A pilot study of the eccentric decline squat in the management of painful chronic patellar tendinopathy

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.

Eccentric Exercises on the Board with 17-Degree Decline Are Equally Effective as Eccentric Exercises on the Standard 25-Degree Decline Board in the Treatment of Patellar Tendinopathy

Background and Objectives: Patellar tendinopathy is one of the most significant problems in jumping and running athletes. Eccentric quadriceps exercise has been introduced into the therapy of patients with patellar tendinopathy in order to avoid weakening the tendon during rehabilitation. The use of decline boards with a decline angle of 25° has been the cornerstone of therapy over the last two decades. Biomechanical studies have suggested that an equal or potentially better outcome could be achieved with lower angles of decline (up to 16°). Materials and Methods: In this present research, we compared the effects of two various decline board angles on the clinical outcome of patients treated for patellar tendinopathy by performing eccentric quadriceps exercises. Patients were randomly allocated into two groups: patients practicing on the standard board with a 25° decline, and patients practicing on the 17° decline (n = 35 per group). Results: After 6 weeks of exercise, we found a significant improvement in all the clinical scores (VISA-P score, KOOS score, Lysholm Knee Questionnaire/Tegner Activity Scale, and VAS scale) of treated patients. However, there was no significant difference between the patients who performed eccentric quadriceps exercises on the standard 25° decline board and those exercising on the 17° decline board. A smaller additional degree of improvement was visible at the end of the follow-up period (at 12 weeks), but, again, no statistical difference could be detected between the investigated groups. We conclude that both treatment options provide similar short-term and midterm benefits regarding improvements in pain and clinical scores. The improvement in clinical scores does not depend on age, sex, BMI, or the professional sport of the patient. Conclusions: Our findings encourage changes in the decline angle of the board in the case of a patient's discomfort in order to achieve better compliance without affecting the recovery.

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.

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.

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.

A comparative study of treatment interventions for patellar tendinopathy: a secondary cost-effectiveness analysis

OBJECTIVE

To compare the cost-effectiveness of three patellar tendinopathy treatments.

DESIGN

Secondary (cost-effectiveness) analysis of a blinded, randomised controlled trial, with follow-up at 10 and 22 weeks.

SETTINGS

Recruitment was performed in sport clubs. The diagnosis and the intervention were carried out at San Jorge University.

PARTICIPANTS

The participants were adults between 18 and 45 years (n = 48) with patellar tendinopathy.

INTERVENTIONS

Participants received percutaneous needle electrolysis, dry needling or sham needling, all of which were combined with eccentric exercise.

MAIN OUTCOME MEASURES

Costs, quality-adjusted life years and incremental cost-effectiveness ratio were calculated for each group.

RESULTS

The total cost per session was similar in the three groups: €9.46 for the percutaneous needle electrolysis group; €9.44 for the dry needling group; and €8.96 for the sham group. The percutaneous needle electrolysis group presented better cost-effectiveness in terms of quality-adjusted life years and 96% and 93% probability of being cost-effective compared to the sham and dry needling groups, respectively.

CONCLUSION

Our study shows that percutaneous needle electrolysis has a greater probability of being cost-effective than sham or dry needling treatment.

Knee Extensor Mechanism Tendinopathy: Evaluation, Treatment, and Prevention

ABSTRACT

Knee extensor mechanism tendinopathy, including patellar and quadriceps tendinopathy, is common among athletes and those involved in jumping sports. It is largely a clinical diagnosis that presents as anterior knee pain and stiffness with associated tenderness over the affected tendon. Imaging modalities, including ultrasound and/or magnetic resonance imaging, may be helpful with the diagnosis of difficult cases or in the planning of interventional procedures. Focused and structured rehabilitation using eccentric or heavy slow resistance exercise in conjunction with load management is important for recovery. Adjuvant therapies (e.g., injections or surgery) may be necessary in recalcitrant cases or those with insufficient response to rehabilitation efforts. Prevention strategies focus on improving biomechanics, landing mechanism and lower-extremity balance, flexibility, and strength.

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.

Novel interventions for recalcitrant patella tendinopathy: Results may favour autologous blood injection (ABI) over radial-extra-corporeal shockwave therapy (r-ESWT) - A prospective cohort study

BACKGROUND

Patella tendinopathy is a common condition in a number of sports and can have a significant impact on activity and quality of life. Whilst rehabilitation leads to improvements in the majority of cases, a number of adjunct treatments are available for resistant cases with limited evidence supporting the use of one treatment over another.Hypothesis/Purpose: To compare the outcomes for patients with chronic patella tendinopathy, following either radial-Extra-Corporeal Shockwave Therapy (r-ESWT) or Autologous Blood Injection (ABI).

STUDY DESIGN

Prospective cohort study.

METHODS

28 consecutive patients with chronic patella tendinopathy, treated with radial-ESWT (n = 14) or ABI (n = 14), with minimum three-month follow-up. Mean age 34.2 years, mean duration of symptoms 32.8 months. Patients received either three sessions of radial-Extra-Corporeal Shockwave Therapy (one session per week for 3 weeks), or two ultrasound-guided Autologous Blood Injections (2 injections performed 2-4 weeks apart). All patients received standardised after-care, including continuation of a structured home exercise programme of flexibility and progressive loading (eccentric strengthening) exercises. Main Outcome Measures were Victoria Institute of Sport - Patella questionnaire (VISA-P), plus 0-10 Visual Analogue Scale (VAS) for self-reported levels of "average pain".

RESULTS

There were statistically significant improvements in self-reported measures of pain/function following either procedure at 6-weeks and at 3-months, but only in the ABI group at 6-months. At 3-months: VISA-P was improved from 32.4% ± 11.7%-60.0% ± 20.7% (p < 0.01) in the ABI group, and from 34.2% ± 14.6%-48.9% ± 17.8% (p < 0.001) in the r-ESWT group.

CONCLUSIONS

Patients with chronic patella tendinopathy improved at 6-weeks and 3-months following either ABI or r-ESWT procedure, with significant benefits at 6-months seen only in the ABI group. Between group analysis demonstrated improved outcomes favouring ABI compared to r-ESWT at the 6-month timepoint using VISA-P, and at all time-points using VAS as outcome measures. The small sample sizes in this pragmatic study are however noted, which limit interpretation, and larger more robust studies are required to investigate this further. This pragmatic prospective cohort study demonstrates improvements following either r-ESWT or ABI procedures, with results potentially favouring ABI over r-ESWT for patients with chronic patella tendinopathy.

Autoregulation in Resistance Training for Lower Limb Tendinopathy: A Potential Method for Addressing Individual Factors, Intervention Issues, and Inadequate Outcomes

Musculoskeletal disorders, such as tendinopathy, are placing an increasing burden on society and health systems. Tendinopathy accounts for up to 30% of musculoskeletal disorders, with a high incidence in athletes and the general population. Although resistance training has shown short-term effectiveness in the treatment of lower limb tendinopathy, more comprehensive exercise protocols and progression methods are required due to poor long-term outcomes. The most common resistance training protocols are predetermined and standardized, which presents significant limitations. Current standardized protocols do not adhere to scientific resistance training principles, consider individual factors, or take the importance of individualized training into account. Resistance training programs in case of tendinopathy are currently not achieving the required intensity and dosage, leading to high recurrence rates. Therefore, better methods for individualizing and progressing resistance training are required to improve outcomes. One potential method is autoregulation, which allows individuals to progress training at their own rate, taking individual factors into account. Despite the finding of their effectiveness in increasing the strength of healthy athletes, autoregulation methods have not been investigated in case of tendinopathy. The purpose of this narrative review was 3-fold: firstly, to give an overview and a critical analysis of the individual factors involved in tendinopathy and current resistance training protocols and their limitations. Secondly, to give an overview of the history, methods, and application of autoregulation strategies both in sports performance and physiotherapy. Finally, a theoretical adaptation of a current tendinopathy resistance training protocol using autoregulation methods is presented, providing an example of how the method could be implemented in clinical practice or future research.

