Increased physical load on the body of American football players, especially in the lower limbs, may be associated with increased risk of foot deformities and injuries, potentially influencing players' overall fitness and performance. The aim of the study was to assess the relationship between American football training, training duration and anthropometric features, and foot posture in Polish players. 70 athletes training American football in Poland and 35 non-training. The study used a questionnaire and the Foot Posture Index - 6 to assess foot shape. An analysis of the relationship between age, Body Mass Index and training experience with foot posture was conducted. The average BMI value between the studied groups of athletes and non-training was significantly different ( < 0.01). The athletes and non-training participants showed good foot posture according to the total Foot Posture Index - 6, but a statistically significant difference between the groups was found in all partial values of the Foot Posture Index measurements 1-6, except for Foot Posture Index 2, left foot. In the group of athletes, no statistically significant relationship was found between anthropometric parameters and Body Mass Index and Foot Posture Index - 6. In the non-training participants, a significant relationship ( < 0.02) was found between the shape of the left foot and BMI. Monitoring foot posture and BMI in athletes practicing American football may be beneficial. Based on the observed tendency toward foot pronation, football players may benefit from individually selected footwear, including anti-pronation options when indicated.

The aim of this study was to compare the biomechanical parameters of runners during overground and treadmill running, to assess the significance of these differences for treadmill training, and to evaluate their relevance for physiotherapy. Ten professional runners (mean age of 31.2 ± 6.8 years) were evaluated using a 10-camera Vicon motion capture system and a Phantom V12 high-speed camera. After completing a 200-meter overground run at a self-selected pace, each athlete entered the calibrated capture volume, where their running velocity and kinetic data were recorded. The individual mean velocities were then replicated on a treadmill positioned within the same capture space. Treadmill running altered lower limb biomechanics compared to over-ground running. Median step length was 3% longer and markedly less variable on the treadmill than over-ground ( < 0.001). The knee-flexion angle differed by surface and side ( < 0.0001), changes were (1° for left, -2° right) but variability narrowed on the treadmill, while the knee-impact angle remained unchanged. Relative to over-ground running treadmill running reduced the horizontal distance between the center of gravity and foot initial contact; ground-contact time (12%) and heel velocity after toe-off by 19% ( < 0.0001). Treadmill running alters lower limb biomechanics by reducing ground contact time, heel velocity, and variability in movement patterns. The consistent mechanics observed on the treadmill may support its use in physiotherapy, particularly for hamstring rehabilitation. However, due to limited replication of natural conditions, treadmill training should complement rather than replace overground running.

Image-guided biopsy is essential for safe and precise procedures. Our primary objective was to develop a software-hardware platform to automate planning and assist the procedure intraoperatively. The novelty lies in a unique combination of modern computational approaches - a voxel-based needle representation on a DICOM-based cost-map with target insertion safety represented in a continuous way by a largest empty sphere, optimized with Differential Evolution, with partial experimental validation. This study presents a prototype hardware-software platform for biopsy assistance, featuring an optimization tool for preplanning and the MentorEye system for real-time needle navigation using a simple support setup. Evaluation was conducted on a custom skull phantom with brain tissue and cancerous lesions. The system optimizes needle paths while considering surrounding structures and provides intraoperative guidance. The planning tool successfully generated viable trajectories for all lesions, typically aligning with the shortest insertion paths. The mean Target Registration Error between CT and optical navigation was 2.08 ± 0.43 mm, similar to that obtained in typical computer-assisted procedures. In seven simulations, all biopsies were successful, with a mean deviation of 2.15 ± 0.84 mm and an nRMSE of 3.7%, comparable even to that reported for robotic-assisted systems. The experiment results confirmed the good efficiency of the developed tools for automatic planning and image-guided biopsy aiding.

