Sonoelastography findings of supraspinatus tendon in rotator cuff tendinopathy without tear: comparison with magnetic resonance images and conventional ultrasonography

Reliability of Magnetic Resonance Imaging Criteria for the Preoperative Assessment of Rotator Cuff Tears: A Systematic Review

BACKGROUND

Magnetic resonance (MR) imaging is the most common modality for assessment of the rotator cuff before and after surgery. Several classifications have been described aiming to define main tear characteristics. However, there is still confusion when it comes to the reliability of those classifications.

PURPOSE

(1) To identify all MR classifications available in the literature for preoperative assessment of rotator cuff tears, (2) to summarize available data on the reliability of identified classifications, and (3) to assess the methodological quality of reliability studies.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

This systematic review was conducted following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. All studies reporting MR assessment in patients with a superior or posterosuperior rotator cuff tear were included. After identification of the available MR criteria, reliability studies were analyzed. Descriptive statistics were used to summarize findings. Methodological quality was assessed using the Quality Appraisal of Reliability Studies checklist.

RESULTS

A total of 75 studies were included in this review. Eight categories of outcomes could be identified. Of the total, 62 studies reported interobserver reliability whereas 32 reported intraobserver reliability of some of the identified criteria. Each category reflected a variety of reliability, ranging from poor to excellent agreement. MR proved to be a reliable imaging modality to detect the structural integrity of the posterosuperior cuff, especially in cases of full-thickness tear; it was also reliable in terms of tear width and length and muscle atrophy based on a tangent sign or Thomazeau classification. All other classifications did not prove acceptable reliability. Methodological quality was high for 23 articles and moderate for 14.

CONCLUSION

Preoperative MR is a reliable imaging modality to identify full-thickness tears, measure tear size and morphology, and identify muscle atrophy with tangent sign or Thomazeau classification. All other outcomes and classifications did not show acceptable reliability; therefore, caution is needed when using them for preoperative evaluation of a rotator cuff tear.

Exercise for rotator cuff tendinopathy: Proposed mechanisms of recovery

Rotator cuff (RC) tendinopathy is a common recurrent cause of shoulder pain, and resistance exercise is the first-line recommended intervention. Proposed causal mechanisms of resistance exercise for patients with RC tendinopathy consist of four domains: tendon structure, neuromuscular factors, pain and sensorimotor processing, and psychosocial factors. Tendon structure plays a role in RC tendinopathy, with decreased stiffness, increased thickness, and collagen disorganization. Neuromuscular performance deficits of altered kinematics, muscle activation, and force are present in RC tendinopathy, but advanced methods of assessing muscle performance are needed to fully assess these factors. Psychological factors of depression, anxiety, pain catastrophizing, treatment expectations, and self-efficacy are present and predict patient-reported outcomes. Central nervous system dysfunctions also exist, specifically altered pain and sensorimotor processing. Resisted exercise may normalize these factors, but limited evidence exists to explain the relationship of the four proposed domains to trajectory of recovery and defining persistent deficits limiting outcomes. Clinicians and researchers can use this model to understand how exercise mediates change in patient outcomes, develop subgroups to deliver patient-specific approach for treatment and define metrics to track recovery over time. Supporting evidence is limited, indicating the need for future studies characterizing mechanisms of recovery with exercise for RC tendinopathy.

Review of human supraspinatus tendon mechanics. Part II: tendon healing response and characterization of tendon health

Overuse injuries of the rotator cuff, particularly of the supraspinatus tendon (SST), are highly prevalent and debilitating in work, sport, and daily activities. Despite the clinical significance of these injuries, there remains a large degree of uncertainty regarding the pathophysiology of injury, optimal methods of nonoperative and operative repair, and how to adequately assess tendon injury and healing. The tendon response to fatigue damage resulting from overuse is different from that of acute rupture and results in either an adaptive (healing) or a maladaptive (degenerative) response. Factors associated with the degenerative response include increasing age, smoking, hypercholesterolemia, biological sex (variable by tendon), diabetes mellitus, and excessive load post fatigue damage. After injury, the average healing rate of tendon is approximately 1% per day and may be significantly influenced by biologic sex (females have lower collagen synthesis rates) and excessive load after damage. Although magnetic resonance imaging (MRI) is considered the gold standard in assessing acute tears as well as tendinopathic change in the SST, ultrasonography has proven to be a valuable tool to measure tendinopathic change in real time. Ultrasonography can determine multiple mechanical and structural parameters of the SST that are altered in fatigue loading. Thus, ultrasonography may be utilized to understand how these parameters change in response to SST overuse, and may aid in determining the activity level that places the SST at greater risk of rupture.

