Achilles Tendon Research Articles

Harnessing Foot Mechanics: The Role of Lacing Techniques in Enhancing Comfort and Reducing Injury Risk

Background: Lacing techniques are often viewed as a functional necessity, but recent research has highlighted their role as a customization tool for foot health and comfort. This review synthesizes findings from studies examining the biomechanical effects of different lacing patterns on pressure distribution, tendon loading, and foot mechanics. Methods: We analyzed studies that investigated various lacing techniques, including tightness and patterns. Objective measurements, such as pressure insoles and cadaveric models, were used to quantify the effects. Diverse study populations, including individuals with foot health concerns and athletes, were considered. This study was conducted as a scoping review following the JBI methodology, adhering to the PRISMA-ScR guidelines. Results: The studies collectively reveal that lacing patterns significantly influence dorsal pressure distribution during activities like running. Customized lacing can optimize foot biomechanics, reducing the risk of injuries related to abnormal pressure distribution. A total of 27 records were identified from the initial search. After removing duplicates and screening, four articles were included in the final review. Additionally, certain lacing configurations were found to reduce peak Achilles tendon tension, a crucial finding for injury-prone individuals. Conclusions: Proper lacing techniques are not just a functional aspect but a means to enhance foot health and prevent injuries. Healthcare professionals can provide personalized lacing recommendations to patients, with implications for those with specific foot conditions, athletes, and individuals at risk of injuries. The importance of patient education on the significance of lacing techniques cannot be overstated, emphasizing the need for informed choices when lacing shoes. These findings underscore the multifaceted role of lacing techniques in promoting foot health and well-being.

HyProCure for Flatfoot Deformity: A Clinical Characteristics Analysis in China.

Flatfoot is a common foot disorder involving progressive foot deformity of the three-dimensional structures of the forefoot, midfoot, and hindfoot. Currently, Chinese surgeons and patients favor subtalar arthroereisis (SA) due to its minimally invasive and low-damage characteristics. HyProCure device is widely used. However, there is limited analysis of large sample sizes. This study utilized statistical evaluation with a large sample size to analyze clinical characteristics trends of SA for flatfoot, including baseline indicators, selection of HyProCure size and surgical strategy, complications, and implant removal. This study will enhance the understanding of SA in China. A retrospective analysis of 732 patients (1008 ft) who underwent SA from June 2015 to June 2023, with 509 pediatric and adolescent patients (772 ft) and 223 adult patients (236 ft). Based on the patient's age, patients aged ≤ 18 were included in the children and adolescent group, while adult acquired flatfoot deformity (AAFD) patients aged > 18 were included in the adult group. General data was collected, including patient sex, age, side, body mass index (BMI), surgery date, HyproCure size, and surgical data, and trends were analyzed. Postoperative complications and HyProCure removal were collected as outcome measures during follow-up. The age of patients treated with SA was gradually getting younger, with male patients predominating, mainly concentrated in the 11-14 age group. HyProCure 7 has the highest usage rate. In the children and adolescent group, 288 ft (37.31%) only underwent SA. In the adult group, 18 ft (7.63%) only underwent SA. Complications include sinus tarsi pain, peroneal spasms, achilles tendon tension, and muscle strength decline. The complication rate in the children and adolescent group was 5.05%, while in the adult group it was 28.81%. Overall, it was 10.62%. The removal rate of HyProCure in the children and adolescent group is 1.04%, in the adult group is 15.25%, and overall is 4.37%. The trend in flatfoot treated with SA was towards children and adolescent male patients, and sinus tarsi pain was the most common complication after SA. The complication rate and removal rate in the children and adolescent group were lower than those in the adult group. HyProCure can be removed without additional adverse effects.

Towards Achilles Tendon Injury Prevention in Athletes with Structural MRI Biomarkers: A Machine Learning Approach.

