INTRODUCTION: Plantar fasciitis (PF) is one of the most common running-related injuries. PURPOSE: The aim of this prospective study was to determine the incidence of PF and identify potential risk or protective factors for PF in runners and non-runners. METHODS: Data from 1206 participants from the 4HAIE cohort study (563 females/643 males; 715 runners/491 non-runners; 18-65 yr of age) were included in the analysis. We collected biomechanical data during overground running using a three-dimensional motion capture system at the baseline and running distance data via retrospective questionnaires and followed the participants for 12 months following the baseline data collection. Participants were asked weekly about any sports-related injury (including PF). A binary logistic regression was performed to reveal potential associations between running distance and biomechanical risk factors and PF while controlling for running distance, sex, and age. RESULTS: The total incidence of PF was 2.3% (28 PF from 1206 participants), 2.5% in runners and 2.0% in non-runners ( P = 0.248). Runners who ran more than 40 km·wk -1 had six times higher odds of suffering PF than individuals who ran 6-20 km·wk -1 ( P = 0.009). There was a significant association between maximal ankle adduction and PF; that is, runners with a lower abduction angle during the stance period had higher risk of PF ( P = 0.024). No other biomechanical variables indicated significant associations with PF. CONCLUSIONS: Regular running with a moderate weekly volume and more toeing out of the foot relative to the shank may reduce the risk against PF in runners, which may be useful for researchers, runners, coaches, and health professionals to minimize PF injury risk.
- MeSH
- běh * fyziologie zranění MeSH
- biomechanika MeSH
- dospělí MeSH
- fasciitida plantární * epidemiologie patofyziologie MeSH
- incidence MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- prospektivní studie MeSH
- rizikové faktory MeSH
- senioři MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
The sacroiliac joint (SIJ) exhibits significant variation in auricular surface morphology. This variation influences the mechanics of the SIJ, a central node for transmitting mechanical energy from upper body to lower limbs and vice versa. The impact of the auricular surface morphology on stress and deformation in the SIJ remains poorly understood to date. Computed tomography scans obtained from 281 individuals were included to extract the geometry of the pelvic ring. Then, the auricular surface area, SIJ cartilage thickness, and total SIJ cartilage volume were identified. Based on these reconstructions, 281 finite element models were created to simulate SIJ mechanical loading. It was found that SIJ cartilage thickness only weakly depended on age or laterality, while being strongly sex sensitive. Auricular surface area and SIJ cartilage volume depended weakly and non-linearly on age, peaking around menopause in females, but without significant laterality effect. Larger SIJs, characterized by greater auricular area and cartilage volume, exhibited reduced stress and deformation under loading. These findings highlight the significant role of SIJ morphology in its biomechanical response, suggesting a potential link between morphological variations and the risk of SIJ dysfunction. Understanding this relationship could improve diagnosis and targeted treatment strategies for SIJ-related conditions.
- MeSH
- analýza metodou konečných prvků MeSH
- biomechanika fyziologie MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mechanický stres MeSH
- mladiství MeSH
- mladý dospělý MeSH
- počítačová rentgenová tomografie * MeSH
- sakroiliakální kloub * anatomie a histologie fyziologie diagnostické zobrazování MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
This study aimed to investigate the effects of performing either eccentric-only (ECC) or eccentric-concentric (ECC-CON) back squats (BS) with a supramaximal load on countermovement jump (CMJ) performance. Changes in front thigh skin surface temperature and mechanical properties (oscillation frequency and stiffness) of the vastus lateralis were also examined. Fourteen male powerlifters participated in this study (age: 22.5 ± 2.3 years, body weight: 84.2 ± 11.1 kg, height: 178 ± 7 cm, training experience: 5.4 ± 1.6 years, BS one-repetition maximum [1RM]: 177 ± 22.8 kg). The experimental sessions included 2 sets of 2 BS at 110% 1RM of either ECC-CON (load distributed by half on the barbell [55%] and on weight releasers [55%]) or ECC (only eccentric phase of BS) and CTRL with no CA applied. CMJ performance, mechanical properties, and skin surface temperature were measured before and at the third, sixth, ninth, and 12th min. After each protocol, only the ECC-CON condition led to a significant increase in CMJ height after individual optimal rest time compared to pre-CA (38.1 ± 5.2 vs. 39.8 ± 5.0 cm; p = 0.003; effect size [ES] = 0.32; Δ = 4.9 ± 5.0%) with a significant rise in skin surface temperature (32.98 ± 1.24 vs. 33.69 ± 0.96°C; p = 0.006; ES = 0.62; Δ = 2.2 ± 2.6%) and no significant changes in mechanical properties of the vastus lateralis. The ECC-CON condition led to a significant acute improvement in CMJ height and an increase in front thigh skin surface temperature among powerlifters. The ECC-CON supramaximal lower limb PAPE protocol should be effectively used among males representing high levels of lower limb muscle strength (>2 × body mass).
