Changes on Tendon Stiffness and Clinical Outcomes in Athletes Are Associated With Patellar Tendinopathy After Eccentric Exercise

Dutch multidisciplinary guideline on anterior knee pain: Patellofemoral pain and patellar tendinopathy

PURPOSE

The purpose of this study was to develop a multidisciplinary guideline for patellofemoral pain (PFP) and patellar tendinopathy (PT) to facilitate clinical decision-making in primary and secondary care.

METHODS

A multidisciplinary expert panel identified questions in clinical decision-making. Based on a systematic literature search, the strength of the scientific evidence was determined according to the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) method and the weight assigned to the considerations by the expert panel together determined the strength of the recommendations.

RESULTS

After confirming PFP or PT as a clinical diagnosis, patients should start with exercise therapy. Additional conservative treatments are indicated only when exercise therapy does not result in clinically relevant changes after six (PFP) or 12 (PT) weeks. Pain medications should be reserved for cases of severe pain. The additional value of imaging assessments for PT is limited. Open surgery is reserved for very specific cases of nonresponders to exercise therapy and those requiring additional conservative treatments. Although the certainty of evidence regarding exercise therapy for PFP and PT had to be downgraded ('very low GRADE' and 'low GRADE'), the expert panel advocates its use as the primary treatment strategy. The panel further formulated weaker recommendations regarding additional conservative treatments, pain medications, imaging assessments and open surgery ('very low GRADE' to 'low GRADE' assessment or absence of scientific evidence).

CONCLUSION

This guideline recommends starting with exercise therapy for PFP and PT. The recommendations facilitate clinical decision-making, and thereby optimizing treatment and preventing unnecessary burdens, risks and costs to patients and society.

LEVEL OF EVIDENCE

Level V, clinical practice guideline.

Evaluating the Reliability of MyotonPro in Assessing Muscle Properties: A Systematic Review of Diagnostic Test Accuracy

Background and Objectives: Muscle properties are critical for performance and injury risk, with changes occurring due to physical exertion, aging, and neurological conditions. The MyotonPro device offers a non-invasive method to comprehensively assess muscle biomechanical properties. This systematic review evaluates the reliability of MyotonPro across various muscles for diagnostic purposes. Materials and Methods: Following PRISMA guidelines, a comprehensive literature search was conducted in Medline (PubMed), Ovid (Med), Epistemonikos, Embase, Cochrane Library, Clinical trials.gov, and the WHO International Clinical Trials platform. Studies assessing the reliability of MyotonPro across different muscles were included. A methodological quality assessment was performed using established tools, and reviewers independently conducted data extraction. Statistical analysis involved summarizing intra-rater and inter-rater reliability measures across muscles. Results: A total of 48 studies assessing 31 muscles were included in the systematic review. The intra-rater and inter-rater reliability were consistently high for parameters such as frequency and stiffness in muscles of the lower and upper extremities, as well as other muscle groups. Despite methodological heterogeneity and limited data on specific parameters, MyotonPro demonstrated promising reliability for diagnostic purposes across diverse patient populations. Conclusions: The findings suggest the potential of MyotonPro in clinical assessments for accurate diagnosis, treatment planning, and monitoring of muscle properties. Further research is needed to address limitations and enhance the applicability of MyotonPro in clinical practice. Reliable muscle assessments are crucial for optimizing treatment outcomes and improving patient care in various healthcare settings.

Ultrasound-guided electrocoagulation of neovascularisation for persistent patellar tendinopathy in athletes: a cohort study of 25 patients with a mean follow-up of 5 years from the SANTI Study Group

Background

Patellar tendinopathy (PT) is a common condition characterised by persistent patellar tendon pain and dysfunction, particularly in athletes. Neovascularisation is frequently observed in the PT and is associated with increased pain. Ultrasound-guided electrocoagulation of neovascularisation has emerged as a minimally invasive alternative treatment for recalcitrant PT.

Hypothesis/purpose

The purpose of this study was to evaluate the clinical outcomes of ultrasound-guided electrocoagulation of neovascularisation in athletes with persistent PT.

Study design

Case series; level of evidence, IV.

Methods

A retrospective analysis of prospectively collected data was performed on 25 athletes who underwent ultrasound-guided electrocoagulation of neovascularisation for recalcitrant PT. Clinical outcomes including complications, reinterventions and patient-reported outcome measures were recorded. Comparisons between variables were assessed using χ2 test or Fisher's exact test for categorical variables and Student's t-test or Wilcoxon test for quantitative variables.

Results

25 patients were included in the final analysis. 96% returned to their preoperative activity level at a mean of 3.8 months. At a mean follow-up of 5 years 4% did not receive significant benefit from electrocoagulation therapy. Significant improvements were observed in outcome measures, including the Victorian Institute of Sport Assessment Questionnaire for Patients with Patellar Tendinopathy, Kujala score, modified Blazina score and Visual Analogue Scale for pain.

Conclusion

Ultrasound-guided electrocoagulation of neovascularisation for persistent PT in elite athletes resulted in a low complication rate, a high rate and rapid return to sport and a significant improvement in outcome measures.

