Search Results (71)

Background: Postoperative recurrence of sacrococcygeal chordomas presents significant clinical challenges due to unusual recurrence patterns. This study aimed to characterize these patterns of recurrence to inform improved adjuvant radiotherapy planning. Methods: We retrospectively analyzed 31 patients with recurrent sacrococcygeal chordoma following surgery, assessing recurrence locations considering initial tumor extent, resection levels, and postoperative anatomical changes on MRI. In 18 patients, pre- and postoperative imaging enabled the spatial mapping of early recurrence origins relative to the initial tumor volume using isotropic expansions. The median initial gross tumor volume was 113 mL. Results: Recurrences were mostly multifocal and predominantly involved soft tissues (e.g., mesorectal/perirectal space (80.6%), piriformis and gluteal muscles (80.6% and 67.7%, respectively) and osseous structures, particularly the sacrum (87.1%)). The median time to recurrence was 15 months. The initial surgery was R0 in 17 patients (55%). The highest infiltrated sacral vertebra was S1 in 3%, S2 in 10%, S3 in 35%, S4 in 23%, S5 in 10%, and coccygeal in 19%. Anatomical changes post-resection, including rectal herniation into gluteal and subcutaneous tissues, significantly affected radiotherapy planning. Expansion of the initial tumor volume by 2 cm failed to encompass all recurrence origins in 72% of cases. A 5 cm expansion was required to achieve full coverage in 56% of patients, though 22% of recurrences still lay beyond this margin and the remaining were covered only partially. Conclusions: Recurrent sacrococcygeal chordomas exhibit complex, soft-tissue-dominant patterns and are influenced by significant anatomical displacement post-surgery. Standard target volume expansions are often insufficient to cover the predominantly multifocal recurrences. Full article

Introduction: Hip abductor strength is essential for pelvic stability, lower limb alignment, and injury prevention. Weaknesses of the gluteus medius and minimus contribute to various musculoskeletal conditions. Lateral band walks and monster walks are elastic resistance exercises commonly used to target the hip abductors and external rotators in functional, weight-bearing tasks. Therefore, the aim was to summarize the current evidence on the biomechanics, muscle activation, and clinical applications of lateral and monster band walks. Methods: This narrative review was conducted following the SANRA guideline. A comprehensive literature search was performed across PubMed, Scopus, Web of Science, and SPORTDiscus up to April 2025. Studies on the biomechanics, electromyography, and clinical applications of lateral band walks and monster walks were included, alongside relevant evidence on hip abductor strengthening. Results: A total of 13 studies were included in the review, of which 4 specifically investigated lateral band walk and/or monster walk exercises. Lateral and monster walks elicit moderate to high activation of the gluteus medius and maximus, especially when performed with the band at the ankles or forefeet and in a semi-squat posture. This technique minimizes compensation from the tensor fasciae latae and promotes selective gluteal recruitment. Proper execution requires control of the trunk and pelvis, optimal squat depth, and consistent band tension. Anatomical factors (e.g., femoral torsion), sex differences, and postural variations may influence movement quality and necessitate tailored instruction. Full article

Background: Short-stem hip replacements are designed to provide improved load distribution and to mimic natural biomechanics. The interplay between implant design, positioning, and resulting bone biomechanics in individual patients remains underexplored, and the relationship between radiographically assessed bone remodeling around short stems and biomechanical predictions has not been previously reported. Methods: This study evaluated three short-stem hip implant designs: Proxima, Collo-MIS, and Minima. Postoperative bone remodeling patterns were analyzed, categorizing remodeling as bone gain, bone loss, or no observable activity, with changes tracked over time. Patient-specific biomechanical models were generated from 6-week postoperative radiographs. Finite element simulations incorporated body weight and gluteal muscle forces to estimate stress and strain distributions within the proximal femur. Strain energy was then applied to a mechanostat-based remodeling algorithm to predict bone remodeling patterns. These biomechanical predictions were compared to observed radiographic remodeling at 2 years post-surgery. A validated biomechanical model was further used to simulate different postoperative positions of the three types of stems. Results: No differences in bone remodeling patterns were observed among the three short-stem designs. Computational modeling demonstrated a statistically significant correlation between predicted remodeling and radiographic measurements at 2 years (p < 0.001). Proxima stems showed a tendency towards increased cortical bone loading under pronounced varus or valgus position in comparison to other two stems, although this observation requires further validation. Conclusions: This exploratory study demonstrates the feasibility of using biomechanical modeling to estimate bone remodeling around short-stem hip implants based on early postoperative radiographs. While the results are promising, they should be interpreted with caution due to the limited cohort size. The proposed modeling approach may offer clinical value in evaluating implant behavior and informing patient-specific treatment strategies. However, further research with larger populations is necessary to refine and validate these predictive tools. Full article