Joint angle analysis during gait is crucial for identifying pathological conditions and estimating joint loading, thereby supporting clinical decision-making for injury prevention. Although various methods are available for analyzing joint angles, webcam-based motion capture systems (MoCap) are gaining attention due to their affordability and user-friendliness. This study aimed to evaluate and compare the inter-rater and intra-trial reliability of a webcam-based MoCap with that of a conventional inertial measurement unit (IMU)-based system. Gait analysis was conducted on 15 participants (6 males, 9 females; mean age: 28.1 ± 5.26 years). While participants walked a 3-meter distance, hip and knee joint angles in the sagittal plane were simultaneously recorded using both inertial measurement unit (IMU) sensors and a webcam-based MoCap. Inter-rater and intra-trial reliability were assessed using intraclass correlation coefficients (ICCs), and agreement between the two systems was evaluated using Bland-Altman analysis. For intra-trial reliability, most IMU-based systems demonstrated excellent reliability (ICC > 0.8). Although slightly lower, the webcam-based MoCap also achieved substantial to almost perfect reliability (ICC = 0.652 - 0.838). Inter-rater reliability between the IMU and webcam-based MoCap generally showed moderate to substantial agreement (ICC = 0.466 - 0.696). These findings suggest that the webcam-based MoCap may serve as a viable alternative in settings where IMU systems are unavailable or impractical. Future studies should aim to refine webcam-based tracking algorithms to improve event detection, assess reliability across diverse populations and movement tasks, and further validate such systems against gold-standard marker-based 3D optical MoCap.

This study aimed to compare the efficacy of four contemporary retreatment file systems, i.e., R-Endo, XP-Endo Retreatment, HyFlex Remover, and MicroMega Remover, in the solvent-free removal of aged bioceramic sealers from root canals, and to elucidate the relationship between file design and retreatment performance using advanced micro-computed tomography (micro-CT). 40 extracted human mandibular premolars with single straight canals were prepared and obturated using either Total Fill BC or BioRoot RCS sealers, then aged for one year. Specimens were randomly assigned to four retreatment file systems ( = 5 per subgroup), and retreatment was performed without solvents according to manufacturers' protocols. Residual filling material was quantified pre- and post-retreatment using micro-CT. Data were analyzed with repeated-measures analysis of variance. XP-Endo Retreatment and HyFlex Remover showed superior removal efficiency, particularly in middle and cervical thirds (>84%), whereas R-Endo consistently exhibited the lowest performance, especially apically. MicroMega Remover demonstrated intermediate efficacy, outperforming R-Endo but less effective than XP-Endo Retreatment and HyFlex. No significant differences were observed between Total Fill BC and BioRoot RCS sealers. Results indicated significant effects of canal third and file system ( < 0.001) and a significant canal third × file system × sealer interaction ( = 0.037). File design and metallurgical properties significantly influence the mechanical retrievability of aged calcium silicate-based sealers in solvent-free retreatment. XP-Endo Retreatment and HyFlex Remover provided superior cleaning under conditions. These findings inform clinicians on the selection of retreatment instruments for predictable removal of bioceramic sealers.

This study examined the biomechanical effects of running-induced fatigue on the kinematic and kinetic changes of the lower limb during a countermovement jump (CMJ) via analyzing variations in joint biomechanics during landing. A running-induced fatigue protocol was employed to explore changes in joint angle, moments, stiffness and loading rate during the CMJ landing pre and post-fatigue. Paired-sample -tests assessed changes in discrete parameters of joint stiffness, loading rates, and time-varying parameters were compared with one-dimensional statistical parametric mapping. Fatigue significantly reduced the range of motion (ROM) during landing, with significant differences in angles, specifically the dorsi-plantar flexion of right ankle, flexion-extension of left hip, rotation of left knee, and adduction-abduction of right knee ( < 0.001). The first loading rate at touchdown decreased by 10%, and the time intervals between the first and second peak and the second and third peak reduced by 40 and 80%, respectively. Joint loading increased and the sagittal joint stiffness of left hip, right knee, and right ankle exhibited significant differences post-fatigue ( < 0.001). Knee joint reduced the flexion angle ( < 0.001) and the load of knee joint ( < 0.001) during post-fatigue, with the role compensated by hip and ankle joints to achieve balance in the lower limb kinetic chain. These findings provide pilot evidence that running fatigue may lead to changes in lower limb joint loadings and provide a scientific foundation for fatigue prediction and injury assessment.