Patellar Tendon Shear Wave Velocity Is Higher and has Different Regional Patterns in Elite Competitive Alpine Skiers than in Healthy Controls

Competitive alpine skiers are exposed to enormous forces acting on their bodies–particularly on the knee joint and hence the patellar tendon - during both the off-season preparation and in-season competition phases. However, factors influencing patellar tendon adaptation and regional pattern differences between alpine skiers and healthy controls are not yet fully understood, but are essential for deriving effective screening approaches and preventative countermeasures. Thirty elite competitive alpine skiers, all members of the Swiss Alpine Ski Team, and 38 healthy age-matched controls were recruited. A set of two-dimensional shear wave elastography measurements of the PT was acquired and projected into three-dimensional space yielding a volumetric representation of the shear wave velocity profile of the patellar tendon. Multivariate linear models served to quantify differences between the two cohorts and effects of other confounding variables with respect to regional shear wave velocity. A significant (p < 0.001) intergroup difference was found between skiers (mean ± SD = 10.4 ± 1.32 m/s) and controls (mean ± SD = 8.9 ± 1.59 m/s). A significant sex difference was found within skiers (p = 0.024), but no such difference was found in the control group (p = 0.842). Regional SWV pattern alterations between skiers and controls were found for the distal region when compared to the mid-portion (p = 0.023). Competitive alpine skiers exhibit higher SWV in all PT regions than healthy controls, potentially caused by long-term adaptations to heavy tendon loading. The presence of sex-specific differences in PT SWV in skiers but not in controls indicates that sex effects have load-dependent dimensions. Alterations in regional SWV patterns between skiers and controls suggest that patellar tendon adaptation is region specific. In addition to the implementation of 3D SWE, deeper insights into long-term tendon adaptation and normative values for the purpose of preventative screening are provided.

Mid- and Long-Term Results Using 448 kHz Stimulation on the Elasticity of the Supraspinatus Tendon Measured by Quantitative Ultrasound Elastographyin Badminton Professionals: Prospective Randomized Double-Blinded Clinical Trial with Nine Months of Follow-Up

The aim of this study is to analyse the changes that occur in the elasticity of the supraspinatus tendon after the application of a 448 kHz capacitive resistive monopolar radiofrequency (CRMR) at 3, 6 and 9 months in professional badminton players. A randomized double-blinded clinical trial that included 9 months of follow-up was used. A private care practice was used to recruit the participants of this study. They were randomly assigned either the CRMR treatment (n = 19) or the placebo treatment (n = 19). The experimental group received a total of nine treatments of 448 kHz CRMR divided into three treatments per week. The control group received the same regimen but with no radiofrequency. Quantitative ultrasound strain elastography was used to report the main values for three areas of the supraspinatus tendon. These were measured at the start (T1) and directly after (T2), one week after, (T3), three months after (T4), six months after (T5) and nine months after (T6) the completion of the intervention program. There were statistically significant differences in the supraspinatus tendon elasticity immediately after (p ≤ 0.001), one week after (p ≤ 0.001) and three months after (p = 0.01) the intervention program. No significant changes were found six or nine months after the intervention program. A three-week intervention program using 448 kHz produced significant changes in the elasticity of the supraspinatus tendon, with the changes lasting up to approximately three months when compared to the control group.

Quantitative evaluation of the Achilles tendon and supraspinatus tendon in end-stage kidney disease patients: A potential tool for predicting spontaneous tendon rupture

Many cases of spontaneous tendon rupture in end-stage kidney disease (ESKD) patients have been reported worldwide. Quantitative assessment of tendon has become an important way to improve the prognosis of patients. In the recruited healthy volunteers and ESKD patients, the thickness and shear wave velocity (SWV) of supraspinatus tendons and Achilles tendons were measured and compared among groups. Potential factors related to the tendon SWV of ESKD patients were screened in multiple linear regression. There was no significant difference in the tendon thickness and supraspinatus tendon SWV among groups. SWV of Achilles tendons in long-term dialysis ESKD patients were significantly lower than those in healthy volunteers (5.1 vs. 5.6 m/s, p < 0.01). Ca²⁺ , creatinine, body mass index, and genders are the significant factors related to the tendon SWV. Shear wave elastography can be used as a potential tool for predicting spontaneous tendon rupture in ESKD patients.