Background: Gluteal augmentation and reshaping have recently gained popularity due to growing patient demand. The rising number of intramuscular gluteal augmentation procedures has led to a corresponding increase in implants, although this has not reduced noticeable esthetic flaws and relatively common postoperative complications. The patient often opts for a secondary gluteal replacement implant. However, studies on this procedure are scarce. Methods: We describe our secondary submuscular gluteal implant replacement technique in patients complaining about dislocation or complications with the primary intramuscular gluteal implant. This procedure involved creating a new round implant pocket in a deeper anatomical plane while keeping the gluteus maximus muscle bridge that joins the intramuscular pocket with the submuscular pocket as intact as possible. To achieve this result, we describe the safest way to remove the intramuscular implant: a small incision is performed posterior to the iliac crest, through which the intramuscular gluteal implant is removed via a small intramuscular-subcutaneous tunnel. We reviewed surgical data, focusing on implant size choice and postoperative complications. Results: We performed this technique on 108 patients. The most frequent complications included three cases of laceration of the muscular bridge between the old intramuscular plane and the new submuscular pocket, resulting in both pockets merging, and eight cases with temporary nerve pain lasting a few days postoperatively. Conclusions: This study validates our approach for addressing and preventing dislocation or other complications from intramuscular gluteal augmentation procedures with implants by applying a safe technique that involves replacing the intramuscular implant with a submuscular one. Full article

Background/Objectives: Muscle tissues are a common source of symptoms related to low back pain (LBP), with myofascial trigger points (MTrPs) being a significant contributor. Since previous meta-analyses support interventions targeting MTrPs for reducing pain and improving functional disability in patients with LBP, this review aimed to synthesize current knowledge on the prevalence of MTrPs in LBP patients. Methods: To conduct this systematic review, data were collected from PubMed, Cochrane, and Web of Science. Published articles at any time up to February 2025 that comprised descriptive, observational, or experimental studies in English/Spanish language reporting the prevalence of active or latent MTrPs in patients with LBP were eligible. After assessing the methodological quality, a structured and qualitative synthesis was conducted using a standardized form that captured participant characteristics, evaluated muscles, the number or percentage of active and latent MTrPs in each group, clinical features, summarized results, and conclusions. Results: Nine articles with acceptable methodological quality were included. The prevalence of active MTrPs in patients with LBP was quadratus lumborum (ranging from 30% to 55%), gluteus medius (from 34% to 45%), piriformis (42%), psoas (from 5% to 10%), and lumbar iliocostalis (from 33% to 38%). Latent MTrPs were most common in the gluteus medius (74%) and quadratus lumborum (14–17%), with the piriformis, psoas, and lumbar iliocostalis also affected. Conclusions: Active and latent MTrPs are common in muscles such as the quadratus lumborum, gluteus medius, and iliocostalis in individuals with LBP, with prevalence varying by pain chronicity and etiology. MTrPs in the gluteal region are more frequent in lumbosacral radiculopathy, suggesting a neurogenic-like component. Since the subjectivity of manual palpation and study heterogeneity limit generalizability of the results, future research should standardize diagnostic criteria of MTrPs to ensure the consistency of results. Full article