Recent advancements in artificial intelligence have proven their effectiveness in orthopaedic settings, especially in tasks like medical image analysis. This study compares human musculoskeletal radiologists to artificial intelligence in a novel, detailed, short, and cost-effective examination of Achilles tendon magnetic resonance images to uncover potential disparities in their reasoning approaches. Aiming to identify relationships between the structured assessment of the Achilles tendon and its function that could support injury prevention. We examined 72 athletes to investigate the link between Achilles tendon structure, as visualised in magnetic resonance images using a precise T2*-weighted gradient echo sequence with very short echo times, and its functional attributes. The acquired data were analysed using advanced artificial intelligence techniques and reviewed by radiologists. Additionally, we conducted statistical assessments to explore relationships with functional studies in four meaningful groups: dynamic strength, range of motion, muscle torque and stabilography. The results show notable linear or non-linear relationships between functional indicators and structural alterations (maximal obtained Spearman correlation coefficients ranged from 0.3 to 0.36 for radiological assessment and from 0.33 to 0.49 for artificial intelligence assessment, while maximal normalised mutual information ranged from 0.52 to 0.57 for radiological assessment and from 0.42 to 0.6 for artificial intelligence assessment). Moreover, when artificial intelligence-based magnetic resonance assessment was utilised as an input, the associations consistently proved more robust, or the count of significant relationships surpassed that derived from radiological assessment. Ultimately, utilising only structural parameters as inputs enabled us to explain up to 59% of the variance within specific functional groups. This analysis revealed that structural parameters influence four key functional aspects related to the Achilles tendon. Furthermore, we found that relying solely on subjective radiologist opinions limited our ability to reason effectively, in contrast to the structured artificial intelligence assessment. Cross-sectional studies.

Structural and Functional Properties of Lower Extremity Tendons in Men.

Comstock, BA, Flanagan, SD, Denegar, CR, Newton, RU, Häkkinen, K, Volek, JS, Maresh, CM, Kraemer, WJ. Structural and functional properties of lower extremity tendons in men. J Strength Cond Res XX(X): 000-000, 2024-The purpose of this study was to understand further patellar and Achilles tendon structure and function, body composition, and serum collagen turnover biomarkers in young men who performed heavy resistance training (RT, n = 13, age: 22.2 ± 1.4 years) compared with recreationally active men who were not resistance-trained (NR, n = 13, age: 22.8 ± 2.2 years). Tendon properties were measured at rest and during maximal voluntary isometric efforts using ultrasonography and dynamometry. Lean body mass (LBM) and bone mineral density (BMD) were assessed with dual X-ray absorptiometry. Serum collagen turnover markers were analyzed and related to tendon measures. Resistance-trained men had significantly (p ≤ 0.05) greater LBM and BMD compared with recreationally active men. Resistance-trained men also showed significantly greater patellar tendon (PT) stiffness (45%) and Young's modulus (36%), though the PT cross-sectional area (CSA) did not differ significantly between groups. Achilles tendon CSA was significantly larger in resistance-trained men. Still, other properties such as stiffness and modulus did not differ significantly between the groups. Serum collagen turnover markers showed no significant differences between groups and were not correlated to any tendon or bone biomarkers. The findings support that resistance-trained men have greater LBM and BMD. However now, it reveals that tendon adaptations differ, as not all measures were similarly affected in both tendons. The blood biomarkers did not show any obvious roles in explaining the differential changes in tendons. Heavy RT induces differential tendon changes potentially due to complex interactions of training variables.

High-volume injections in Achilles tendinopathy: a systematic review.

Achilles tendinopathy (AT) is common, particularly in runners. High-volume injections (HVIs) may be beneficial in the management of AT compared to other conservative management options, including exercise regimens, platelet-rich plasma (PRP) injections, and extracorporeal shockwave therapy. The published research on the effectiveness of HVI in the treatment of AT was evaluated in this systematic review. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed when conducting this systematic review. The electronic databases PubMed, Embase, Cochrane, Web of Science, CINAHL, and OVID were thoroughly searched, from inception to 13 September 2023, for articles assessing HVI for AT. A total of 10 studies with 460 participants met the inclusion criteria. HVI typically consisted of saline, local anaesthetic, and corticosteroids. HVI combined with corticosteroids demonstrated immediate and long-term improvements in ankle function. Compared to HVI without corticosteroids, HVI with corticosteroids exhibited greater, early improvements in pain and function, with no significant differences at later follow-up points. Significant reductions in tendon thickness and neovascularity were also found with HVI treatment over time. No adverse events were reported with HVI, despite the use of corticosteroids. HVI is an effective and safe modality, particularly in the short term, to significantly reduce pain and discomfort in the Achilles tendon, especially when supplemented with corticosteroids. More robust randomized controlled trials, with longer-term follow-ups and homogeneity, are needed to fully establish its efficacy for AT.

