to -0.13) and from the second to the third year (p=0.0004; mean difference: -0.29; 95%CI: -0.46 to -0.12) and supraspinatus decreased from the second to the third year (p=0.006; mean difference: -0.17; 95%CI: -0.28 to -0.06). For girls, there were no significant differences in the absolute strength. Considering the weight-normalized data, lower trapezius decreased from the first to the third year (p=0.02; mean difference: -0.15; 95%CI: -0.27 to 0.03). Considering both sexes, the external rotators/internal rotators ratio decreased from the first to the second (p<0.0001; mean difference -0.12N; 95%CI -0.13 to -0.11) and third years (p<0.0001; mean difference -0.15N; 95%CI -0.16 to -0.14).

CONCLUSION

Muscle imbalance can occur in the shoulder girdle in young swimmers in 3 years, with increased internal rotators and decreased external rotators and supraspinatus strength in boys, and decreased strength of the lower trapezius in girls. Attention should be given in young swimmers' shoulder girdle muscle balance.

Effects of 3 Different Elastic Therapeutic Taping Methods on the Subacromial Joint Space

OBJECTIVE

The purpose of this study was to examine the effects of 3 different elastic therapeutic taping methods on the subacromial joint space in healthy adults.

METHODS

Pre-/post-test laboratory study method was used in this study. Forty-eight healthy adults with no prior history of shoulder injury or surgery and no history of dominant shoulder pain in the past 6 months were enrolled in the study. Participants were placed into 3 groups (8 males and 8 females per group) on the basis of a consecutively assigned allocation design. A baseline measurement of the acromiohumeral distance (AHD) was taken by using diagnostic ultrasonography for every participant. On the basis of group assignment, participants were then taped according to the Kinesio Tape (Kinesio Tex Classic Tape) guidelines in one of 3 conditions: (1) taping of the supraspinatus from insertion to origin; (2) taping of the anterior and posterior deltoids from insertion to origin; and (3) a combination of both techniques. After a 5-minute wait period, the AHD was remeasured with the tape intervention in place, with each participant serving as his or her own control.

RESULTS

Data analysis showed a statistically significant increase in AHD when using the taping technique over the anterior and posterior deltoids (Condition 2). The subacromial space increased in both males and females when the supraspinatus was taped from insertion to origin (Condition 1), but not at a statistically significant level. Condition 3, in which both taping techniques were used simultaneously, did not show an increase at a statistically significant level.

CONCLUSIONS

The application of the Kinesio Tape from insertion to muscle origin of the supraspinatus or the anterior and posterior deltoid increased the subacromial joint space.

The Effect of Shoulder Muscle Fatigue on Acromiohumeral Distance and Scapular Dyskinesis in Women With Generalized Joint Hypermobility

Muscle fatigue is considered to be one cause of shoulder pain, and subjects with generalized joint hypermobility (GJH) are affected more by shoulder pain. The purpose of this study was to examine the effects of muscle fatigue on acromiohumeral distance (AHD) and scapular dyskinesis in women with GJH. Thirty-six asymptomatic participants were assigned to either a GJH (n = 20) or control group (n = 16) using the Beighton scale. Before and after elevation fatigue trials, AHD was measured with ultrasonography at rest and when the arm was in 90° active elevation. A scapular dyskinesis test was used to visually observe alterations in scapular movement. Our results showed that in both groups, the fatigue reduced AHD in the 90° elevation position and increased the presence of scapular dyskinesis; however, no differences were found between the two groups. Although GJH has been identified as a factor for developing musculoskeletal disorders, generalized joint hypermobility did not result in changes to scapular dyskinesis or AHD, even after an elevation fatigue task. More studies are needed to evaluate the effects of muscle fatigue in subjects with GJH and a history of shoulder instability.

Systematic review of quantitative imaging biomarkers for neck and shoulder musculoskeletal disorders

Background

This study systematically summarizes quantitative imaging biomarker research in non-traumatic neck and shoulder musculoskeletal disorders (MSDs). There were two research questions: 1) Are there quantitative imaging biomarkers associated with the presence of neck and shoulder MSDs?, 2) Are there quantitative imaging biomarkers associated with the severity of neck and shoulder MSDs?

Methods

PubMed and SCOPUS were used for the literature search. One hundred and twenty-five studies met primary inclusion criteria. Data were extracted from 49 sufficient quality studies.

Results

Most of the 125 studies were cross-sectional and utilized convenience samples of patients as both cases and controls. Only half controlled for potential confounders via exclusion or in the analysis. Approximately one-third reported response rates. In sufficient quality articles, 82% demonstrated at least one statistically significant association between the MSD(s) and biomarker(s) studied. The literature synthesis suggested that neck muscle size may be decreased in neck pain, and trapezius myalgia and neck/shoulder pain may be associated with reduced vascularity in the trapezius and reduced trapezius oxygen saturation at rest and in response to upper extremity tasks. Reduced vascularity in the supraspinatus tendon may also be a feature in rotator cuff tears. Five of eight studies showed an association between a quantitative imaging marker and MSD severity.

Conclusions

Although research on quantitative imaging biomarkers is still in a nascent stage, some MSD biomarkers were identified. There are limitations in the articles examined, including possible selection bias and inattention to potentially confounding factors. Recommendations for future studies are provided.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-017-1694-y) contains supplementary material, which is available to authorized users.

Tendon vascularity in overhead athletes with subacromial pain syndrome and its correlation with the resting subacromial space

BACKGROUND

Supraspinatus tendinopathy is one of the common causes of subacromial pain syndrome (SAPS) in overhead athletes. Changes in tendon vascularity have been reported in painful tendons; however, the prevalence and distribution have not been investigated in young overhead athletes.

METHODS

We conducted a cross-sectional study of 47 overhead athletes (male, 31; female, 16) aged 18 to 36 years with SAPS for >3 months. A sonographer graded the severity of the tendinopathy and area of vascularization. Ultrasound imaging was used to measure supraspinatus tendon thickness, vascularity, and resting subacromial space. A self-written program was used to semiquantify the intensity of vascularity, expressed as the vascular index.

RESULTS

The majority (87.2%) of the participants had signs of tendinopathy in the supraspinatus tendon, and 40 (85.1%) of the tendinopathic tendons had vascularity. The majority (66.0%) of the vascularized subjects presented with minimal increase in vascularity, and 19.1% had moderate to severe vascularization. Most (79.2%) of the vascularization was observed in the pericortical region. The vascular index was negatively correlated with the resting subacromial space in male athletes with a reduced subacromial space (ρ = -0.63; P = .038).

CONCLUSION

Of overhead athletes with SAPS, 87.2% had supraspinatus tendinopathy with minimal to moderate vascularization, with the majority of vascularization occurring in the pericortical region. In male athletes with a reduced subacromial space, greater vascularity in the supraspinatus tendon was associated with a smaller resting subacromial space.