Short-term effects of 448 kilohertz radiofrequency stimulation on supraspinatus tendon elasticity measured by quantitative ultrasound elastography in professional badminton players: a double-blinded randomized clinical trial

OBJECTIVE

To study changes in supraspinatus tendon elasticity after a 448 kHz capacitive resistive monopolar radiofrequency (CRMR) intervention in professional badminton players.

DESIGN

Double-blinded randomized clinical trial.

SETTING

All participants were recruited in a private care practice. Participants were randomized to receive either a CRMR treatment (n = 19) or placebo (n = 19).

SUBJECTS

Professional badminton players (n = 38).

INTERVENTION

A total of nine intervention (three per week) with CRMR at 448 kHz were carried out in the experimental group. The same intervention without an active CRMR current was carried out in the control group.

MAIN MEASURES

Mean values of three different regions of the supraspinatus tendon were reported at baseline (T1), immediately after the intervention (T2) and one week after the end of the whole intervention program (T3) using quantitative ultrasound strain elastography (SEL).

RESULTS

There were statistically significant differences in the supraspinatus tendon elasticity immediately after the intervention (p= <.001) and one week after the end of the whole intervention program (p=.001).

CONCLUSION

CRMR at 448 kHz produces significant changes in supraspinatus tendon elasticity after an intervention program of three weeks and those changes last for a week when compared to control group. Clinical trial registration: NCT04273633 (ClinicalTrials.gov).

Three-Dimensional Mapping of Shear Wave Velocity in Human Tendon: A Proof of Concept Study

Ultrasound-based shear wave elastography (SWE) provides the means to quantify tissue mechanical properties in vivo and has proven valuable in detecting degenerative processes in tendons. Its current mode of use is for two-dimensional rendering measurements, which are highly position-dependent. We therefore propose an approach to create a volumetric reconstruction of the mechano-acoustic properties of a structure of interest based on optically tracking the ultrasound probe during free-hand measurement sweeps. In the current work, we aimed (1) to assess the technical feasibility of the three-dimensional mapping of unidirectional shear wave velocity (SWV), (2) to evaluate the possible artefacts associated with hand-held image acquisition, (3) to investigate the reproducibility of the proposed technique, and (4) to study the potential of this method in detecting local adaptations in a longitudinal study setting. Operative and technical feasibility as well as potential artefacts associated with hand-held image acquisition were studied on a synthetic phantom containing discrete targets of known mechanical properties. Measurement reproducibility was assessed based on inter-day and inter-reader scans of the patellar, Achilles, and supraspinatus tendon of ten healthy volunteers and was compared to traditional two-dimensional image acquisition. The potential of this method in detecting local adaptations was studied by testing the effect of short-term voluntary isometric loading history on SWV along the tendon long axis. The suggested approach was technically feasible and reproducible, with a moderate to very good reliability and a standard error of measurement in the range of 0.300-0.591 m/s for the three assessed tendons at the two test-retest modalities. We found a consistent variation in SWV along the longitudinal axis of each tendon, and isometric loading resulted in regional increases in SWV in the patellar and Achilles tendons. The proposed method outperforms traditional two-dimensional measurement with regards to reproducibility and may prove valuable in the objective assessment of pathological tendon changes.

Strain Elastography and Tendon Response to an Exercise Program in Patients With Supraspinatus Tendinopathy: An Exploratory Study

Background

Shoulder pain is common, with a lifetime prevalence of up to 67%. Evidence is conflicting in relation to imaging findings and pain in the shoulder. Sonoelastography can be used to estimate tissue stiffness and may be a clinically relevant technique for diagnosing and monitoring tendon healing.

Purpose

To evaluate changes in supraspinatus tendon stiffness using strain elastography (SEL) and associations with changes in patient-reported outcomes, supraspinatus tendon thickness, and grade of tendinopathy after 12 weeks of unilateral shoulder exercises in patients with supraspinatus tendinopathy.

Study Design

Controlled laboratory study.