Effect of a common exercise programme with an individualised progression criterion based on the measurement of neuromuscular capacity versus current best practice for lower limb tendinopathies (MaLaGa trial): a protocol for a randomised clinical trial

INTRODUCTION

High-load resistance training has shown positive effects in pain and function in lower limb tendinopathies. However, some authors suggest that current exercise programmes produce an increase in tolerance to load and exercise in general but without fixing some existing issues in tendinopathy. This may indicate the need to include training aspects not currently taken into account in the current programmes. The main objective of this study will be to compare the effect of a common exercise protocol for the three predominant lower limb tendinopathies (Achilles, patellar and gluteal), based on an individualised control of the dose and training of specific aspects of the neuromuscular system versus the current best practice for each location.

METHODS AND ANALYSIS

This study will be conducted among people with mid-portion Achilles, patellar or gluteal tendinopathy. The participants allocated to the experimental group will perform a 14-week innovative common therapeutic exercise programme. Participants allocated to the control group will carry out a 14-week exercise programme based on the best current practice for each of the studied locations. The Victorian Institute of Sports Assessment questionnaire will be considered the primary outcome. Pain, central sensitisation, fear avoidance behaviour, quality of life, treatment satisfaction, lower-limb strength and function, and high-density electromyography profile will be evaluated as secondary outcomes. Outcomes will be assessed at baseline, 7 weeks, after the intervention (week 14), 26 weeks and 52 weeks.

ETHICS AND DISSEMINATION

The study has been approved by the Portal de Ética de la Investigación Biomédica de Andalucía Ethics Committee (1221-N-19). All participants will be informed about the purpose and content of the study and written informed consent will be completed. The results of this study will be published in a peer-reviewed journal and will be disseminated electronically and in print.

TRIAL REGISTRATION NUMBER

NCT03853122; Pre-results.

Inertial flywheel vs heavy slow resistance training among athletes with patellar tendinopathy: A randomised trial

OBJECTIVES

To compare the efficacy of inertial flywheel and heavy slow resistance training in reducing pain and improving function in patellar tendinopathy.

DESIGN

Randomised clinical trial.

METHODS

Fourty two participants (1 woman, 41 men) with longstanding (>3 months) patellar tendinopathy were randomised into inertial flywheel resistance (N = 21) or heavy slow resistance (N = 21) group. Both programmes consisted of three supervised inertial flywheel or heavy slow resistance exercise sessions per week in a fitness center during 12 weeks. Primary outcome was pain and function, assessed by the Spanish Victorian Institute of Sport Assessment for Patella (VISA-P) score at 6 and 12 weeks. Secondary outcomes were activity limitation using Patient Specific Functional Scale (PSFS), health status (EuroQol-5D), patient impression of change on pain and function, adherence, adverse events, pain provocation test for the patellar tendon (numerical rating score of pain between 0 and 10), physical test, patellar tendon thickness and doppler signal on ultrasound. Secondary outcomes were taken at 0 and 12 weeks.

RESULTS

Both groups showed significant improvements in VISA-P scores from 0 to 12 weeks but there was not statistically significant between-group difference (P = 0.506). No adverse events or side effects occurred in any of the groups during the intervention period.

CONCLUSIONS

Inertial flywheel resistance three times a week during 12 weeks resulted in similar pain and function benefit at 12 weeks compared with the heavy slow resistance training among people with patellar tendinopathy. Flywheel training is another exercise option for managing people with patellar tendinopathy. CLINICALTRIALS.

GOV REGISTRY

NCT03917849.

Expanded adipose derived mesenchymal stromal cells are effective in treating chronic insertional patellar tendinopathy: clinical and MRI evaluations of a pilot study

Purpose

Effect of ultrasound guided injections of autologous ASCs in chronic recalcitrant patellar tendinopathy.

Methods

Fourteen patients (16 knees, 12/2 males/females) with chronic, recalcitrant (unsuccessfully treated with nonoperative treatments) insertional PT underwent clinical evaluation and magnetic resonance imaging (MRI) before intervention. Stromal vascular fraction cells (SVF) were expanded by in-vitro culture and characterized by flow cytometry. Players were injected with three bi-weekly injections of ASCs followed by physiotherapy. They underwent serial clinical evaluations during a 12-month period with repeated MRI at 6-month post-injection.

Results

Victorian Institute of sports assessment-patellar tendon questionnaire (VISA-P) scores improved from 43.8 ± 4.9 at baseline to 58.1 ± 7.1, 70.3 ± 7.9 and 78.7 ± 7.5 at 3, 6, and12months follow-up, respectively. (p = 0.0004 comparing each variable with the previous one). Mean Visual analogue pain in sports (VAS-sport) score during practice significantly decreased from 7.4 ± 0.5 at baseline to 5.2 ± 1.5 9 (p = 0.0005), 3.3 ± 1.1 (p = 0.0004) and 1.5 ± 0.7 (P = 0.0004) at 3, 6, and 12 months, respectively. Mean Tegner-scores for patients were 8.0 ± 0.8 before injury and 2.3 ± 0.9 before treatment, thereafter, improving to 4.8 ± 0.8 and 7.2 ± 0.7 at 6- and 12- months, respectively (p = 0.0001). MRI assessed tendon width’ did not change over the first 6 months post-intervention. Significant changes were observed for: tendon thickness (12.8 ± 1.1 to 10.9 ± 0.7, P = 0.0001); tear length (9.3 ± 1.3 to 2.3 ± 0.7, P = 0.0001), tear width (6.3 ± 0.8 to 3.4 ± 0.4, P = 0.0001), and tear thickness (4.6 ± 0.4 to 2.6 ± 0., P = 0.0001) at baseline and 6 months, respectively.

Conclusion

Patients with recalcitrant insertional PT showed significant clinical improvement and structural repair at the patellar insertional tendinopathy after injections of autologous ASCs. Results of this study are promising and open a new biological therapeutic modality to treat PT.

Effects of Cross-Education After 6 Weeks of Eccentric Single-Leg Decline Squats Performed With Different Execution Times: A Randomized Controlled Trial

BACKGROUND

Cross-education of strength refers to the strength gain that is transferred to the contralateral limb after a unilateral training program.

HYPOTHESIS

Unilateral eccentric training using different muscle contraction times would improve the structural and functional properties of the untrained contralateral limb.

STUDY DESIGN

Randomized controlled trial.

LEVEL OF EVIDENCE

Level 2.

METHODS

Thirty-six participants were randomized into a control group, experimental group 1 (EG6s; eccentric contraction runtime = 6 seconds) and experimental group 2 (EG3s; eccentric contraction runtime = 3 seconds). The thickness and elastographic index of the patellar tendon (PT), lean mass and fat percentage of the thigh, contractile properties of the vastus lateralis (VL), as well as isometric, concentric, and eccentric knee extensor peak torques, and eccentric single-leg decline squat (SLDS_e) 1 repetition maximum (1-RM) were measured after 6 weeks of SLDS_e training (3 times per week, 80% of 1-RM) and after 6 weeks of detraining in the untrained contralateral limb.

RESULTS

After training, there was an increase in lean thigh mass of the untrained limb in both groups: EG6s (0.17 ± 0.29 kg;P = 0.03; effect size [ES] = 0.15) and EG3s (0.15 ± 0.23 kg; P = 0.04; ES = 0.19). Likewise, both EG6s (62.30 ± 19.09 kg; P < 0.001; ES = 4.23) and EG3s (68.09 ± 27.49 kg; P < 0.001; ES = 3.40) increased their 1-RM, isometric (EG6s: 48.64 ± 44.82 N·m, P < 0.001, ES = 0.63; EG3s: 34.81 ± 47.30 N·m, P = 0.004, ES = 0.38), concentric at 60 deg/s and 180 deg/s and eccentric at 60 deg/s and 180 deg/s knee extensor peak torques (P < 0.05) in the untrained limb. However, no differences were found in the contractile properties of the VL or in the thickness of the PT after eccentric training in either of the 2 experimental groups.

CONCLUSION

Regardless of the runtime of the contraction, 6 weeks of SLSD_e was effective for inducing structural and strength adaptations in the contralateral untrained limb. However, most of these adaptations were lost after 6 weeks of detraining.

CLINICAL RELEVANCE

Our study suggests that cross-education training can be of great importance for clinical application and musculoskeletal and neuromuscular rehabilitative processes after unilateral injury.