The aim of the analysis was to develop design principles for a new material having properties similar to those of the natural aortic artery. This involved replacing the complex structure of the aortic wall with a new material with a layer-composite structure having the same strength and hemodynamic properties. The structure of the material used to construct the new aortic prosthesis consists of three layers. The fibers in inner layer were embedded in a liquid matrix, which does not degrade or change its properties in contact with the moving fiber. The FEM was used to develop the strength properties of the new material. Constitutive equations were defined to relate the state of stress and the state of strain in the material. Based on the results of the identification process, a material specimen was prepared. Due to the orthotropic properties of the material. In the experimental studies, a specimen developed for the circumferential direction was tested. In the circumferential direction, the Young's modulus was 1090 kPa, and the fiber shape factor was 0.056. In the axial direction, the Young's modulus was 440 kPa, the fiber shape factor was 0.067. The paper presents the process of optimizing the material model of a new bioprosthesis, which mechanically imitates the natural material of the aorta. A simple fiber structure was immersed in a liquid matrix and described using basic material parameters. This approach allows to obtain a material with non-linear characteristics and high compliance.

To examine the relationship between the frontal plane alignment of the lower extremity, adductor longus muscle architecture (cross-sectional area and thickness), and anaerobic power capacity. Football players aged 14-16 joined the study and were evaluated for lower extremity alignment in the frontal plane radiographs. We examined adductor longus muscle thickness and cross-sectional area on both sides with ultrasound. To evaluate anaerobic power capacity, we did a 30-second Wingate test. Correlation analysis and multiple regression analysis were performed. 27 football players were enrolled in the study. The anatomical axis angle of the right side was 2.85 ± 1.75, and left side was 2.67 ± 1.62. A positive and strong correlation was found between both side muscle cross-sectional area and maximum and average power (right: = 0.829, < 0.001; = 0.851, < 0.001, left: = 0.742, < 0.001; = 0.789, < 0.001, respectively), and the right and left muscle thickness and the maximum and average power (right: = 0.678, < 0.001; = 0.717, < 0.001, left: = 0.714, < 0.001; = 0.741, < 0.001, respectively). The multiple regression analysis found that average power could be assessed with right and left axis angles, right muscle cross-sectional area, age, body mass index, and career duration. The analysis showed that these variables accounted for 80.3% of the variability in the average power ( (6,20) =13.558, < 0.001). Same independent variables could explain 77.6% of the variability in the maximum power ( (6,20) = 11.577, < 0.001). Muscle thickness and cross-sectional area strongly correlate with average and maximum power. The cross-sectional area and lower extremity alignment angle in the dominant leg could be used to estimate anaerobic power outputs.

The aim of this study was to evaluate absorbable and non-absorbable surgical sutures exposed to an environment with a chemical composition similar to that of ocular body fluids. The evaluation was based on the results of tests of the mass, diameter and mechanical properties of samples immersed in physiological saline solution (BSS) at different time intervals. Based on the conducted research, it was found that multifilament threads made of PGCL dissolve the fastest under these conditions, while PDS monofilament threads dissolve the longest. In the first case, the last measurements could be taken after 14 days of immersion, while in the second case, the mono-filament was not completely dissolved even after 80 days. Despite numerous publications in this area, available from various sources, it is very difficult to compare the obtained results to those of other authors. This is due to the fact that studies conducted on threads made of different materials and diameters, as well as in different environments, can have a significant impact on the resorption process. This justifies the need for this type of research.