This study investigates differences in lower limb muscle activity during isometric external hip rotation while standing using static and dynamic models within the AnyBody Modeling System. Thirty-three participants performed controlled isometric rotations using a custom-designed device capable of simultaneously measuring rotational moments and ground reaction forces. Both static and dynamic simulations were conducted for each subject using personalized biomechanical models. Muscle activity values at the point of peak rotational moment were analyzed for twelve key muscles involved in hip rotation and stabilization of the knee joint, and statistical differences were assessed for significance. Muscles from the gluteal group (Gluteus minimus, medius, and maximus) generally showed lower activation in dynamic simulations, although this trend was not statistically significant for all muscles or test conditions. The mean difference in muscle activity values between static and dynamic simulations was between 0.03 and 0.08 for the gluteal group muscles and up to 0.15 for the Iliopsoas. Static models overestimated the role of stabilizers. Significant differences (p ≤ 0.05, Wilcoxon signed-rank test) were observed between the two approaches in terms of predicted muscle activation. In conclusion, discrepancies in muscle activity predictions between static and dynamic simulations highlight the need for task-specific simulation design and careful result interpretation. Full article

Background: Repeated short maximal sprints induce high blood lactate concentrations and may influence neuromuscular coordination, but the relationship between lactate accumulation and inter-limb asymmetry in elite athletes remains unclear. Objectives: This study sought to investigate how blood lactate dynamics during repeated sprint efforts relate to sprint performance and inter-limb muscle asymmetry in elite female sprinters. Methods: Eight elite women (21.3 ± 5.4 y; 54.2 ± 5.1 kg; 165.4 ± 4.3 cm) performed four sets of five all-out 50 m sprints (1 min rest between reps; 5 min between sets). Sprint times were electronically timed. Capillary lactate was measured at rest and 1 min/4 min post-set. Quadricep, hamstring, and gluteal asymmetry was assessed via textile electromyography. Nonparametric statistics (Spearman’s ρ, Friedman test) were applied. Results: From Set 1 to Set 4, sprint time fell from 7.25 ± 0.13 s to 7.07 ± 0.16 s (p = 0.044), 1 min lactate rose from 8.51 ± 2.65 to 15.60 ± 2.66 mmol/L (p < 0.001), and 4 min lactate from 7.16 ± 2.32 to 13.64 ± 2.76 mmol/L (p = 0.002). Muscle group asymmetries decreased (p < 0.01), with lactate at 1 min, correlating negatively with quadriceps (ρ = −0.59) and gluteal (ρ = −0.48) asymmetry. Conclusions: In elite female sprinters, progressive lactate accumulation during repeated 50 m bouts is linked to faster times and reduced muscle asymmetry, suggesting that lactate may enhance neuromuscular coordination under fatigue. Full article

Background and Objectives: We conducted a retrospective observational study. Background: While traditional rehabilitation approaches emphasize trunk muscle conditioning, emerging evidence suggests that leg muscle strength plays a critical role in postoperative functional mobility. Previous studies have focused on trunk muscle rehabilitation in patients with adult spinal deformity (ASD). However, recent findings suggest that leg muscle conditioning may be a better predictor of postoperative improvement. Strengthening the gluteal and iliopsoas muscles has been linked to improved sagittal balance, gait stability, and mobility, ultimately leading to enhanced surgical outcomes. This study examines the relationship between the preoperative functional cross-sectional area (FCSA) of trunk and leg muscles and postoperative improvement in mobility, as assessed by the Timed Up and Go (TUG) test, in patients undergoing surgery for ASD. Materials and Methods: Sixty-two patients (57 women, mean age 71.2 ± 7.1 years) who underwent ASD surgery between April 2017 and April 2024 were retrospectively analyzed. The FCSA of key muscles—psoas major (PM), erector spinae (ES), multifidus (MF), gluteus maximus (GM), and gluteus medius (GMed)—was measured using CT images. Patients were categorized into an improvement group and a non-improvement group based on whether they achieved the minimum clinically important difference (MCID) of −2 s in the TUG test 12 months after surgery. Propensity score matching (PSM) was applied to adjust for baseline differences between the groups. A significance level of 5% was used for all comparisons. Results: Thirty-three patients achieved a clinically meaningful improvement in TUG, while 29 did not. Before PSM, patients with worse preoperative TUG and Oswestry Disability Index (ODI) scores showed greater improvements (p < 0.01). After PSM, no significant differences were found between the groups in terms of age, sex, or BMI. However, the improvement group showed significantly greater FCSA values in PM (6.1 ± 2.3 mm² vs. 3.9 ± 1.5 mm², p = 0.021) and GM (19.9 ± 5.9 mm² vs. 15.3 ± 3.9 mm², p = 0.019). Conclusions: This study demonstrates that leg muscle quality, particularly that of the gluteus maximus and psoas major, is a significant predictor of postoperative mobility improvement in patients with ASD. These findings challenge the conventional focus on trunk muscles and suggest the inclusion of leg muscle training in preoperative rehabilitation strategies to enhance surgical outcomes. Full article