Comparison of Pain Measures Between Tendons of Elite Basketball Players With Different Sonographic Patterns

CONTEXT

The prevalence and negative consequences of the symptoms surrounding patellar tendinopathy constitute an important problem for sports medicine professionals. The identification of potential pain mediators is, therefore, of major interest to improve both the prevention and management of this injury.

OBJECTIVE

To compare the pain experienced by elite male adult basketball players and patterns of patellar tendon abnormalities. Also, to identify whether structural and vascular sonographic abnormalities (focal area of hypoechogenicity, thickening, and neovascularization [NV]) are equal in determining pain perceptions.

DESIGN

An observational study with professional basketball teams (ACB-Spanish league).

PARTICIPANTS

A total of 73 male basketball players (mean age 26.8 y).

MAIN OUTCOME MEASURES

Patellar tendon ultrasonography images. Pain scores were compared between the identified patterns. Multiple regression analysis was used to examine the relative importance of abnormalities.

RESULTS

Of the 146 tendons, 91 had some degree of sonographic abnormality. Three main patterns were identified: I (1 structural abnormality without NV), II (2 structural abnormalities without NV), and III (2 structural abnormalities and NV). A total of 31 tendons (21.2%) exhibited pattern I, 46 (31.5%) presented pattern II, and 13 tendons (8.9%) exhibited pattern III. The mean visual analog scale and the Victorian Institute of Sport assessment questionnaire-patellar tendon (VISA-P) scores for pattern III were significantly different (P < .05) compared with patterns I and II; however, the pain pressure threshold (PPT) scores were not. NV was significantly associated with worsened scores for all pain measures; however, the focal area of hypoechogenicity was only associated with PPT scores.

CONCLUSION

Patterns of sonographic abnormalities, including NV, demonstrated greater pain. Although NV determined scores for the visual analog scale, VISA-P, and PPT, the presence of focal area of hypoechogenicity on its own is a determining factor for the PPT. This study suggests that the combination of 2 or more sonographic abnormalities may help explain pain variations among basketball players.

The implementation of resistance training principles in exercise interventions for lower limb tendinopathy: A systematic review

OBJECTIVES

The primary purpose of this systematic review is to examine the literature on resistance training interventions for lower limb tendinopathy to evaluate the proportion of interventions that implemented key resistance training principles (specificity, progression, overload, individualisation) and reported relevant prescription components (frequency, intensity, sets, repetitions) and reported intervention adherence.

METHODS

Two reviewers performed a systematic review after screening titles and abstracts based on eligibility criteria. Identified papers were obtained in full text, with data extracted regarding the implementation of resistance training principles. Included articles were evaluated by the Cochrane risk of bias tool, with a scoring tool out of 10 used for implementation and reporting of the 5 key principles. Scientific databases were searched in November 2020 and included Medline, CINAHL, AMED, and Sportsdiscus.

RESULTS

52 randomised controlled trials investigating resistance training in five different lower limb tendinopathies were included. Although most studies considered the principles of progression (92%) and individualisation (88%), only 19 studies (37%) appropriately described how this progression in resistance was achieved, and only 18 studies (35%) reported specific instruction on how individualisation was applied. Adherence was considered in 27 studies (52%), with only 17 studies (33%) reporting the levels of adherence. In the scoring criteria, only 5 studies (10%) achieved a total maximum score of 10, with 17 studies (33%) achieving a maximum score of 8 for implementing and reporting the principles of specificity, overload, progression and individualisation.

CONCLUSION

There is meaningful variability and methodological concerns regarding the application and reporting of resistance training principles, particularly progression and individualisation, along with intervention adherence throughout studies. Collectively, these findings have important implications for the prescription of current resistance training interventions, including the design and implementation of future interventions for populations with lower limb tendinopathies.

Effect of Autologous Expanded Bone Marrow Mesenchymal Stem Cells or Leukocyte-Poor Platelet-Rich Plasma in Chronic Patellar Tendinopathy (With Gap >3 mm): Preliminary Outcomes After 6 Months of a Double-Blind, Randomized, Prospective Study

BACKGROUND

Patellar tendinopathy is common. The success of traditional management, including isometric or eccentric exercises combined with shockwave therapy and even surgery, is limited. Therefore, it is important to determine whether biological treatments such as ultrasound-guided intratendinous and peritendinous injections of autologous expanded bone marrow mesenchymal stem cells (BM-MSCs) or leukocyte-poor platelet-rich plasma (Lp-PRP) improve clinical outcomes in athletic patients with patellar tendinopathy.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 2.

METHODS

A prospective, double-blinded, randomized, 2-arm parallel group, active controlled, phase 1/2 single-center clinical study was performed in patients who had proximal patellar tendinopathy with a lesion >3 mm. A total of 20 participants (age 18-48 years) with pain for >4 months (mean, 23.6 months) and unresponsive to nonoperative treatments were randomized into 2 groups. Of these, 10 participants were treated with BM-MSC (20 × 10⁶ cells) and 10 with Lp-PRP. Both groups performed the same postintervention rehabilitation protocol. Outcomes included the Victorian Institute of Sport Assessment for pain (VISA-P), self-reported tendon pain during activity (visual analog scale [VAS]), muscle function by dynamometry, tendon thickness and intratendinous vascularity by ultrasonographic imaging and Doppler signal, ultrasound tissue characterization (UTC) echo type changes, and magnetic resonance imaging (MRI) T2-weighted mapping changes. Participants were followed longitudinally for 6 months.

RESULTS

The average VAS scores improved in both groups at all time points, and there was a significant reduction in pain during sporting activities (P < .05). In both groups, the average mean VISA-P scores at 6 months were significantly increased compared with baseline (66 BM-MSC group and 72.90 Lp-PRP group), with no significant differences in VAS or VISA-P scores between the groups. There were statistically significant greater improvements in tendon structure on 2-dimensional ultrasound and UTC in the BM-MSC group compared with the Lp-PRP group at 6 months. Similarly, the BM-MSC group demonstrated significant evidence of restoration of tendon structure on MRI compared with the Lp-PRP group at 6 months. Only the participants in the BM-MSC group showed evidence of normalization of tendon structure, with statistically significant differences between the groups on T2-weighted, fat-saturated sagittal and coronal scans and hypersignal in T2-weighted on spin-echo T2-weighted coronal MRI scan. Both treatments were safe, and no significant adverse events were reported in either group.

CONCLUSION

Treatment with BM-MSC or Lp-PRP in combination with rehabilitation in chronic patellar tendinopathy is effective in reducing pain and improving activity levels in active participants. Participants who received BM-MSC treatment demonstrated greater improvement in tendon structure compared with those who received Lp-PRP.

REGISTRATION

2016-001262-28 (EudraCT identifier); NCT03454737 (ClinicalTrials.gov identifier).

Pain-guided activity modification during treatment for patellar tendinopathy: a feasibility and pilot randomized clinical trial

BACKGROUND

Activity modification is a key component of patellar tendinopathy treatment but there is a lack of evidence guiding activity modification prescription. Use of activity modification in treatment studies has varied widely and the impact of those recommendations has not been directly investigated or compared. The purpose of this study was to assess (1) the feasibility of using pain-guided activity modification during treatment for patellar tendinopathy and (2) if our outcome measures are responsive to changes in tendon health over the course of treatment.

METHODS

This was an unblinded, randomized two-arm pilot and feasibility study randomized clinical trial with parallel assignment, conducted in Newark, DE. Individuals between the ages of 16 and 40 years old with patellar tendinopathy were included. Participants were randomly assigned to a pain-guided activity (PGA) or pain-free activity (PFA) group using a spreadsheet-based randomization scheme. All participants received standardized treatment using a modified version of the heavy-slow resistance protocol 3×/week for 12 weeks. For the first 6 weeks, the PGA group used the Pain-Monitoring Model to guide activity outside of treatment and the PFA group was restricted from running, jumping, or activities that provoked their patellar tendon pain. Feasibility outcomes included recruitment, enrollment, randomization, compliance, and retention percentages. Clinical evaluations were conducted at baseline, 6, and 12 weeks to assess symptom severity, psychological factors, tendon morphology and mechanical properties, lower extremity function, and quadriceps muscle performance.