- MeSH
- biomechanika MeSH
- čtyřhlavý sval stehenní fyziologie MeSH
- dospělí MeSH
- kosterní svaly fyziologie MeSH
- lidé MeSH
- mladý dospělý MeSH
- odporový trénink MeSH
- sportovní výkon * fyziologie MeSH
- stehno fyziologie MeSH
- svalová síla fyziologie MeSH
- teplota kůže * fyziologie MeSH
- vzpírání * fyziologie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
The cerebellum, a lateralised organ, plays a crucial role in motor control. Still, its involvement in hand and foot dominance remains inadequately understood, primarily in the right and left-side dominant population. A potential manifestation of this lateralisation is the neocerebellar extinction syndrome, previously linked to mild muscle hypotonia and moderate passivity in the non-preferred hand. A more precise understanding of the cerebellum's role in limb dominance patterns could provide valuable insights into motor learning, rehabilitation therapies, and neuroplasticity. This study explored the relationship between physiological neocerebellar extinction syndrome and hand/ft dominance in left and right-side dominant individuals. Data were collected from 80 university participants (40 left-side dominant, 40 right-side dominant, mean age = 24.7 ± 0.92 years) during controlled limb falls using 3D kinematic analysis. In these falls, theoretically suggested hypotonia in non-dominant limbs was analysed through attenuation coefficients and frequency differences. Using a linear mixed model, we found significantly lower hand attenuation in the non-dominant hand-(β = 0.10, p < 0.001), showing hypotonia compared to the dominant hand regardless of upper limb side dominance. Foot preference and dominance had minimal influence on leg attenuation or frequency, although right-footed, right-dominant individuals demonstrated significantly higher leg oscillation frequency, likely due to increased proximal muscle mass. Our findings suggest that distinct differences in cortical representation, lateralised control, and pathway specialisation exist due to the unique demands of each limb's motor functions, which are pronounced more neocerebellar extinction syndrome in the upper extremities. Therefore, the results showed potentially new perspectives on the cerebellum's nuanced role in motor control and laterality. The differential effects observed between the upper and lower limbs point to distinct cerebellar pathways and hypotonia. This work could significantly enhance the precision of therapeutic approaches and broaden our knowledge of laterality in motor function.
- MeSH
- biomechanika MeSH
- dospělí MeSH
- funkční lateralita * fyziologie MeSH
- lidé MeSH
- mladý dospělý MeSH
- mozeček * patofyziologie MeSH
- noha (od hlezna dolů) fyziologie MeSH
- ruka MeSH
- svalová hypotonie patofyziologie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
INTRODUCTION: Although the effects of carrying loads on gait biomechanics have been well-documented, to date, little evidence has been provided whether such loads may impact spatial and temporal gait asymmetries under the different foot regions. Therefore, the main purpose of the study was to examine the effects of carrying a standardized police equipment on spatiotemporal gait parameters. MATERIALS AND METHODS: In this population-based study, participants were 845 first-year police recruits (age: 21.2 ± 2.3 years; height: 178.1 ± 10.2 cm; weight: 78.4 ± 11.3 kg; body mass index: 24.7 ± 3.2 kg/m2; 609 men and 236 women; 72.1% men and 27.9% women) measured in 2 conditions: (i) "no load" and (ii) "a 3.5 kg load." Spatiotemporal gait parameters were derived from the FDM Zebris pressure platform. Asymmetry was calculated as (xright-xleft)/0.5*(xright + xleft)*100%, where "x" represented a given parameter being calculated and a value closer to 0 denoted greater symmetry. RESULTS: When compared to "no load" condition, a standardized 3.5 kg/7.7 lb load significantly increased asymmetries in spatial gait parameters as follows: gait phases of stance (mean diff. = 1.05), load response (mean diff. = 0.31), single limb support (mean diff. = 0.56), pre-swing (mean diff. = 0.22), and swing (mean diff. = 0.90) phase, while no significant asymmetries in foot rotation, step, and stride length were observed. For temporal gait parameters, we observed significant asymmetries in step time (mean diff. = -0.01), while no differences in cadence and gait speed were shown. CONCLUSIONS: The findings indicate that the additional load of 3.5 kg/7.7 lb is more likely to increase asymmetries in spatial gait cycle components, opposed to temporal parameters. Thus, external police load may have hazardous effects in increasing overall body asymmetry, which may lead to a higher injury risk and a decreased performance for completing specific everyday tasks.