MSTN has been used as a candidate gene in the genetics, breeding, and improvement of animal breeds. However, the possible mechanism by which the MSTN gene regulates muscle development through PSMA6 is not well understood. Previous methylome and transcriptome sequencing analyses of gluteal muscle tissues from MSTN+/−Luxi cattle and wild-type Luxi cattle identified that the PSMA6 gene exhibited a negative correlation between methylation levels and transcriptional activity. To investigate whether MSTN expression regulates PSMA6 gene expression, we examined the effects of MSTN on DNA methyltransferases (DNMT1, DNMT2, DNMT3A, and DNMT3B) and DNA demethylases (TET1, TET2, and TET3). Additionally, chromatin immunoprecipitation (ChIP) assays were performed to detect the binding interaction between PSMA6 and TET2. In this paper, we first established an MSTN knockdown cellular model to preliminarily validate its regulatory effect on PSMA6 expression. Subsequently, the developmental impact of PSMA6 on bovine skeletal muscle satellite cells was further investigated through both knockdown and overexpression of the PSMA6 gene. Furthermore, we examined changes in the expression of key components of the AKT/mTOR signaling pathway to elucidate the mechanisms underlying the PSMA6-mediated regulation of satellite cell development. The results demonstrate that myostatin (MSTN) inhibition significantly decreased proteasome 20S subunit alpha-6 (PSMA6) gene expression, while increasing demethylase expression, particularly ten-eleven translocation-2 (TET2), which exhibited the most pronounced changes. During the cell proliferation stage, the markers Paired Box 7 (PAX7) and Ki-67 exhibited no significant changes, whereas the PSMA6 gene was either overexpressed or disrupted. Conversely, PSMA6 overexpression altered the myogenic differentiation markers, causing the differential regulation of myosin heavy chain (MyHC) and myogenin (MyoG) expression, with MyHC upregulation and concurrent MyoG downregulation. PSMA6 gene overexpression led to the downregulation of AKT1 and Rac1, as well as the activation of the AKT/mTOR pathway, including key factors such as mTOR, p-mTOR, RPS6, p-RPS6, and RhoA. PSMA6 interference resulted in the downregulation of p-mTOR and the upregulation of p-RPS6. Gene expression profiling in our study revealed that the myostatin (MSTN) knockout model significantly reduced the transcriptional levels of the proteasome α6 subunit (PSMA6) (p < 0.05), with the regulatory intensity showing a significant negative correlation with MSTN expression. This molecular evidence substantiates a negative regulatory axis between MSTN and PSMA6. Functional experiments demonstrated that PSMA6 overexpression specifically enhanced myotube formation rates in bovine skeletal muscle satellite cells, whereas siRNA-mediated PSMA6 knockdown exhibited no significant effects on cellular proliferation, indicating the functional specificity of this gene in myogenic differentiation. Mechanistic investigations further revealed that PSMA6 activates the canonical AKT/mTOR signaling transduction cascade through the phosphorylation of AKT and its downstream effector mTOR, thereby mediating the expression of myogenic regulatory factors MyoD and myogenin. Collectively, these findings demonstrate that MSTN deficiency alleviates the transcriptional repression of PSMA6, remodels skeletal muscle differentiation-associated signaling networks, and ultimately drives the directional differentiation of satellite cells toward myofiber specification. Full article