This study aims to investigate whether unilateral low-volume, high-intensity isometric strength activation (ISA) can enhance jump performance and bilateral isokinetic flexion and extension strength within 24 and 48 hours post-intervention. A total of 68 participants (40 males and 28 females) were included, all free from muscle, ligament or skeletal disorders that could affect physical performance, and none had undergone lower limb surgery due to injury in the past year. Participants were randomly assigned to either the experimental group or the control group using a balanced randomization scheme. Athletic performance was assessed using unloaded countermovement jump (CMJ), unloaded squat jump (SJ), and isokinetic knee flexion and extension strength tests. The experimental group received an isometric activation protocol, while the control group maintained their regular exercise routines. The isometric activation protocol led to varying degrees of improvement across genders in the experimental group. Among male participants, there were significant increases in CMJ performance 24 hours post-activation, with flight time ((FT): +5%) and jump height ((JH): +9%) both showing statistical significance ( < 0.05). SJ performance also improved significantly, with FT ( < 0.01, ES = 1.101) and JH ( < 0.01, ES = 1.335) demonstrating large effect sizes. Furthermore, SJ performance remained significantly elevated 48 hours post-intervention compared to baseline ( < 0.05, JH: ES = 0.829). For female participants, SJ performance showed significant improvement 24 hours after activation ( < 0.05, FT: ES = 1.847; JH: ES = 1.789), although no other significant changes were observed. Regarding knee flexion and extension strength, at an angular velocity of 60°/s, the male group exhibited significantly greater strength at 48 hours post-intervention compared to 24 hours ( < 0.05, ES = 1.791). In the female group, bilateral knee strength significantly improved at both 24 and 48 hours post-intervention ( < 0.05, ES = 0.152). ISA interventions can enhance knee joint strength in both male and female participants within 24 and 48 hours post-intervention, and also induce a cross-activation effect. Therefore, when coaches aim to improve athletes' performance in subsequent training sessions or competition days, ISA can be considered as an effective method to activate lower limb strength.

This study aimed to develop feature extraction strategies for Center of Pressure (CoP) signals using adaptive genetic programming to characterize fall risk in older adults. The individual performance of CoP indices reported in the state-of-the-art was optimized through adaptive genetic programming across mathematical domains, such as entropy, time-based (distance, area, hybrid measures) and frequency-based ones. The validity of the new CoP indices was tested using mean difference tests for groups with and without fall risk, measuring the correlation with existing measures, as well as through the performance of univariate and multiple logistic regressions, which were reported in terms of the macro-average 1-score, recall, accuracy, specificity, sensitivity, and Area Under the Curve (AUC). The newly generated genetic CoP indices outperformed state-of-the-art indices in fall risk identification. The genetic-frequency CoP index achieved the best performance in univariate logistic regression, with an AUC of 0.763 using five-fold cross-validation. Moreover, all genetic indices showed statistically significant differences between older adults with and without fall risk. These results suggest that the proposed methodology provides some simple calculation formulas that facilitate its future adoption in clinical settings and increase fall risk classification performance by up to 27.0%.

The implantation angle of Bileaflet Mechanical Heart Valve (BMHV) is critical issue in valve replacement surgery. Investigating the local hemodynamic characteristics and analyzing the postoperative flow dynamics can provide valuable insights for determining the optimal implantation angle, thereby offering clinical guidance for improved surgical outcomes. Three-dimensional anatomical model of the Left Ventricle (LV) and BMHV was reconstructed based on patient-specific medical imaging data and anatomical parameters. The hemodynamic effects of varying implantation angles were investigated using Computational Fluid Dynamics (CFD) integrated with a Fluid-Structure Interaction (FSI) framework. The key analyses focused on the downstream shear stress distribution, vortex dynamics, clinically relevant hemodynamic indicators. When the valve was implanted along the axis of the aortic outflow tract (referred to as the AO angle), several benefits were observed. Blood flow penetrability improved, high shear stress regions were reduced, mechanical trauma to blood cells was significantly lessened. Quantitative metrics further demonstrated that the AO angle minimized values of Time-Averaged Wall Shear Stress (TAWSS), Oscillatory Shear Index (OSI) and Relative Residence Time (RRT). These metrics indicate more stable hemodynamics and a lower risk of ventricular wall inflammation and thrombosis. Furthermore, the Hemolysis Index (HI) reached its lowest level under the AO angle, suggesting optimal mitigation of hemolysis. This study systematically examines how the orientation of BMHV implantation affects LV hemodynamics. It identifies the AO angle as the most effective strategy for positioning. These findings provide quantitative evidence that can inform preoperative planning and support the advancement of precision-guided cardiac valve interventions based on hemodynamics considerations.