Methods

A total of 23 patients with unilateral clinical supraspinatus tendinopathy performed 12 weeks of "standard care" exercises. At baseline and follow-up, supraspinatus tendon stiffness was measured bilaterally using SEL and compared with tendinopathy grading on magnetic resonance imaging scans and tendon thickness measured using conventional ultrasound. Patient-reported outcome measures included physical function and symptoms from the Disabilities of the Arm, Shoulder and Hand questionnaire and pain rating (visual analog scale).

Results

No significant changes in SEL within or between groups (asymptomatic vs symptomatic tendon) were seen. All patient-reported outcomes showed significant improvement from baseline to follow-up, but with no change in tendinopathy grading and tendon thickness. No significant differences in the proportion of patients changing above the minimal detectable change in SEL and PROM were seen, except for discomfort while sleeping.

Conclusion

Despite no significant within-group or between-group changes in SEL, significant improvements were found in patient-reported outcomes. An acceptable agreement between patients changing above the minimal detectable change in SEL and patient-reported outcome measure was seen. Further studies should explore the use of SEL to detect changes after tendon repair and long-term training potentially in subgroups of different tendinopathy phases.

Clinical Relevance

In the short term, structural changes in supraspinatus tendons could not be visualized using SEL, indicating that a longer time span should be expected in order to observe structural changes, which should be considered before return to sports. Subgrouping based on stage of tendinopathy may also be important in order to evaluate changes over time with SEL among patients with supraspinatus tendinopathy.

Registration

NCT03425357 (ClinicalTrials.gov identifier).

ELASTOGRAPHIC ANALYSIS OF THE SUPRASPINATUS TENDON IN DIFFERENT AGE GROUPS

OBJECTIVE

To compare the mechanical properties of the supraspinatus tendon in different age groups using Supersonic Shearwave Imaging (SSI) elastography.

METHODS

We evaluated 38 healthy individuals of both genders, 20 being in the range of 20 to 35 years and 18 being over 60 years. The shear modulus of the supraspinatus tendon was measured by SSI elastography, always on the right side. Means between age groups were compared and statistically analyzed using the Shapiro-Wilk normality test followed by the student's t-test and were established as a statistically significant value of p ≤ 0.05.

RESULTS

A statistically significant difference was observed when the mean values of the shear modulus of the supraspinatus tendon of young adults (23.98 ± 9.94 KpA) were compared with those of older adults (17.92 ± 6.17 KpA).

CONCLUSION

We found a difference between the means of the shear modulus measured by the SSI elastography, showing a significant decrease of the shear modulus with the chronological age progression. Level of Evidence III, Diagnostic Studies - Investigating a Diagnostic Test.

Discriminative and convergent validity of strain elastography for detecting tendinopathy within the supraspinatus tendon: a cross-sectional study

Background

We aimed to explore the discriminative validity of ultrasound strain elastography (SEL) between patients with painful supraspinatus tendinopathy and healthy control shoulders, as well as the associations between SEL and magnetic resonance imaging (MRI), conventional ultrasound (tendon thickness), and the Disabilities of the Arm, Shoulder and Hand questionnaire (DASH).

Methods

Thirty patients with shoulder pain and MRI-verified supraspinatus tendinopathy and 30 healthy control shoulders (no pain) were examined using SEL, MRI, and conventional ultrasound of the supraspinatus tendon. SEL variables included raw data, ratios between the deltoid muscle and supraspinatus tendon (deltoid ratio), color rating, and presence of red/yellow lesions (middle, worst part, and total tendon).

Results

Statistically significant increases in odds ratios for being symptomatic (increased softening) were seen for all raw data variables, corresponding to 3.978 (95% confidence interval [CI], 1.414-11.197) for middle, 4.602 (95% CI, 1.536-13.788) for worst, and 4.865 (95% CI, 1.406-16.836) for total tendon, and 1.260 (95% CI, 1.027-1.545) for the deltoid ratio (worst), adjusted for sex and body mass index (BMI). Tendon thickness was not associated with SEL; however, significantly positive associations were found between raw data variables and MRI (β ≥ 0.58, P < .01), and positive associations were found between raw data variables and the DASH score (β = 0.01, P ≤ .04), adjusted for sex and BMI.

Conclusions

Raw data variables and the deltoid ratio (worst) discriminated between patients with painful supraspinatus tendinopathy and healthy control shoulders when adjusted for sex and BMI. Associations were statistically significant for raw data variables and MRI or DASH score when adjusted for sex and BMI. Further studies are needed to understand SEL and the role of sex and BMI, including the responsiveness of SEL.

