Youth Athletes With Sever's Disease Exhibit Altered Achilles Tendon Ultrasound Characteristics: A Retrospective Case-Control Study.

OBJECTIVES: Calcaneal apophysitis (Sever's disease) is an overuse condition caused by repetitive traction stress to the calcaneal apophysis. Whether Achilles tendon morphology is altered in this young patient population remains unknown. Therefore, we aimed to identify differences in Achilles tendon morphology between youth athletes diagnosed with calcaneal apophysitis and healthy controls. METHODS: This retrospective chart review included 46 patients (n = 23 Sever's disease, 15F/8M, 12.4 ± 2.3 years old) and (n = 23 healthy controls, 13F/10M, 15.9 ± 1.5 years old) who sought care in a Children's Hospital Sports Medicine/Orthopedics Department between 2012 and 2022. We measured ultrasound-derived degree of tendon thickening, Achilles tendon thickness (cm), and cross-sectional area (CSA [cm2]). Separate multivariate analyses of covariance (MANCOVAs) were used to compare degree of thickening, mass-normalized Achilles tendon thickness, and CSA between participant groups, covarying for age. Cohen's d effect sizes were used to assess the magnitude of mean differences and standard error (MDSE) between groups. RESULTS: Young athletes with Sever's disease had a significantly greater degree of tendon thickening with a large effect compared with healthy controls (MDSE: 0.07 [0.01] mm P < .001, d = 1.39). Achilles tendon thickness and CSA did not statistically differ between groups; however, the magnitude of between-group differences for these measures (MDSE: 0.18 [0.05] cm, MDSE: 0.27 [0.07] cm2, respectively) were moderate. CONCLUSIONS: Our findings demonstrate previously unrecognized differences in Achilles tendon morphology between young athletes with clinically diagnosed Sever's disease and healthy controls. Our study supports incorporating diagnostic ultrasound as part of a comprehensive examination to ensure appropriate diagnosis and clinical management for adolescents with heel pain.

Walking Exercise Sustainability Through Telehealth for Veterans With Lower-Limb Amputation: A Study Protocol.

OBJECTIVE: This randomized controlled superiority trial will determine if an 18-month telehealth walking exercise self-management program produces clinically meaningful changes in walking exercise sustainability compared to attention-control education for veterans living with lower-limb amputation. METHODS: Seventy-eight participants with lower-limb amputation (traumatic or nontraumatic) aged 50 to 89 years will be enrolled. Two groups will complete 6 one-on-one intervention sessions, and 6 group sessions over an 18-month intervention period. The experimental arm will receive a self-management program focusing on increasing walking exercise and the control group will receive attention-control education specific to healthy aging. Daily walking step count (primary outcome) will be continuously monitored using an accelerometer over the 18-month study period. Secondary outcomes are designed to assess potential translation of the walking exercise intervention into conventional amputation care across the Veteran Affairs Amputation System of Care. These secondary outcomes include measures of intervention reach, efficacy, likelihood of clinical adoption, potential for clinical implementation, and ability of participants to maintain long-term exercise behavior. IMPACT: The unique rehabilitation paradigm used in this study addresses the problem of chronic sedentary lifestyles following lower-limb amputation through a telehealth home-based walking exercise self-management model. The approach includes 18 months of exercise support from clinicians and peers. Trial results will provide rehabilitation knowledge necessary for implementing clinical translation of self-management interventions to sustain walking exercise for veterans living with lower-limb amputation, resulting in a healthier lifestyle.

Maximal daily stepping cadence partially explains functional capacity of individuals with end-stage knee osteoarthritis.

