Physiotherapy management of patellar tendinopathy (jumper's knee)

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.

Relationship Between Postural Stability and Proprioception, Pain, Quadriceps Strength, and Muscle Tightness in Athletes With Patellar Tendinopathy

BACKGROUND

Athletes with patellar tendinopathy (PT) have postural stability deficits; however, the underlying mechanisms and factors responsible remain unknown. The effect on postural stability in PT of decreased quadriceps strength, altered proprioception, lower-limb muscle tightness, and knee pain, which explain postural stability deficiency in other populations, is uninvestigated.

HYPOTHESIS

Proprioceptive acuity, muscle tightness, quadriceps strength, and pain predict postural stability in athletes with PT.

STUDY DESIGN

Cross-sectional comparative study.

LEVEL OF EVIDENCE

Level 2.

METHODS

A total of 43 athletes with PT and 43 healthy athletes were enrolled. Static and dynamic postural stability, proprioceptive acuity, muscle tightness, quadriceps strength, and pain were evaluated using a force platform, Y-balance test (YBT), a weight discrimination protocol, a goniometer, an isometric dynamometer, and a valid questionnaire, respectively.

RESULTS

Athletes with PT had significantly worse static and dynamic postural stability in the affected limb (AL) compared with the nonaffected limb (NAL) (P < 0.01) and the control group (P < 0.01). Athletes suffering from PT revealed lower quadriceps strength (P < 0.01), proprioceptive acuity (P = 0.02), and higher muscle tightness in the AL compared with the NAL and controls. Quadriceps weakness of the AL and pain in athletes with PT explained the variance of dynamic postural stability impairment.

CONCLUSION

Athletes with PT have postural stability deficiency compared with healthy peers. Our results demonstrate that quadriceps muscle weakness and pain are the factors that explain postural stability impairment.

CLINICAL RELEVANCE

These results can assist clinicians in the design of therapeutic balance rehabilitation programs by acting not only on pain relief but also on quadriceps strengthening through resistance training to avoid subsequent injuries in athletes with PT.

Increasing or decreasing load during resistance training is not associated with changes in pain among individuals with patellar tendinopathy: a randomized crossover study

OBJECTIVES

This study investigated whether exercising with different relative loads would be associated with different experienced pain intensities in individuals with patellar tendinopathy.

MATERIALS AND METHODS

We recruited 14 individuals with patellar tendinopathy for this randomized crossover study. In a randomized order, participants performed one set of single-legged leg presses during one session with three relative loads (6 repetition maximum (RM), 10RM, and 14RM). The primary outcome was pain during exercise measured on a 0-10 Numerical Rating Scale (NRS) (0 = no pain, 10 = worst pain), which participants rated after performing the exercise set with each relative load.

RESULTS

No differences in pain during either of the three relative loads were observed (F(2, 26) = 0.06, p = 0.942). The participants' experienced pain was 4.5 NRS (SD1.7), 4.5 NRS (SD1.7), and 4.6 NRS (SD2.0) during the 6RM, 10RM, and 14RM loads, respectively. A secondary analysis revealed no statistically significant difference in pain intensity between the performance of the first, second, or third exercise set regardless of the load (F(2, 26) = 1.06, p = 0.367).

CONCLUSIONS

There was no difference in pain intensity during either relative load among individuals with patellar tendinopathy. Therefore, higher loads may be applied, associated with enhanced tendon adaptation.

Incidence of lower limb tendinopathy: A 3-year prospective study of a youth elite athletes in a Brazilian sport club

INTRODUCTION

The purpose of this study was to investigate lower limb tendinopathy incidence over 3 seasons in Brazilian youth elite athletes.

DESIGN

Prospective epidemiological study.

METHODS

A prospective study was performed during 2015, 2016 and 2017 seasons, with a total of 1553 Brazilian youth athletes (1.195 male and 358 female) out of 6 sports (volleyball, basketball, judo, gymnastics, tennis and futsal). The mean age was 14.1 (11.2; 17.0) years, mean height was 1.75 (1.55; 1.95) meters and mean body mass was 59.4 (42.0; 76.4) kilograms. The diagnosis of lower limb tendinopathy (LLT) was made by an experienced sports physician based on a detailed history and clinical exam. The incidence of LLT was determined by number of injuries/total exposure hours x 1000.

RESULTS

In total, 100 LLT were recorded during the 3 seasons. The most frequent type of LLT was patellar (79%), adductor (12%) and Achilles (9%). The frequency of patellar tendinopathy was higher in male's volleyball, basketball and female volleyball (41%, 25%, 13%, respectively) and the frequency of Achilles tendinopathy was higher in basketball and female volleyball (33%,22%). The LLT incidence was 2.5/1000h in 2015, 4.2/1000h in 2016 and 2.1/1000h in 2017.

CONCLUSION

Lower limb tendinopathies are relatively common in youth elite athletes. In 3-season, the most frequent type was patellar tendinopathy. A higher LLT incidence was observed in male volleyball athletes when compared to female volleyball athletes. Basketball athletes presented a higher frequency of patellar, adductor and Achilles tendinopathies in 3-seasons when compared to other sports.

Changes in patellar tendon complaints and shear wave velocity patterns among competitive alpine skiers during a 4-year post-growth spurt follow-up

Patellar tendon (PT) complaints are frequent in competitive alpine skiers and such complaints are characterized by a long-lasting affection. Since PTs are subject to maturation up to 1-2 years after growth spurt, this early career stage may be decisive for the further course of complaints. The aim of this study was to investigate the evolution of PT complaints and shear wave velocity patterns among competitive alpine skiers during a 4-year post-growth spurt follow-up. The PT complaints and SWV patterns of forty-seven skiers were analysed at baseline (i.e., immediately after their peak height growth at 13-15 years of age) and were re-analysed at 4-year follow-up. The PTs were scanned via three-dimensional SWE. Symptomatic skiers were identified based on pain sensation under loading and pressure-induced pain around the PT. The prevalence of PT complaints decreased from 29.8% at baseline to 12.8% at follow-up (Pearson's χ2 = 9.429; p = 0.002). SWV decreased from the baseline assessment to the follow-up in the proximal and distal regions (p < 0.05). SWV coefficient of variation (CV) in the distal and mid-portion regions was greater at baseline than at follow-up (p < 0.05). At the follow-up assessment, compared to "healthy" skiers, "healed" skiers who recovered from PT complaints had lower SWVs in the proximal region (p = 0.020) and greater SWV CVs in the proximal region (p = 0.028). Moreover, symptomatic skiers had significantly greater SWV CVs in the mid-portion region than did "healthy" subjects with no history of PT complaints (p = 0.020). The average SWV was negatively correlated with the SWV (proximal: r = -0.74, p < 0.001; mid-portion: r = -0.37 p = 0.011; and distal: r = -0.58, p < 0.001). The occurrence of PT complaints decreased over a 4-year post-growth spurt follow-up. "Healed" skiers who were symptomatic at baseline had an even greater average decrease in the proximal and mid-portion SWV than "healthy" skiers with no history of PT complaints. This may lead to the hypothesis that PT complaints in adolescent skiers are not self-eliminating towards the end of adolescence, as at least structural irregularities appear to persist for several years after the onset of initial symptoms. Furthermore, "healed" and symptomatic tendons exhibited increased SWV variability, supporting the hypothesis that SWV CV may provide additional valuable information on the mechanical properties of PTs affected by overuse-related complaints.