RESULTS

In a ~ 13-month period, 108 individuals were screened, 47/108 (43.5%) were eligible for participation, and 15/47 (32.0%) of those were enrolled (9 PGA, 6 PFA). The recruitment rate was 1.15 participants/month. The mean ± SD compliance with treatment was PGA: 86.1 ± 13.0% and PFA: 67.1 ± 30.7%. There was one missed evaluation session and two adverse events, which were not due to study interventions. Changes exceeding the smallest detectable change were observed for at least one outcome in each domain of tendon health.

CONCLUSIONS

Use of pain-guided activity modification during exercise therapy for patellar tendinopathy was found to be feasible, and the proposed outcome measures appropriate. Computer-based allocation concealment, blinding of evaluators, and greater recruitment of high-level athletes should be implemented in future trials.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03694730 . Registered 3rd of October, 2018.

Effects of Physical Training on Physical and Psychological Parameters in Individuals with Patella Tendon Myopathy: A Systematic Review and Meta-Analysis

The effectiveness of physical training on physical and psychological parameters in individuals with patella tendinopathy has not been investigated in a systematic review and meta-analysis. The aim of the present study was to determine the effects of physical exercise interventions for measures of physical and psychological performance in subjects with patella tendinopathy. A computerised systematic literature search was conducted in the electronic databases PubMed, Medline, and Web of Science from January 1960 to July 2020. Initially, 506 articles were identified for review of which eleven articles met the inclusion criteria. Our results revealed a small effect (weighted mean standardized mean difference (SMD) = 0.12; nine studies) of physical training on the psychological measure Victorian Institute of Sport Assessment–Patellar tendon scale and a medium effect (weighted mean SMD = 0.61; five studies) on the psychological measure visual analogue scale—both in favour of the intervention group. In contrast, a small effect (weighted mean SMD = −0.05; two studies) in favour of the control group was detected for the physical measure muscle power. Compared to the control condition, physical training seems to be an effective means to improve psychological but not physical parameters in individuals with patella tendinopathy; although conclusions on the latter could have been biased by the small amount of eligible studies (n = 2). In addition, the predetermined cut-off value of ≥6 for the Physiotherapy Evidence Database scale score (i.e., assessment of methodological quality) was only achieved by six out of eleven studies. Thus, further research of high methodological quality is needed to verify whether there is or is not an effect of physical training on physical parameters in persons with patella tendinopathy.

IN-SEASON REHABILITATION PROGRAM USING BLOOD FLOW RESTRICTION THERAPY FOR TWO DECATHLETES WITH PATELLAR TENDINOPATHY: A CASE REPORT

Background and Purpose

Patellar tendinopathy is an overuse injury experienced primarily by athletes; especially athletes who participate in sports that involve frequent jumping. Therapeutic exercise is the primary conservative treatment for patients with this condition. However, some patients with patellar tendinopathy may be unable to tolerate the loading that occurs during exercise. The use of blood flow restriction (BFR) therapy for patients with patellar tendinopathy may allow the athlete to exercise with a lower load while still experiencing the physiological benefits associated with training at a higher intensity. The purpose of this case report was to detail the outcomes from a rehabilitation program utilizing BFR for two collegiate decathletes with patellar tendinopathy.

Study Design

Case ReportCase Descriptions and Interventions: Two NCAA Division III freshmen collegiate decathletes with a history of left knee pain prior to college and who had been complaining of increasing pain during the initial month of track practices. Findings from the musculoskeletal examinations included left sided lower extremity weakness, pain during functional testing, pain when palpating the left patellar tendon, and VISA-P scores less than 80. Ultrasound imaging at baseline revealed thickened tendons on the left with hypoechoic regions. Both athletes participated in 20 therapy sessions consisting of therapeutic exercises performed with BFR.

Outcomes

Both athletes experienced improvements in pain scores, increases in lower extremity strength, improved functional test performance, higher VISA-P scores, and improvements in tendon size and appearance as measured by diagnostic ultrasound.

Conclusion

Both athletes experienced improvements with the BFR-based therapeutic exercise program and were able to compete throughout the track season. The use of BFR may allow patients who are unable to tolerate exercise due to pain an alternative approach during rehabilitation. Future research should compare therapeutic exercise programs for this condition with and without BFR.

Level of Evidence

Level V.

Effects of Eccentric Single-Leg Decline Squat Exercise on the Morphological and Structural Properties of the Vastus Lateralis and Patellar Tendon

The purpose was to examine the effect of 6-week eccentric single-leg decline squat (SLDSe) training with two technical execution times (3 s or 6 s) on changes related to the structural properties of the vastus lateralis (VL) and patellar tendon (PT). Thirty-six physical active volunteers were randomly divided into three groups: control group (CG, n = 13, age = 20.8 ± 1.9 years, no intervention program), experimental group 1 (EG1, n = 11, age = 21.6 ± 2.5 years, execution time = 6 s) and experimental group 2 (EG2, n = 12, 21.1 ± 1.2 years, execution time = 3 s). Participants completed a 6-week SLDSe training program (80% of 1-RM) three days a week. The structural characteristics of the VL and the PT were measured with ultrasonography before and after 6-week SLDSe training and after 6 weeks of de-training. Our results indicate that EG1 increased ≈21.8% the thickness of the PT and EG2 increased ≈15.7% the thickness of the VL after the 6-week intervention program. EG1 and EG2 showed greater values (p < 0.05) of lean mass and lower values (p < 0.05) of fat percentage on the thigh after the intervention program. In conclusion, the SLDSe training carried out with the execution time of 6 s had greater effects on the structural and elastic properties of the PT, and the exercise with the execution time of 3 s caused greater structural adaptations in the VL musculature.

Rehabilitation of patellar tendinopathy

Patellar tendinopathy is a common musculoskeletal disorder characterized by progressive activity-related anterior knee pain and patellar tendon dysfunction. It is highly prevalent in sports which involve running and jumping. Various treatment methods are used in the management of PT including rest, activity modification, anti-inflammatory medication, injection therapies, taping, eccentric exercises, extra corporeal shock wave therapy, percutaneous electrolysis, and surgery. Even though various treatment options are available for patellar tendinopathy, no single method has proven to result in a consistent and near complete recovery in patients. Conservative management is considered to be the first line of treatment. This study presents an overview of the current practice about the management of patellar tendinopathy with an emphasis on rehabilitation. This review can act as a guide to sports medicine and rehabilitation professionals' decision making in the management of this disorder.

The Effectiveness of Isometric Contractions Compared With Isotonic Contractions in Reducing Pain For In-Season Athletes With Patellar Tendinopathy

Clinical Scenario: Patellar tendinopathy is a common musculoskeletal disorder affecting the lower-extremities and a difficult condition to manage for athletes that are in season. To facilitate improvement in function and to decrease pain, initial treatment for patellar tendinopathy is typically conservative. Traditional interventions may include eccentric training, cryotherapy, patellar counterforce straps, oral anti-inflammatories, injectable agents, phonophoresis, iontophoresis, orthotics, therapeutic ultrasound, and extracorporeal shockwave. In addition, recent literature suggests that implementing isometric and isotonic contractions may be effective in reducing patellar tendon pain. Focused Clinical Question: How effective are isometric contractions compared with isotonic contractions in reducing pain for in-season athletes with patellar tendinopathy? Summary of Key Findings: Implementation of isometric and isotonic exercises statistically reduced pain levels in the short term of 4 weeks for in-season athletes; however, isometric contractions provided statistically greater pain relief immediately for up to 45 minutes postintervention compared with isotonic contractions. Clinical Bottom Line: Current evidence supports the use of isometric and isotonic contractions to reduce pain for in-season athletes with patellar tendinopathy. Based on the reviewed literature, clinicians should consider utilizing heavy loaded isometrics or progressive heavy loaded isotonic exercises, which showed reduction in pain levels immediately after intervention and at 4-week follow-up for both intervention groups. Isometric contractions appear to provide greater pain relief immediately after intervention. Strength of Recommendation: There is Grade B evidence from 2 level 2 randomized controlled trials and 1 level 3 randomized crossover study supporting the use of isometric and isotonic contractions to reduce patellar tendon pain for in-season athletes.