Achilles Pain, Stiffness, and Muscle Power Deficits: Midportion Achilles Tendinopathy Revision – 2024

The Academy of Orthopaedic Physical Therapy (AOPT) has an ongoing effort to create evidence-based clinical practice guidelines (CPG) for orthopaedic physical therapy management of patients with musculoskeletal impairments described in the World Health Organization's International Classification of Functioning, Disability, and Health (ICF). The 2024 Achilles Pain, Stiffness, and Muscle Power Deficit: Midportion Achilles Tendinopathy Clinical Practice Guideline (CPG) is a revision of the 2018 CPG and represents the third CPG from AOPT on this topic. The goals of the revision were to provide a concise summary of the contemporary evidence and to develop new recommendations or revise previously published recommendations to support evidence-based practice. This current CPG covers prevalence, pathoanatomical features, risk factors, clinical course, diagnosis, examination, imaging and physical therapy interventions for the management of midportion Achilles tendinopathy.

Trans-Achilles percutaneous fixation technique for posterior malleolus fracture: a cadaveric study

BackgroundIt has been reported that 43.6% of ankle fractures are accompanied by posterior malleolus fractures. The aim of this study is to define a safe zone for posterior malleolus fractures by determining the locations of the important anatomical structures in this region. Additionally, it aims to identify the trans-Achilles passage line for Kirschner wire insertion through a posteroanterior approach for posterior malleolus fragments.MethodsSix below-knee amputee fresh-frozen leg cadavers were used in this study. A trans-Achilles Kirschner wire was applied to the cadavers in the posteroanterior direction under the guidance of fluoroscopy. The areas where the Kirschner wire passed were dissected, and their proximity to vital anatomical structures was measured.ResultsIn all cadavers, the transverse thickness of the Achilles tendon at the level of the trans-Achilles Kirschner wire was 15.5 mm and the trans-Achilles Kirschner wire application was 18.6 mm from the sural nerve, 16 mm from the posterior tibial tendon, and 12.16 mm from the flexor digitorum longus muscle. It was performed 15.16 and 14.6 mm from the posterior tibial artery and vein, 12.3 mm from the tibial nerve, 13.6 mm from the tibiofibular joint, and 55.5 mm from the insertion site of the Achilles tendon to the calcaneus and at a sufficient distance from vital anatomical structures.ConclusionsThe proposed trans-Achilles percutaneous surgical technique is safe from neurovascular structures for fixing posterior malleolar fractures. However, the long-term clinical outcomes of this technique need to be explored.Level of evidenceLevel III, A cadaveric study.

UK Foot and Ankle Thromboembolism (UK-FATE).