Histological differences in cartilage layer growth at various tendon and ligament insertions in rabbits

Objectives: Histological differences in cartilage layer growth in Achilles tendon (AT), quadriceps tendon (QT), patellar tendon (PT), and anterior cruciate ligament (ACL) insertion are unclear. Therefore, this study aimed to investigate the differences in cartilage layer growth in AT, QT, PT, and ACL insertions. Materials and Methods: Forty-eight male Japanese white rabbits were used. Six animals were euthanized at different stages (day 1 and 1, 2, 4, 6, 8, 12, and 24 weeks). Safranin O-stained glycosaminoglycan (GAG) production area, chondrocyte count, and insertion width were investigated. Results: A two-way analysis of variance (ANOVA) revealed a significant difference in the main effects of time and insertion for all parameters. In addition, the time × insertion interaction was significant. Multiple comparisons showed a significant difference between the ACL insertion and all other variables; however, the GAG production area was not significantly different for the QT, PT, and AT insertions. AT insertions were significantly different from all other groups; however, the number of chondrocytes and insertion width were not significantly different for ACL, QT, and PT insertions. Conclusion: Cartilage layer growth differed between the AT, QT, PT, and ACL insertions. The differences between the insertions may also be due to the differences in their structures, locations, and mechanical environments.

Patellar height: an important parameter in knee MRI associated with tendinopathy, quadriceps fat pad edema (QFPE), anterior cruciate ligament mucoid degeneration (ACL-MD), and lateral cartilage damage

BACKGROUND

Some pathologies associated with abnormal patellar height have been reported in the literature. However, its relationship with some pathologies, such as anterior cruciate ligament mucoid degeneration (ACL-MD) and focal cartilage defect, has not been investigated.

PURPOSE

To investigate the relationship between patellar height with patellar-quadriceps tendinopathy, quadriceps fat pad edema, ACL-MD, and focal cartilage defect.

MATERIAL AND METHODS

Magnetic resonance imaging of the knees of 261 patients were classified into three groups as normal, patella alta, and patella baja, and evaluated in terms of patellar-quadriceps tendinopathy, quadriceps fat pad edema, ACL-MD, and focal cartilage defect.

RESULTS

There were 261 patients (140 men, 121 women; age range = 18-60 years; mean age = 30 ± 4.7 years). Of the 261 patients, 181 (69.3%) were normal, 56 (21.4%) were patella alta, and 24 were patella baja (9.1%). Patellar-quadriceps tendinopathy, quadriceps fat pad edema, and ACL-MD rates were significantly higher compared to the normal group (P <0.05). While a moderate positive correlation was found between patellar height shift and patellar-quadriceps tendinopathy and ACL-MD, there was a small correlation between patellar height shift and quadriceps fat pad edema. The rate of focal cartilage defect was significantly higher in the middle part of the lateral femoral condyle and lateral knee joint only in patella alta.

CONCLUSION

The risk of patellar-quadriceps tendinopathy, quadriceps fat pad edema, ACL-MD, and lateral focal cartilage defect is higher in patients with alta-baja. The radiologist should evaluate these pathologies more carefully, especially subtle ones, in patients with abnormal patellar height.

Rehabilitation exercise program after surgical treatment of patellar tendon rupture: A case report

OBJECTIVE

This case report describes in detail a rehabilitation and exercise program following surgical treatment of patellar tendon rupture and offers postoperative therapeutic goals and recommendations, with the aim of expediting the resumption of activities of daily living and sports participation following the surgical procedure. In addition, this report analyzes the cause of the patellar tendon rupture in this case.

DESIGN

Case report.

PARTICIPANTS

The patient, a 25-year-old male recreational athlete (height: 184 cm; weight: 80 kg; right-hand dominant), experienced a complete rupture of the patellar tendon upon landing on the left lower extremity during an unopposed dribble turn.

REHABILITATION EXERCISE PROGRAM

A well-structured rehabilitation program was implemented. Passive knee flexion range of motion (ROM) exceeded 90° at week 5 and was fully recovered at week 16. A second surgery was performed at week 19 to remove the decompression wires, and the patient progressively resumed basic physical and specialized training at 7 months post-surgery.

MAIN OUTCOME MEASURES

Morphometric and functional tests were performed to measure the effectiveness of rehabilitation throughout the postoperative process.

CONCLUSIONS

Early surgical repair and an immediate postoperative rehabilitation program have a positive impact on knee ROM, function, and muscle strength. The causes of the patellar tendon rupture in this patient included long-standing uncontrolled patellar tendinopathy, impaired mobility of the ankle and hip joints, poor landing technique, and muscle strength imbalances.

A Novel Tendon Injury Model, Induced by Collagenase Administration Combined with a Thermo-Responsive Hydrogel in Rats, Reproduces the Pathogenesis of Human Degenerative Tendinopathy

Patellar tendinopathy is a common clinical problem, but its underlying pathophysiology remains poorly understood, primarily due to the absence of a representative experimental model. The most widely used method to generate such a model is collagenase injection, although this method possesses limitations. We developed an optimized rat model of patellar tendinopathy via the ultrasound-guided injection of collagenase mixed with a thermo-responsive Pluronic hydrogel into the patellar tendon of sixty male Wistar rats. All analyses were carried out at 3, 7, 14, 30, and 60 days post-injury. We confirmed that our rat model reproduced the pathophysiology observed in human patients through analyses of ultrasonography, histology, immunofluorescence, and biomechanical parameters. Tendons that were injured by the injection of the collagenase-Pluronic mixture exhibited a significant increase in the cross-sectional area (p < 0.01), a high degree of tissue disorganization and hypercellularity, significantly strong neovascularization (p < 0.01), important changes in the levels of types I and III collagen expression, and the organization and presence of intra-tendinous calcifications. Decreases in the maximum rupture force and stiffness were also observed. These results demonstrate that our model replicates the key features observed in human patellar tendinopathy. Collagenase is evenly distributed, as the Pluronic hydrogel prevents its leakage and thus, damage to surrounding tissues. Therefore, this model is valuable for testing new treatments for patellar tendinopathy.

Adaptive neuro-fuzzy inference system model driven by the non-negative matrix factorization-extracted muscle synergy patterns to estimate lower limb joint movements

BACKGROUND AND OBJECTIVE

For patients with movement disorders, the main clinical focus is on exercise rehabilitation to help recover lost motor function, which is achieved by relevant assisted equipment. The basis for seamless control of the assisted equipment is to achieve accurate inference of the user's movement intentions in the human-machine interface. This study proposed a novel movement intention detection technology for estimating lower limb joint continuous kinematic variables following muscle synergy patterns, to develop applications for more efficient assisted rehabilitation training.

