Rodrigo Scattone Silva

Background: Achilles tendinopathy is one of the most frequent conditions affecting runners. Exercise-based interventions are the main treatment options for Achilles tendinopathy; however, the ideal exercise dosage remains unknown. Objective: The objective of this study is to investigate the effects of a moderate-load exercise intervention compared to a high-load exercise intervention in runners with Achilles tendinopathy in terms of pain, symptom severity, quality of life, muscle strength, and function. Methods: Sixty amateur runners will be randomly allocated to one of two groups: high-load exercise group (HLG) and moderate-load exercise group (MLG). The HLG will start the treatment with calf exercises with 55% of 1 repetition maximum (1RM) and progressively increase the exercise load in 12 weeks to 90% 1RM. The MLG will perform exercises with 55% 1RM during the 12 weeks of intervention. The RM load will be reassessed every 2 weeks, and the total training volume (total repetitions and tendon time under tension per week) will be the same in both groups. Both groups will also perform strengthening exercises for the quadriceps and gluteal muscles. The primary outcome will be symptom severity (Victorian Institute of Sport Assessment−Achilles), which will be evaluated at baseline, at week 6, at week 12 (end of intervention), and 6 months after the intervention. Pain will be evaluated using the visual analogue scale during the same time points. Secondary outcomes will include peak isometric strength of ankle, knee, and hip muscles, function of plantar flexor muscles, quality of life, and perception of improvement. Results will be analyzed under the intention-to-treat principle using generalized estimating equations (GEE) and Bonferroni-adjusted post hoc tests. Discussion: This will be the first randomized controlled trial comparing high-load exercises versus moderate-load exercises in individuals with Achilles tendinopathy applying equal training volume. Trial registration number: RBR-4vwy5xj

Background: The main cause for military training attrition is musculoskeletal injuries to the knee, such as patellofemoral pain (PFP). Objective: To identify which factors increase the risk of PFP occurrence in military personnel. Design: Systematic review with meta-analysis. Data Sources: Searches were performed in MEDLINE/PubMed, CINAHL, Embase, SPORTDiscus, Web of Science, Scopus, and OpenGray databases. Study Selection: Included studies included military personnel and had a prospective cohort design investigating at least 1 variable as a risk factor for PFP. Data Extraction: Extraction was performed by 2 independent evaluators, and the data were separated between the military personnel who developed PFP and those who did not. Data Synthesis: Meta-analyses were performed using standardized mean differences (SMDs) and 95% CIs, and levels of recommendation were determined. Results: From 11 articles, this review grouped 7518 military personnel, of whom 572 (7.61%) developed PFP. We found moderate evidence that isokinetic knee-extensor weakness at 60°/s predicts PFP in the military (SMD = −0.69; 95% CI = −1.02, −0.35). A larger frontal-plane knee-projection angle during the single-legged squat was also identified as a risk factor for PFP in male military personnel (SMD = 0.55; 95% CI = 0.14, 0.97) with a moderate level of evidence. We found moderate evidence that sex, body mass index, isometric knee-extensor strength, and isokinetic knee-flexor strength do not predict PFP in military personnel. Finally, we found strong evidence that age and body mass do not predict PFP in this population. Conclusions: Deficits in isokinetic knee-extensor strength and a greater frontal-plane knee-projection angle are risk factors for PFP in military personnel. Given that these are modifiable factors, these aspects should be considered in injury-prevention interventions in the military.

Objective: To systematically review studies investigating alterations in shoulder range of motion (ROM), muscle strength, and upper limb performance immediately following participation in throwing or racket sports. Methods: The search was conducted in MEDLINE via Ovid, EMBASE, CINAHL, SPORTDiscus, Cochrane Central Register for Controlled Trials (CENTRAL), Web of Science, and Scopus databases. Studies assessing changes in shoulder ROM, muscle strength, and upper limb performance immediately after exposure to throwing or racket sports were selected. The Quality Assessment Tool for Before-After Studies (NIH) was used to quantify the risk of bias. Meta-analyses were conducted to verify clinical changes in the selected outcomes. Results: A total of 9149 records were identified, and 27 were included in the meta-analysis. There was a decrease in internal rotation (IR) ROM of the shoulder (SMD: 0.50; 95% confidence interval [CI]: 0.22, 0.79) and throwing speed (SMD: 0.42; 95% CI: 0.15, 0.70) immediately after participation in throwing sports, while no significant changes were observed in racket sports. Conclusion: Exposure to real or simulated matches reduced IR ROM and ball speed in throwers but not in racket sports athletes. These results will assist clinicians in planning strategies to mitigate the decreases in sports performance in these athletes between matches.