Venous thromboembolism (VTE) is a potential complication of foot and ankle surgery. There is a lack of agreement on contributing risk factors and chemical prophylaxis requirements. The primary outcome of this study was to analyze the 90-day incidence of symptomatic VTE and VTE-related mortality in patients undergoing foot and ankle surgery and Achilles tendon (TA) rupture. Secondary aims were to assess the variation in the provision of chemical prophylaxis and risk factors for VTE. This was a multicentre, prospective national collaborative audit with data collection over nine months for all patients undergoing foot and ankle surgery in an operating theatre or TA rupture treatment, within participating UK hospitals. The association between VTE and thromboprophylaxis was assessed with a univariable logistic regression model. A multivariable logistic regression model was used to identify key predictors for the risk of VTE. A total of 13,569 patients were included from 68 sites. Overall, 11,363 patients were available for analysis: 44.79% were elective (n = 5,090), 42.16% were trauma excluding TA ruptures (n = 4,791), 3.50% were acute diabetic procedures (n = 398), 2.44% were TA ruptures undergoing surgery (n = 277), and 7.10% were TA ruptures treated nonoperatively (n = 807). In total, 11 chemical anticoagulants were recorded, with the most common agent being low-molecular-weight heparin (n = 6,303; 56.79%). A total of 32.71% received no chemical prophylaxis. There were 99 cases of VTE (incidence 0.87% (95% CI 0.71 to 1.06)). VTE-related mortality was 0.03% (95% CI 0.005 to 0.080). Univariable analysis showed that increased age and American Society of Anesthesiologists (ASA) grade had higher odds of VTE, as did having previous cancer, stroke, or history of VTE. On multivariable analysis, the strongest predictors for VTE were the type of foot and ankle procedure and ASA grade. The 90-day incidence of symptomatic VTE and mortality related to VTE is low in foot and ankle surgery and TA management. There was notable variability in the chemical prophylaxis used. The significant risk factors associated with 90-day symptomatic VTE were TA rupture and high ASA grade.

Current Concepts in Orthobiologics for Achilles Tendon Injuries: A Critical Analysis Review.

» Platelet-rich plasma and hyaluronic acid are low-risk and potentially high-reward treatments for Achilles tendinopathy, although clinical studies have yielded mixed results with questionable methodological quality» Case series and reports have reported that bone marrow aspirate, stem cells, and amniotic membrane products can improve functional outcomes, alleviate pain, and facilitate return to sport and activities, but high-level evidence studies are lacking» Exosomes are a promising novel biologic with laboratory studies showing improved collagen organization and cell proliferation, greater tendon mechanical properties, and prevention of extracellular matrix breakdown.» Standardization of protocols with clear reporting is necessary for future studies evaluating orthobiologic therapies for Achilles tendon injuries.

Degree of twist in the Achilles tendon interacts with its length and thickness in affecting local strain magnitude: a finite element analysis

IntroductionThe relationship between the twisting of the three subtendons of the Achilles tendon (AT) and local strain has received attention in recent years. The present study aimed to elucidate how the degree of twist in the AT affects strain using finite element (FE) analysis, while also considering other geometries (e.g., length, thickness, and width) and their combinations.MethodsA total of 59 FE models with different degrees of twist and geometries were created. A lengthening force (z-axis) of 1,000 N was applied to each subtendon (total: 3,000 N). The average value of the first principal Lagrange strain was calculated for the middle third of the total length of the model.ResultsStatistical (stepwise) analysis revealed the effects of the degree of twist, other geometries, and their combinations on AT strain. The main findings were as follows: (1) a greater degree of twist resulted in higher average strains (t = 9.28, p < 0.0001) and (2) the effect of the degree of twist on the strain depended on dimensions of thickness of the most distal part of the AT (t = −4.49, p < 0.0001) and the length of the AT (t = −3.82, p = 0.0005). Specifically, when the thickness of the most distal part and length were large, the degree of twist had a small effect on the first principal Lagrange strain; however, when the thickness of the most distal part and length were small, a greater degree of twist results in higher first principal Lagrange strain.ConclusionThese results indicate that the relationship between the degree of twist and local strain is complex and may not be accurately assessed by FE simulation using a single geometry.

Percutaneous repair of achilles tendon ruptures: short-term results of 41 patients