METHODS

This study recruited 16 healthy males and 16 male patients with symptomatic patellar tendinopathy (VISA-P: 59.1 ± 8.7). The surface electromyography of 12 muscles and lower limb joint kinematic and kinetic data from healthy subjects and patients during step-off landings from 30 cm-high stair steps were collected. We subsequently solved the preprocessed data based on the established recursive model of second-order differential equation to obtain the muscle activation matrix, and then imported it into the non-negative matrix factorization model to obtain the muscle synergy matrix. Finally, the lower limb neuromuscular synergy pattern was then imported into the developed adaptive neuro-fuzzy inference system non-linear regression model to estimate the human movement intention during this movement pattern.

RESULTS

Six muscle synergies were determined to construct the muscle synergy pattern driven ANFIS model. Three fuzzy rules were determined in most estimation cases. Combining the results of the four error indicators across the estimated variables indicates that the current model has excellent estimated performance in estimating lower limb joint movement. The estimation errors between the healthy (Angle: R2=0.98±0.03; Torque: R2=0.96±0.04) and patient (Angle: R2=0.98±0.02; Torque: R2=0.96±0.03) groups are consistent.

CONCLUSION

The proposed model of this study can accurately and reliably estimate lower limb joint movements, and the effectiveness will also be radiated to the patient group. This revealed that our models also have certain advantages in the recognition of motor intentions in patients with relevant movement disorders. Future work from this study can be focused on sports rehabilitation in the clinical field by achieving more flexible and precise movement control of the lower limb assisted equipment to help the rehabilitation of patients.

The Basas Spanish Squat: Superimposition of Electrical Stimulation to Optimize Patellar Tendon Strain: A Case Series

Background

The Basas Spanish Squat with electrical stimulation (E-stim) has shown promising results as a potential key exercise in treatment of athletes with patellar tendinopathy. Gold standard exercise therapy for tendon injuries consists of tendon loading exercises, or exercises that appropriately applies high levels of mechanical strain to the tendon. The theoretical pathway in which the Basas Spanish Squat with E-stim improves tendinopathy has been speculated to be the additional strain applied through the patellar tendon during superimposition of E-stim. This theory, however, has yet to be confirmed.

Purpose

The purpose of this case series was to compare patellar tendon strain, during the Basas Spanish Squat with, and without E-stim, and open kinetic chain knee extension.

Methods

Four healthy participants performed the three exercises while a physical therapist collected simultaneous unilateral ultrasound images from the patellar tendon. Strain was calculated as the change in patellar tendon length during contraction divided by the resting length.

Results

Amongst all participants, patellar tendon strain was smallest during the Basas Spanish Squat without E-stim, followed by the open kinetic chain knee extension at 60% maximum voluntary isometric contraction. The Basas Spanish Squat with E-stim yielded approximately double or more strain compared to the without E-stim condition and demonstrated higher level of strain compared to open kinetic chain knee extension in all participants.

Conclusion

The findings reflect a clear trend of increased strain through the patellar tendon when E-stim was superimposed. The results support the theory that the Basas Spanish Squat with E-stim increases patellar tendon strain and could explain the reported clinical benefits in individuals with patellar tendinopathy.

Level of Evidence

4, Case series.

Evidence for exercise therapy in patients with hand and wrist tendinopathy is limited: A systematic review

BACKGROUND

Several studies reported the efficacy of exercise therapy in hand and wrist tendinopathy. However, no systematic review synthesized the effect of exercise therapy on these patients.

PURPOSE

This study aimed to perform a systematic review to summarize evidence if exercise therapy may be considered an effective treatment in conservative management for patients with hand and wrist tendinopathy.

STUDY DESIGN

This was a systematic review.

METHODS

A literature search in MEDLINE, Cochrane Library, PEDro, and Embase was conducted from their inception until April 10, 2022. Two independent reviewers included the studies administering exercise therapy in patients with hand and/or wrist tendinopathy in the review and extrapolated the data. Methodological quality was assessed using the framework developed by Murad et al for case reports and case series and the PEDro score for clinical trials.

RESULTS

Seven case reports, 3 case series, and 2 randomized controlled studies were included and methodologically evaluated, obtaining a low score for all the analyzed studies. The total number of included patients in the analyzed studies was 106, of which 54 were female, 13 were male, and 39 were not specified. The type of exercise was widespread and often not really well described: it varies from eccentric forearm training to mobilization with movement, passing through strengthening exercises, grip proprioception training, and self-management exercises according to the McKenzie method. The dosage was often not precise, making it difficult to reproduce the therapeutic proposals. Exercise therapy was always administered together with different treatments; therefore, its efficacy alone is difficult to distinguish, although in some cases, the patients improved pain and functionality.

CONCLUSIONS

Evidence on the efficacy of exercise therapy in patients with hand and wrist tendinopathies is limited. Future research is strongly recommended to determine the appropriate dosage of the exercise therapy to determine clinical changes in these patients.

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.

Bibliometric Analysis of the Top 50 Most Influential Studies on Patellar Tendon Injury

Background

There is a wide range of literature on patellar tendon injury, making it increasingly difficult to stay informed on the most influential studies in this field. It is essential to be familiar with the foundational articles of patellar tendon injury research to understand the current state of the literature and deliver high quality care.

Purpose

To objectively identify the 50 most influential articles relating to patellar tendon injury and conduct a bibliometric analysis to identify key features of these articles.

Study Design

Cross-sectional study.

Methods

The Clarivate Analytics Web of Knowledge database was utilized to gather metrics on the 50 most cited articles on patellar tendon injury on June 27, 2022. The information extracted from each article included publication year, number of citations, author information, article type, level of evidence, country of origin, journal name, study focus, and industry influence.

Results

The top 50 studies were cited a total of 8543 times and published between 1977 and 2015. The majority of articles were published after 2003, and the majority of citations were accrued after 2011. The most prevalent article types were cohort studies (n = 23), and the majority of studies were of evidence level 2 (n = 14) or 4 (n = 13). Australia and the United States (US) each published the most studies (n = 11). Only 4 (8%) studies focused on patellar tendon rupture, and 12 (24%) of the top 50 studies were associated with industry.

Conclusion

The majority of the top 50 most influential articles in patellar tendon injury were published and accumulated citations in the past 10 to 20 years. Non-US countries, institutions, and journals published many of the top 50 studies, reflecting a global interest and commitment to research in this field. Patellar tendon rupture and surgical repair represents a minority of research in the top 50 studies and could be a point of growth in the future.

Epidemiology of Patellar Tendinopathy in Athletes and the General Population: A Systematic Review and Meta-analysis

Background

Patellar tendinopathy (PT) mainly affects athletes who use the tendon for repeated energy storage and release activities. It can have a striking impact on athletes' careers, although data on its real prevalence and incidence are sparse. Research efforts should start from the results of reliable and updated epidemiological research to help better understand the impact of PT and underpin preventative measures.

Purpose

To determine the prevalence and incidence of PT in athletes and the general population.

Design

Systematic review; Level of evidence, 3.

Methods

A systematic review of the literature was performed on January 17, 2022, and conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The PubMed, Web of Science, and Wiley Cochrane Library databases were searched for epidemiological reports of any evidence level and clinical studies reporting data on the incidence or prevalence of PT for the 11,488 retrieved records. The primary endpoint was the prevalence and incidence of PT in sport-active patients. The secondary endpoints were PT prevalence and incidence in subgroups of athletes based on sex, age, sport type, and sport level played, as well as the same epidemiological measures in the general population.

