Biomechanical Methods Research Articles

Deformation and Trapping of Cell Nucleus Using Micropillar Substrates Possibly Affect UV Radiation Resistance of DNA

DNA damage induced by the ultraviolet (UV) light, which affects adversely on genome stability, causes many kinds of diseases. Thus, a biochemical or biomechanical method in DNA damage protection is well required. In the present study, we investigated the effects of mechanical factors, such as deformation of cell nucleus using polydimethylsiloxane (PDMS)-based microfabricated array of micropillars, on UV radiation resistance of DNA in cultured cells. The epithelial-like cells spread normally in the spaces between micropillars and their nuclei showed remarkable deformation and appeared to be “trapped” mechanically on the array of pillars. We found that the UV radiation-induced DNA damage estimated by the fluorescent intensity of the phospho-histone γ-H2AX, was significantly inhibited with the nucleus deformation on the pillars. The result indicates that the inhibition of UV radiation-induced DNA damages might be resulted from structural change of DNA caused by the mechanical stress of the cell nucleus on the micropillars.

Intraprocedural Versus Initial Follow-up Minimal Ablative Margin Assessment After Colorectal Liver Metastasis Thermal Ablation: Which One Better Predicts Local Outcomes?

The aim of this study was to investigate the prognostic value of 3-dimensional minimal ablative margin (MAM) quantified by intraprocedural versus initial follow-up computed tomography (CT) in predicting local tumor progression (LTP) after colorectal liver metastasis (CLM) thermal ablation. This single-institution, patient-clustered, tumor-based retrospective study included patients undergoing microwave and radiofrequency ablation between 2016 and 2021. Patients without intraprocedural and initial follow-up contrast-enhanced CT, residual tumors, or with follow-up less than 1 year without LTP were excluded. Minimal ablative margin was quantified by a biomechanical deformable image registration method with segmentations of CLMs on intraprocedural preablation CT and ablation zones on intraprocedural postablation and initial follow-up CT. Prognostic value of MAM to predict LTP was tested using area under the curve and competing-risk regression model. A total of 68 patients (mean age ± standard deviation, 57 ± 12 years; 43 men) with 133 CLMs were included. During a median follow-up of 30.3 months, LTP rate was 17% (22/133). The median volume of ablation zone was 27 mL and 16 mL segmented on intraprocedural and initial follow-up CT, respectively ( P < 0.001), with corresponding median MAM of 4.7 mm and 0 mm, respectively ( P < 0.001). The area under the curve was higher for MAM quantified on intraprocedural CT (0.89; 95% confidence interval [CI], 0.83-0.94) compared with initial follow-up CT (0.66; 95% CI, 0.54-0.76) in predicting 1-year LTP ( P < 0.001). An MAM of 0 mm on intraprocedural CT was an independent predictor of LTP with a subdistribution hazards ratio of 11.9 (95% CI, 4.9-28.9; P < 0.001), compared with 2.4 (95% CI, 0.9-6.0; P = 0.07) on initial follow-up CT. Ablative margin quantified on intraprocedural CT significantly outperformed initial follow-up CT in predicting LTP and should be used for ablation endpoint assessment.

Textile smart sensors based on a biomechanical and multi-layer perceptron hybrid method

Resistance training is becoming increasingly important and widespread. Decomposition of the muscle loads applied is important for injury prevention and determining the load on the targeted muscles. In this study, a flexible textile PET (polyethylene terephthalate)/SP(Spandex) SWCNT (Single-walled carbon nanotube) stretch sensor was fabricated and attached at four locations: the elbow, brachioradialis/flexor carpi radialis, biceps brachii, and triceps brachii. The stretch sensors attached to the elbow can measure the angle of elbow flexion without an IMU 9-axis sensor using quadratic fitting. A Multi-Layer Perceptron (MLP) was used to decompose the muscle volume expansions of the 3muscle by angle. The model provided a good fit for all three muscles, with R-squared values ranging from Test set 0.98725 to 0.99815. Through one input and three ouput fitting, the muscle volume expansion quantities during the bicep barbell curl were decomposed and compared with data. The results showed that the brachioradialis/flexor carpi radialis muscle maintained 13% of the arm muscle volume up to 60°, then increased to 44% at 100°. The biceps brachii muscle steadily increased to 70% from 0° up to 60°, and then maintained 40% at 100° due to the volume increase of other muscles. The triceps brachii muscle maintained 9% of the arm muscle volume up to 90°, then increased to 20% at 100°. This study shows that muscle volume expansion can be easily measured with a non-body contact wearable device, unlike many existing contact methods for measuring muscle activity like EMG (electro-myography), etc. This study provides a novel approach for easily measuring muscle volume expansion and decomposition in wearable devices, which can indirectly indicate injury prevention and muscle loading in target areas through balance optimization among local muscles.

Influence of foot excitation and shin posture on the vibration behavior of the entire spine inside a seated human body

Due to ethical issues and simplification of traditional biomechanical models, experimental methods and traditional computer methods were difficult to quantify the effects of foot excitation and shin posture on vibration behavior of the entire spine inside a seated human body under vertical whole-body vibration. This study developed and verified different three-dimensional (3D) finite element (FE) models of seated human body with detailed anatomical structure under the biomechanical characteristics to predict vibration behavior of the entire spine inside a seated human body with different foot excitation (with and without vibration) and shin posture (vertical and tilt posture). Random response analysis was performed to study the transmissibility of the entire spine to seat under vertical white noise excitation between 0 and 20 Hz at 0.5 m/s2 r.m.s. The results showed that although the foot excitation could reduce the fore-aft transmissibility in the cervical spine (23% reduction), it could significantly increase that in the lumbar spine (52% increase), which resulted in complex alternating stresses at lumbar spine and made the lumbar spine more vulnerable to injury in long-term vibration environment. Moreover, the shin tilt posture made the maximum fore-aft transmissibility in the lumbar spine move to the upper lumbar spine. The study provided new insights into the influence of foot excitation and shin posture on the vibration behavior of the entire spine inside a seated human body. Foot excitation exposed the lumbar spine to complex alternating stresses and made it more vulnerable to injury in long-term whole body vibration.