Patellar Tendon Load Progression during Rehabilitation Exercises: Implications for the Treatment of Patellar Tendon Injuries

PURPOSE

This study aimed to evaluate patellar tendon loading profiles (loading index, based on loading peak, loading impulse, and loading rate) of rehabilitation exercises to develop clinical guidelines to incrementally increase the rate and magnitude of patellar tendon loading during rehabilitation.

METHODS

Twenty healthy adults (10 females/10 males, 25.9 ± 5.7 yr) performed 35 rehabilitation exercises, including different variations of squats, lunge, jumps, hops, landings, running, and sports specific tasks. Kinematic and kinetic data were collected, and a patellar tendon loading index was determined for each exercise using a weighted sum of loading peak, loading rate, and cumulative loading impulse. Then the exercises were ranked, according to the loading index, into tier 1 (loading index ≤0.33), tier 2 (0.33 < loading index <0.66), and tier 3 (loading index ≥0.66).

RESULTS

The single-leg decline squat showed the highest loading index (0.747). Other tier 3 exercises included single-leg forward hop (0.666), single-leg countermovement jump (0.711), and running cut (0.725). The Spanish squat was categorized as a tier 2 exercise (0.563), as was running (0.612), double-leg countermovement jump (0.610), single-leg drop vertical jump (0.599), single-leg full squat (0.580), double-leg drop vertical jump (0.563), lunge (0.471), double-leg full squat (0.428), single-leg 60° squat (0.411), and Bulgarian squat (0.406). Tier 1 exercises included 20 cm step up (0.187), 20 cm step down (0.288), 30 cm step up (0.321), and double-leg 60° squat (0.224).

CONCLUSIONS

Three patellar tendon loading tiers were established based on a combination of loading peak, loading impulse, and loading rate. Clinicians may use these loading tiers as a guide to progressively increase patellar tendon loading during the rehabilitation of patients with patellar tendon disorders and after anterior cruciate ligament reconstruction using the bone-patellar tendon-bone graft.

Use of extracorporeal shockwave therapies for athletes and physically active individuals: a systematic review

OBJECTIVE

To determine the efficacy of extracorporeal shockwave therapy (ESWT) and investigate outcomes following the use of ESWT for athletes and physically active individuals.

DESIGN

Systematic review.

DATA SOURCES

We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and searched four databases: PubMed (NLM), Embase (Elsevier), CINAHL Complete (EBSCO) and Web of Science (Clarivate).

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Included studies were randomised controlled trials, cohort and case-control studies, cases series and reports that evaluated outcomes following ESWT for athletes, physically active individuals and occupational groups requiring regular physical activity such as military cadets.

RESULTS

56 studies with 1874 athletes or physically active individuals were included. Using the Oxford level of evidence rating, included studies were 18 level I (32.1%), 3 level II (5.4%), 10 level III (17.9%), 13 level IV (23.2%) and 12 level V (21.4%). Based on the level I studies, ESWT may be effective alone in plantar fasciitis, lateral epicondylitis and proximal hamstring tendinopathy and as an adjunct to exercise treatment in medial tibial stress syndrome and osteitis pubis in athletes or physically active individuals. In most studies, athletes were allowed to continue activities and training and tolerated ESWT with minimal side effects.

CONCLUSION

ESWT may offer an efficacious treatment alone or as an adjunct to concurrent exercise therapy in selected sports-related injuries and without major adverse events. Further high-level research is needed to better define the role and clinical outcomes of ESWT.

Maximal Lower Limb Strength in Patellar Tendinopathy: A Systematic Review With Meta-Analysis

OBJECTIVE

To investigate whether lower limb strength is reduced in people with patellar tendinopathy (PT) compared with asymptomatic control individuals or the asymptomatic contralateral limb.

DATA SOURCES

MEDLINE, PubMed, Scopus, and Web of Science.

STUDY SELECTION

To be included in the systematic review and meta-analysis, studies were required to be peer reviewed, published in the English language, and case control investigations; include participants with a clinical diagnosis of PT and an asymptomatic control or contralateral limb group; and include an objective measure of lower limb maximal strength.

DATA EXTRACTION

We extracted descriptive statistics for maximal strength for the symptomatic and asymptomatic limbs of individuals with PT and the limb(s) of the asymptomatic control group, inferential statistics for between-groups differences, participant characteristics, and details of the strength-testing protocol. The risk of bias was assessed using the Joanna Briggs Institute critical appraisal tool for analytical cross-sectional studies.

DATA SYNTHESIS

Of the 23 included studies, 21 reported knee strength, 3 reported hip strength, and 1 reported ankle strength. Random-effects models (Hedges g) were used to calculate the pooled effect sizes (ESs) of muscle strength according to the direction of joint movement and type of contraction. The pooled ESs (95% CI) for maximal voluntary isometric contraction knee-extension strength, concentric knee-extension strength, and concentric knee-flexion strength were 0.54 (0.27, 0.80), 0.78 (0.30, 1.33), and 0.41 (0.04, 0.78), respectively, with all favoring greater strength in the asymptomatic control group. Researchers of 2 studies described maximal eccentric knee-extensor strength with no differences between the PT and asymptomatic control groups. In 3 studies, researchers measured maximal hip strength (abduction, extension, and external rotation), and all within-study ESs favored greater strength in the asymptomatic control group.