Results

A total of 28 studies, with 28,171 participants, were selected and used for the qualitative and quantitative analysis. The general and athletes' populations reported an overall PT prevalence of 0.1% and 18.3%, respectively. In athletes, the prevalence of PT was 11.2% in women and 17% in men (P = .070). The prevalence of PT in athletes <18 years was 10.1%, while it was 21.3% in athletes ≥18 years (P = .004). The prevalence of PT was 6.1% in soccer players, 20.8% in basketball players, and 24.8% in volleyball players. Heterogeneous PT diagnostic approaches were observed. Higher prevalence values were found when PT diagnoses were made using patient-reported outcomes versus clinical evaluations (P = .004).

Conclusion

This review demonstrated that PT is a common problem in the male and female sport-active populations. There are twice as many athletes aged ≥18 years than there are <18 years. Volleyball and basketball players are most affected by PT.

MRI Characteristics and Alterations in Patellar Height in Patients with Patellar Tendinopathy-A Retrospective Study

(1) Background: Patellar tendinopathy (PT) is an overuse condition of the knee extensor mechanism characterized by ventral knee pain at the lower pole of the patella and limited functionality. (2) Methods: In this retrospective study, a group of patients with PT (n = 41) was compared with a control group (n = 50) in terms of patient-related data and magnetic resonance imaging (MRI) characteristics. (3) Results: Patellar height was higher in the PT patient group and there was a significant difference in Caton-Deschamps index (CD) compared to the control group (p = 0.021). Patients with PT showed a lower patella-patellar tendon angle (PPTA) (p = 0.011). The patellar tendon thickness (PTT) in the proximal (PTTprox), middle (PTTmid) and distal (PTTdistal) part of the tendon was significantly thickened (p < 0.001). Increased signal intensity in MRI was detected in symptomatic tendons over 6 months compared to a duration of less than 6 months (p = 0.025). A significant relationship between the PTTprox and an increased signal intensity was observed (p < 0.001). (4) Conclusions: Patients with PT showed a significant difference in the patellar height and PPTA. With persistence of symptoms over 6 months, MRI seems suitable to detect the morphologic tendon changes and further identify patients suitable for surgical procedures.

Efficacy of Proprioceptive Training on Plantar Pressure and Jump Performance in Volleyball Players: A Proof-of-Principle Study

Volleyball players are often subject to micro-traumatisms of the heel fat pad and ankle injuries. Recently, mat-based proprioceptive training has assumed a key role in recovery from these disorders. Therefore, this proof-of-principle study aimed to assess the efficacy of proprioceptive mat training on plantar pressures and athletic performance in volleyball players. The participants included adult semi-professional volleyball players allocated into two groups: an experimental group, with mat-based proprioceptive and balance training, and a control group, with a sham protocol. For the outcome, we evaluated the barefoot plantar pressure, performing an analysis on a baropodometric resistive platform. The countermovement jump and squat jump were measured using an inertial measurement unit. Nineteen subjects were included in the two groups: the active proprioceptive group (n = 10) or the control group (n = 9). The results show a more uniform redistribution of loads with pressure hindfoot relief in the experimental group compared to the control group (p = 0.021, RBC = 0.67). Moreover, we observed a significant increase in peak landing force and high concentric power development in the experimental group compared to the controls. Focused proprioceptive management provided hindfoot load attenuation by stimulating higher peaks of concentric force in the experimental group compared to the sham group. Even though the study included a small sample, the results obtained in this proof-of-principle study suggest a positive role of proprioceptive stimulation in the inter-seasonal scenario for volleyball players to improve their jump performance and reduce the micro-traumatisms of the heel fat pad and the ankle injury rate. However, further studies performed on larger samples are needed to confirm these preliminary results.

The use of physical function capacity measures in the management of lower limb tendinopathy: A scoping review of expert recommendations

BACKGROUND

Physical function capacity measures are recommended as outcome measures for people with lower limb tendinopathy.

OBJECTIVE

(i) Explore measures of physical function capacity recommended by experts in lower limb tendinopathy (ii) the context they were used, (ii) identify recommended criteria for exercise progression and return to sport or activity.

DESIGN

Scoping Review.

METHOD

Three databases were searched using keywords for lower limb tendinopathy and physical function capacity to identify studies that outlined a progressive exercise rehabilitation program. A 15-item tool was used for data extraction.

RESULTS

26 studies were included, only eight recommended a physical function capacity measure. There were 10 physical function capacity measures identified for a range of lower limb tendinopathies including patellar (50%), Achilles (13%), proximal hamstring (13%), gluteal (13%), combined patellar and Achilles (13%). Pain was the most common criterion that was used to determine the progression of rehabilitation (96%), with physical function capacity measures rarely used (12%).

CONCLUSION

Physical function capacity measures are used infrequently across expert recommended exercise rehabilitation programs. There remains a high reliance on pain as the criterion for progression of exercises during rehabilitation. There is a need to develop measures of physical function capacity to better inform and progress rehabilitation.

Patellar ligament desmopathy in the horse – a review and comparison to human patellar tendinopathy (‘Jumper’s knee’)

Patellar ligament desmopathy in horses is regarded as an uncommon condition with unclear aetiology. Of the three patellar ligaments in the horse, the intermediate is the one most often diagnosed with desmopathy in horses presenting with chronic lameness. This structure corresponds to the patellar tendon in humans. As diagnostic imaging modalities continuously improve, changes in echogenicity of the patellar ligaments are identified ultrasonographically with increasing frequency. However, disruption of the normal fibre pattern may be present also in patellar ligaments in horses that show no signs of lameness. Similarly, there is a poor correlation between pain and diagnostic imaging findings in human patellar tendinopathy. Consequently, there appears to be a knowledge gap pertaining to normal ultrasonographic variation and diagnostic criteria for disease of the patellar ligaments in horses. Furthermore, local anaesthetic techniques to verify the diagnosis are poorly described, and due to the low number of treated cases, no specific treatment modality can be recommended on a scientific basis. The aim of this paper is to review the current knowledge regarding the pathogenesis, diagnosis and management of patellar ligament desmopathy in horses, compare this condition with patellar tendinopathy in humans, and identify areas for further research to increase the diagnostic accuracy in horses. We conclude that there is a profound need for better descriptions of ultrasonographic variation and pathological changes of the equine patellar ligaments. Identification of areas of maximal ligament strain and descriptions of early histopathological changes could render more information on the possible aetiology, preventive measurements and treatment options of desmopathy. Description of regional innervation could aid in development of methods for diagnostic anaesthesia to verify pain originating from the ligaments.