The aim of this study was an exploration of the multiscale vibratory response of the spine following orthopedic surgery in patients with idiopathic scoliosis and postoperative traumatic fatigue injury. In this paper, the postoperative macroscopic spine model in the modal, time and frequency domains to obtain the vibration response of the patient's entire spine were analyzed. Subsequently, the stresses in the cortical bone mesoscopic bone units around the surgically damaged interface were calculated using submodeling algorithms. The pore stresses and pore flow velocities of the osteocytes were then derived from the stresses of the mesoscopic bone units to predict fatigue damage at the fusion surface. The findings indicated that the first three orders of intrinsic frequency exerted the most significant influence on the spine model. The maximum stress of the bone unit was observed at the X3 bone plate on the left side of the fusion surface, and the maximum pore pressure and flow velocity of the bone cells occurred at the X4 on the right side of the fusion surface. The medical implants used in spinal orthopedics, titanium cages and pedicle nails, change the mobility of the adjacent segments and also create a stress shielding effect that impacts the fusion of bone tissues. Microscopic bone cell synapses experience greater pore pressures and pore flow velocities in the vibration environment compared to those under the static environment, which may promote cell growth. Vibration at low loads typically does not induce fatigue damage to cancellous bone at the fusion surface of medical implants.

In this study, the authors attempted to determine whether and to what extent the vibrations generated while driving a baby stroller could pose a potential hazard to an infant. For this purpose, the measurement of whole body vibrations inside a baby stroller was carried out, using a dummy infant weighing 5 kg. The study was conducted using four baby strollers of similar overall weight and design. Based on the results, it was concluded that the vibrations occurring in the baby stroller exceed the comfort limit defined by ISO 2631 and could be potentially dangerous to children. The comfort limit for the vertical axis is exceeded in the frequency range that corresponds to the resonant frequencies of the head (6-8 Hz), torso (6-17 Hz) or pelvis (6-17 Hz). For this type of study, the ISO 2631 standard can only be considered as a guideline in analyzing the results since the standard is intended for adults. There is no norm in the literature that defines the limit of vibrations acting on children. It seems necessary to develop a standard specifically for children. Based on the results obtained, the effect of speed and the way of driving a baby carriage on the magnitude of vibration received is evident.

The purpose of this study was to investigate the effects of foot strike patterns and running-induced fatigue on the biomechanical responses of the knee and ankle joints in amateur marathon runners by analyzing the combined effects of these two factors on lower limb joint kinematics, kinetics, and muscle activation characteristics under different conditions. A total of 26 participants were recruited.13 male amateur marathon runners with habitual non-rearfoot strike and 13 with rearfoot strike patterns underwent mild, moderate and severe running-induced fatigue interventions. Kinematic, ground reaction force and electromyographic data were collected. A two-way analysis of variance was performed in SPSS for statistical analysis. Fatigue level significantly affected knee joint range of motion ( = 0.023), peak joint moment ( = 0.003), and joint stiffness ( = 0.040). The non-rearfoot strike runners exhibited significantly greater ankle joint range of motion ( < 0.001) and lower peak joint moments ( < 0.001) compared to rearfoot strike runners. A significant interaction effect between fatigue and foot strike pattern was observed on the Root Mean Square amplitude of the medial gastrocnemius ( = 0.017) and biceps femoris ( = 0.021). A significant interaction effect between fatigue and foot strike patterns was observed in Root Mean Square. Given the impact of localized muscle fatigue on joint kinematics and kinetics, the nonrearfoot strike runners may demonstrate intense fatigue-related biomechanical alterations to the knee and ankle joints during the latter stages of long-distance running. These results suggest that understanding foot strike biomechanics under fatigue may inform training and injury prevention.