Aims: Despite the current popularity of surgical treatment of Achilles tendon ruptures, there is no clear consensus about which technique should be applied. The aim of this study is to evaluate the short- to mid-term results of acute Achilles tendon ruptures treated with the percutaneous method and to discuss these results in light of the literature. Methods: In this study, 41 patients who were operated on percutaneously with the diagnosis of acute Achilles tendon rupture between 2016 and 2019, whose treatment was completed, and who had a follow-up period of at least 1 year were included. At the patients’ final follow-up visits, the range of motion of the ankle joint, time to return to work and sports, and complications were evaluated. For functional evaluations, the scoring system of the American Orthopaedic Foot & Ankle Society (AOFAS) for the ankle joint was used. Results: The mean age of the patients was 29.3 (18-50) years and the mean follow-up duration was 23 (12-38) months. The mean dorsiflexion angle was 32.27° (20-45°) and the mean plantar flexion angle was 34.58° (20-45°). The time to return to work was 14.2 (8-21) weeks, while time to return to sports was 30.4 (17-49) weeks. The mean AOFAS score of the patients was 91.63 (74-100). The complications included infection in 2 (4.8%) patients, wound necrosis in 1 (2.4%) patient, re-rupture in 1 (2.4%) patient, and sural nerve neuropraxia in 1 (2.4%) patient. Conclusion: The findings of this study suggest that percutaneous repair is an effective method in the treatment of acute Achilles tendon ruptures, like other surgical methods that offer good functional results with low complication rates.

The achilles tendon rupture: A deeper dive into its impact on professional and high-performance athletes

Background: The Achilles tendon rupture (ATR) is an injury that has been detrimental to professional athletes over the years, recently rising to unforeseen heights as the intensity of sports has increased. Methods: To obtain relevant statistics for this paper, a review of prior research, including original research and case studies, was conducted. Digital publications and clinical data were reviewed to dissect factors such as injury causes, operations, current initiatives, the role of technology, and future implications. Results: The data revealed a significant increase in documented ATRs in athletes and the National Football League (NFL) over the years; most recently, these injuries increased from 11 in the 2019-2020 season to 24 in the 2021-2022 season.3 Despite advancements in technology and recovery methods, dynamic changes involving training, conditioning, physicality, and intensity in sports have greatly contributed to the increased rates of injuries. With modernized resources such as advanced testing and rehabilitation procedures incorporating artificial intelligence (AI), specialists continue to search for new ways to treat injury and improve functional outcomes more effectively. Conclusion: This paper examines ATRs in athletes, its risk factors, current surgical methods for treatment, and modern rehabilitation methods. Future research should continue to develop comprehensive assessment and treatment methods to decrease the time to return to play, reduce the risk of re-injuries, and ensure cost-effective standards in implementing advanced rehabilitation modalities.

Tensile Strength of the Achilles Tendon Allograft: A Comparative Study of Graft Preparation Technique

Background/Objectives: The Achilles tendon is a popular allograft option for anterior cruciate ligament (ACL) reconstruction. Structurally, the tendon is known to have a 90-degree rotational fiber track. Preparation techniques, with this consideration, may influence the strength of the graft. This study aims to assess the tensile strength of a novel Achilles tendon allograft harvest procedure following the rotational fiber track. Methods: Both Achilles tendons were harvested from formalin-embalmed cadavers [(n = 20), male n = 13, female n = 7, average age = 70]. Ten cadavers had the right Achilles as the control and the left Achilles as the fiber track sample; 10 cadavers had the opposing designation. Tensile strength was tested utilizing a Bose machine. An unpaired t-test was used to compare data across groups. Results: The average ultimate load for the control group was 874.17 N, with an average elastic stiffness of 76.01 N/mm. The ultimate load for the fiber track group was 807.84 N, with an average elastic stiffness of 64.75 N/mm. No statistically significant difference (p = 0.21) was determined between the average ultimate loads or elastic loads (p = 0.18) across groups. Conclusions: These data suggest that the rotational fiber track method of Achilles allograft has consistent tensile strength and elastic stiffness as compared to the common harvest procedure. The rotational fiber track method for ACL harvesting is a viable alternative option to the common harvest procedure for usage in an ACL reconstruction.

Mini-open versus percutaneous surgical repair for acute Achilles tendon rupture: a systematic review and meta-analysis.