Assessing Low Skeletal Mass in Patients Undergoing Hip Surgery: The Role of Sonoelastography

Purpose

To analyze the utility of sonoelastography—a radiation-free procedure to characterize muscle properties—as an instrument to qualitatively and quantitatively assess the rectus femoris muscle.

Materials and Methods

Fifty-one consecutive patients who underwent a pelvic computed tomography (CT) exam were enrolled prospectively. The final analysis was conducted using data from 39 patients after 12 were removed due to exclusion criteria (muscle strength could not be measured due to poor cognition [n=11]; too young [n=1]). The potential correlation between average Hounsfield unit (HFU) at the rectus femoris muscle (measured by CT) and muscle quality grade (determined by sonoelastography) was assessed along with a retrospective analysis of the relationship between hand grip strength, knee extensor power, history of intensive care unit stay, length of hospital day and sonoelastographic grade.

Results

There was a significant correlation between sonoelastographic grade and the average HFU (P<0.001). Furthermore, hand grip strength (P<0.001) and knee extensor power (P<0.001) decreased significantly as the sonoelastographic grade increased. The likelihood of an intensive care unit stay and prevalence of low skeletal mass increased significantly with an increase in sonoelastography grade (P=0.037, P<0.001, respectively). The sensitivity, specificity, and accuracy of sonoelastographic images for predicting low skeletal mass were 77.3%, 100%, and 87.5%, respectively.

Conclusion

Sonoelastography advantages, including the lack of radiation and greater accessibility, may make it a valuable alternative to qualitatively and quantitatively identify sarcopenia and low skeletal mass.

Ultrasonic strain elastography for detecting abnormalities in the supraspinatus tendon: an intra- and inter-rater reliability study

OBJECTIVES

The reliability of ultrasonic strain elastography (SEL) used to detect abnormalities in the supraspinatus tendon is unclear. Thus, the aim of this study was to investigate the reliability of SEL in the supraspinatus tendon.

DESIGN

An intra-rater and inter-rater reliability study.

SETTING

A single-centre study conducted at the University of Southern Denmark.

PARTICIPANTS

Twenty participants with shoulder pain and MRI-verified supraspinatus tendinosis and 20 asymptomatic participants (no MRI).

PRIMARY AND SECONDARY OUTCOME MEASURES

Raw values (RAW) and ratios (deltoid muscle (DELT) and gel pad (GEL) as reference tissues) were calculated and mean values of measurements from three regions of the supraspinatus tendon were reported. Colour scale ratings and number of yellow/red lesions from the three areas were also included.

RESULTS

Intra-rater reliability showed intraclass correlation coefficients (ICCs) for RAW, DELT and GEL: 0.97 (minimal detectable change (MDC): 0.28 (6.36% of the mean)), 0.89 (MDC: 2.91 (20.37%)) and 0.73 (MDC: 1.61 (58.82%)), respectively. The ICCs for inter-rater reliability were 0.89 (MDC: 0.47 (10.53%)), 0.78 (MDC: 3.69 (25.51%)) and 0.70 (MDC: 1.75 (62.63%)), respectively.For colour scale ratings, intra-rater reliability (linear weighted kappa) ranged from 0.76 to 0.79, with the inter-rater reliability from 0.71 to 0.81. For the number of lesions, intra-rater reliability ranged from 0.40 to 0.82 and inter-rater reliability from 0.24 to 0.67.

CONCLUSIONS

Intra-rater and inter-rater reliability were excellent for raw values and for ratios with deltoid muscle as the reference tissue, and good for ratios with gel pad as the reference tissue. The reliability of colour scale ratings was substantial-to-almost perfect, and for the number of lesions fair-to-almost perfect.Although high reliability was found, validity and responsiveness of these elastographic methods needs further investigation.

ETHICS APPROVAL

The study protocol was approved by the Ethics Committee for the Region of South Denmark (S-20160115) and reported to the Danish Data Protection Agency (2014-41-3266).

The value of sonoelastography in the diagnosis of supraspinatus tendinopathy-a comparison study

OBJECTIVE:

This study assessed the association between tendon stiffness on sonoelastography and grades of tendinopathy on MRI in patients with supraspinatus tendinopathy.