Treatment of Jumper’s Knee with Extracorporeal Shockwave Therapy: A Systematic Review and Meta-Analysis

The aim of this systematic review and meta-analysis was to determine the therapeutic efficacy of extracorporeal shockwave therapy (ESWT) for athletes with patellar tendinopathy. We searched PubMed, EBSCOHost and Ovid for randomized controlled trials (RCTs) which evaluated the therapeutic efficacy of ESWT in athletes with jumper’s knee. The methodological quality of RCTs was rated with the Physiotherapy Evidence Database scale. Data in the meta-analysis were expressed as standardized mean difference (SMDs) and 95% confidence intervals (CIs). Heterogeneity was assessed with I2 statistics. Of 192 records identified, a total of seven articles met the inclusion criteria. The ESWT and control groups with any other conservative treatment did not differ significantly with respect to the Visual Analogue Scale (VAS) long-term scores obtained at ≥ 6 months of therapy completion (SMD: -0.33; 95% CI: -4.64 to 3.98; p = 0.87; I2= 98%). Furthermore, no significant differences were found between the ESWT and control groups regarding the pooled Victorian Institute of Sports Assessment for Patella (VISA-P) scores for long-term outcomes (SMD: 8.21; 95% CI: -39.3 to 55.73; p = 0.73; I2= 99%). The ESWT and control groups did not differ significantly on the VAS and VISA-P scores for long-term outcomes. In both cases, heterogeneity was considered to be high. Hence, no clear and generalized conclusions can be drawn regarding ESWT effectiveness in athletes with patellar tendinopathy.

Two-Experiment Examination of Habitual and Manipulated Foot Placement Angles on the Kinetics, Kinematics, and Muscle Forces of the Barbell Back Squat in Male Lifters

This two-experiment study aimed to examine the effects of different habitual foot placement angles and also the effects of manipulating the foot placement angle on the kinetics, three-dimensional kinematics and muscle forces of the squat. In experiment 1, seventy lifters completed squats at 70% of their one repetition maximum using a self-preferred placement angle. They were separated based on their habitual foot angle into three groups HIGH, MEDIUM and LOW. In experiment 2, twenty lifters performed squats using the same relative mass in four different foot placement angle conditions (0°, 21°, 42° and control). Three-dimensional kinematics were measured using an eight-camera motion analysis system, ground reaction forces (GRF) using a force platform, and muscle forces using musculoskeletal modelling techniques. In experiment 1, the impulse of the medial GRF, in the descent and ascent phases, was significantly greater in the HIGH group compared to LOW, and in experiment 2 statistically greater in the 42° compared to the 21°, 0° and control conditions. Experiment 2 showed that the control condition statistically increased quadriceps muscle forces in relation to 0°, whereas the 0° condition significantly enhanced gluteus maximus, gastrocnemius and soleus forces compared to control. In experiment 1, patellofemoral joint stress was significantly greater in the HIGH group compared to LOW, and in experiment 2, patellar and patellofemoral loading were statistically greater in the control compared to the 42°, 21°, 0° and control conditions. Owing to the greater medial GRF's, increased foot placement angles may improve physical preparedness for sprint performance and rapid changes of direction. Reducing the foot angle may attenuate the biomechanical mechanisms linked to the aetiology of knee pathologies and to promote gluteus maximus, gastrocnemius and soleus muscular development. As such, though there does not appear to be an optimal foot placement angle, the observations from this study can be utilised by both strength and conditioning and sports therapy practitioners seeking to maximise training and rehabilitative adaptations.

A Population-Level Summary of Health Care Utilization for the Management of Patellar Tendinopathy in the Military Health System

Patellar tendinopathy (PT) is a common nontraumatic orthopaedic disorder of the knee suffered by many service members. Understanding the make-up of usual care for PT at the system level can better frame current clinical gaps and areas that need improvement. Exercise therapy is recommended as a core treatment for PT, but it is unclear how often it is used as a part of usual care for PT within the Military Health System (MHS). The purpose of the study was to identify interventions used in the management of PT and the timing of these interventions. A secondary purpose was to determine if exercise therapy use was associated with reduced recurrence of knee pain. In total, 4,719 individuals aged 17 to 50 years in the MHS diagnosed with PT between 2010 and 2011 were included. Pharmacological and nonpharmacological interventions, visits to specialty providers, and imaging services were captured. Descriptive statistics were used to report the findings. Interventions were further categorized as being part of initial care (within the first 7 days), the initial episode of care (within the first 60 days), or the 2-year time period after diagnosis. Linear regression assessed the relationship between the number of exercise therapy visits in the initial episode of care and recurrences of knee pain. In total, 50.6% of this cohort had no more than one medical visit total for PT. Exercise therapy (18.2%) and nonsteroidal anti-inflammatory drugs (4.3%) were the two most used interventions in the initial episode of care. Radiographs were ordered for 23.1% of the cohort in the initial episode of care. The number of exercise therapy visits a patient received during the initial episode of care was not associated with recurrences of knee pain. Half of the individuals received no further care beyond an initial visit for the diagnosis of PT. Exercise therapy was the most common intervention used during the initial episode of care, but exercise therapy did not influence the recurrence of knee pain.

Interventions for prevention and in-season management of patellar tendinopathy in athletes: A scoping review

INTRODUCTION

Patellar tendinopathy (PT) has a high prevalence in jumping athletes and presents a significant burden on athletes and clinicians due to its long-lasting duration and persistent symptoms. This scoping review aimed to map existing evidence on prevention and in-season management interventions for PT in athletes, evaluating intervention parameters and outcomes.

METHODS

This scoping review was reported in accordance with the PRISMA-ScR. Databases searched included MEDLINE, CINAHL, AMED, EMBase, SPORTDiscus, and the Cochrane library (Controlled trials, Systematic reviews). All primary study designs investigating prevention or in-season management interventions for PT, while maintaining athletes in sport were considered for inclusion.

RESULTS

5987 articles were identified with 29 included in the review. Five studies investigated exercise-based prevention interventions on athletes at risk for PT, including two randomized controlled trials (RCTs), two cohort studies and one case-control study. 24 studies investigated in-season management or rehabilitation in athletes with PT, including 18 RCTs, three case reports, one cohort study, one case series, and one retrospective review. Of these 24 studies, 22 used various resistance training interventions, one used ESWT and one used patellar strapping and taping. The types of resistance training included eccentric, heavy-slow, isometric, inertial flywheel, blood-flow restriction, and isotonic training. Eccentric training was used in 9 studies, with single leg decline squats the most common exercise used in 7 studies. Outcome measures and intervention parameters were heterogenous throughout studies.

CONCLUSION

Despite a dearth of studies on preventative interventions for athletes with PT, resistance training may be a useful prophylactic method. Eccentric, heavy slow and isometric resistance training have been found to be feasible and clinically beneficial in-season. There are a lack of studies showing that ESWT offers any additional benefit over resistance training in competing athletes. Patellar strapping and taping may offer short-term pain relief during training and competition. Systematic reviews are required to make definitive recommendations for PT.

Patellar Tendinopathy—Does Injection Therapy Have a Role? A Systematic Review of Randomised Control Trials

Injection treatment is one of the most widely used methods for the conservative management of patellar tendinopathy. The objective of this systematic review was to synthesise data from randomised control trails on the effectiveness of various injections used in the management of patellar tendinopathy. An electronic search was conducted in the Web of Science, Scopus, PubMed, and SPORTDiscus databases. To be included in the current systematic review, the study had to be an RCT conducted on human participants that investigated the effect of at least one injection treatment on the management of patellar tendinopathy. Selected studies were required to report either patient-reported outcomes or biological and clinical markers of the tendon healing. The methodological quality of the studies was appraised using the revised Cochrane risk of bias tool for RCTs (RoB 2.0). Nine RCTs on seven types of injections were included in this review, with an overall positive outcome. Pain intensity was measured in all the studies. The VISA P score was the most used outcome measure (n = 8). A wide variety of interventions were compared with injection therapy, including eccentric training, extracorporeal shockwave, and arthroscopy. It can be concluded that the injection treatments can produce promising results in the management of patellar tendinopathy. However, because of the limited number of studies and the disparities in the study populations and protocols, it is not possible to make a firm conclusion on the efficacy of these injection methods, and these results should be inferred with care.