To compare the clinical outcomes and complications of mini-open (MOT) and percutaneous techniques (PT) in the surgical repair of acute Achilles tendon rupture (AATR). We systematically searched PubMed, Scopus, Web of Science, Clinical Trials, and the Cochrane Library for studies comparing MOT with PT for AATR. We assessed functional outcomes, complication rates, and operation time. Statistical analyses were performed using RevMan Web. Odds ratios (ORs) and mean difference (MD) with 95% confidence intervals (CIs) were pooled with a fixed-effects model for dichotomous and continuous endpoints, respectively. Heterogeneity was evaluated with I2 statistics. Eight studies, comprising 484 patients, were included, of whom 226 (46%) underwent MOT. MOT was associated with a significantly lower re-rupture rate (1.48% vs. 6.11%; OR 0.28; 95% CI 0.09-0.86; p = 0.03; I2 = 6%) and sural nerve injury rate (0.57% vs. 5.64%; OR 0.24; 95% CI 0.07-0.81; p = 0.02; I2 = 0%). No significant differences were observed in venous thrombosis (OR 0.81; 95% CI 0.17-3.94; p = 0.33; I2 = 0%), wound infection (OR 0.56; 95% CI 0.12-2.62; p = 0.46; I2 = 0%), or operation time (MD 1.83min; 95% CI -1.13-4.79; p = 0.23; I2 = 88%). Functional outcomes showed higher American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot scores in the MOT group (MD 1.52 points; 95% CI 0.62-2.42; p = 0.001; I2 = 3%), while (Achilles Tendon Total Rupture Score) ATRS, time to return to activities, and ankle plantar and dorsiflexion were comparable. MOT for AATR repair seems to reduce re-ruptures and sural nerve injuries while improving AOFAS scores, with no significant differences in other complications compared to PT. These findings suggest that the MOT may offer a safer and equally effective alternative to PT for AATR.

Lipoprotein(a) levels and cholesterol efflux capacity: inverse association and impact on atherosclerosis in familial hypercholesterolemia patients on lipid-lowering therapy

Abstract Backgrounds Familial hypercholesterolemia (FH) patients have higher serum lipoprotein(a) (Lp(a)) levels than non-FH patients, and high Lp(a) levels raise atherosclerotic cardiovascular disease (ASCVD) risk 1). We previously reported that decreased cholesterol efflux capacity (CEC) is a risk marker for ASCVD in patients with statin-treated FH 2). Others have reported that Lp(a) interferes with the enhancement of ABCA1-mediated cholesterol efflux by plasminogen and that ABCA1-mediated CEC is lower in patients with Lp(a) >50 mg/dL. However, the association of CEC, not necessarily ABCA1-mediated, with Lp(a) is not clear and has not been studied in patients with FH. It is also unclear whether high Lp(a) and low CEC in patients with FH are associated with the severity of atherosclerosis. Purpose We examined whether Lp(a) levels are negatively associated with ABCA1-independent CEC in patients with FH receiving lipid-lowering therapy. We also examined the impact of the combination of high Lp(a) and low CEC on the presence of corneal arcus, Achilles tendon thickness, carotid intima-media thickness (IMT), and pre-existing ASCVD. Methods This cross-sectional study included 371 patients clinically diagnosed with FH receiving lipid-lowering therapy. CEC was measured in apolipoprotein B-depleted plasma and 3H-cholesterol-labeled J774.1 cells without cAMP-stimulated ABCA1 overexpression. Lp(a) was measured by enzymatic methods (Sekisui Medical, Tokyo, Japan) using an automated analyser. Achilles tendon thickness was measured by X-ray and carotid IMT by ultrasound. Results Mean age was 55±16 years, and 191 (51%) were women. The median serum Lp(a) level was 18.7 mg/dL, higher than the previously reported median level (13 mg/dL) in a Japanese population. One hundred nineteen patients (32%) had serum Lp(a) levels of 30 mg/dL or higher, and they had significantly lower CEC (P=0.0015). This negative association persisted after adjusting for age, sex, BMI, smoking status, serum LDL-cholesterol, serum triglycerides, and eGFR in a multiple linear regression model (beta-coefficient: -0.047, 95% CI: -0.075 - -0.019, P=0.0011). In addition, patients with both Lp(a) > 30 mg/dL and CEC lower than the median had a higher percentage of corneal arcus, thicker Achilles tendons, greater carotid IMT, and a higher prevalence of pre-existing ASCVD compared to patients with either or neither. Conclusions We found an inverse relationship between Lp(a) levels and CEC in FH patients receiving lipid-lowering therapy. Our results suggest that Lp(a) may also inhibit ABCA1-independent CEC, including passive cholesterol diffusion from peripheral cells. Furthermore, the combination of high Lp(a) and low CEC may be a residual risk for patients with FH receiving lipid-lowering therapy. Future studies are needed to determine whether agents that decrease Lp(a) levels will increase CEC and thereby resolve part of the residual ASCVD risk in FH.