CONCLUSIONS

Isometric and concentric knee-extensor strength are reduced in people with PT compared with asymptomatic control individuals. In contrast, evidence for reduced eccentric knee-extension strength in people with PT compared with asymptomatic control individuals is limited and inconsistent. Although evidence is emerging that both knee-flexion and hip strength may be reduced in people with PT, more examination is needed to confirm this observation.

The Use of Shear-Wave Ultrasound Elastography in the Diagnosis and Monitoring of Musculoskeletal Injuries

Ultrasound elastography is a valuable method employed to evaluate tissue stiffness, with shear-wave elastography (SWE) recently gaining significance in various settings. This literature review aims to explore the potential of SWE as a diagnostic and monitoring tool for musculoskeletal injuries. In total, 15 studies were found and included in the review. The outcomes of these studies demonstrate the effectiveness of SWE in detecting stiffness changes in individuals diagnosed with Achilles tendinopathy, Achilles tendon rupture, rotator cuff rupture, tendinosis of the long head of the biceps tendon, injury of the supraspinatus muscle, medial tibial stress syndrome, and patellar tendinopathy. Moreover, SWE proves its efficacy in distinguishing variations in tissue stiffness before the commencement and after the completion of rehabilitation in cases of Achilles tendon rupture and patellar tendinopathy. In summary, the findings from this review suggest that SWE holds promise as a viable tool for diagnosing and monitoring specific musculoskeletal injuries. However, while the field of ultrasound elastography for assessing musculoskeletal injuries has made considerable progress, further research is imperative to corroborate these findings in the future.

Exercise therapy for tendinopathy: a mixed-methods evidence synthesis exploring feasibility, acceptability and effectiveness

Background

Tendinopathy is a common, painful and functionally limiting condition, primarily managed conservatively using exercise therapy.

Review questions

(i) What exercise interventions have been reported in the literature for which tendinopathies? (ii) What outcomes have been reported in studies investigating exercise interventions for tendinopathy? (iii) Which exercise interventions are most effective across all tendinopathies? (iv) Does type/location of tendinopathy or other specific covariates affect which are the most effective exercise therapies? (v) How feasible and acceptable are exercise interventions for tendinopathies?

Methods

A scoping review mapped exercise interventions for tendinopathies and outcomes reported to date (questions i and ii). Thereafter, two contingent systematic review workstreams were conducted. The first investigated a large number of studies and was split into three efficacy reviews that quantified and compared efficacy across different interventions (question iii), and investigated the influence of a range of potential moderators (question iv). The second was a convergent segregated mixed-method review (question v). Searches for studies published from 1998 were conducted in library databases (n = 9), trial registries (n = 6), grey literature databases (n = 5) and Google Scholar. Scoping review searches were completed on 28 April 2020 with efficacy and mixed-method search updates conducted on 19 January 2021 and 29 March 2021.

Results

Scoping review - 555 included studies identified a range of exercise interventions and outcomes across a range of tendinopathies, most commonly Achilles, patellar, lateral elbow and rotator cuff-related shoulder pain. Strengthening exercise was most common, with flexibility exercise used primarily in the upper limb. Disability was the most common outcome measured in Achilles, patellar and rotator cuff-related shoulder pain; physical function capacity was most common in lateral elbow tendinopathy. Efficacy reviews - 204 studies provided evidence that exercise therapy is safe and beneficial, and that patients are generally satisfied with treatment outcome and perceive the improvement to be substantial. In the context of generally low and very low-quality evidence, results identified that: (1) the shoulder may benefit more from flexibility (effect sizeResistance:Flexibility = 0.18 [95% CrI 0.07 to 0.29]) and proprioception (effect sizeResistance:Proprioception = 0.16 [95% CrI -1.8 to 0.32]); (2) when performing strengthening exercise it may be most beneficial to combine concentric and eccentric modes (effect sizeEccentricOnly:Concentric+Eccentric = 0.48 [95% CrI -0.13 to 1.1]; and (3) exercise may be most beneficial when combined with another conservative modality (e.g. injection or electro-therapy increasing effect size by ≈0.1 to 0.3). Mixed-method review - 94 studies (11 qualitative) provided evidence that exercise interventions for tendinopathy can largely be considered feasible and acceptable, and that several important factors should be considered when prescribing exercise for tendinopathy, including an awareness of potential barriers to and facilitators of engaging with exercise, patients' and providers' prior experience and beliefs, and the importance of patient education, self-management and the patient-healthcare professional relationship.

Limitations

Despite a large body of literature on exercise for tendinopathy, there are methodological and reporting limitations that influenced the recommendations that could be made.

Conclusion

The findings provide some support for the use of exercise combined with another conservative modality; flexibility and proprioception exercise for the shoulder; and a combination of eccentric and concentric strengthening exercise across tendinopathies. However, the findings must be interpreted within the context of the quality of the available evidence.

