The diagnosis and management of Achilles tendon ailments continue to be widely discussed by the scientific community. Also, the nomenclature used to describe the tendinopathic lesion in patients changed over the last decades together with the evolution in the knowledge of the physiopathology of Achilles tendinopathy, and unfortunately, through ignorance and possibly laziness, confusion still abounds. To emerge from these foggy paths, some clarifications are still necessary. The present Editorial tries to clarify some of these issues.

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

MEDLINE, PubMed, Scopus, and Web of Science.

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

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

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

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

Gymnastics is a popular sport with a high injury rate, particularly at the collegiate level. Achilles tendon rupture is a catastrophic injury with career-changing impact. Over the last decade, there has been a growing incidence of Achilles tendon ruptures, especially in female gymnasts. Currently, neither the effects of contributing risk factors on Achilles tendon rupture nor the research frameworks to guide future intervention strategies have been well described. This article reviews the functional anatomy and mechanical properties of the Achilles tendon, provides precollegiate and collegiate intrinsic and extrinsic risk factors for Achilles tendon rupture, and proposes a research framework to address this injury from a systemic perspective. Potential clinical interventions to mitigate Achilles tendon injury are proposed based on currently available peer-reviewed evidence.

Ultrasonographic signs of tendinopathies are an increase in thickness, loss of alignment in collagen fibers and the presence of neovascularization. Nevertheless, analysis of intratendinous vascular resistance (IVR) can be more useful for understanding the physiological state of the tissue. To show thermal, echotextural, and Doppler signal differences in athletes with patellar tendinopathy and controls. Twenty-six athletes with patellar tendinopathy (PT) participants (30.1 years; SD = 9.0 years) and 27 asymptomatic athletes (23.3 years; SD = 5.38 years) were evaluated with thermographic and Doppler ultrasonography (DS). Area of Doppler signals (DS), echotextural parameters (echointensity and echovariation) and IVR were determined by image analysis. The statistical analysis was performed by Bayesian methods and the results were showed by Bayes Factor (BF10: probability of alternative hypothesis over null hypothesis), and Credibility intervals (CrI) of the effect. The absolute differences of temperature (TD) were clearly greater (BF10 = 19) in the tendinopathy group (patients) than in controls. Regarding temperature differences between the affected and healthy limb, strong evidence was found (BF₁₀ = 14) for a higher temperature (effect = 0.53°C; 95% CrI = 0.15°C-0.95°C) and very strong for reduced IVR compared (BF₁₀ = 71) (effect = -0.67; 95% CrI = -1.10 to 0.25). The differences in area of DS (BF₁₀ = 266) and EV (BF₁₀ = 266) were higher in tendinopathy group. TD showed a moderate positive correlation with VISA-P scores (tau-B = .29; 95% CrI = .04-.51) and strong correlation with IVR (r = -.553; 95%CrI = -.75 to .18). Athletes with patellar tendinopathy showed a more pronounced thermal difference, a larger area of Doppler signal, a lower IVR and a moderately higher echovariaton than controls. The correlation between temperature changes and IVR might be related with the coexistence of degenerative and inflammatory process in PT.

Both in tendon repair following a tear and in tendinopathy, recovery from pain and restoration of (acceptable) function does not go hand in hand with the appearance of the affected tendon at imaging. The tendon may remain altered for a long while and possibly forever, indicating a possible dissociation between morphology and symptoms. The predictive value of asymptomatic abnormal findings remains limited, and interventions in such instances are inappropriate and not supported by current evidence. Once an initial imaging investigation has depicted the condition of the tendon, additional imaging investigations are unlikely to provide further information or change prognosis in patients in whom abnormalities compatible with a diagnosis of tendinopathy have been identified by either ultrasonography or MRI. Patient education and close clinical monitoring are recommended. This is applicable to the patellar tendon, Achilles tendon, rotator cuff, for both tendon repair and tendinopathy. Given the modest risk of sonographic abnormalities to develop in symptomatic tendinopathy, planning and trying to implement any form of intervention may not be warranted. The current evidence mostly arises from low-quality studies, with heterogeneous risk factors and populations, and caution must be maintained when interpreting the significance of such incidental findings in athletes.

Ultrasound often corroborates clinical diagnosis of Achilles tendinopathy (AT). Traditional measures assess macromorphological features or use qualitative grading scales, primarily focused within the free tendon. Shear wave imaging can non-invasively quantify tendon elasticity, yet it is unknown if proximal structures are affected by tendon pathology. The purpose of the study was to determine the characteristics of both traditional sonographic measures and regional shear wave speed (SWS) between limbs in patients with AT.