Discipline-specific adaptation patterns in respiratory and lower limb musculotendinous structures: cyclists vs. basketball players.

This study aimed at assessing how chronic exposure to specific exercise training (high-intensity intervals vs. endurance), comparing experienced basketball-players (BP, N.=16), cyclists (CY, N.=16), and non-specifically trained individuals (CN, N.=16), influences the structural and functional characteristics of both lower limb and respiratory musculotendinous structures. Vastus lateralis, gastrocnemius lateralis, and medialis, diaphragm muscles, as well as patellar tendon and Achilles tendon, were assessed using B-mode ultrasonography. Maximal voluntary isometric and passive torque measurements were conducted in the knee-extensors and plantar-flexors. Additionally, a subset of participants (N.=10 for each group) underwent a fatigue-inducing exercise-till-exhaustion protocol, and the strength of lower limb and respiratory muscles was evaluated immediately before and after the trial. Athletes had bigger and stronger musculotendinous structures and greater endurance to fatigue than CN (P<0.05). BP had bigger plantar-flexors and diaphragm, greater fascicles length, more explosive plantar-flexors and respiratory muscles and bigger tendons than CY (P<0.05). On the other hand, CY showed greater muscle pennation angle and greater endurance to fatigue for both, lower limb, and respiratory muscles (P<0.05). The present study emphasizes that chronic and specific exercise training leads to distinctive adaptations, not only in lower limb musculotendinous structures but also in other components such as respiratory muscles.

Conventional radiography and correlated factors of enthesopathies of the Achilles tendon and plantar fascia in patients with axial spondyloarthritis.

This study aimed to investigate the correlated risk factors and presence of radiological enthesopathies of the Achilles tendon and plantar fascia in patients with axial spondyloarthropathy (axSpA). 242 patients (121 female and 121 male) with axSpA were included in this study. The Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), the Bath Ankylosing Spondylitis Functional Index (BASFI), the Ankylosing Spondylitis Disease Activity Score with C-reactive protein (ASDAS-CRP), the Bath Ankylosing Spondylitis Radiology Index (BASRI), the Maastricht Ankylosing Spondylitis Enthesitis Score (MASES), and CRP were evaluated in all patients. The lateral foot X-rays of the patients were assessed for enthesopathies of the Achilles tendon and plantar fascia attachments. Calcaneal spur and Achilles enthesopathies were present in 57.4% of the patients. 39.3% of patients had enthesopathies in both regions. The male and female groups differed statistically in terms of weight, height, body mass index (BMI), positive family history, and duration since diagnosis (p<0.05). The presence of calcaneal spur and Achilles enthesopathies was found to be significantly correlated with age, weight, BMI, symptom duration, and the score of BASDAI, BASFI, ASDAS-CRP, BASRI, and MASES (p<0.05). The presence of enthesopathies appears to be associated with age, weight, BMI, symptom duration, and disease activity. Conventional radiography can be used as an auxiliary tool in the evaluation of entheseal abnormalities in patients with SpA, especially in patients with advanced age, long symptom duration, and high BMI.