This meta-analysis investigated muscle activity and sprint biomechanics by reviewing EMG, kinematic, and kinetic studies, with a focus on changes across sprint phases and the effects of fatigue. Following PRISMA 2020 guidelines, twelve studies were selected from databases such as PubMed and Scopus, analyzing lower limb muscles (e.g., biceps femoris, semitendinosus, gluteus maximus) and biomechanical variables like step length, stride frequency, and ground reaction forces. Using random-effects models and meta-regression, the analysis revealed that increased sprint speed is associated with greater activation of the posterior thigh muscles and gluteus maximus. The biceps femoris peaks in the late swing phase (~110% MVC), while the gluteus maximus is most active in early stance. Sprinting faster typically results in a 15–20% increase in step length and moderate changes in stride frequency. Fatigue causes earlier muscle activation, reduced hip and knee flexion, and longer ground contact times, which may impair efficiency and raise injury risk. A strong linear relationship (R² = 0.881, p < 0.001) was found between sprint speed and muscle activation, with activation increasing by ~6.3% MVC per 1 m/s. These findings highlight the importance of hamstring and gluteal strength, as well as fatigue resistance, in sprint training and injury prevention. Full article

Hip injuries are common in contact sports, particularly in high-impact activities. A well-known type of hip trauma is the hip pointer, which is a contusion of the iliac crest caused by a direct blow. Typically, hip pointers involve the lateral aspect of the iliac crest. In this case report, we present an unusual variation of this injury affecting the posterior iliac crest near the posterior superior iliac spine (PSIS). We describe two cases of elite athletes who sustained posterior iliac crest trauma, a condition we propose naming the “posterior hip pointer”. This report highlights the clinical presentation, imaging findings, treatment approach, and implications for sports medicine. Full article

Background: Venous malformations (VMs) are congenital vascular abnormalities characterized by tortuosity, slow blood flow, and gradual growth. Intra-articular venous malformations (IAVMs) of the knee are rare and often present with symptoms similar to juvenile idiopathic arthritis (JIA) or late sequelae of trauma. VM in children is commonly misdiagnosed as hemangioma. This study aims to analyze the clinical and MRI features of IAVM in the knee joint. Methods: This retrospective study analyzed patients from a reference unit for the treatment of vascular malformations in the Pediatric Surgery Department. The group was collected starting from the year 2014 until the 100th patient was identified in the year 2018, all with MRI-confirmed VM based on a predefined protocol. From this group, 19 patients with lower limb symptoms were identified, and 9 patients with VM involving the knee joint were selected for further analysis. Results: The most common symptoms in IAVM patients were pain and swelling, chronic in five (55%) and intermittent in four (45%). Four (45%) reported worsening pain during or after physical activity. A history of intra-articular bleeding was noted in five (55%), leading to mild knee contracture (10° reduction in extension) and decreased mobility. Limb deformities were observed in eight (89%). Diffuse VMs, affecting both intra- and extra-articular tissues, were present in eight (89%), involving the thigh in seven (78%), crus in five (56%), gluteal muscles in three (33%), and foot tissues in one (11%). The suprapatellar recess and Hoffa’s fat pad were involved in all patients (100%). Conclusions: IAVMs are rare causes of knee dysfunction in children and young adults, particularly in cases of unexplained pain, swelling, or instability. They should be considered in the differential diagnosis of hemophilic arthropathy, JIA, or late post-traumatic sequelae. Untreated IAVMs can lead to intra-articular bleeding, cartilage degeneration, and disability. Early diagnosis via MRI and ultrasound is crucial to identifying IAVMs and preventing joint degeneration. Timely treatment helps avoid further damage and long-term disability. Full article