Twenty patients with chronic AT were recruited. Traditional sonographic measures of tendon structure were measured. Regional SWS was collected in a resting ankle position along the entire length of the tendon bilaterally. SWS measures were extracted and interpolated across evenly distributed points corresponding to the free tendon (FT), soleus aponeurosis (SA), and gastrocnemius aponeurosis (GA). Comparisons were made between limbs in both traditional sonographic measures and regional SWS.

Symptomatic tendons were thicker (10.2 (1.9) vs. 6.8 (1.8) mm; p < 0.001) and had more hyperemia (p = 0.001) and hypoechogenicity (p = 0.002) than the contralateral tendon. Regional SWS in the FT was lower in the symptomatic limb compared to the contralateral limb (11.53 [10.99, 12.07] vs. 10.97 [10.43, 11.51]; p = 0.03). No differences between limbs were found for the SA (p = 0.13) or GA (p = 0.99).

Lower SWS was only observed in the FT in AT patients, indicating that alterations in tendon elasticity associated with AT were localized to the FT and did not involve the proximal passive tendon structures.

• Baseline characteristics of a pilot sample of 20 subjects suffering from chronic Achilles tendinopathy showed differences in conventional sonographic measures of tendon thickness, qualitatively assessed hypoechogenicity, hyperemia, and quantitative measures of shear wave speed. • Regional shear wave speeds were lower in the free tendon but not in the proximal regions of the soleus or gastrocnemius aponeuroses in Achilles tendinopathy patients. • Using shear wave imaging to estimate tendon stiffness may prove beneficial for clinical validation studies to address important topics such as return to activity and the effectiveness of rehabilitation protocols.

Patellar tendon adaptations occur in response to mechanical load. Appropriate loading is necessary to elicit positive adaptations with increased risk of injury and decreased performance likely if loading exceeds the capacity of the tendon. The aim of the current study was to examine intra-individual associations between workloads and patellar tendon properties and neuromuscular performance in collegiate volleyball athletes.

National Collegiate Athletics Association Division I men's volleyball athletes (n = 16, age: 20.33 ± 1.15 years, height: 193.50 ± 6.50 cm, body mass: 84.32 ± 7.99 kg, bodyfat%: 13.18 ± 4.72%) competing across 9 weeks of in-season competition participated. Daily measurements of external workloads (i.e., jump count) and internal workloads [i.e., session rating of perceived exertion (sRPE)] were recorded. Weekly measurements included neuromuscular performance assessments (i.e., countermovement jump, drop jump), and ultrasound images of the patellar tendon to evaluate structural adaptations. Repeated measures correlations (r-rm) assessed intra-individual associations among performance and patellar tendon metrics.

Workload measures exhibited significant negative small to moderate (r-rm =-0.26-0.31) associations with neuromuscular performance, negative (r-rm = -0.21-0.30), and positive (r-rm = 0.20-0.32) small to moderate associations with patellar tendon properties.

Monitoring change in tendon composition and performance adaptations alongside workloads may inform evidence-based frameworks toward managing and reducing the risk of the development of patellar tendinopathy in collegiate men's volleyball athletes.

The clinical relevance of altered tendon structure in patellar tendinopathy is contested since structural change persists after symptom resolution. The purpose of this study was to explore the relationships between tendon structure and clinical impairments in patellar tendinopathy. In this retrospective, secondary analysis of individuals with patellar tendinopathy (n = 41), tendon structure (thickness, cross-sectional area [CSA], shear modulus, and viscosity), symptom severity, lower extremity function (counter-movement jump [CMJ] height), and quadriceps muscle performance (knee extension force and central activation ratio [CAR]) were recorded for the symptomatic limb. Relationships among structure, symptom severity, lower extremity function, and quadriceps muscle performance were examined using sequential regression models. Adjusting for age, sex, body mass index, and pain levels, there were significant positive relationships for thickness (p < 0.001, β = 0.718) and viscosity (p = 0.006, β = 0.496) with CMJ height. There were significant negative relationships between CSA with both CMJ height (p = 0.001, β = -0.538) and CAR (p = 0.04, β = -0.517). This is the first study to demonstrate relationships between tendon structure and lower extremity function or quadriceps muscle performance in patients with patellar tendinopathy. Clinical significance: Since structural changes persist after symptom resolution, addressing these changes may assist in restoring lower extremity function and quadriceps muscle performance.