Portal hypertension (PHT) leads to complications such as variceal bleeding, hepatic remodeling and thrombosis, driven by altered hemodynamics. This study aims to elucidate flow structure, shear stress and helicity changes under PHT, and their potential roles in promoting thrombosis and vascular remodeling. A patient-specific portal venous system model was reconstructed from CT images. Computational fluid dynamics (CFD) simulations were conducted to evaluate flow velocity, wall shear stress (WSS), oscillatory shear index (OSI), relative residence time (RRT) and helicity. Compared to the healthy model, the PHT condition demonstrated reduced flow velocity, lower TAWSS and elevated RRT, particularly near bifurcations. Moreover, the strength and symmetry of helical flow were significantly impaired in PHT, especially at the main portal vein bifurcation - an area frequently associated with thrombosis. This study highlights the role of hemodynamic disruption, particularly helicity loss, in the pathogenesis of PHT-related complications. CFD-based helicity analysis offers novel insight into biomechanical risk assessment and may inform future interventional strategies.

Fluid-structure interaction (FSI) techniques have become widely accepted numerical tools for analysing transient flows through compliant channels and tubes. However, FSI remains computationally demanding and requires assumptions about certain parameters that are often difficult to determine, particularly in biomedical applications. This study aimed to demonstrate the importance of key decisions required to conduct FSI simulations. Appropriate material properties were selected and parameters that define the magnitude of external reactions and cushioning effects (which are usually unknown but can be discovered through reverse engineering were set). Using a simplified model of an elastic straight tube, which represents a high-flow artery, reduced the influence of shape and associated mesh imperfections on the results. Wall deformation, von Mises stress, wall shear stress and the pressure drop along the tube were analysed. Verification with various mesh densities for the compliant wall demonstrated that mesh fidelity significantly affects von Mises stress and computation time on a standard PC but has a negligible effect on wall deformation, wall shear stress and pressure drop. Varying wall stiffness and foundation stiffness affected the resulting compliance and all monitored parameters. Additionally, applying different mass and stiffness coefficients to define Rayleigh damping identified a safe range of applicability of this type of damping, however, experimental validation is necessary to determine appropriate values for specific applications and avoid overdamping. Finally, the results were discussed in the context of other FSI research and relevant in vivo and in vitro blood flow studies.

The aim of this study was to investigate a novel data mining approach for early and effective diagnosis of Gestational Diabetes Mellitus (GDM). Gestational Diabetes Mellitus (GDM) data contains two classes (healthy and diabetic), 15 features and 3525 instances. In the first stage, the widely used and effective KNN and regression methods were employed for the filling of missing data. Then, the data source transformed into grayscale images as primary images and multiplexed images. Finally, both original data and transformed data are classified with KNN, SVM and CNN using -fold cross validation technique. Performance metrics were compared to extract the best suitable system. The original GDM source and the missing values replacement of GDM are classified with KNN and SVM methods. Also, primary images of this dataset and multiplexed images are classified with CNN 50%-50% and 70%-30% train-test respectively. The results of classification performance demonstrated that reaching up to 97.91% with CNN, recall of 97.61%, specificity of 97.61%, precision of 97.97% and F1-score of 97.79%. This result outperformed all previous studies conducted on the same dataset in the literature. This work is demonstrated a new approach that the best results of classification accuracy when compared with previous studies related to proposed methods to identify GDM disease. It can be clearly stated that applying a data mining method to impute missing values, followed by converting the dataset into images based on certain criteria and classifying with CNN, is the most effective approach for predicting GDM.