Management of Achilles and patellar tendinopathy: what we know, what we can do

Tendinopathies are challenging conditions frequent in athletes and in middle-aged overweight patients with no history of increased physical activity. The term “tendinopathy” refers to a clinical condition characterised by pain, swelling, and functional limitations of tendons and nearby structures, the effect of chronic failure of healing response. Tendinopathies give rise to significant morbidity, and, at present, only limited scientifically proven management modalities exist. Achilles and patellar tendons are among the most vulnerable tendons, and among the most frequent lower extremity overuse injuries. Achilles and patellar tendinopathies can be managed primarily conservatively, obtaining good results and clinical outcomes, but, when this approach fails, surgery should be considered. Several surgical procedures have been described for both conditions, and, if performed well, they lead to a relatively high rate of success with few complications. The purpose of this narrative review is to critically examine the recent available scientific literature to provide evidence-based opinions on these two common and troublesome conditions.

Landing biomechanics are not immediately altered by a single-dose patellar tendon isometric exercise protocol in male athletes with patellar tendinopathy: A single-blinded randomized cross-over trial

OBJECTIVES

To a) determine the acute effects of a single-dose patellar tendon isometric exercise protocol on involved limb landing biomechanics in individuals with patellar tendinopathy and asymptomatic patellar tendon pathology, and b) determine if individuals with patellar tendinopathy demonstrated changes in pain following a single-dose patellar tendon isometric exercise protocol.

DESIGN

Single-blinded randomized cross-over trial.

SETTING

Laboratory; PARTICIPANTS: 28 young male athletes with symptomatic (n = 13, age: 19.62 ± 1.61) and asymptomatic (n = 15, age: 21.13 ± 1.88) patellar tendinopathy.

MAIN OUTCOME MEASURES

Participants completed a single-dose patellar tendon isometric exercise protocol and a sham-TENS protocol, randomized and separated by 7-10 days. Pain-levels during a single-limb decline squat (SLDS) and three-dimensional biomechanics were collected during a double-limb jump-landing task before and after each intervention protocol. A mixed-model repeated measures ANOVA was conducted to compare change scores for all dependent variables.

RESULTS

There were no group × intervention interactions for change in pain (F_{(1, 26)} = 0.555, p = 0.463). There was one significant group × intervention interaction for vertical ground reaction force (VGRF) (F_{(1, 26)} = 5.33, p = 0.029). However, post-hoc testing with Bonferroni correction demonstrated no statistical significance for group (SYM: t = -1.679, p = 0.119; ASYM: t = -1.7, p = 0.107) or intervention condition (isometric: t = -2.58, p = 0.016; sham-TENS: 0.72, p = 0.460). There were no further significant group × intervention interactions (p > 0.05).

CONCLUSIONS

A single-dose patellar tendon isometric exercise protocol did not have acute effects on landing biomechanics or pain levels in male athletes with patellar tendinopathy or asymptomatic patellar tendon pathology.

Ultrasound-guided tendon debridement improves pain, function and structure in persistent patellar tendinopathy: short term follow-up of a case series

There is a need for effective therapeutic options for resistant patellar tendinopathy. Ultrasound (US)-guided arthroscopic debridement has demonstrated promising clinical results.

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

OBJECTIVE

Eccentric exercise is commonly used as a form of loading exercise for individuals with patellar tendinopathy. This study investigated the change of mechanical properties and clinical outcomes and their interrelationships after a 12-week single-legged decline-board exercise with and without extracorporeal shockwave therapy (ESWT).

DESIGN

Randomized controlled trial.

SETTING

Outpatient clinic of a university.

PARTICIPANTS

Thirty-four male in-season athletes with patellar tendinopathy for more than 3 months were randomized into exercise and combined groups.

INTERVENTIONS

The exercise group received a 12-week single-legged decline-squat exercise, and the combined group performed an identical exercise program in addition to a weekly session of ESWT in the initial 6 weeks.

MAIN OUTCOME MEASURES

Tendon stiffness and strain were examined using ultrasonography and dynamometry. Visual analog scale and Victoria Institute of Sports Assessment-patella (VISA-p) score were used to assess pain and dysfunction. These parameters were measured at preintervention and postintervention.

RESULTS

Significant time effect but no significant group effect on the outcome measures; significant reduction in tendon stiffness (P = 0.02) and increase in tendon strain (P = 0.00); and reduction of intensity of pain (P = 0.00) and dysfunction (P = 0.00) were observed. Significant correlations between changes in tendon stiffness and VISA-p score (ρ = -0.58, P = 0.05); alteration in tendon strain, pain intensity (ρ = -0.63, P = 0.03); and VISA-p score (ρ = 0.60, P = 0.04) were detected after the exercise program.

CONCLUSIONS

Eccentric exercise-induced modulation on tendon mechanical properties and clinical symptoms are associated in athletes with patellar tendinopathy.

High-energy dose of therapeutic ultrasound in the treatment of patellar tendinopathy: protocol of a randomized placebo-controlled clinical trial

BACKGROUND

Patellar tendinopathy is an extremely debilitating condition and its treatment usually requires a combination of clinical approaches. Therapeutic ultrasound (TUS) is one of the most available electrophysical agent in rehabilitation settings; however, there is also a lack of high-quality studies that test different dosimetric aspects of TUS. Thus, the purpose of this study is to evaluate the short-, medium-, and long-term effects of the combination of high-energy TUS with a rehabilitation program for patellar tendinopathy.

METHODS

This will be a randomized, placebo-controlled trial with blinding of patients, assessors, and therapist. The setting is an outpatient physical therapy clinic. We will recruit 66 participants (male and female) aged between 18 and 40 years and presenting with patellar tendinopathy. A treatment combining high-energy dose TUS and a rehabilitation program for patellar tendinopathy will be delivered twice a week for 8 weeks. The control group will receive the same treatment, but with a placebo TUS. The effectiveness of the intervention will be measured at the beginning (baseline), midpoint (4 weeks), and end of treatment (8 weeks), as well as at 3- and 6-months post-treatment. Primary outcomes will be pain intensity (visual analogue scale, VAS), and VISA-P questionnaire and primary time points will be baseline (T0) and the end of the program (T2). Also, IPAQ-short form questionnaire, muscle strength (manual dynamometry), 2D kinematics, pain pressure threshold (PPT) algometry, thermography, and magnetic resonance imaging (MRI) will be collected.

DISCUSSION

TUS will be applied in an attempt to enhance the results obtained with the rehabilitation program proposed in this study, as well as stimulate some repair responses in individuals undergoing treatment for patellar tendinopathy, which in turn may optimize and improve treatment programs for patellar tendinopathy as well as to establish new guidelines for the application of TUS.

TRIAL REGISTRATION

This study was prospectively registered at April-3rd-2018 and updated at September-1st-2019 in the Brazilian Registry of Clinical Trials (REBEC) under the registration number: RBR-658n6w.

Sesamoids in tetrapods: the origin of new skeletal morphologies

Along with supernumerary bones, sesamoids, defined as any organized intratendinous/intraligamentous structure, including those composed of fibrocartilage, adjacent to an articulation or joint, have been frequently considered as enigmatic structures associated with the joints of the skeletal system of vertebrates. This review allows us to propose a dynamic model to account for part of skeletal phenotypic diversity: during evolution, sesamoids can become displaced, attaching to and detaching from the long bone epiphyses and diaphysis. Epiphyses, apophyses and detached sesamoids are able to transform into each other, contributing to the phenotypic variability of the tetrapod skeleton. This dynamic model is a new paradigm to delineate the contribution of sesamoids to skeletal diversity. Herein, we first present a historical approach to the study of sesamoids, discussing the genetic versus epigenetic theories of their genesis and growth. Second, we construct a dynamic model. Third, we present a summary of literature on sesamoids of the main groups of tetrapods, including veterinary and human clinical contributions, which are the best-studied aspects of sesamoids in recent decades. Finally, we discuss the identity of certain structures that have been labelled as sesamoids despite insufficient formal testing of homology. We also propose a new definition to help the identification of sesamoids in general. This review is particularly timely, given the recent increasing interest and research activity into the developmental biology and mechanics of sesamoids. With this updated and integrative discussion, we hope to pave the way to improve the understanding of sesamoid biology and evolution.