Future work

There is an urgent need for high-quality efficacy, effectiveness, cost-effectiveness and qualitative research that is adequately reported, using common terminology, definitions and outcomes.

Study registration

This project is registered as DOI: 10.11124/JBIES-20-00175 (scoping review); PROSPERO CRD 42020168187 (efficacy reviews); https://osf.io/preprints/sportrxiv/y7sk6/ (efficacy review 1); https://osf.io/preprints/sportrxiv/eyxgk/ (efficacy review 2); https://osf.io/preprints/sportrxiv/mx5pv/ (efficacy review 3); PROSPERO CRD42020164641 (mixed-method review).

Funding

This project was funded by the National Institute for Health and Care Research (NIHR) HTA programme and will be published in full in HTA Journal; Vol. 27, No. 24. See the NIHR Journals Library website for further project information.

The effectiveness of shockwave therapy on patellar tendinopathy, Achilles tendinopathy, and plantar fasciitis: a systematic review and meta-analysis

Background

Tendinopathy is a growing global concern affecting many people, like athletes, workers, and the elderly. Despite its commonality among the sporting population, there is no practical clinical guideline for patellar tendinopathy (PT). Furthermore, there is conflicting evidence between clinical guidelines on shockwave therapy's application and clinical utility for Achilles tendinopathy (AT) and plantar fasciitis (PF). Thus, our aim of this study is to evaluate the evidence for shockwave therapy; to provide a Grading of Recommendation, Assessment, Development and Evaluation (GRADE) level of the evidence and effectiveness of shockwave therapy for patellar tendinopathy, Achilles tendinopathy, and Plantar fasciitis.

Method

Medical Literature Analysis and Retrieval System Online (Medline), Embase, The Cumulative Index to Nursing and Allied Health Literature (CINAHL), Physiotherapy Evidence Database (PEDro) and China National Knowledge Infrastructure database (CNKI) were searched to find relevant studies published before December 14th, 2022.

Results

Our study showed that for PT in the short term, extracorporeal shockwave therapy (ESWT) or ESWT + eccentric exercise (EE) has a negligible effect on pain and function compared to a placebo or placebo + EE. On the contrary, ESWT significantly affects pain compared to conservative treatment (CT). For AT, ESWT has a small inconclusive effect on pain and function in the short term compared to EE. On the other hand, a placebo outperformed ESWT in improving function for AT but not pain outcomes. PF showed that ESWT significantly affects short- and long-term pain and function. When ESWT was compared to other interventions such as low laser therapy (LLLT), corticosteroid injection (CSI), or CT, there was a small inconclusive effect on pain and function in the short term.

Conclusion

There is low-moderate evidence that ESWT has a negligible effect on pain and function for PT and AT. However, high-quality evidence suggests ESWT has a large effect on pain and function for PF.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023396835, identifier CRD42023396835.

Electromyographic activity of quadriceps muscles during eccentric squat exercises: implications for exercise selection in patellar tendinopathy

This study investigated the quadriceps muscle activity during eccentric squat exercises (ESE) with different decline angles and arcs of motion regarding the proper exercise selection for patellar tendinopathy management. Electromyographic activity of the rectus femoris, vastus lateralis, and vastus medialis obliquus (VMO) muscles was measured during ESE on 0°, 5°, 10°, 15°, and 20° decline in 20 recreationally active participants. The eccentric phase was divided into 0-30°, 30-60°, 60-90°, 0-60°, 30-90°, and 0-90° of knee flexion simultaneously via motion-analysis system. The analyses showed that there was a significant decline angle × arc interaction effect on electromyographic activity of all muscles during knee flexion movement. The main effect was found for the arc of motion of knee flexion, and the main effect for the decline angle also was present for each muscle, except for VMO. This study demonstrated that most selective quadriceps eccentric activation occurred during ESE performed on 20° decline throughout 60-90° of knee flexion.

Achilles and patellar tendon structure following a prevention program in male combat soldiers

OBJECTIVES

The aims of the study were to compare the prevalence of soldiers with musculoskeletal symptoms between soldiers that participated in a prevention program (INT) and a control group (CONT); and, to assess whether 'high risk' for a symptom indicator [participants with patellar tendon (PT) echo-type III+IV >10% or Achilles tendon (AT) echo-type III >8.5%] applies when a prevention intervention is used.

METHODS

Soldiers from two consecutive infantry commanders courses (year 1-CONT, n = 165; year 2-INT, n = 196) were examined pre-course for AT and PT structure using ultrasound tissue characterization (UTC), and their musculoskeletal overuse symptoms were assessed and recorded by military physicians throughout the course. A prevention program was provided to the INT group (year 2) during the 14-week course.

RESULTS

No significant differences were found in the prevalence of soldiers with symptoms between the two groups [INT: 39 (19.9%), CONT: 40 (24.2%); p = .32]. Using the indicator at baseline, 20 soldiers (10.2%) were suggested to be at 'high risk.' Of those 20 soldiers, 17 actually had symptoms during the course (positive predictive value-85%). The prevalence of soldiers with a suggested 'high risk' according to our indicator who had no symptoms during the course was low (3/20, 15%). Twenty-two soldiers who had symptoms during the course had not been suggested to be at 'high risk' by our indicator.