BACKGROUND: Individuals with end-stage knee osteoarthritis (OA) walk at a lower intensity (ie, slower step cadence) contributing to worse physical function. Previous literature reports daily step counts and sedentary time, with little information regarding stepping bouts or cadence. Determining relationships between daily higher stepping cadence duration and clinical outcomes can move the field toward optimal daily stepping prescription. OBJECTIVE: To quantify daily physical activity patterns of individuals with end-stage knee OA and determine the contribution of high stepping cadence to explain functional capacity variability. DESIGN: Cross-sectional analysis. SETTING: Veterans Administration medical center. PARTICIPANTS: U.S. military veterans (n = 104; age: 67.1 years [7.2]; mean [SD]; male [89.3%]) with end-stage knee OA were enrolled. INTERVENTION: Not applicable. MAIN OUTCOME MEASURE: Functional capacity (6-Minute Walk Test [6MWT]). Physical activity (activPAL wearable sensor; cadence and time sitting, standing, and stepping), pain (Western Ontario and McMaster Universities Osteoarthritis Index-pain subscale) sociodemographic variables, and comorbidities (body mass index and Functional Comorbidity Index) are the main explanatory variables. RESULTS: Participants' wake time was mainly sitting (11.0 h/day) in ≥60-minute bouts (29.7% ± 12.7 of sitting time). Standing (3.4 hours/day) and stepping (1.4 h/day) primarily occurred in 0-5 minute bouts (standing: 87.7% ± 14.4 of standing time, stepping: 98.7% ± 12.7 of stepping time) and stepping cadence was predominantly incidental (1-19 spm; 52.9% ± 9.6 of total stepping time). Backward elimination model results indicated shorter medium-to-brisk cadence bout duration, older age, and higher pain significantly explained shorter 6MWT distance (Adj R2 =0.24, p < .01). CONCLUSIONS: Individuals with knee OA spend most of their waking hours sitting, while standing and stepping occurs in short bouts at very low stepping cadence. Decreased time in high stepping cadence is associated with lower functional capacity. Future studies should explore if increasing the daily time spent in higher step cadence can improve functional capacity in this population.

Effect of Symptom Duration on Injury Severity and Recovery in Patients With Achilles Tendinopathy.

Background: Achilles tendinopathy is a common overuse condition. Distinguishing between early- and late-stage tendinopathy may have implications on treatment decisions and recovery expectations. Purpose: To compare the effects of time and baseline measures of tendon health on outcomes among patients with varying symptom durations after 16 weeks of comprehensive exercise treatment. Study Design: Cohort study; Level of evidence, 3. Methods: Participants (N = 127) were categorized into 4 groups based on the number of months since symptom onset: ≤3 months (n = 24); between >3 and ≤6 months (n = 25); between >6 and ≤12 months (n = 18); or >12 months (n = 60). All participants received 16 weeks of standardized exercise therapy and pain-guided activity modification. Outcomes representing symptoms, lower extremity function, tendon structure, mechanical properties, psychological factors, and patient-related factors were assessed at baseline and at 8 and 16 weeks after the initiation of exercise therapy. Chi-square tests and 1-way analysis of variance were used to compare baseline measures between groups.Time, group, and interaction effects were evaluated using linear mixed models. Results: The mean age of the participants was 47.8 ± 12.6 years, 62 participants were women, and symptoms ranged from 2 weeks to 274 months. No significant differences were found among symptom duration groups at baseline for any measure of tendon health. At 16 weeks, all groups demonstrated improvements in symptoms, psychological factors, lower extremity function, and tendon structure, with no significant differences among the groups (P > .05). Conclusion: Symptom duration did not influence baseline measures of tendon health. Additionally, no differences were observed among the different symptom duration groups in response to 16 weeks of exercise therapy and pain-guided activity modification.

Differences in Recovery of Tendon Health Explained by Midportion Achilles Tendinopathy Subgroups: A 6-Month Follow-up.

OBJECTIVES: To (1) evaluate whether the defining characteristics of previously reported Achilles tendinopathy subgroups were reproducible in a cohort with midportion Achilles tendinopathy and (2) compare recovery trajectories and outcomes. DESIGN: Prospective single cohort study. METHODS: Participants (n = 114; 57 women; age [mean ± standard deviation]: 47 ± 12 years) received the Silbernagel protocol and were evaluated at baseline, and at 8, 16, and 24 weeks. Subgroups were identified using mixture modeling. Main effects of group and time, and interaction effects were evaluated using linear mixed models for 23 outcome measures representing symptoms, lower extremity function, tendon structure, psychological factors, and patient-related factors. Recovery trajectories were reported descriptively to reflect clinically meaningful change for outcomes. RESULTS: Activity-Dominant (n = 34), Function-Dominant (n = 38), Psychosocial-Dominant (n = 27), and Structure-Dominant (n = 15) subgroups were identified. There were significant effects of group and time for all primary outcome measures, except heel-rise and viscosity limb symmetry indexes. The Activity- and Function-Dominant subgroups achieved functional recovery despite persisting symptoms. The Psychosocial-Dominant subgroup reported the greatest impairments in symptom and foot- and ankle-related quality of life at all time points. The Structure-Dominant subgroup experienced delayed improvement in symptoms and was the only subgroup to not achieve structural recovery. No subgroup met our criteria for complete recovery. CONCLUSION: The defining characteristics of Achilles tendinopathy subgroups were reproduced in a cohort with midportion Achilles tendinopathy. The Activity- and Function-Dominant subgroups had superior outcomes compared to the Psychosocial- and Structure-Dominant subgroups for symptomatic, functional, and structural recovery. J Orthop Sports Phys Ther 2023;53(4):1-18. Epub: 23 January 2023. doi:10.2519/jospt.2023.11330.