To evaluate magnetic resonance imaging (MRI) features of the contralateral side in weightlifting athletes with pectoralis major (PM) tears. We hypothesized that MRI of the non-injured side may present increased pectoralis major tendon (PMT) length and thickness and greater pectoralis major muscle (PMM) volume and cross-sectional area when compared with the control group.

We retrospectively identified MRI cases with unilateral PM injury and reviewed imaging findings of the contralateral side. Also, we evaluated MRI from ten asymptomatic control weightlifting athletes, with PM imaging from both sides. Two musculoskeletal radiologists independently reviewed MRI and measured PMT length, PMT thickness, PMM volume (PMM-vol) and PMM cross-sectional area (PMM-CSA), as well as humeral shaft cross-sectional area (Hum-CSA) and the ratio between PMM-CSA and Hum-CSA (PMM-CSA/Hum-CSA). Data were compared between the non-injured side and controls. The MRI protocol from both groups was the same and included T1 FSE and T2 FATSAT axial, coronal, and sagittal images, one side at a time.

We identified 36 male subjects with unilateral PM injury with mean age 35.7 ± 8 years and 10 age- and gender-matched controls (p = 0.45). A total of 36 PM MRI with non-injured PM and 20 PM MRI studies were included in this study. PMT length and PMT thickness were significantly higher in contralateral PM injury versus control subjects (both P < 0.001). Also, PM-CSA and Hum-CSA were greater in the contralateral PM injury group (P = 0.032 and P < 0.001, respectively). PMT thickness > 2.95 mm had 80.6% sensitivity and 90.0% specificity to differentiate the non-injured PM group from controls.

Non-injured side MR imaging of patients with previous contralateral PM lesion demonstrates greater PMT thickness and length as well as PM-CSA and Hum-CSA than controls.

Pain is the main symptom in entheseal diseases (enthesopathies) despite a paucity of nerve endings in the enthesis itself. Eicosanoids, cytokines, and neuropeptides released during inflammation and repeated nonphysiologic mechanical challenge not only stimulate or sensitize primary afferent neurons present in structures adjacent to the enthesis, but also trigger a "neurovascular invasion" that allows the spreading of nerves and blood vessels into the enthesis. Nociceptive pseudounipolar neurons support this process by releasing neurotransmitters from peripheral endings that induce neovascularization and peripheral pain sensitization. This process may explain the frequently observed dissociation between subjective symptoms such as pain and the structural findings on imaging in entheseal disease.

Achilles tendinopathy (AT) is a common musculoskeletal disorder, and its management remains challenging. Hypothesis/Purpose. By conducting a pilot study, we aimed to assess the feasibility, safety, and clinical improvement of a new home-based 4-stage rehabilitation program with progressive loading including isometric exercises on a small scale prior to setting up a randomized controlled trial.

Ten recreational athletes with chronic midportion AT were included. The primary outcome was change in VISA-A score after 1, 2, 3, 6, and 12 months. Secondary outcomes included tenderness on palpation of the tendon and ultrasonographic changes after 6 months.

Average VISA-A improvements of 26.9 points (P=0.004) and 35.4 points (P=0.006) were observed at 6- and 12-month follow-up, respectively. Tenderness on palpation of the tendon (0-10) was reduced from 5.5 to 2.5 (P < 0.001). Color Doppler ultrasound activity (0-4) was reduced by 50%, from an average of grade 2 to grade 1 (P=0.023). The hypoechoic cross-sectional area of the Achilles tendon was reduced from an average of 29.1% to 8.5% (P=0.001). Tendon thickness showed no statistically significant change (P=0.415).

Following the 4-stage rehabilitation program for AT based on isometric training and progressive loading, we observed improvement in both VISA-A score and ultrasonography in a group of athletes who had previously failed to benefit from standard AT rehabilitation. The study was feasible in terms of high adherence to the program and with no observed safety issues. The results of this pilot study support a further assessment of this specific approach for rehabilitation in a future randomized controlled trial.