Impact of changes of Achilles tendon thickening on cardiovascular events among patients with familial hypercholesterolemia

Abstract Backgrounds Achilles tendon thickening (ATT) can be regressed through LDL-lowering in patients with familial hypercholesterolemia (FH). The Japan Atherosclerosis Society (JAS) determined the threshold of ATT as ≥8.0 mm in male and ≥7.5 mm in female. Purpose We aimed to determine clinical impact of changes of ATT in development of major adverse cardiovascular events (MACE). Methods Patients with clinically diagnosed FH (N=1,273, male/female=614/659) with ATT data using X-ray were assessed. We divided the patients into 4 groups (group 1: patients without ATT from baseline to their follow-up, group 2: patients without ATT at baseline, but developed ATT at follow-up, group 3: patients with ATT at baseline, but regressed at follow-up, group 4: patients with ATT from baseline to their follow-up). Cox proportional hazards models were used to assess factors associated with MACE, including cardiovascular death and any coronary events. Results The median follow-up period was 10.9 years. During the follow-up period, 142 MACEs were observed, and median ATT was regressed from 7.8 to 7.6 mm. We found that there was more significant positive correlation between cholesterol-year score and ATT among patients with and without MACE (p &amp;lt;0.001; Spearman’s r=0.33, and p &amp;lt;0.001; Spearman’s r=0.35, respectively). Under these circumstances, changes of ATT were significantly associated with the occurrence of MACE (hazard ratio (HR): 2.73; 95% confidence interval (CI): 1.33–4.13; p&amp;lt;0.001, HR: 2.18; 95% CI: 1.08–3.28; p&amp;lt;0.001, HR: 6.34; 95% CI: 3.10–9.58; p&amp;lt;0.001, in group 2, group 3, and group 4, respectively when group 1 was considered as reference). Conclusion Assessments of ATT condition represent diagnostic values and risk stratification information among patients with FH.

Muscle‐Inspired Robust Anisotropic Cellulose Conductive Hydrogel for Multidirectional Strain Sensors and Implantable Bioelectronics

AbstractIntegrating superior mechanical performance, anisotropic conductivity, and biocompatibility into conductive hydrogels as all‐in‐one human‐machine interaction device remains challenging. Herein, by mimicking the anisotropic structures of human muscles, a robust anisotropic conductive hydrogel is developed by initially aligning polyvinyl alcohol with polypyrrole decorated cellulose nanofibrils to form an anisotropically oriented polymer networks, followed by post‐crosslinking with tannic acid (TA). Introducing TA into hydrogel network permanently secures its hierarchically anisotropic structure through multiple hydrogen bonds, thus endowing the hydrogel with exceptional mechanical properties (tensile strength of 11.41 MPa, toughness of 12.44 MJ m−3), anisotropic adhesive property, and direction‐dependent conductivity. With these attributes, a hydrogel strain sensor with excellent multidirectional sensitivity is developed, enabling stable monitoring of multi‐degrees of freedom joint movements in the human body and facilitating the control of a multiaxial virtual robot manipulator. Moreover, the in vitro/vivo tests demonstrate exceptional biocompatibility and anti‐biofouling properties of the as‐prepared hydrogel sensor, maintaining stable electronic response signals for over 14 days after successful implantation into the Achilles tendon of mice. Overall, this study presents a promising approach for designing conductive hydrogels with superior mechanical properties and anisotropic functionality for emerging applications in both in vitro and in vivo human‐machine interface materials.

Single-nucleus transcriptional and chromatin accessibility analyses of maturing mouse Achilles tendon uncover the molecular landscape of tendon stem/progenitor cells.

Tendons and ligaments are crucial connective tissues linking bones and muscles, yet achieving full functional recovery after injury remains challenging. We investigated the characteristics of tendon stem/progenitor cells (TSPCs) by focusing on the declining tendon repair capacity with growth. Using single-cell RNA sequencing on Achilles tendon cells from 2- and 6-week-old mice, we identified Cd55 and Cd248 as novel surface antigen markers for TSPCs. Combining single-nucleus ATAC and RNA sequencing analyses revealed that Cd55 and Cd248 positive fractions in tendon tissue are TSPCs, with this population decreasing at 1 weeks. We also identified candidate upstream transcription factors regulating these fractions. Functional analyses of isolated CD55/CD248 positive cells demonstrated high clonogenic potential and tendon differentiation capacity, forming functional tendon-like tissue in vitro . This study establishes CD55 and CD248 as novel TSPC surface antigens, potentially advancing tendon regenerative medicine and contributing to the development of new treatment strategies for tendon and ligament injuries.