Determining the feasibility of exercise therapy and activity modification for treating adolescents with heel pain: a study protocol.

Calcaneal apophysitis and Achilles tendinopathy are common overuse injuries characterised by insidious posterior heel pain with activity. Calcaneal apophysitis is commonly diagnosed in adolescents, although Achilles tendinopathy is understudied in the adolescent population and is therefore rarely considered until adulthood. Exercise therapy and activity modification have the highest level of evidence for treating Achilles tendinopathy, while calcaneal apophysitis is treated with anecdotal and passive treatment or complete rest. It remains unknown whether exercise therapy is effective for adolescents with heel pain related to either diagnosis. This is a pilot and feasibility study. Thirty participants between the ages of 7 years and 17 years with posterior heel pain will be recruited from the local community and club sports team and local physicians, school nurses, and athletic trainers through flyers and social media. Participants will be asked to complete evaluations and treatment sessions every 4 weeks with three virtual visits every 2 weeks in between for 12 weeks. All participants will receive standardised treatment consisting of daily Achilles tendon loading exercises and education on pain-guided activity modification. Feasibility outcomes will include recruitment, enrolment, retention and compliance. Clinical outcomes will include the measures of symptom severity, quality of life, tendon morphology and lower extremity function. This protocol will provide preliminary data to inform a larger clinical trial based on the feasibility of the proposed intervention and methodology. Additionally, the results will provide preliminary evidence on whether Achilles tendon injury occurs in the adolescent population. The trial is registered with clinicaltrials.gov (ID:1652996).

ICON 2020-International Scientific Tendinopathy Symposium Consensus: A Systematic Review of Outcome Measures Reported in Clinical Trials of Achilles Tendinopathy.

BACKGROUND: Nine core domains for tendinopathy have been identified. For Achilles tendinopathy there is large variation in outcome measures used, and how these fit into the core domains has not been investigated. OBJECTIVE: To identify all available outcome measures outcome measures used to assess the clinical phenotype of Achilles tendinopathy in prospective studies and to map the outcomes measures into predefined health-related core domains. DESIGN: Systematic review. DATA SOURCES: Embase, MEDLINE (Ovid), Web of Science, CINAHL, The Cochrane Library, SPORTDiscus and Google Scholar. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Clinical diagnosis of Achilles tendinopathy, sample size ≥ ten participants, age ≥ 16 years, and the study design was a randomized or non-randomized clinical trial, observational cohort, single-arm intervention, or case series. RESULTS: 9376 studies were initially screened and 307 studies were finally included, totaling 13,248 participants. There were 233 (177 core domain) different outcome measures identified across all domains. For each core domain outcome measures were identified, with a range between 8 and 35 unique outcome measures utilized for each domain. The proportion of studies that included outcomes for predefined core domains ranged from 4% for the psychological factors domain to 72% for the disability domain. CONCLUSION: 233 unique outcome measures for Achilles tendinopathy were identified. Most frequently, outcome measures were used within the disability domain. Outcome measures assessing psychological factors were scarcely used. The next step in developing a core outcome set for Achilles tendinopathy is to engage patients, clinicians and researchers to reach consensus on key outcomes measures. PROSPERO REGISTRATION: CRD42020156763.

Beyond the Diagnosis: Using Patient Characteristics and Domains of Tendon Health to Identify Latent Subgroups of Achilles Tendinopathy.

OBJECTIVE: To identify latent subgroups among patients with Achilles tendinopathy, describe patient characteristics and clinical attributes that defined each subgroup, and develop a clinical classification model for subgroup membership. DESIGN: Cross-sectional study. METHODS: One hundred forty-five participants (men, n = 73; mean ± SD age, 51 ± 14 years) with clinically diagnosed Achilles tendinopathy completed a baseline evaluation, including demographics and medical history, patient-reported outcome measures, a clinical exam, tendon structure measures via ultrasound imaging and continuous shear-wave elastography, and a functional test battery. Subgroups were identified using mixture modeling. We compared the subgroups using a 1-way analysis-of-variance or chi-square test and the Tukey post hoc test to identify defining attributes. We developed a clinical classification model using logistic regression and receiver operating characteristic curves. RESULTS: Three latent subgroups were identified and named by their distinctive patient characteristics and clinical attributes. The activity-dominant subgroup (n = 67), on average, had the highest physical activity level, function, and quality of life; reported mild symptoms; and was the youngest. The psychosocial-dominant subgroup (n = 56), on average, had the worst symptoms, impaired function, heightened psychological factors, the poorest quality of life, minimal tendon structural alterations, and was obese and predominantly female. The structure-dominant subgroup (n = 22), on average, had the most tendon structural alterations, severe functional deficits, moderate symptoms and psychological factors, reduced quality of life, and was the oldest, obese, and predominantly male. The clinical classification model correctly classified 85% (123/145) of participants. CONCLUSION: Three Achilles tendinopathy subgroups (activity dominant, psychosocial dominant, and structure dominant) differed in patient characteristics and clinical attributes. J Orthop Sports Phys Ther 2021;51(9):440-448. Epub 1 Jun 2021. doi:10.2519/jospt.2021.10271.