Current understanding of the diagnosis and management of the tendinopathy: An update from the lab to the clinical practice

Tendinopathy is labeled by many authors as a troublesome, common pathology, present in up to 30% medical care consultations involving musculoskeletal conditions. Despite the lasting interest for addressing tendon pathology, current researchers agree that even the exact definition of the term tendinopathy is unclear. Tendinopathy is currently diagnosed as a clinical hypothesis based on the patient symptoms and physical context. One of the main goals of current clinical management is to personalize treatment approaches to adapt them to the many different needs of the population. Tendons are complex structures that unite muscles and bones with two main objectives: to transmit forces and storage and release energy. Regarding the tensile properties of the tendons, several authors argued that tendons have higher tensile strength compared with muscles, however, are considered less flexible. Tendinopathy is an accepted term which is used to indicated a variety of tissue conditions that appear in injured tendons and describes a non-rupture damage in the tendon or paratendon, which is intensified with mechanical loading Even when the pathoetiology of tendinopathy is unclear, there is a wide array of treatments available to treat and manage tendinopathy. Although tendinitis usually debuts with an inflammatory response, the majority of chronic tendinopathies do not present inflammation and so the choosing of treatment should vary depending on severity, compliance, pain and duration of symptoms. The purpose of this article is to review and provide an overview about the currently research of the tendon diagnosis, management and etiology.

Management of Patellar Tendinopathy Through Monitoring, Load Control, and Therapeutic Exercise: A Systematic Review

CONTEXT

Patellar tendinopathy presents with persistent tendon pain located in the lower pole of the patella and loss of function related to mechanical load. Although its pathogenesis is not completely clear, conservative treatment including exercise is the main intervention of patellar tendinopathy treatment.

OBJECTIVE

To describe the efficacy of patellar tendinopathy management through therapeutic exercise, and control and monitoring of loads.

EVIDENCE ACQUISITION

MEDLINE, WoS, Cochrane Plus, PEDro, and the gray literature were searched from inception to July 2021. Based on the PICO strategy, the inclusion criteria were clinical trials published in English or Spanish; outcomes of function, pain, and strength; patients with patellar tendinopathy with no age or gender limitations; using an active intervention; and at least a methodological quality equal to or greater than 3 points on the Jadad scale. All data were analyzed by 2 independent reviewers (P.N.-M. and D.H.-G.). Studies were qualitatively synthesized using a descriptive synthesis. The methodological quality and risk of bias assessment were performed with the PEDro and Jadad scale, respectively.

EVIDENCE SYNTHESIS

A total of 136 articles were identified, of which 12 met the eligibility criteria. All of them were regarded as presenting a moderate risk of bias and their methodological quality was considered acceptable to good. Recovering patellar tendinopathy with therapeutic exercise seems to significantly improve function, pain, and strength after intervention and even lasted over time.

CONCLUSION

A treatment based on load monitoring and physical exercise has proven to be effective in rehabilitating patellar tendinopathy, with positive results in the short and medium term.

Tendinopathy and tendon material response to load: What we can learn from small animal studies

Tendinopathy is a debilitating disease that causes as much as 30% of all musculoskeletal consultations. Existing treatments for tendinopathy have variable efficacy, possibly due to incomplete characterization of the underlying pathophysiology. Mechanical load can have both beneficial and detrimental effects on tendon, as the overall tendon response depends on the degree, frequency, timing, and magnitude of the load. The clinical continuum model of tendinopathy offers insight into the late stages of tendinopathy, but it does not capture the subclinical tendinopathic changes that begin before pain or loss of function. Small animal models that use high tendon loading to mimic human tendinopathy may be able to fill this knowledge gap. The goal of this review is to summarize the insights from in-vivo animal studies of mechanically-induced tendinopathy and higher loading regimens into the mechanical, microstructural, and biological features that help characterize the continuum between normal tendon and tendinopathy. STATEMENT OF SIGNIFICANCE: This review summarizes the insights gained from in-vivo animal studies of mechanically-induced tendinopathy by evaluating the effect high loading regimens have on the mechanical, structural, and biological features of tendinopathy. A better understanding of the interplay between these realms could lead to improved patient management, especially in the presence of painful tendon.

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.

Substantiating the Use of Ultrasound Tissue Characterization in the Analysis of Tendon Structure: A Systematic Review

OBJECTIVE

To determine the role of ultrasound tissue characterization (UTC) in predicting, diagnosing, and monitoring tendon structure and/or tendinopathy. In addition, this study aims to provide recommendations for standardized methodology of UTC administration and analysis.

DATA SOURCE

The PubMed, Embase, and Web of Science databases were searched (up to September 2018). All scientific literature concerning the use of UTC in assessing tendons was collected. The initial search resulted in a total of 1972 hits, and after screening by eligibility criteria, 27 articles were included.

RESULTS

In total, 18 investigating the Achilles tendon, 5 the patellar tendon, and 4 both Achilles and patellar tendons were included. The methods of UTC administration and analysis differed and were not uniform. The studies showed that the use of UTC to predict Achilles tendinopathy (AT) is inconclusive, but that a higher amount of tendon disorganization increases the risk of developing patellar tendinopathy (PT). In terms of diagnosis, UTC might provide additional information in AT cases. In addition, promising results were found for the use of UTC in both AT and PT in monitoring the effect of load or treatment on tendon structure.

CONCLUSION

More research regarding the use of UTC in predicting tendon pathology is required. Ultrasound tissue characterization seems useful as an adjunct diagnostic modality because it can be used to differentiate symptomatic from asymptomatic tendons. In addition, UTC is a promising device to be used to monitor changes in tendon structure in response to load or treatment. Moreover, we provide recommendations of a standardized protocol concerning the methods of UTC measurement and analysis.

Rehabilitation and return to sport of a high-level track & field athlete with low back pain - a case report

INTRODUCTION: Low back pain is prevalent among elite athletes with initial high levels of physical activity. Currently, there is a lack of evidence describing the optimal management strategy of high-level track and field athletes presenting with low back pain. CASE DESCRIPTION: This case report describes the clinical management and return-to-sport strategies of a male high-level track and field athlete presenting with low back pain in an outpatient physiotherapy clinic. Mechanical diagnosis and therapy (MDT) served as an important tool in the clinical management of the athlete. Patient-Specific Function Scale (PSFS), an 11-point scale (0 = unable to perform activity to 10 = able to perform activity at preinjury level), was used during three activities: hammer throw, squats and getting socks and shoes on.OUTCOMES: Eight weeks after initial consultation (15 weeks after the index injury), the athlete returned to sport and competition at national championship-level. PFPS scores at final consultation: hammer throw - 10/10; squats - 10/10 and getting socks and shoes on - 10/10. CONCLUSION: In combination with modern rehabilitation strategies, MDT provided the opportunity to engage the athlete as an active collaborator, which is in accordance with current clinical guidelines and best practice.