Background and Objectives: The aim of this study was to compare the effects of pelvic floor muscle contraction training (PFMCT) using verbal education, digital vaginal palpation (DVP), or perineometer on the common errors made during pelvic floor muscle contraction (PFMC) in women. Materials and Methods: A total of 48 women participated, and they were randomly assigned to three groups (Group I: PFMCT with verbal education, n = 16; Group II: PFMCT with DVP, n = 16; and Group III: PFMCT with perineometer, n = 16). Participants who had not previously received PFMCT were evaluated for pelvic floor muscle strength using the Modified Oxford Scale (MOS), and pelvic floor muscle activation was assessed with electromyographic biofeedback (EMG-BF). Possible errors during pelvic floor muscle contraction (gluteal, adductor and/or abdominal muscle contractions, stop breathing (breath holding), enhanced inhaling, and straining) were evaluated through inspection, palpation, or EMG-BF. After pre-training evaluations, all participants received training on pelvic floor. After this general training, each group received PFMCT using the specific training method for their group. After the training, the same evaluations were repeated. The sessions were conducted one-on-one and lasted for an average of one hour. Results: After the training, MOS values increased in Group II and Group III, while EMG-BF values only increased in Group II (p < 0.05). The number of incorrect movements during PFMC decreased after the training in all three groups (p < 0.05). The abdominal muscle contraction value monitored by EMG-BF only decreased in Group II (p < 0.05). Conclusions: Our study demonstrated that the PFMCT applied using the DVP method was more effective in creating more accurate and stronger muscle contractions and reducing common errors when compared to pre- and post-training values. Significant differences were observed between the groups in terms of performance improvements, with Group II showing the most notable progress. These results support the potential for DVP to yield better outcomes when used in PFMT. Full article

Background: Pelvic girdle pain (PGP) is described in the literature as a subgroup of low back pain (LBP), characterized by pain localized between the posterior iliac crest and the gluteal fold, particularly near the sacroiliac joints. This condition can manifest in different forms non-specific PGP, occurring during pregnancy or postpartum (pregnancy-related PGP), which represents the most prevalent form and non-pregnancy-related PGP, resulting from mechanical alterations caused by trauma or microtrauma. Specific PGP, associated with identifiable causes such as fractures, infections, or arthritis. Over the years, research has focused on identifying the most effective approaches for managing this condition and addressing its associated biopsychosocial impairments. The aim of this narrative review is to determine the types of motor control exercises (MCEs) used to reduce short-term pain in patients with PGP and to assess whether these exercises are designed in accordance with the principles of motor control (MC) theories. Methods: A narrative review was conducted through searches in various medical and rehabilitation databases, including MEDLINE (via PubMed), PEDro, Scopus, and Web of Science. The inclusion criteria of the review encompassed case studies, case reports, editorials, original research articles, randomized controlled trials (RCTs), and systematic reviews (SRs). Results: Six articles met the eligibility criteria, comprising two SRs and four RCTs, all of which were included in the qualitative analysis. Among these, two studies examine MCEs for non-pregnancy-related PGP, while all the other studies focus on pregnancy-related PGP. The exercises described focused on lumbar–pelvic stabilization or deep spinal muscle activation. Among the six included studies, five did not report statistically significant changes in pain outcomes, while only one study demonstrated a statistically significant improvement. Conclusions: The analysis highlighted that the exercises currently employed are generally unspecific and not systematically structured according to the principles outlined in MC theories. The available evidence, combined with the incorrect design of these exercises, does not allow for definitive conclusions regarding the efficacy of MCEs in reducing short-term pain in patients with both pregnancy-related and non-pregnancy-related PGP. Full article

Venous hypertension in the pelvic veins can result in the development of varicosities in the perineum, and sometimes also in the lower extremities. These varicose veins are anatomically and functionally different from typical varicosities associated with an incompetence of the saphenous veins. Since the pelvic cavity is anatomically separated from the lower extremity and perineum by muscles and skeleton, there are only a few routes through which pelvic veins can communicate with extra-pelvic veins. These routes should primarily be examined during diagnostic workout. In this review article, clinical anatomy concerning varicose veins of pelvic origin is presented, and the anatomically-driven diagnostics for these atypical varicose veins are discussed. Focus on ultrasonographic detection of the escape points, which are located at the sites where the incompetent intra-pelvic and extra-pelvic veins are connected—such as the perineal veins, veins running alongside the round ligament of the uterus, the obturator vein, as well as the inferior and superior gluteal veins—is emphasized. Full article