- MeSH
- biomechanika fyziologie MeSH
- chůze (způsob) * fyziologie MeSH
- dospělí MeSH
- lidé MeSH
- mladý dospělý MeSH
- policie * statistika a číselné údaje MeSH
- zatížení muskuloskeletálního systému * fyziologie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Bio-nano interactions have been extensively explored in nanomedicine to develop selective delivery strategies and reduce systemic toxicity. To enhance the delivery of nanocarriers to cancer cells and improve the therapeutic efficiency, different nanomaterials have been developed. However, the limited clinical translation of nanoparticle-based therapies, largely due to issues associated with poor targeting, requires a deeper understanding of the biological phenomena underlying cell-nanoparticle interactions. In this context, we investigate the molecular and cellular mechanobiology parameters that control such interactions. We demonstrate that the pharmacological inhibition or the genetic ablation of the key mechanosensitive component of the Hippo pathway, i.e., yes-associated protein, enhances nanoparticle internalization by 1.5-fold. Importantly, this phenomenon occurs independently of nanoparticle properties, such as size, or cell properties such as surface area and stiffness. Our study reveals that the internalization of nanoparticles in target cells can be controlled by modulating cell mechanosensing pathways, potentially enhancing nanotherapy specificity.
- MeSH
- adaptorové proteiny signální transdukční metabolismus MeSH
- buněčný převod mechanických signálů účinky léků MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- nanočástice * chemie MeSH
- nanomedicína MeSH
- signální dráha Hippo MeSH
- signální proteiny YAP MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Background: Femoroacetabular impingement syndrome (FAI) is a complex, often post-traumatically developing impairment of the hip joint. It is characterized by ambiguous symptomatology, which makes early diagnosis difficult. Aim: The study was conducted to evaluate the applicability of a triaxial gyroscopic sensor in routine practice as an additional indication criterion for operative versus conservative treatment procedures. Methods: Ninety-two patients were included in the experimental retrospective study and 62 completed the examination. All patients signed informed consent. A gyroscopic sensor was placed on the right side of the pelvis above the hip joint and patients walked approximately 15 steps. Data were also evaluated while the patients climbed stairs. A complete clinical examination of the dynamics and physiological movements in the joint was performed. The data measured by the gyroscopic sensor were processed using differential geometry methods and subsequently evaluated using spectral analysis and neural networks. Results: FAI diagnosis using gyroscopic measurement is fast and easy to implement. Our approach to processing the gyroscopic signals used to detect the stage of osteoarthritis and post-traumatic FAI could lead to more accurate detection and capture early in FAI development. Conclusions: The obtained data are easily evaluated, interpretable, and beneficial in the diagnosis of the early stages of FAI. The results of the study show that this approach can lead to more accurate and early detection of osteoarthritis and post-traumatic FAI.
- MeSH
- analýza chůze metody MeSH
- biomechanika * MeSH
- femoroacetabulární impingement * chirurgie diagnóza patofyziologie MeSH
- kyčelní kloub patofyziologie MeSH
- lidé MeSH
- nositelná elektronika * MeSH
- osteoartróza diagnóza patofyziologie MeSH
- retrospektivní studie MeSH
- telemedicína metody MeSH
- umělá inteligence MeSH
- Check Tag
- lidé MeSH
BACKGROUND: The interaction between joint kinematics and kinetics is usually assessed by linear correlation analysis, which does not imply causality. Understanding the causal links between these variables may help develop landing interventions to improve technique and create joint-specific strengthening programs to reduce reaction forces and injury risk. OBJECTIVE: Therefore, the aim of this study was to analyze the causal interaction between lower limb sagittal kinematics and vertical ground reaction force (VGRF) during single-leg jump landing in children who are jumpers (volleyball and gymnastics) and non-jumpers, using the causal empirical decomposition method. Our hypothesis is that children who participate in jumping sports, compared to those who do not, employ a different joint strategy to regulate ground reaction forces during landing, particularly at the ankle level. METHODS: Two groups were compared: the jumpers group (n = 14) and the non-jumpers (control group, n = 11). The causal interaction between sagittal kinematics and VGRF was assessed using ensemble empirical mode decomposition (EEMD) and time series instantaneous phase dependence in bi-directional causality. The relative causal strength (RCS) between the time series was quantified as the relative ratio of absolute cause strength between kinematics and VGRF. RESULTS: A significant interaction between joint and group was found for RCS (p = 0.035, η2p = 0.14). The post-hoc analysis showed the jumpers group had higher ankle-to-VGRF RCS than the control group (p = 0.017, d = 1.03), while in the control group the hip-to-VGRF RCS was higher than the ankle-to-VGRF RCS (p = 0.004, d = 0.91). CONCLUSION: Based on the causal decomposition approach, our results indicate that practicing jumping sports increases the causal effect of ankle kinematics on ground reaction forces in children. While non-jumper children rely more on the hip to modulate reaction forces, jumper children differ from non-jumpers by their greater use of the ankle joint. These findings could be used to develop specific training programs to improve landing techniques according to practice level, potentially helping to reduce the risk of injury in both athletes and non-athletes.