Failed Surgery for Patellar Tendinopathy in Athletes: Midterm Results of Further Surgical Management

Background:

Tendon injuries are commonly seen in sports medicine practice. Many elite players involved in high-impact activities develop patellar tendinopathy (PT) symptoms. Of them, a small percentage will develop refractory PT and need to undergo surgery. In some of these patients, surgery does not resolve these symptoms.

Purpose:

To report the clinical results in a cohort of athletes who underwent further surgery after failure of primary surgery for PT.

Study Design:

Case series; Level of evidence, 4.

Methods:

A total of 22 athletes who had undergone revision surgery for failed surgical management of PT were enrolled in the present study. Symptom severity was assessed through the Victorian Institute of Sport Assessment Scale for Patellar Tendinopathy (VISA-P) upon admission and at the final follow-up. Time to return to training, time to return to competition, and complications were also recorded.

Results:

The mean age of the athletes was 25.4 years, and the mean symptom duration from the index intervention was 15.3 months. At a mean follow-up of 30.0 ± 4.9 months, the VISA-P score improved 27.8 points (P < .0001). The patients returned to training within a mean of 9.2 months. Fifteen patients (68.2%) returned to competition within a mean of 11.6 months. Of these 15 patients, a further 2 had decreased their performance, and 2 more had abandoned sports participation by the final follow-up. The overall rate of complications was 18.2%. One patient (4.5%) had a further revision procedure.

Conclusion:

Revision surgery was feasible and effective in patients in whom PT symptoms persisted after previous surgery for PT, achieving a statistically significant and clinically relevant improvement of the VISA-P score as well as an acceptable rate of return to sport at a follow-up of 30 months.

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.

Lower Extremities Strength Differences in Female Volleyball Players With Stage 1 Patellar Tendinopathy

Kabacinski, J, Murawa, M, Fryzowicz, A, Gorwa, J, and Dworak, LB. Lower extremities strength differences in female volleyball players with stage 1 patellar tendinopathy. J Strength Cond Res XX(X): 000-000, 2020-The main purpose of the study was to compare the muscle strength between the involved knee (IK) and uninvolved knee (UK) in 12 female volleyball players with stage 1 chronic patellar tendinopathy. Evaluation included the isometric maximal strength to body mass (MS/BM) of the lower extremities extensors for unilateral and bilateral conditions, concentric isokinetic peak torque to body mass (PT/BM) of the hamstrings and quadriceps at 60°·s and 180°·s, IK to UK extensors maximal strength ratio (SR), IK to UK hamstrings (or quadriceps) peak torque ratio (TR), and hamstrings to quadriceps peak TR (H/Q). The results indicated a significantly lower unilateral and bilateral MS/BM of lower extremities extensors for IK than UK (p < 0.001). However, there were no significant differences in SR variable between the unilateral condition and bilateral condition (p = 0.448). Only at the 60°·s velocity, significantly lower quadriceps PT/BM for IK compared with the UK (p < 0.001) and the control group (p < 0.001) were observed. Torque ratio related to the quadriceps group was significantly lower at 60°·s than 180°·s (p = 0.004). Furthermore, significantly higher H/Q for IK compared with UK (p < 0.001) and control group (p = 0.008) only at 60°·s was found. These findings show a significant isometric strength asymmetry for both unilateral and bilateral conditions and a significant concentric strength asymmetry at the low velocity. This study suggests strengthening the weaker quadriceps group and balancing the strength between hamstrings and quadriceps within the knee with patellar tendinopathy.

Deep Friction Massage in the Management of Patellar Tendinopathy in Athletes: Short-Term Clinical Outcomes

CONTEXT

Deep friction massage (DFM) is often used in the treatment of tendinopathies; however, the pressure applied may vary and interfere with the obtained results.

OBJECTIVE

To assess whether the immediate effects of DFM on pain (pain intensity and time to onset of analgesia) and muscle strength are dependent on the pressure applied during the DFM application in athletes with patellar tendinopathy.

DESIGN

Randomized, controlled, cross-over trial.

SETTING

University research laboratory (institutional).

PARTICIPANTS

Ten athletes with diagnosis of unilateral patellar tendinopathy (age 27.90 [5.24] y).

INTERVENTIONS

All participants attended 4 sessions, 3 treatment sessions with DFM applied with different pressures (the mean pressure-previously determined for each participant-and the mean pressure ± 25%) and a control session, each of which was separated by 48 hours.

MAIN OUTCOME MEASURES

Pain (intensity upon palpation and time to onset of analgesia), and muscle strength of knee extensors were assessed before and immediately after each session.

RESULTS

Pain intensity changed significantly over time (F1,9 = 52.364; P < .001; ηp2=.853) and among sessions (F3,27 = 82.588; P < .001; ηp2=.902), with a significant interaction for group × time (F3,27 = 19.841; P < .001; ηp2=.688). The knee extensors strength did not change significantly over time (F1,9 = 2.240; P = .17; ηp2=.199), nor a significant interaction for session × time was observed (F3,27 = 3.276; P = .07; ηp2=.267). Regardless of the pressure applied, the time to onset of analgesia was not significantly different (F2,18 = 1.026; P > .05; ηp2=.102).

CONCLUSION

It was shown that DFM induces an immediate reduction in pain intensity upon palpation, regardless of the pressure performed. Notwithstanding, the reader should take into account the small sample size and the caution needed in the results' interpretation.

The effect of Kinesio-tape® on pain and vertical jump performance in active individuals with patellar tendinopathy

BACKGROUND

Patellar tendinopathy is a common inflammatory condition in athletes who undergo large volumes of running and jumping. Kinesio-tape® (KT) is proposed to provide pain relief; however, its effect has not been examined on patellar tendinopathy.

OBJECTIVE

To examine the effects of KT on pain modulation for active individuals with patellar tendinopathy during functional activities.

METHODS

Thirteen symptomatic knees from seven college-aged females (6 bilateral; 1 unilateral) were included. Participants underwent three data collection sessions with KT, sham, and no tape (NT) in a randomized order. During the session, participants performed a maximum vertical jump, single-leg squats and isometric knee extension. The KT intervention was applied according to the KT manual and the sham utilized the same pattern without tension. Pain level was evaluated using the numeric pain scale before, during and after each activity. Function was assessed as maximum vertical jump height and maximum isometric strength. A separate repeated measures ANOVA was used to compare each dependent variable (pain level, vertical jump height, and isometric strength) among the conditions.

RESULTS

Reported pain scores were significantly lower (p = 0.05) during the maximal vertical jump test for KT (3.38 ± 1.26) compared to NT (4.54 ± 2.22). Significantly lower jump heights were found under KT (17.73 ± 3.06in) during the maximum vertical jump test compared to sham (18.65 ± 2.17in, p = 0.000) and NT (18.18 ± 2.93in, p = 0.008).

CONCLUSIONS

The use of the KT tape with a tendon corrective strip and muscle facilitative strip was effective for decreasing pain associated with patellar tendinopathy during jump landing but led to decreased maximum jump height.