CONCLUSION

Our intervention did not reduce the prevalence of soldiers with symptoms. Our 'high risk' pre-course, AT and PT structure indicator is valid and can be used as a screening tool to reduce the prevalence of symptoms in combat soldiers; with the caution that soldiers that were not identified by the indicator, might also have symptoms along the course.

Whole body vibration for chronic patellar tendinopathy: A randomized equivalence trial

Purpose: Whole body vibration (WBV) triggers anabolic responses in various tissues, including tendons, without requiring high force production. In this waitlist-controlled equivalence trial, we tested its clinical effectiveness as an alternative treatment for patellar tendinopathy against conventional heavy slow resistance training (HSR). Methods: Thirty-nine patients were randomized to either 3 months of WBV training (n = 13), HSR training (n = 11), or a waitlist control (WLC) group (n = 15). In a partly cross-over design, 14 patients of the WLC group were redistributed to one of the two intervention groups (5 in WBV, 9 in HSR). Pre- and post-intervention testing included pain assessments (VAS), functional limitations (VISA-P), knee extension strength and tendon morphological, mechanical and material properties. Follow-up measurements (VAS, VISA-P) were performed in the WBV and HSR groups 6 months after the intervention. Results: Comparisons with the WLC group revealed significant improvements in VISA-P and VAS scores after HSR (41%, p = 003; 54%, p = 0.005) and WBV (22%, p = 0.022; 56%, p = 0.031) training. These improvements continued until follow-up (HSR: 43%, 56%; WBV: 24%, 37%). Pre-post improvements in VAS scores were equivalent between WBV and HSR groups but inconclusive for the VISA-P score and all pre-test to follow up comparisons. The mid-tendon cross-sectional area was significantly reduced after WBV (-5.7%, p = 0.004) and HSR (-3.0%, p = 0.004) training compared to WLC although the equivalence test between interventions was inconclusive. Conclusion: Whole body vibration improved symptoms typically associated with patellar tendinopathy. This type of intervention is as effective as HSR against maximum pain, although equivalence could not be confirmed for other variables. The beneficial responses to WBV and HSR treatments persisted for 6 months after the end of the intervention. Clinical Trial Registration: https://www.drks.de/drks_web/setLocale_EN.do, identifier DRKS00011338.

The Influence of Different Modes of Exercise on Healthy and Injured Tendons

Tendons are essential components of the musculoskeletal system that links the skeletal muscle to the skeleton. This dense connective tissue exhibits great plasticity. Therefore, research on the influence of types of exercise, including acute and long-term training, on the structural and mechanical properties of tendons in athletic and sedentary populations is of critical importance in the design of scientific-based exercise plans and effective tendinopathy treatment. Here, we review recent studies on the relationship between exercise and tendon health and tendinopathy repair to provide a general understanding of how exercise may reshape tendons.

The Effects of Eccentric Contraction Execution Time on the Properties of the Patellar Tendon

The purpose of this study was to assess the effects of eccentric contraction execution time on the morphological and elastic properties of the patellar tendon (PT) in a six-week, single-leg decline squat (SLDS) exercise training program. In addition, the effects of a six-week detraining period on the same variables were evaluated. Fifty participants were randomized into the control group (CG; n = 15), experimental group 1 (EG6s; n = 17; eccentric contraction execution time = 6 s) and experimental group 2 (EG3s; n = 18; eccentric contraction execution time = 3 s). The thickness and elastographic index (EI) in different regions of interest (ROIs) in the PT were measured after 6 weeks of eccentric training using the single-leg decline squat exercise (three sessions per week, 80% of the eccentric one-repetition maximum) and after 6 weeks of detraining. There was an increase in the thickness of the PT in the different ROIs analyzed in both experimental groups at the end of the training period. Especially worth noting was the increase in the thickness of the PT at the proximal level in EG3s (p = 0.001), and the increase at the distal level in EG6s (p = 0.001). On the other hand, there was a reduction in EI in EG6S at the end of the intervention program (p = 0.021), and both experimental groups increased EI in the three regions of interest analyzed after the detraining period (p < 0.01). In conclusion, the execution time of the eccentric contraction in the SLDS exercise determines the anatomical level of the morphological adaptations in the PT. These morphological adaptations are lost after 6 weeks of detraining, producing an increase in tendon stiffness.

MiR-192-5p Alleviated Fibrosis and Inflammatory Responses of Tendon Cells by Targeting NFAT5

Objective

To explore the effect of microRNA (miR)-192-5p on the inflammatory and fibrotic responses of tendon cells.

Methods

Tendon cells were treated with transforming growth factor-β1 (TGF-β1). The expression of miR-192-5p and nuclear factor of activated T cells 5 (NFAT5) in tendon cells were detected by RT-qPCR. The expressions of inflammatory and fibrosis-related factors were detected by RT-qPCR and Western blot. MiR-192-5p binds to NFAT5 targeting by TargetScan and dual-luciferase reporter gene assay. The expression of the NFAT5 gene was detected by RT-qPCR and Western blot. Detection of apoptosis in tendon cells by flow cytometry.