Exercise therapy in the treatment of tendinopathies of the lower limbs: a protocol of a systematic review

BACKGROUND

Tendinopathies are specific degenerative conditions of the tendon characterized by pain and disability. The most common tendinopathies of the lower limbs are patellar, Achilles, gluteal, and proximal tendinopathy of the hamstring muscles. Exercise therapy has been studied for the treatment of these tendinopathies; however, different types of muscle contraction, exercise, dose, and intensity are found in the literature, which can make choosing the best treatment option difficult. The purpose of this systematic review is to analyze the available evidence about the effectiveness of exercise therapy in the treatment of patients with lower limb tendinopathies and the effects of different types of exercise therapy in the treatment of these patients.

METHODS

The search strategy will be performed in the following databases: CENTRAL, MEDLINE, EMBASE, PEDro, SPORTDiscus, and CINAHL. The inclusion criteria of the studies will be randomized controlled trials with patients with one of the following tendinopathies: patellar, Achilles, gluteal, and proximal tendinopathy of the hamstring muscles. The primary outcomes will be pain and disability. The intervention will be exercise therapy, and the comparators will be different types of exercise, control groups, or any other type of intervention.

DISCUSSION

Other systematic reviews have been published about the prescription of exercise therapy in the treatment of tendinopathies of the lower limbs. However, the results of these reviews are limited to only one type of tendinopathy or specific exercise. Because some of these reviews are also outdated, this systematic review will investigate whether exercise therapy is more effective than any other type of intervention and if there is a best form of exercise therapy, considering modality, dose, and intensity, for the treatment of lower limb tendinopathies. Furthermore, this study will present data related to the sample size, recruitment period, methodological quality, and visibility of the eligible studies.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO ( CRD42018093011 ).

Isometric Exercise to Reduce Pain in Patellar Tendinopathy In-Season: Is It Effective "on the Road"?

OBJECTIVE

To investigate the effectiveness of an isometric squat exercise using a portable belt, on patellar tendon pain and function, in athletes during their competitive season.

DESIGN

Case series with no requirements to change any aspect of games or training. The object of this pragmatic study was to investigate this intervention in addition to "usual management." A control or sham intervention was considered unacceptable to teams.

SETTING

In-season.

PARTICIPANTS

A total of 25 male and female elite and subelite athletes from 5 sports.

INTERVENTION

5 × 30-second isometric quadriceps squat exercise using a rigid belt completed over a 4-week period.

MAIN OUTCOME MEASURES

(1) single-leg decline squat (SLDS)-a pain provocation test for the patellar tendon (numerical rating score of pain between 0 and 10), (2) VISA-P questionnaire assessing patellar tendon pain and function, and (3) self-reported adherence with completing the exercise over a 4-week period.

RESULTS

Baseline SLDS pain was high for these in-season athletes, median 7.5/10 (range 3.5-9) and was significantly reduced over the 4-week intervention (P < 0.001, ES r = 0.580, median change 3.5). VISA-P scores improved after intervention (P < 0.001, ES r = 0.568, mean change 12.2 ± 8.9, percentage mean change 18.8%, where minimum clinical important difference of relative change for VISA-P is 15.4%-27%). Adherence was high; athletes reported completing the exercise 5 times per week.

CONCLUSIONS

This pragmatic study suggests that a portable isometric squat reduced pain in-season for athletes with patellar tendinopathy (PT). This form of treatment may be effective, but clinical trials with a control group are needed to confirm the results.

Comparison of the Effect of 5 Different Treatment Options for Managing Patellar Tendinopathy: A Secondary Analysis

OBJECTIVE

Currently, no treatments exist for patellar tendinopathy (PT) that guarantee quick and full recovery. Our objective was to assess which treatment option provides the best chance of clinical improvement and to assess the influence of patient and injury characteristics on the clinical effect of these treatments.

DESIGN

A secondary analysis was performed on the combined databases of 3 previously performed double-blind randomized controlled trials.

PATIENTS

In total, 138 patients with PT were included in the analysis.

INTERVENTIONS

Participants were divided into 5 groups, based on the treatment they received: Extracorporeal shockwave therapy (ESWT) (n = 31), ESWT plus eccentric training (n = 43), eccentric training (n = 17), topical glyceryl trinitrate patch plus eccentric training (n = 16), and placebo treatment (n = 31).

MAIN OUTCOME MEASURES

Clinical improvement (increase of ≥13 points on the Victorian Institute of Sport Assessment-Patella score) after 3 months of treatment.

RESULTS

Fifty-two patients (37.7%) improved clinically after 3 months of treatment. Odds ratios (ORs) for clinical improvement were significantly higher in the eccentric training group (OR 6.68, P = 0.009) and the ESWT plus eccentric training group (OR 5.42, P = 0.015) compared with the other groups. We found evidence that a high training volume, a longer duration of symptoms, and older age negatively influence a treatment's clinical outcome (trend toward significance).

CONCLUSIONS

Our study confirmed the importance of exercise, and eccentric training in particular, in the management of PT. The role of ESWT remains uncertain. Further research focusing on the identified prognostic factors is needed to be able to design patient-specific treatment protocols for the management of PT.

Patellar tendon stress between two variations of the forward step lunge

BACKGROUND

Patellar tendinopathy (PT) or "jumper's knee" is generally found in active populations that perform jumping activities. Graded exposure of patellar tendon stress through functional exercise has been demonstrated to be effective for the treatment of PT. However, no studies have compared how anterior knee displacement variations during the commonly performed forward step lunge (FSL) affect patellar tendon stress.

METHODS

Twenty-five subjects (age: 22.69 ± 0.74 years; height: 169.39 ± 6.44 cm; mass: 61.55 ± 9.74 kg) performed 2 variations of an FSL with the anterior knee motion going in front of the toes (FSL-FT) and the knee remaining behind the toes (FSL-BT). Kinematic and kinetic data were used with an inverse-dynamics based static optimization technique to estimate individual muscle forces to determine patellar tendon stress during both lunge techniques. A repeated measures multivariate analysis was used to analyze these data.

RESULTS

The peak patellar tendon stress, stress impulse, quadriceps force, knee moment, knee flexion, and ankle dorsiflexion angle were significantly greater (p < 0.001) during the FSL-FT as compared to the FSL-BT. The peak patellar tendon stress rate did not differ between the FSL-FT and FSL-BT.

CONCLUSION

The use of an FSL-FT as compared to an FSL-BT increased the load and stress on the patellar tendon. Because a graded exposure of patellar tendon loading with other closed kinetic chain exercises has proven to be effective in treating PT, consideration for the prescription of variations of the FSL and further clinical evaluation of this exercise is warranted in individuals with PT.

Nonsurgical Treatments of Patellar Tendinopathy: Multiple Injections of Platelet-Rich Plasma Are a Suitable Option: A Systematic Review and Meta-analysis

BACKGROUND

Patellar tendinopathy is a condition characterized by anterior knee activity-related pain. It has a high incidence among athletes engaged in jumping sports and may become a chronic condition. Nonoperative management is the first choice in these patients, and several nonsurgical treatment options have been proposed. Nonetheless, clear indications on the most effective approach to address patellar tendinopathy are still lacking.

PURPOSE

To analyze the evidence on nonoperative options to treat chronic patellar tendinopathy through a systematic review of the literature and to perform a meta-analysis to identify the most effective nonsurgical option.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

The search was conducted with the PubMed and Cochrane databases on January 4, 2017. All clinical English-language reports of any level of evidence on nonsurgical treatment of patellar tendinopathy were included. The quality of each article was assessed by use of the Coleman score. A meta-analysis was performed on all articles reporting the Victorian Institute of Sport Assessment scale for patellar tendinopathy to evaluate the results of the most described treatments.

RESULTS

A total of 70 studies involving 2530 patients were included in the qualitative data synthesis. The Coleman score showed an overall poor study quality. The most described treatment groups that could be included in the meta-analysis were reported in 22 studies on eccentric exercise, extracorporeal shockwave therapy (ESWT), and platelet-rich plasma (PRP). Single and multiple PRP injections were evaluated separately. Eccentric exercise therapies obtained the best results ( P < .05) at short-term (<6 months, mean 2.7 ± 0.7 months). However, multiple injections of PRP obtained the best results ( P < .05), followed by ESWT and eccentric exercise, at long-term follow-up (≥6 months, mean 15.1 ± 11.3 months).