Objectives: To examine whether asymptomatic ultrasonographic abnormalities in the Achilles and patellar tendons in runners are associated with an increased risk of pain development.Methods: This is a longitudinal, prospective cohort study with 139 runners recruited at a half and full marathon race. Ultrasound examination of the Achilles and patellar tendons was performed bilaterally the day prior to the race. Self-reported injury data were collected at 1, 3, 6 and 12 months. 104 (74.8%) runners were included in the data analysis.Results: Ultrasonographic tendon abnormalities were found in 24.1% of the Achilles and in 23.1% of the patellar tendons prior to the race. Runners with tendon abnormality were 2-3 times more likely to develop pain within 12 months than those without (relative risk = 3.14, p = 0.010 for Achilles; relative risk = 2.52, p = 0.008 for patellar tendon). After adjusting for gender, age, years of running, average miles per week of running over a year, and pre-race pain, runners with ultrasound abnormality were about 3 times (hazard ratio = 2.89, p = 0.039 for Achilles; hazard ratio = 2.73, p = 0.030 for patellar tendon) more likely to develop pain after the race. Tendon delamination was most strongly associated with pain in both the Achilles (relative risk = 6.00; p = 0.001) and patellar tendons (relative risk = 3.81; p = 0.001).Conclusions: Structural changes in asymptomatic tendons were found in almost 25% of runners. Presence of structural changes was associated with increased development of Achilles and patellar tendon pain within one year.

Running injuries are very common, and there are well-established protocols for clinicians to manage specific musculoskeletal conditions in runners. However, competitive and elite runners may experience different injuries than the average recreational runner, due to differences in training load, biomechanics, and running experience. Additionally, injury-specific rehabilitation protocols do not consider the broader goal of return to competitive running, including the unique psychosocial and cardiorespiratory fitness needs of elite athletes. This review aims to suggest a guideline for running-specific progression as part of a comprehensive rehabilitation program for injured competitive runners. Tools to evaluate an athlete's psychosocial preparedness to return to competition are presented. Recommendations are also provided for monitoring cardiorespiratory fitness of injured runners, including the nuances of interpreting these data. Finally, a six-phase training paradigm is proposed to guide clinicians as they help competitive runners transition from the early stages of injury through a full return to competition.

Achilles injury risk in women's collegiate gymnastics is 10-fold higher than in all other collegiate sports. This study aims to identify risk factors for Achilles tendon ruptures in collegiate female gymnasts.

Gymnasts with Achilles tendon ruptures will be more likely to report early gymnastics specialization, elite-level training before college, and performance of high-difficulty skills on floor and vault.

Cross-sectional study.

Level 4.

Anonymous surveys were distributed to current and former collegiate female gymnasts, aged 18 to 30 years, via coaches, athletic trainers, Twitter, and ResearchMatch. Information about Achilles tendon ruptures, gymnastics-related injuries, sport specialization, event/skills participation, and medication use were collected.

A total of 581 gymnasts were included. One hundred gymnasts (17.2%; 95% CI: 14.1%-20.3%) reported Achilles tendon ruptures during collegiate training or competition. Most ruptures (91%) occurred on floor exercise; 85.7% of these occurred during back tumbling-take-off. Compared with gymnasts without ruptures during college, a greater percentage of gymnasts with ruptures competed at a Division I program, trained elite, competed difficult vaults and floor passes before and during college, competed in all 4 events during college, identified as Black/African American, and used retinoid medications.

Achilles tendon ruptures are more common in women's collegiate gymnastics than other sports. Competing at the elite level, performing difficult floor and vault skills, and competing in all 4 events may increase the risk for an Achilles tendon rupture. Potential nontraining risk factors include retinoid exposure and Black/African American race. Future studies regarding the mechanisms of Achilles tendon ruptures in female collegiate gymnasts are warranted.

Collegiate gymnasts who compete at the elite level, perform high levels of difficulty on floor and vault, and compete in all 4 events may be at increased risk for Achilles tendon ruptures.

Patellar tendinopathy is characterized by tendon pain which may reduce the level of performance. This study's main aim was to compare isokinetic knee strength and jump performances at the start of the sport season between players with patellar tendinopathy and those without. Secondary aims were to assess the relationship between knee strength and jump function. Sixty-two professional basketball players were enrolled (mean age: 25.0 ± 4.0). All players performed knee isokinetic measurements, single leg countermovement jumps, and one leg hop tests. Correlations between knee strength and jump performances were examined. Twenty-four players declared a patellar tendinopathy and were compared to the 38 players without tendinopathy. The isokinetic quadriceps strength was lower in cases of patellar tendinopathy, and a camel's back curve was observed in 58% of the cases of patellar tendinopathy. However, jump performances were preserved. No link was found between quadriceps and hamstring limb symmetry indexes at 60 and 180°/s with jumps. This preseason screening enabled us to identify the absence of consequences of patellar tendinopathy in professional basketball players. Jump performances were not altered, possibly due to compensatory strategies.