CLINICAL TRIAL IDENTIFIER

NCT04153877.

Quadriceps tendon anterior cruciate ligament reconstruction

Quadriceps tendon is a promising alternative graft option for anterior cruciate ligament (ACL) reconstruction, which can be harvested with or without a bone block as well as a full or partial thickness graft. Therefore, quadriceps tendon graft could be used in primary and revision ACL reconstruction based on the requirements (tunnel size, tunnel position, etc.). The all soft tissue, partial thickness quadriceps tendon graft in detail and pitfalls of the harvest are described in the present review. After quadriceps tendon harvest, especially in soccer players, who need a strong quadriceps to strike a ball with power, the postoperative rehabilitation may need to be adapted. LEVEL OF EVIDENCE: V.

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

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

Association Between Clinical and Imaging Outcomes After Therapeutic Loading Exercise in Patients Diagnosed With Achilles or Patellar Tendinopathy at Short- and Long-Term Follow-up: A Systematic Review

OBJECTIVE

To determine the association between clinical and imaging outcomes after therapeutic loading exercise in Achilles tendinopathy (AT) and patellar tendinopathy (PT) populations at both short- and long-term follow-up.

DATA SOURCES

The PUBMED and EMBASE databases were searched (up to June 2017) to identify articles that meet the inclusion criteria: (1) patients diagnosed with AT (insertional or midportion) or PT; (2) rehabilitation based on therapeutic loading exercise; and (3) assessment of clinical outcomes and tendon structure using an imaging modality.

MAIN RESULTS

Two independent reviewers screened 2894 search results, identifying 21 suitable studies. According to the studies included in this review, clinical results showed significant improvements for patients with AT and PT after eccentric exercise (ECC) and heavy slow resistance (HSR) at short- and long-term follow-up. Imaging outcomes were not consistent. Moderate-to-strong evidence for patients with AT suggested an association between clinical outcomes and imaging outcomes (tendon thickness and tendon neovascularization) after ECC at long-term follow-up. For patients with PT, there was moderate evidence supporting an association between clinical outcomes (questionnaire score and pain) and imaging (tendon thickness and tendon neovascularization) after ECC at short-term follow-up. For both the AT and PT groups, there was moderate evidence for an association between clinical outcomes and tendon thickness and neovascularization after HSR exercise. Results related to the HSR exercise should be interpreted with caution because of the small number of studies.

CONCLUSIONS

Based on the findings of the present review, the use of imaging outcomes as a complementary examination to the clinical assessment was confirmed. Overall, an improvement in clinical outcomes seems to be associated with a reduction in tendon thickness and tendon neovascularization. Clinicians should be aware that during the interpretation of the imaging outcomes, factors such as tendinopathy location, exercise modality performed, and a follow-up period should be considered.

Internal and External Workload in Youth Basketball Players Who Are Symptomatic and Asymptomatic for Patellar Tendinopathy

OBJECTIVE

To examine the differences in external and internal workload in players with and without patellar tendinopathy.

DESIGN

Nested case-control study.

METHODS

Workload was monitored in 152 players (aged 13-18 years) for a 1-week period, including all practices, games, and conditioning sessions. Players were prescreened into patellar tendinopathy cases and controls without patellar tendinopathy, using the previously validated Oslo Sports Trauma Research Center-patellar tendinopathy questionnaire. Simple linear regression analysis, with adjustment for clustering by team and Bonferroni correction, was used to examine mean differences in measures of external workload (cumulative jump counts and sessions completed) and internal workload (session rating of perceived exertion in arbitrary units) between cases and controls.

RESULTS

A total of 144 players (19 cases, 125 controls) met the inclusion criteria for final analysis. No significant differences were found between players with patellar tendinopathy and those without patellar tendinopathy in the 3 outcomes: jump count (mean difference, 45 jumps; 98.3% confidence interval [CI]: -41, 130; P = .177), basketball sessions completed (mean difference, 0.9; 98.3% CI: -0.3, 2.2; P = .067), and session rating of perceived exertion (mean difference, 346 arbitrary units; 98.3% CI: -459, 1151; P = .260).

CONCLUSION

In the current study, a significant difference in workload was not detected between youth basketball players with patellar tendinopathy and players without patellar tendinopathy. Efforts toward identifying players at early stages of patellar tendinopathy and applying relevant interventions are warranted. J Orthop Sports Phys Ther 2020;50(7):402-408. Epub 6 Sep 2019. doi:10.2519/jospt.2020.9094.

Reliability and validity of Kannada version of Victorian Institute of Sports Assessment for patellar tendinopathy (VISA-P-K) questionnaire

BACKGROUND

In sporting activities, patellar tendon is commonly subjected to overuse and it influences the athletes' career especially in elite basketball and volleyball players. A condition specific and self-administrated questionnaire is required for clinical and research purpose to rate disability. The Victorian Institute of Sports Assessment for patellar tendinopathy (VISA-P) questionnaire is widely accepted and a valid tool to assess pain and athletes, suffering from PT, ability to participate in sports. So, the objective of this study is to develop and validate Kannada version of VISA-P questionnaire among Kannada speaking population athletes.

OBJECTIVE

To translate VISA-P questionnaire into Kannada and to study reliability and validity of Kannada version.

METHODOLOGY

Translation and cross-culture adaptation were performed according to the guidelines followed internationally. Those are: translation, synthesis, back-translation, revision by expert committee, pretesting and appraisal by advisory committee. The psychometric properties were tested by administering the questionnaire to 70 subjects (35 symptomatic and 35 asymptomatic). For test-retest reliability, athletes with patellar tendinopathy were tested twice within a week and test-retest reliability was assessed by Intra-class correlation coefficient (ICC). The validity was tested by comparing the VISA-P-Kannada questionnaire (VISA-P-K) against Blazina classification of patellar tendinopathy (BCPT) using Spearman correlation coefficient.

RESULT

The test-retest reliability was excellent (ICC 0.97). Internal consistency was found to be good (Cronbach's alpha = 0.98). The VISA-PK showed significant correlation by comparing against Blazina and Spearman's score (r = 0.72, p < 0.01).

CONCLUSION

The VISA-P-K translation and adaptation processes were successful. The adapted instrument demonstrated good psychometric properties. The VISA-P-K has proven to be reliable and valid tool and can be used in the Kannada speaking patients with patellar tendinopathy.

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 ).

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.

Biomaterials to Mimic and Heal Connective Tissues

Connective tissue is one of the four major types of animal tissue and plays essential roles throughout the human body. Genetic factors, aging, and trauma all contribute to connective tissue dysfunction and motivate the need for strategies to promote healing and regeneration. The goal here is to link a fundamental understanding of connective tissues and their multiscale properties to better inform the design and translation of novel biomaterials to promote their regeneration. Major clinical problems in adipose tissue, cartilage, dermis, and tendon are discussed that inspire the need to replace native connective tissue with biomaterials. Then, multiscale structure-function relationships in native soft connective tissues that may be used to guide material design are detailed. Several biomaterials strategies to improve healing of these tissues that incorporate biologics and are biologic-free are reviewed. Finally, important guidance documents and standards (ASTM, FDA, and EMA) that are important to consider for translating new biomaterials into clinical practice are highligted.

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.