CONCLUSION

The literature documents several nonsurgical approaches for the treatment of chronic patellar tendinopathy with important limitations in terms of study quality. The available evidence showed an overall positive outcome, but some differences have been highlighted. Eccentric exercises may seem the strategy of choice in the short-term, but multiple PRP injections may offer more satisfactory results at long-term follow-up and can be therefore considered a suitable option for the treatment of patellar tendinopathy.

Kinematic and kinetic differences between military patients with patellar tendinopathy and asymptomatic controls during single leg squats

BACKGROUND

Knee valgus alignment has been associated with lower-limb musculoskeletal injury. This case-control study aims to: assess biomechanical differences between patients with patellar tendinopathy and healthy controls.

METHODS

43 military participants (21 cases, 22 controls) were recorded using 3D-motion capture performing progressively demanding, small knee bend, single leg and single leg decline squats. Planned a priori analysis of peak: hip adduction, knee flexion, pelvic tilt, pelvic obliquity and trunk flexion was conducted using MANOVA. Kinematic and kinetic data were graphed with bootstrapped t-tests and 95% CI's normalised to the squat cycle. ANOVA and correlations in SPSS were used for exploratory analysis.

FINDINGS

On their symptomatic side cases squatted to less depth (-6.62°, p < 0.05) than controls with exploratory curve analysis revealing a pattern of increased knee valgus collapse throughout the squatting movement (p < 0.05). Greater patella tendon force was generated by: the eccentric than concentric phase of squatting (+30-43%, ES 0.52-1.32, p < 0.01), declined (plantarflexed) compared to horizontal surface (+36-51%, ES 1.19-1.68, p < 0.01) and deeper knee flexion angles (F ≥ 658.3, p < 0.01) with no difference between groups (F ≤ 1.380, p > 0.05). Cases experienced more pain on testing on decline board (ES = 0.69, p < 0.01). For symptomatic limbs pain (r_s = 0.458-0.641, p ≤ 0.05), but not VISA-P (Victoria Institute of Sport Assessment) (r_s = 0.053-0.090, p > 0.05), correlated with extensor knee moment.

INTERPRETATION

Knee valgus alignment is a plausible risk factor for patellar tendinopathy. Conclusions relating to causation are limited by the cross-sectional study design. Increasing squat depth, use of a declined surface and isolating the eccentric phase enable progression of loading prescription guided by pain.

Immediate effect of infrapatellar strap on pain and jump height in patellar tendinopathy among young athletes

BACKGROUND:

Infrapatellar strapping is a treatment technique used in various knee pathologies; however, its effect on pain and functional performance among young athletes has not been studied.

OBJECTIVES:

To evaluate the effect of infrapatellar strap on pain and jumping performance among young athletes diagnosed with patellar tendinopathy.

STUDY DESIGN:

Pre-/post-test (within-subject research design).

METHODS:

A total of 16 young male basketball and volleyball athletes (age range, 12-18 years) diagnosed with patellar tendinopathy were included in the study. Infrapatellar strap was applied beneath the patella, over the patellar tendon. The athletes performed four jumping tests: squat jump, drop jump, single-leg jump, and jumps 30 s test, with and without the strap. Pain severity in the symptomatic knee during jumping was assessed using a visual analog scale and jumping performance parameters were assessed using an Optojump Next optical measurement system.

RESULTS:

Pain severity reported by the participants decreased in drop test, single-leg jump test, and jumps 30 s test while using the infrapatellar strap compared with no strap condition ( p < 0.05). No significant difference in jumping performance was found between jumping with and without the strap.

CONCLUSION:

The infrapatellar strap was effective in reducing local pain among young male athletes without altered jumping performance.

CLINICAL RELEVANCE

The infrapatellar strap can be recommended to use during physical activity as part of the physical therapy treatments for patellar tendinopathy. Given the low cost, ease to use, and being a non-invasive method without adverse effects, it is an appropriate intervention for young athletes.

The decline step-down test measuring the maximum pain-free flexion angle: A reliable and valid performance test in patients with patellofemoral pain

OBJECTIVES

Patients with patellofemoral pain (PFP) experience pain while descending stairs. To date no reliable and valid performance-test exists to assess the maximum pain-free knee flexion angle (MPFFA) as outcome measure during a step-down task. Therefore, the intra- and inter-observer reliability and construct validity of the decline step-down test (DSDT) measuring the MPFFA in patients with PFP were evaluated.

DESIGN

Reliability and construct validity.

SETTING

Private practices in Nijmegen and Utrecht, the Netherlands.

PARTICIPANTS

Patients with PFP.

MAIN OUTCOME MEASURES

The reliability was assessed by repeated measurements of the MPFFA during the DSDT. The construct validity was assessed by correlating the measurements on the DSDT with the Anterior Knee Pain Scale Dutch Version (AKPS-DV) based on a pre-set hypothesis.

RESULTS

Thirty-two participants (forty-eight knees) were eligible for inclusion. The intraclass correlation coefficient (ICC) for intra-observer reliability was ICC_2,1 = 0.83 and ICC_2,1 = 0.85 for inter-observer reliability. The 95% limits of agreement (LoA) showed a width of 27.56° for intra-observer reliability and a width of 24.42° for inter-observer reliability. There was an average positive correlation between the DSDT and the total score on the AKPS-DV (r_s = 0.31, p = 0.030).

CONCLUSION

The DSDT measuring the MPFFA is reliable and valid in patients with PFP.

Current trends in tendinopathy: consensus of the ESSKA basic science committee. Part II: treatment options

The treatment of painful chronic tendinopathy is challenging. Multiple non-invasive and tendon-invasive methods are used. When traditional non-invasive treatments fail, the injections of platelet-rich plasma autologous blood or cortisone have become increasingly favored. However, there is little scientific evidence from human studies supporting injection treatment. As the last resort, intra- or peritendinous open or endoscopic surgery are employed even though these also show varying results. This ESSKA basic science committee current concepts review follows the first part on the biology, biomechanics and anatomy of tendinopathies, to provide a comprehensive overview of the latest treatment options for tendinopathy as reported in the literature.

Effects of a strength protocol combined with electrical stimulation on patellar tendinopathy: 42 months retrospective follow-up on 6 high-level jumping athletes

STUDY DESIGN

A retrospective study.

INTRODUCTION

Patellar tendinopathy (PT) or jumper's knee (JK) in elite athletes is a challenging condition for sports medicine professionals. This study analyzes the development of a protocol using eccentric, isometric, concentric exercises, and electrostimulation to treat elite athletes suffering from JK. The semiannual strength protocol was completed during a total of 36 months by six high-level jumping athletes with chronic painful JK. Pain during patellar tendon loading activity was evaluated on a visual analogue pain scale (VAS). Upon protocol completion, promising clinical results were evidenced by significant pain reduction during tendon loading activity.

MATERIAL AND METHODS

Six high level jumping athletes with chronic painful JK completed a semiannual strength program using eccentric, isometric, concentric and electrical stimulation exercises. The protocol was done 12 weeks in the winter pre-season and 10 weeks in the summer pre-season, for altogether 36 months, with an interruption of the protocol at 24 months for 6 months. Pain during patellar tendon loading activity was evaluated on a visual analogue pain scale (VAS), before the first session and then every 6 months, coinciding with the competitive phase, the time of maximum pain.

RESULTS

There was a significant (p < 0.01) decrease in the VAS from start to the 18, 24 and 48 months follow-ups.

CONCLUSIONS

In a small group of high level jumping athletes with chronic painful JK, a strength protocol combined with electrical stimulation showed promising clinical results with significant pain reduction during tendon loading activity.

Effects of isometric, eccentric, or heavy slow resistance exercises on pain and function in individuals with patellar tendinopathy: A systematic review

BACKGROUND AND PURPOSE

The purpose of this study is to evaluate current evidence and provide a review on the effects of isometric, eccentric, or heavy slow resistance (HSR) exercises on pain and function in individuals with patellar tendinopathy (PT).