Results

MiR-192-5p was downregulated in tendon cells, and the expression level gradually decreased with the prolong of TGF-β1 treatment. The expression of NFAT5 increased with the treatment time of TGF-β1. The expression of miR-192-5p decreased collagen III (COLIII), α smooth muscle actin (α-SMA), matrix metalloproteinase- (MMP-) 1, and MMP-8 expression, thereby inhibiting TGF-β1-induced fibrosis in tendon cells. The expression of miR-192-5p decreased the expression of tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and IL-1β, thereby alleviating TGF-β1-induced inflammatory response and reduce apoptosis in tendon cells. NFAT5 is a direct target of miR-192-5p in tendon cells. The upregulation of NFAT5 reversed the effect of miR-192-5p on the fibrotic activity and inflammatory response of TGF-β1-stimulated tendon cells.

Conclusions

MiR-192-5p alleviates fibrosis and inflammatory responses of tendon cells by targeting NFAT5.

Women Have Tendons… and Tendinopathy: Gender Bias is a "Gender Void" in Sports Medicine with a Lack of Women Data on Patellar Tendinopathy-A Systematic Review

INTRODUCTION

Patellar tendinopathy is one of the most common musculoskeletal problems associated with sport. While commonly perceived as a predominantly male problem, recent epidemiological studies revealed that it also affects a large number of sport-active women. The aim of this systematic review was to understand how the available treatments apply to women affected by patellar tendinopathy.

METHODS

We analysed the available literature with a systematic review on three databases (PubMed, Cochrane, Web of Science) on February 2021, retrieving a total of 136 studies published from 1983.

RESULTS

The overall scientific field offers an astonishingly low number of data on treatment results referring to only 78 women (2%) in the entire literature. Only 5% of the retrieved articles considered focusing only or mostly on men to be a limitation.

CONCLUSIONS

Women represent only a minority of patients studied for this topic. The few documented cases are further fragmented by being related to different treatments, thus basically offering no solid evidence for results and limitations of any therapeutic approach in women. This literature analysis showed a greater gender gap than what is recognized in science and general medicine; it showed a gender blindness in sports medicine when investigating a common problem like patellar tendinopathy.

Resistance Training Interventions for Lower Limb Tendinopathies: A Scoping Review of Resistance Training Reporting Content, Quality, and Scientific Implementation

The objectives of this scoping review were as follows: (1) to describe what exercises and intervention variables are used in resistance training interventions for lower limb tendinopathy,  (2) to assess the completeness of reporting as assessed by the Consensus on Exercise Reporting Template (CERT) and the Toigo and Boutellier framework, and (3) to assess the implementation of scientific resistance training principles. We searched MEDLINE, CINAHL, AMED, Embase, SPORTDiscus, and Cochrane Library databases. Randomized controlled trials, cohort studies, case series, case reports, and observational studies that reported using resistance exercises for lower limb tendinopathies were considered for inclusion, with 194 studies meeting the inclusion criteria. Completeness of the reporting of exercise descriptors and programme variables was assessed by the CERT and the Toigo and Boutellier framework. Reporting of exercise descriptor items from the Toigo and Boutellier framework ranged from 0 to 13, with an average score of 9/13, with only 9 studies achieving a full 13/13. Reporting of items from the CERT ranged from 0 to 18, with an average score of 13/19. No study achieved a full 19/19; however, 8 achieved 18/19. Scoring for resistance training principles ranged from 1 to 10, with only 14 studies achieving 10/10. Eccentric heel-drops were the most common exercise (75 studies), followed by isotonic heel raises (38), and single-leg eccentric decline squats (27). The reporting of exercise descriptors and intervention content was high across studies, with most allowing exercise replication, particularly for Achilles and patellar tendinopathy. However, reporting for some tendinopathies and content items such as adherence was poor, limiting optimal translation to clinical practice.

Management of patellar tendinopathy: a systematic review and network meta-analysis of randomised studies

Objectives

We performed a systematic review and network meta-analysis (NMA) of randomised controlled trials (RCTs) to provide insights into the effectiveness of available treatment modalities in patellar tendinopathy(PT).

Methods

Several databases were searched in May 2021 for RCTs assessing the effectiveness of any intervention compared with any other intervention, placebo or no treatment for pain and/or function in PT. The risk of bias and strength of evidence were assessed with the Cochrane Collaboration and GRADE (Grading of Recommendations, Assessment, Development and Evaluations)/GRADE-NMA tools.

Results

A total of 37 RCTs were eligible that assessed 33 different interventions and their combinations, most represented by single studies. Based on pairwise meta-analyses of two RCTs, extracorporeal shockwave therapy (ESWT) does not appear to be superior to sham ESWT (eccentric exercise in both groups) for short-term pain (mean differences (MD) +0.1, 95% CI (−0.8 to 1), p=0.84) or function (MD −1.8, 95% CI (–8 to 4.4), p=0.57). Based on a pairwise meta-analysis of three RCTs, isometric exercise appears as effective as isotonic exercise for immediate postintervention pain relief (MD −1.03, 95% CI (−2.6 to 0.5), p=0.19). Our NMA showed that topical glyceryl trinitrate (GTN) and hyaluronic acid injection, both combined with eccentric exercise and moderate, slow resistance exercise had the highest probability of being the most effective interventions (low/very low strength of evidence).