: The objective of this study was to numerically reconstruct a collision between a minivan and a pedestrian, and to reproduce the injury conditions of the pedestrian's head, chest, and lower extremities. This research aimed to provide a reference for the numerical reconstruction studies of traffic collisions based on human body models. : The walking posture of the Chinese 50th percentile male pedestrian model AC-HUMs (Advanced China Human body Models) was transformed, after which an analysis model was established for simulation based on the simplified model of the minivan vehicle and the collision information. Subsequently, the injury conditions of the model's lower extremities, chest and head were extracted, and compared with the information of the injured person. : The findings reveal that the pedestrian model exhibits tibia-fibula fractures in the lower limbs, six rib fractures in the chest and a head injury classified as AIS5 (Abbreviated Injury Scale), suggesting a potential risk of concussion. While the injuries to the lower limbs and chest are predicted with considerable accuracy, the head injuries in the model are more severe. : In the reconstruction of a minivan-pedestrian collision using the AC-HUMs model, AC-HUMs showed good injury prediction capabilities for the pedestrian's lower limbs and chest, and while the head injury prediction based on intracranial pressure was more severe, that, based on brain strain, was consistent with the actual situation, reflecting the model's satisfactory performance. This research provides valuable insights for studying injury patterns among Chinese pedestrians through numerical reconstruction.

Basketball requires high lower limb performance. Assessing jump biomechanics is vital for enhancing performance and injury prevention. Marker-based (MB) systems are common but limited. In recent years, Markerless (ML) motion capture systems have gradually become emerging tools in sports biomechanics research due to their characteristic of not requiring physical marker points. However, their specific application and verification in basketball events are still relatively limited. : In this study, lower limb kinematics and kinetics estimated by MB and ML motion capture systems during jumps were compared. : Twelve subjects performed the standing vertical jump (SVJ), standing long jump (SLJ) and running vertical jump (RVJ) tests. Data was collected using 10 infrared cameras, 6 high-resolution cameras and two force platforms via Vicon Nexus software. Markerless motion capture calculated sagittal plane angles, torque and power of the Hip, Knee and Ankle joints via Theia3D software, with these parameters also collected by the marker-based Vicon system. Both systems' '64ata were then processed in Visual3D. We analyzed the correlation coefficient (), root mean square difference (RMSD), and maximum/minimum errors, as well as using statistical parametric mapping (SPM) to compare temporal patterns between groups and determine specific moments where significant differences occurred. : SLJ capture was slightly inferior in both systems. SPM analysis of the sagittal plane showed significant differences only at the hip joint. Joint angle RMSD was < 8.2°, torque RMSD < 0.41 N·M/kg, and power RMSD < 1.76 W/kg. : The ML system accurately captures knee and ankle joints in the sagittal plane but shows significant differences in hip measurement and certain movements, requiring further validation.

: The mechanical environment of the extracellular matrix strongly influences how cells behave - affecting their adhesion, migration, growth, and differentiation. While stiffness has been widely studied, recent research highlights the importance of viscoelasticity, especially the stress relaxation timescale, in how cells sense and respond to their surroundings. According to the widely accepted motor-clutch model, optimal cell spreading occurs when the stress relaxation timescale is similar to the timescale of molecular clutch binding. : Polyacrylamide (PAAm) hydrogels, due to their tunable mechanical properties and bioinert nature, are commonly used as model substrates in mechanobiology. In this study, we investigated how changing the concentrations of crosslinker (N,N'-methylenebisacrylamide) and initiator (ammonium persulfate) affects the viscoelastic behavior of PAAm hydrogels. Using creep-recovery tests and fitting the data to the Standard Linear Solid model, we extracted mechanical parameters and calculated the stress relaxation timescale. : We found that the relaxation timescale increases with crosslinker concentration up to 0.05%, then decreases - suggesting an optimal crosslinking density. At a fixed 0.05% crosslinker, increasing initiator concentration reduced the relaxation timescale, likely due to faster gelation and less organized network formation. : These findings demonstrate how simple adjustments in polymerization parameters can tune hydrogel relaxation behavior for mechanobiological applications.