METHODS:

25 consecutive adult patients with clinically suspected supraspinatus tendinopathy and no prior history of trauma referred for MRI of the shoulder were selected for this study. The supraspinatus tendinopathy was graded in consonance with MRI findings (Grade I, normal; Grade II, mild tendinopathy; Grade III, moderate tendinopathy; and Grade IV, marked tendinopathy). Strain ratios were evaluated. Spearman rank correlation test was used, to analyze the association of the MRI grade with strain ratios.

RESULTS:

Out of 25 patients, Grade I changes on MRI were found in 5 patients (20.0%), Grade II tendinopathy in 13 patients (52.0%), Grade III in 6 patients (24.0%), and Grade IV in 1 patient (4.0%). The mean sonoelastography strain ratio of supraspinatus tendons were 0.76 ± 0.32 in patients with Grade I, 0.59 ± 0.40 in Grade II, 0.31 ± 0.10 in Grade III and 0.15 ± 0.02 in Grade IV patients respectively. The strain ratios showed good correlation with the MRI grade p < 0.05.

CONCLUSION:

We compared the MRI findings of supraspinatus tendinopathy with sonoelastography strain ratios. Sonoelastography showed good correlation with MRI.

ADVANCES IN KNOWLEDGE:

Sonoelastography in supraspinatus tendinopathy may help in predicting improvement or worsening of the tendon health at the tissue level. Therefore, there is a possibility that it has use in the rehabilitation of professionals suffering from supraspinatus tendinopathy.

Ultrasound elastography: compression elastography and shear-wave elastography in the assessment of tendon injury

Ultrasound elastography (USE) is a recent technology that has experienced major developments in the past two decades. The assessment of the main mechanical properties of tissues can be made with this technology by characterisation of their response to stress. This article reviews the two major techniques used in musculoskeletal elastography, compression elastography (CE) and shear-wave elastography (SWE), and evaluates the studies published on major electronic databases that use both techniques in the context of tendon pathology. CE accounts for more studies than SWE. The mechanical properties of tendons, particularly their stiffness, may be altered in the presence of tendon injury. CE and SWE have already been used for the assessment of Achilles tendons, patellar tendon, quadriceps tendon, epicondylar tendons and rotator cuff tendons and muscles. Achilles tendinopathy is the most studied tendon injury with USE, including the postoperative period after surgical repair of Achilles rupture tendon. In relation to conventional ultrasound (US), USE potentially increases the sensitivity and diagnostic accuracy in tendinopathy, and can detect pathological changes before they are visible in conventional US imaging. Several technical limitations are recognised, and standardisation is necessary to ensure repeatability and comparability of the results when using these techniques. Still, USE is a promising technique under development and may be used not only to promote an early diagnosis, but also to identify the risk of injury and to support the evaluation of rehabilitation interventions. KEY POINTS: • USE is used for the assessment of the mechanical properties of tissues, including the tendons. • USE increases diagnostic performance when coupled to conventional US imaging modalities. • USE will be useful in early diagnosis, tracking outcomes and monitoring treatments of tendon injury. • Technical issues and lack of standardisation limits USE use in the assessment of tendon injury.

What Is the Most Effective Eccentric Stretching Position in Lateral Elbow Tendinopathy?

Background

A variety of treatment options suggest that the optimal treatment strategy for lateral elbow tendinopathy (LET) is not known, and further research is needed to discover the most effective treatment for LET. The purpose of the present study was to verify the most effective position of eccentric stretching for the extensor carpi radialis brevis (ECRB) in vivo using ultrasonic shear wave elastography.

Methods

A total of 20 healthy males participated in this study. Resting position was defined as 90° elbow flexion and neutral position of the forearm and wrist. Elongation of the ECRB was measured for four stretching maneuvers (forearm supination/pronation and wrist extension/flexion) at two elbow angles (90° flexion and full extension). The shear elastic modulus, used as the index of muscle elongation, was computed using ultrasonic shear wave elastography for the eight aforementioned stretching maneuverangle combinations.

Results

The shear elastic modulus was the highest in elbow extension, forearm pronation, and wrist flexion. The shear elastic moduli of wrist flexion with any forearm and elbow position were significantly higher than the resting position. There was no significant difference associated with elbow and forearm positions except for elbow extension, forearm pronation, and wrist flexion positions.

Conclusions

This study determined that elbow extension, forearm pronation, and wrist flexion was the most effective eccentric stretching for the ECRB in vivo.