- MeSH
- biomechanika fyziologie MeSH
- dítě MeSH
- dolní končetina fyziologie MeSH
- gymnastika * fyziologie MeSH
- hlezenní kloub fyziologie MeSH
- lidé MeSH
- volejbal fyziologie MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Surgical treatments of benign primary bone tumors of the femur face the challenge of limiting tissue damage and contamination while providing sufficient stabilization to avoid fracture. While no clear treatment guidelines exist, surgical treatment commonly consists of femoral fenestration and curettage with optional filling and plating of the defect. Mono- or bicortical plating of distal femoral defects aim to reduce fracture risk and have been shown to increase axial stability. However, it remains unclear whether plating increases torsional stability of the affected femur. QUESTIONS/PURPOSES: This biomechanical study aimed to determine how much additional stability can be achieved by mono- or bicortical plating of femoral defects after fenestration. The following hypotheses were investigated: 1. Preventive plating of distal femur bone defects enhances torsional stability when compared to femoral fenestration alone. 2. A condition close to the intact (nonpathological) bone can be achieved by bone plating. 3. Defect shape influences torsional stability. PATIENTS AND METHODS: Thiel embalmed human femora (n = 24) were left intact or subjected to the following surgical treatments (A) defect creation via fenestration, (B) defect with short monocortical plating, (C) defect with long bicortical plating. All femora were torsion tested in midstance position using pre-cycling and testing until failure. Quantitative computed tomography pre and post testing allowed bone mineral density calculation and crack path analysis. Finite element analysis provided insight into defect shape variations. RESULTS: Torsion experiments showed no relevant enhancement of torsional stability due to mono- or bicortical plating. There were no significant differences in maximum torque between unplated and plated femora with defect (defect: 35.38 ± 7.53 Nm, monocortical plating: 37.77 ± 9.82 Nm, bicortical plating: 50.27 ± 9.72 Nm, p > 0.05). Maximum torque for all treatment groups was significantly lower compared to intact femora (155-200 Nm, p < 0.001). Cracks originated predominantly from the proximal posterior corner of the defect and intersected with screw holes in plated femora. The influence of variations of the defect corner shapes had no significant influence on maximum torque and angle. CONCLUSION: This biomechanical study shows that mono- or bicortical plating is not an effective preventive treatment against torsional failure of femora with distal defects as the resulting maximum torque was drastically reduced compared to intact femora. Thus, the initial hypotheses have to be rejected. As habitual loading of the femur includes a combination of axial and torsional loading, the observed lack of prevention against torsional failure might help to explain the occurrence of fractures despite plating. Future research towards ameliorating clinical outcome should address the role of defect filling with bone cement or bone grafts regarding the improvement of torsional stability after primary bone tumor treatment in the femur.
- MeSH
- biomechanika MeSH
- femur * chirurgie MeSH
- kostní destičky * MeSH
- kyretáž MeSH
- lidé středního věku MeSH
- lidé MeSH
- mechanické testy MeSH
- senioři MeSH
- torze mechanická MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
STATEMENT OF PROBLEM: Accurate implant placement is essential for the success of dental implants. This placement influences osseointegration and occlusal forces. The freehand technique, despite its cost-effectiveness and time efficiency, may result in significant angular deviations compared with guided implantation, but the effect of angular deviations on the stress-strain state of peri-implant bone is unclear. PURPOSE: The purpose of this finite element analysis (FEA) study was to examine the effects of angular deviations on stress-strain states in peri-implant bone. MATERIAL AND METHODS: Computational modeling was used to investigate 4 different configurations of dental implant positions, each with 3 angles of insertion. The model was developed using computed tomography images, and typical mastication forces were considered. Strains were analyzed using the mechanostat hypothesis. RESULTS: The location of the implant had a significant impact on bone strain intensity. An angular deviation of ±5 degrees from the planned inclination did not significantly affect cancellous bone strains, which primarily support the implant. However, it had a substantial effect on strains in the cortical bone near the implant. Such deviations also significantly influenced implant stresses, especially when the support from the cortical bone was uneven or poorly localized. CONCLUSIONS: In extreme situations, angular deviations can lead to overstraining the cortical bone, risking implant failure from unfavorable interaction with the implant. Accurate implant placement is essential to mitigate these risks.