Conclusions

Promising interventions with inadequate evidence, such as topical GTN, hyaluronic acid injections and isometric and slow resistance exercise, should be further investigated through high-quality RCTs. Meanwhile, eccentric loading with or without adjuncts should remain the first-line treatment for all individuals with patellar tendinopathy.

A catalogue of PROMs in sports science: Quality assessment of PROM development and validation

Choosing the most adequate PROM for a study is a non-trivial process. The aim of this study was to provide a catalogue with analyses of content and construct validity of PROMs relevant to research in sports science, including all published local translations. The most commonly used PROMs in sports research were selected from a PubMed search "patient reported outcome measures sports", identifying 439 articles and 194 different PROMs. Articles describing development of the 61 selected PROMs were assessed for content validity, and all articles regarding construct validity of each PROM and all published translations (in total 622 articles) were analyzed. A catalogue with assessments of the 61 PROMs was produced. The majority were of inferior validity, with few exceptions. The most common reason for this was that the PROM had not been developed by methods that ensure high content validity. Another major reason for inferior validity was that construct validity had not been secured by adequate statistical methods. In conclusion, this catalogue provides a tool for researchers to facilitate choosing the most valid PROM for studies in sports research. Furthermore, it shows for popular PROMs where further validation is needed, and for fields in musculoskeletal medicine where valid PROMs are lacking. It is suggested that a targeted effort is made to develop valid PROMs for major conditions in musculoskeletal research. The current method is easier to practice compared with assessment after COSMIN guidelines.

Lower Limb Tendinopathy Tissue Changes Assessed through Ultrasound: A Narrative Review

Tendinopathy is a common disease that affects athletes, causing pain and dysfunction to the afflicted tendon. A clinical diagnose is usually combined with imaging and, among all the existing techniques, ultrasound is widely adopted. The aim of this review is to sum up the existing evidence on ultrasound as an imaging tool and guide for treatments in lower limbs tendinopathy. Using three different databases—PubMed, MEDLINE and CENTRAL—a literature search has been performed in May 2020 combining MeSH terms and free terms with Boolean operators. Authors independently selected studies, conducted quality assessment, and extracted results. Ultrasound imaging has a good reliability in the differentiation between healthy and abnormal tendon tissue, while there are difficulties in the identification of tendinopathy stages. The main parameters considered by ultrasound imaging are tendon thickness, hypoechogenicity of tendon structure and neovascularization of the tendon bound tissue. Ultrasound-guide is also used in many tendinopathy treatments and the available studies gave encouraging results, even if further studies are needed in this field.

Eccentric Resistance Training in Youth: Perspectives for Long-Term Athletic Development

The purpose of this narrative review is to discuss the role of eccentric resistance training in youth and how this training modality can be utilized within long-term physical development. Current literature on responses to eccentric exercise in youth has demonstrated that potential concerns, such as fatigue and muscle damage, compared to adults are not supported. Considering the importance of resistance training for youth athletes and the benefits of eccentric training in enhancing strength, power, speed, and resistance to injury, its inclusion throughout youth may be warranted. In this review we provide a brief overview of the physiological responses to exercise in youth with specific reference to the different responses to eccentric resistance training between children, adolescents, and adults. Thereafter, we discuss the importance of ensuring that force absorption qualities are trained throughout youth and how these may be influenced by growth and maturation. In particular, we propose practical methods on how eccentric resistance training methods can be implemented in youth via the inclusion of efficient landing mechanics, eccentric hamstrings strengthening and flywheel inertia training. This article proposes that the use of eccentric resistance training in youth should be considered a necessity to help develop both physical qualities that underpin sporting performance, as well as reducing injury risk. However, as with any other training modality implemented within youth, careful consideration should be given in accordance with an individual's maturity status, training history and technical competency as well as being underpinned by current long-term physical development guidelines.

Comparative Effectiveness of Different Nonsurgical Treatments for Patellar Tendinopathy: A Systematic Review and Network Meta-analysis

PURPOSE

To investigate the functional improvement and pain reduction of different nonsurgical treatments for patellar tendinopathy (PT), a systematic review with network meta-analysis was performed.

METHODS

Studies were comprehensively searched for without language restrictions in the CENTRAL, MEDLINE, EMBASE, Web of Science, Physiotherapy Evidence Database, and SPORTDiscus databases from inception to May 2018. Randomized controlled trials about nonsurgical treatments for PT were included. The outcome measurements were the Victorian Institute of Sports Assessment (VISA) scale and pain scores (such as the visual analog scale or Numerical Rating Scale). Study quality was evaluated using the Physiotherapy Evidence Database score. Direct comparisons were performed using pairwise meta-analysis, whereas network meta-analysis was performed using a frequentist method in a multivariate random-effects model.