METHODS

Academic journals from CINAHL, Embase, MEDLINE, Scopus, SPORTDiscus™, and The Cochrane Library were searched from inception to August 2017. Screening of reference lists was also performed. Human interventional studies investigating outcomes of pain and function in PT using either isometric, eccentric, or HSR training exercises were included. The McMaster Critical Review Form-Quantitative Studies was used to assess for risk of bias. Levels of evidence were obtained using the National Health and Medical Research Council (NHMRC) evidence hierarchy. The NHMRC Body of Evidence Framework was utilized to formulate recommendations for clinical practice. Extraction of data was performed by two independent reviewers according to predefined data criterion, data were then tabulated, and a descriptive, qualitative data synthesis was performed.

RESULTS

Fifteen studies (3 isometric, 2 HSR, and 10 eccentric) were included for this review. Mean quality score across all studies was 81.6% (range 70% to 93%). Nine studies were of high quality, whereas six studies were of moderate quality. Nine studies were randomized controlled trials, which provided good Level II evidence; four studies were of satisfactory Level III evidence; and two studies were case series (Level IV evidence).

CONCLUSIONS

Findings from isometric exercises can be trusted to guide clinical practice (Grade A), whereas eccentric exercises can be trusted to guide clinical practice in most clinical situations (Grade B). It is recommended that HSR exercises should be applied carefully to individual clinical circumstances (Grade C) and interpreted with care. Isometric exercises appear to be more effective during competitive seasons for short-term pain relief, whereas HSR or eccentric exercises are more suitable for long-term pain reduction and improvement in knee function.

[Jumper's Knee]

Zusammenfassung. Sportliche Aktivitäten mit Sprungabläufen stellen für die Kniegelenke eine mechanische Herausforderung dar. Häufig projizieren sich chronisch auftretende, atraumatische Beschwerden auf den Patellaunterpol, welcher pathomorphologisch eine patellare Tendinopathie entspricht. Extrinsische und intrinsische Risikofaktoren können unterschieden werden. In der klinischen Untersuchung zeigt sich ein meist unauffälliges Knie mit einer Druckdolenz am kaudalen Teil der Kniescheibe beim Übergang zum Ligamentum patellae. In der Bildgebung ist sonografisch ein degenerierter Sehnenanteil der tiefen Patellarsehne zu erkennen, der magnettomografisch mit Hyperintensität des Hoffa-Körpers einhergehen kann. Abhängig von der klinischen Entwicklung wird das Jumper’s Knee nach Blazina Grad I–IV eingeteilt. Bis zu 90 % der Patienten können konservativ therapiert werden. Operativ stehen offene und arthroskopische Verfahren mit ordentlichem Resultat zur Verfügung.

The Influence of Exercise Dosing on Outcomes in Patients With Knee Disorders: A Systematic Review

Study Design Systematic review. Background Therapeutic exercise is commonly used to treat individuals with knee disorders, but dosing parameters for optimal outcomes are unclear. Large variations exist in exercise prescription, and research related to specific dosing variables for knee osteoarthritis, patellar tendinopathy, and patellofemoral pain is sparse. Objectives To identify specific doses of exercise related to improved outcomes of pain and function in individuals with common knee disorders, categorized by effect size. Methods Five electronic databases were searched for studies related to exercise and the 3 diagnoses. Means and standard deviations were used to calculate effect sizes for the exercise groups. The overall quality of evidence was assessed using the Physiotherapy Evidence Database scale. Results Five hundred eighty-three studies were found after the initial search, and 45 were included for analysis after screening. Physiotherapy Evidence Database scale scores were "fair" quality and ranged from 3 to 8. For knee osteoarthritis, 24 total therapeutic exercise sessions and 8- and 12-week durations of exercise were parameters most often associated with large effects. An exercise frequency of once per week was associated with no effect. No trends were seen with exercise dosing for patellar tendinopathy and patellofemoral pain. Conclusion This review suggests that there are clinically relevant exercise dosing variables that result in improved pain and function for patients with knee osteoarthritis, but optimal dosing is still unclear for patellar tendinopathy and patellofemoral pain. Prospective studies investigating dosing parameters are needed to confirm the results from this systematic review. Level of Evidence Therapy, level 1a. J Orthop Sports Phys Ther 2018;48(3):146-161. Epub 10 Jan 2018. doi:10.2519/jospt.2018.7637.

Effects of eccentric overload training on patellar tendon and vastus lateralis in three days of consecutive running

BACKGROUND

The analysis of structural changes in patellar tendon and muscle of healthy subjects in response to mechanical loads provides useful insight into the mechanism underlying overuse injuries.

METHODS

Changes produced in tendon and muscles structures after eccentric overload training and three consecutive running days were examined. Twenty healthy subjects were recruited and divided into two groups. One group (ECC) performed eccentric overload squat training (six weeks). After such training, the ECC group performed three running sessions on consecutive days, as did the control group (CONT). The structure of their patellar tendons and vastus lateralis muscles was quantified using ultrasound and Doppler imaging. Images were obtained before and after eccentric training for the ECC group and on every day of running performance for both groups.

RESULTS

After eccentric training, the ECC group experienced an increase in cross-sectional area (CSA) of patellar tendon (P=0.012). After every day of running, the ECC group experienced a decrease in CSA (P=0.027). In the CONT group, after one day of running a significant increase was observed in anteroposterior width of their patellar tendon (P=0.028), as well as a decrease in pennation angle of vastus lateralis muscle (P=0.028) within three days of running sessions.

CONCLUSIONS

Eccentric overload training brought about changes in the patellar tendon consistent with an improvement in the quality of the tissue. The ECC group in our study showed a more normalised pattern than the CONT group in the running performance, in agreement with previous research.

LEVEL OF EVIDENCE

Level 3, controlled trial.

Current trends in tendinopathy: consensus of the ESSKA basic science committee. Part I: biology, biomechanics, anatomy and an exercise-based approach

Chronic tendinopathies represent a major problem in the clinical practice of sports orthopaedic surgeons, sports doctors and other health professionals involved in the treatment of athletes and patients that perform repetitive actions. The lack of consensus relative to the diagnostic tools and treatment modalities represents a management dilemma for these professionals. With this review, the purpose of the ESSKA Basic Science Committee is to establish guidelines for understanding, diagnosing and treating this complex pathology.

Isometric Contractions Are More Analgesic Than Isotonic Contractions for Patellar Tendon Pain: An In-Season Randomized Clinical Trial

OBJECTIVE

This study aimed to compare the immediate analgesic effects of 2 resistance programs in in-season athletes with patellar tendinopathy (PT). Resistance training is noninvasive, a principle stimulus for corticospinal and neuromuscular adaptation, and may be analgesic.

DESIGN

Within-season randomized clinical trial. Data analysis was conducted blinded to group.

SETTING

Subelite volleyball and basketball competitions.

PARTICIPANTS

Twenty jumping athletes aged more than 16 years, participating in games/trainings 3 times per week with clinically diagnosed PT.

INTERVENTIONS

Two quadriceps resistance protocols were compared; (1) isometric leg extension holds at 60 degrees knee flexion (80% of their maximal voluntary isometric contraction) or (2) isotonic leg extension (at 80% of their 8 repetition maximum) 4 times per week for 4 weeks. Time under load and rest between sets was matched between groups.

MAIN OUTCOME MEASURES

(1) Pain (0-10 numerical rating score) during single leg decline squat (SLDS), measured preintervention and postintervention sessions. (2) VISA-P, a questionnaire about tendon pain and function, completed at baseline and after 4 weeks.

RESULTS

Twenty athletes with PT (18 men, mean 22.5 ± 4.7 years) participated (isotonic n = 10, isometric n = 10). Baseline median SLDS pain was 5/10 for both groups (isotonic range 1-8, isometric range 2-8). Isometric contractions produced significantly greater immediate analgesia (P < 0.002). Week one analgesic response positively correlated with improvements in VISA-P at 4 weeks (r = 0.64).

CONCLUSIONS

Both protocols appear efficacious for in-season athletes to reduce pain, however, isometric contractions demonstrated significantly greater immediate analgesia throughout the 4-week trial. Greater analgesia may increase the ability to load or perform.