This review presents a framework for constructing a differential diagnosis for chronic anterior knee pain associated with overuse other than patellofemoral pain. Traumatic, systemic, and pediatric injuries will not be covered.

From superficial to deep, the anterior knee can be conceptually organized into four layers: (1) soft tissue, (2) extensor mechanism, (3) intracapsular/extrasynovial, and (4) intra-articular. From superficial to deep, diagnoses to consider include bursitis, patellar and quadriceps tendinosis, fat pad impingement, and plica syndromes.

The aim of this study was to confirm our clinical observation that a pseudo-tear appearance of the Achilles tendon is commonly seen on MRI and is of no clinical relevance.

Forty-one ankles were imaged on a 3 T MR system, and PD weighted images with fat saturation were obtained in three orthogonal planes (TR, 2969 ms; TE, 30 ms; NA, 2; slice thickness, 2.5 mm). Volunteer exclusion criteria were symptoms of Achilles tendon pathology (such as acute or chronic posterior heel pain), history of trauma or surgery of the Achilles tendon. Internal signal of the Achilles tendon on axial and sagittal images was assessed independently by two observers. Internal signal of the Achilles tendon was classified from homogenously dark to different degree of hyperintense signal, where 0 means no internal hyperintensity, 1-minimal hyperintensity, 2-moderate and 3-marked. Descriptive statistics were calculated. Correlation between the two readers was also assessed. Two fresh cadavers were used in this study, one specimen being sliced in the sagittal plane and one specimen being dissected by an experienced anatomist.

Twenty one volunteers (8 men, 13 women), mean age of 24.7 years (19-43 years) were included in the study. On sagittal images both raters appreciated any degree of hyperintense signal in 59% of tendons. On axial images any degree of hyperintensity was seen in almost half of the cases (46 vs. 49%). Minimal hyperintensities were seen most commonly. Cohen's kappa coefficient for sagittal images was 0.964 (almost perfect agreement); for axial images 0.764 (substantial agreement). The anatomical studies demonstrated that the Achilles tendon is made up of different components that are partially separated and twist around each other explaining the pseudo-tear appearance.

The Achilles tendon is frequently not homogenously dark in normal volunteers as would be expected. Hyperintense signal is common in the long and short axis and related to the underlying anatomical features.

The asymptomatic side of unilateral Achilles tendinopathy (AT) is used as a reference in ultrasound. However, this procedure has not been evaluated in a comparative analysis using B-mode (B-US), power Doppler (PD-US), ultrasound tissue characterization (UTC) and shear wave elastography (SWE).

Retrospective cross-sectional study. Tendons were assigned to 3 groups: 1) asymptomatic side of unilateral AT N.=55; 2) symptomatic side of unilateral AT N.=55; and 3) young reference group N.=29. The following parameters were analyzed separately for the insertion and midportion: UTC (echo type I, II, III, IV), B-US (diameter, cross sectional area), PD-US (Öhberg Score) and SWE (SWE 3 mm, SWE area) using a Wilcoxon Test (group 1 vs. 2) and a Kruskal-Wallis Test (group 1 vs. 2 vs. 3).

The Wilcoxon Test making an isolated comparison between group 1 vs. 2 revealed a significant difference for all parameters of B-US, PD-US, UTC and SWE (P<0.001, P=0.042), except for the insertion in UTC. However, in the overall analysis including the reference group, the Kruskal-Wallis Test could only detect a significant difference between group 1 vs. 2 for PD-US (P<0.001). Thus, group 1 and 2 had significantly more pathological parameters in B-US (P<0.001, P=0.027), SWE (P<0.001, P=0.008) and UTC (type I, III, IV P<0.001) in both, insertion and midportion, compared to the reference group.

The asymptomatic side of unilateral AT seems to show subclinical tendons alterations in B-US, SWE and UTC in comparison to a young and healthy control group. The asymptomatic side of unilateral AT especially with detectable neovascularization might be at risk for future symptoms. Further studies must examine whether the asymptomatic side can still serve as a reference for intra individual comparison in clinical evaluation.