Background: The proximal-distal energy transfer between body segments occurs through the kinetic chain. Although some kinetic chain aspects have been investigated in individuals not engaged in sports, their relationship with shoulder pain in this population remains unclear. This cross-sectional study aimed to verify associations between kinetic chain factors and the presence of shoulder pain in adults. Methods: Lumbopelvic stability (single-leg bridge test); active range of motion of the shoulder, trunk, and hip; and isometric peak strength of shoulder, trunk, hip, and knee muscles were assessed. A multivariate binary logistic regression analyzed the likelihood of shoulder pain based on these clinical results. Results: Forty individuals (26.3 ± 10.4 years, 19 with shoulder pain) were assessed. The isometric strength of trunk extensor muscles significantly influenced the regression model (odds ratio = 0.99 [0.98–1.00]; p = 0.027), indicating that each 1 N increase in strength reduced the likelihood of shoulder pain by about 1%. No significant relationships were observed between other outcomes and shoulder pain. Discussion: Isometric strength of trunk extensor muscles may be associated with shoulder pain. No associations were observed between shoulder pain and stability, mobility, and strength of other kinetic chain segments.

Achilles tendon pathologies are prevalent, impacting ~6% of the general population and up to 50% of elite endurance runners over their lifetimes. These conditions substantially affect quality of life and work productivity, leading to substantial societal costs. Achilles tendinopathy (AT) is a condition marked by localized pain and functional impairment related to mechanical loading. AT can considerably impair participation and potentially also performance in sports and daily activities. The aetiology of AT is multifactorial and repetitive overloading of the tendon is often observed as the inciting factor by health professionals. However, AT can also be associated with adverse effects of certain medication, ageing and various comorbidities. Characteristic tendon changes include proteoglycan accumulation, fluid accumulation with swelling and hypervascularization. Tissue disorganization advances as pathological changes in matrix structure are driven by altered cellular function and makeup, often accompanied by persistent inflammation. Treatment strategies include various interventions, although these can be protracted and challenging for both patients and health-care providers, often with high failure rates. Current research focuses on understanding the pathological processes at the cellular and molecular levels to distinguish between disease categories and to investigate the role of inflammation, metabolic maladaptation and mechanical stress. Emerging therapeutic approaches need to be developed to address these underlying mechanisms. These approaches focus on optimizing rehabilitation protocols and advancing the development of adjunct therapies, such as advanced therapy medicinal products, alongside the integration of precision medicine to improve treatment outcomes.

Background: Anterior cruciate ligament reconstruction (ACLR) often involves harvesting a bone–patellar tendon–bone (BPTB) autograft. How graft harvest affects tendon strain across the 3 distinct regions (medial, lateral, and central) is not known. Purpose: To (1) quantify strain in the 3 regions of the patellar tendon during 60% of maximum voluntary isometric contraction (MVIC) in 90° of knee flexion and (2) assess how effort level in 2 different knee joint angles (60° and 90°) impacts strain in the medial and lateral regions of the patellar tendon, in 2 cohorts of patients after ACLR using a BPTB autograft (one group P < .01). The central region also had lower strain than the medial and lateral regions regardless of group (both P < .01). Finally, the rate at which strain increased with increasing effect levels differed between time from surgery groups in both medial and lateral regions. Conclusion: The short-term group had lower strain in all regions of the patellar tendon after ACLR using BPTB autograft. The medial and lateral regions showed varying strain based on time from surgery and effort level. Varying knee joint angles and effort levels for graft site rehabilitation may have to be considered to target specific regions of the patellar tendon. Clinical Relevance: Clinicians should consider the time elapsed since surgery and the manipulation of knee angle as factors that can exert varying levels of strain on different regions of the patellar tendon after ACLR. Accelerating quadriceps strengthening to enhance strain distribution across the patellar tendon to promote tendon healing may be of benefit for optimizing postsurgery rehabilitation.

Introduction: Triathlon’s global popularity, with over 120 national federations and millions of athletes, has led to an increase in injuries, particularly Achilles tendinopathy, affecting 12−24% of long‐distance and 7.7% of short‐distance triathletes. Understanding the morphological adaptations of the Achilles tendon and calf muscles is crucial. Objective: This study compares the stiffness of the Achilles tendon and calf muscles between triathletes and physically active controls, while identifying differences in the superficial, middle, and deep layers of the calf muscles across and within these groups. Methods: A cross‐sectional study was conducted with 42 participants divided into four groups: 10 male triathletes, 10 male controls, 11 female triathletes, and 11 female controls. Shear wave elastography assessed the stiffness of the Achilles tendon and calf muscles. Results: No between‐group differences were found for the overall stiffness of the Achilles tendon and calf muscles. In the soleus muscle, the stiffness of the superficial layer was greater in the male control group compared to female triathletes ( p = 0.002). Also, the middle layer was greater in the male control group compared to the male triathletes ( p = 0.023) and female triathletes ( p = 0.028). Finally, the middle layer was greater in male controls compared to female triathletes ( p = 0.008). Within‐group differences showed that the superficial layer was generally stiffer than the middle and deep layers across all groups and muscles. Notably, in the lateral gastrocnemius, the deep layer showed greater stiffness compared to the middle layer only for female controls ( p = 0.014). Conclusion: Triathlon does not affect the overall stiffness of the Achilles tendon and calf muscles, but differences in muscle layers highlight the need for a segmented approach in elastography, which may reveal specific training effects or injury risks.