RESULTS

Eleven studies with 430 affected patellar tendons were included in the systematic review. The summary mean difference of improvement in the VISA scale versus the control group for corticosteroid injection was -23.00 (95% confidence interval [CI] -36.73 to -9.27), for leukocyte-rich platelet-rich plasma (LR-PRP) was 13.22 (95% CI 2.37-24.07), for focused extracorporeal shockwave therapy (ESWT) was -1.28 (95% CI -6.25 to 3.68), for radial ESWT was -6.68 (95% CI -20.20 to 6.84), for ultrasound was -0.70 (95% CI -11.23 to 9.83), for autologous blood injection was -0.60 (95% CI -9.30 to 8.10), for dry needling was 17.51 (95% CI -2.57 to 37.60), for topical glyceryl trinitrate was -0.90 (95% CI -13.07 to 11.27), and for skin-derived tendon-like cells was 10.40 (95% CI -1.59 to 22.39). LR-PRP (Surface Under the Cumulative Ranking curve [SUCRA] = 87.5%) or dry needling (SUCRA = 90.5%) was most likely to be ranked the best in terms of improvement on the VISA scale. Compared with the control group, the summary mean difference of the change in pain score for corticosteroid injection was 0.80 (95% CI -3.48 to 5.08), for LR-PRP was -1.87 (95% CI -3.28 to -0.46), for focused ESWT was 0.13 (95% CI -0.68 to 0.93), for radial ESWT was 0.03 (95% CI -1.92 to 1.98), for ultrasound was -0.20 (95% CI -1.49 to 1.09), for autologous blood injection was 0.60 (95% CI -0.73 to 1.93), for dry needling was -0.37 (95% CI -2.71 to 1.97), and for topical glyceryl trinitrate was -0.50 (95% CI -2.55 to 1.55). The treatment most likely to be ranked the best in terms of change in pain score was LR-PRP (SUCRA = 94.9%).

CONCLUSIONS

The network meta-analysis demonstrated that LR-PRP has the greatest functional improvement and pain reduction for PT compared with other treatment options. However, the treatment effect estimates can be biased by the possible intransitivity and should not be overestimated.

LEVEL OF EVIDENCE

Level I, meta-analysis of Level I studies.

How strong is the evidence that conservative treatment reduces pain and improves function in individuals with patellar tendinopathy? A systematic review of randomised controlled trials including GRADE recommendations

OBJECTIVE

To determine the effectiveness of conservative treatment (CT) on pain and function in patients with patellar tendinopathy (PT) compared with minimal intervention (MI) or other invasive intervention, or in addition to decline eccentric squat.

METHODS

Searches were performed in MEDLINE, Embase, Cochrane, PEDro, SPORTDiscus, CINAHL and AMED databases. All randomised trials that evaluated CT (any intervention not involving invasive procedures or medication) in individuals with PT were included. Two reviewers screened studies, extracted data and assessed risk of bias of all included studies. Where suitable, meta-analyses were conducted; we assessed certainty of the evidence using GRADE methodology.

RESULTS

When compared with MI, CT did not improve pain (weighted mean difference (WMD) -2.6, 95% CI -6.5 to 1.2) or function (WMD 1.8, 95% CI -2.4 to 6.1) in the short-term (up to 3 months) follow-up. When compared with invasive intervention, CT did not improve pain (WMD 0.7, 95% CI -0.1 to 1.4) or function (WMD -6.6, 95% CI -13.3 to 0.2) in the short-term follow-up. No overall effects were found for combined CT (when a conservative intervention was added to decline eccentric squat) on pain (WMD -0.5, 95% CI -1.4 to 0.4) or function (WMD -2.3, 95 % -9.1 to 4.6) at short-term follow-up. Single studies showed an effect on pain with iontophoresis at short-term follow-up (d = 2.42) or dry needling at medium/long-term follow-up (d = 1.17) and function with exercise intervention at medium/long-term follow-up (over 3 months) (d = 0.83).

SUMMARY/CONCLUSION

Our estimates of treatment effect have only low to very low certainty evidence to support them. This field of sports medicine/sports physiotherapy urgently needs larger, high-quality studies with pain and function among the potential primary outcomes.

Partial mid-portion Achilles tear resulting in substantial improvement in pain and function in an amateur long-distance runner

This case presents symptom resolution for a long-distance runner with chronic Achilles tendinopathy (AT), following a partial tear of his Achilles tendon. The patient reported a sudden pain during a morning run, with preserved function. Three hours postinjury, he was reviewed in a musculoskeletal clinic. An ultrasound scan confirmed a partial Achilles tear, associated with significant Doppler activity. His index of AT severity The Victorian Institute of Sports Assessment - Achilles Questionnaire (VISA-A) 4 hours postinjury was markedly higher compared with 2 weeks preinjury, indicating reduced symptom severity. A follow-up scan 4 weeks postinjury showed minimal mid-portion swelling and no signs of the tear. His VISA-A score showed continued symptom improvement. This case represents resolution of tendinopathic symptomatology post partial Achilles tear. While the natural histories of AT and Achilles tears remain unknown, this case may indicate that alongside the known role of loading, inflammation may be a secondary mediator central to the successful resolution of AT pain.