Shear-stress sensing by PIEZO1 regulates tendon stiffness in rodents and influences jumping performance in humans.

Athletic performance relies on tendons, which enable movement by transferring forces from muscles to the skeleton. Yet, how load-bearing structures in tendons sense and adapt to physical demands is not understood. Here, by performing calcium (Ca2+) imaging in mechanically loaded tendon explants from rats and in primary tendon cells from rats and humans, we show that tenocytes detect mechanical forces through the mechanosensitive ion channel PIEZO1, which senses shear stresses induced by collagen-fibre sliding. Through tenocyte-targeted loss-of-function and gain-of-function experiments in rodents, we show that reduced PIEZO1 activity decreased tendon stiffness and that elevated PIEZO1 mechanosignalling increased tendon stiffness and strength, seemingly through upregulated collagen cross-linking. We also show that humans carrying the PIEZO1 E756del gain-of-function mutation display a 13.2% average increase in normalized jumping height, presumably due to a higher rate of force generation or to the release of a larger amount of stored elastic energy. Further understanding of the PIEZO1-mediated mechanoregulation of tendon stiffness should aid research on musculoskeletal medicine and on sports performance.

Current Clinical Concepts: Conservative Management of Achilles Tendinopathy.

Achilles tendinopathy is a painful overuse injury that is extremely common in athletes, especially those who participate in running and jumping sports. In addition to pain, Achilles tendinopathy is accompanied by alterations in the tendon's structure and mechanical properties, altered lower extremity function, and fear of movement. Cumulatively, these impairments limit sport participation and performance. A thorough evaluation and comprehensive treatment plan, centered on progressive tendon loading, is required to ensure full recovery of tendon health and to minimize the risk of reinjury. In this review, we will provide an update on the evidence-based evaluation, outcome assessment, treatment, and return-to-sport planning for Achilles tendinopathy. Furthermore, we will provide the strength of evidence for these recommendations using the Strength of Recommendation Taxonomy system.

Examining Ankle-Joint Laxity Using 2 Knee Positions and With Simulated Muscle Guarding.

CONTEXT: Several factors affect the reliability of the anterior drawer and talar tilt tests, including the individual clinician's experience and skill, ankle and knee positioning, and muscle guarding. OBJECTIVES: To compare gastrocnemius activity during the measurement of ankle-complex motion at different knee positions, and secondarily, to compare ankle-complex motion during a simulated trial of muscle guarding. DESIGN: Cross-sectional study. SETTING: Research laboratory. PATIENTS OR OTHER PARTICIPANTS: Thirty-three participants aged 20.2 ± 1.7 years were tested. INTERVENTION(S): The ankle was loaded under 2 test conditions (relaxed, simulated muscle guarding) at 2 knee positions (0°, 90° of flexion) while gastrocnemius electromyography (EMG) activity was recorded. MAIN OUTCOME MEASURE(S): Anterior displacement (mm), inversion-eversion motion (°), and peak EMG amplitude values of the gastrocnemius (µV). RESULTS: Anterior displacement did not differ between the positions of 0° and 90° of knee flexion (P = .193). Inversion-eversion motion was greater at 0° of knee flexion compared with 90° (P < .001). Additionally, peak EMG amplitude of the gastrocnemius was not different between 0° and 90° of knee flexion during anterior displacement (P = .101). As expected, the simulated muscle-guarding trial reduced anterior displacement compared with the relaxed condition (0° of knee flexion, P = .008; 90° of knee flexion, P = .016) and reduced inversion-eversion motion (0° of knee flexion, P = .03; 90° of knee flexion, P < .001). CONCLUSIONS: In a relaxed state, the gastrocnemius muscle did not appear to affect anterior ankle laxity at the 2 most common knee positions for anterior drawer testing; however, talar tilt testing may be best performed with the knee in 0° of knee flexion. Finally, our outcomes from the simulated muscle-guarding condition suggest that clinicians should use caution and be aware of reduced perceived laxity when performing these clinical examination techniques immediately postinjury.