Biomechanical evaluation and optimal design of a pedicle screw with double bent rods internal fixation system based on PE-PLIF fusion

Problems, such as broken screws, broken rods, and cage subsidence after clinical spinal fusion surgery affect the success rate of fusion surgery and the fixation effect of fusion segments, and these problems still affect the treatment and postoperative recovery of patients. In this study, we used the biomechanical finite element analysis method to analyze and study the fixation effect of three kinds of spinal internal fixation systems on L4–L5 lumbar spine segments in percutaneous endoscopic posterior lumbar interbody fusion (PE-PLIF). The three different fixation systems compared in this study include bilateral pedicle screw fixation (M1); bilateral pedicle screw with cross-link fixation (M2); bilateral pedicle screws with double bent rods fixation (M3). The internal fixation systems with different structures were analyzed with the help of Hypermesh, and Abaqus. It was found that the internal fixation system with double bent rods reduced screw stresses by 23.8 and 22.2% in right and left axial rotation than the traditional bilateral pedicle screw system, while titanium rod stresses were reduced by 9.6, 3.7, 9.6, and 2.9% in flexion, left and right lateral bending, and right axial rotation, respectively, and L5 upper endplate stresses were reduced by 35.5, 18.9, 38.4, 10.2, and 48.3% in flexion, left and right lateral bending, and left and right axial rotation, respectively. The spinal range of motion (ROM) of the M3 internal fixation system was less than that of the M1 and M2 internal fixation systems in left lateral bending, left lateral rotation, and right axial rotation, and the intact vertebral ROM was reduced by 93.7, 94.9, and 90.9%, respectively. The double bent rod structure of the spinal internal fixation system has better biomechanical properties, which can effectively reduce the risk of screw breakage, loosening, cage subsidence, and endplate collapse after fusion surgery.

Total Knee Arthroplasty for Contractures in Patients with Rheumatoid Arthritis

Summary. Knee joint injury in patients with rheumatoid arthritis (RA) occurs in 70% of cases. This is the most common cause of loss of work capacity and the ability to selfcare; patients become severely disabled, since the disease is accompanied by contractures with the development of discordant positions of the lower limbs, which leads to a partial or complete loss of the function of support and walking. Thus, this problem needs to be studied.&#x0D; Objective: to analyze the orthopedic treatment of secondary arthrosis of the knee joints in patients with RA, complicated by contractures.&#x0D; Materials and Methods. In this study, we have analyzed the orthopedic treatment of 66 RA patients with secondary arthrosis with contractures, who underwent 75 total knee replacements between 2013 and 2020. Anamnestic data, clinical, biomechanical and statistical research methods were used.&#x0D; Results. The analysis of the results of total knee replacement was followed in the period from 6 months to 5 years. The results were evaluated according to the 100-point scale by J. Joseph,&#x0D; E.E. Kaufman (1550). The majority of patients had good treatment results.&#x0D; Conclusions. Total knee replacement is required in patients with 2nd phase of the stage II of the disease and higher. In our opinion, this is the most optimal time for surgical treatment, which allows patients with RA to fully use the capabilities of an implanted endoprosthesis.

Biomechanical Assessments in Woodwind Musicians: A Systematic Review.

Biomechanical methods are frequently used to provide information about the kinematics and kinetics of posture and movement during musical performance. The aim of this review was to identify and analyze the biomechanical methods performed on woodwind musicians to understand their musculoskeletal demands. A systemic review was carried out following the guidelines of the document Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). It was registered in PROSPERO (code 430304).The databases PubMed, Cochrane, CINAHL, Scopus, and Web of Science were consulted between January 2000 and March 2022. The search in the databases identified 1625 articles, and 16 different studies were finally included in the review, with a sample size of 390 participants. Pressure sensors, surface electromyography, infrared thermography, goniometry in two dimensions, and ultrasound topometry in three dimensions were biomechanical methods useful to broaden the knowledge of musculoskeletal demands during musical practice. Piezoresistive pressure sensors were the most widely used method. The great heterogeneity of the studies limited the comparability of the results. The findings raised the need to increase both the quantity and the quality of studies in future research.

PREDICTION OF COLLAGEN CONTENT THROUGH BIOMECHANICAL PARAMETERS IN MICE SKIN WOUND: A COMPARISON OF ANN AND ANFIS MODELS

Pathological analysis as well as biomechanical methods are powerful approaches for collagen assessment, which plays an important role in understanding the wound healing process and choosing a treatment method in clinical situations. Due to the limitations of preparing and evaluating pathological images, this study was designed to establish a machine learning technique to predict the wound collagen content through its biomechanical parameters. For this purpose, the artificial neural network (ANN) and adaptive neuro-fuzzy inference system (ANFIS) were compared. The wound was created with an incision on the back of 30 male BALB/c mice. On the 7th and 14th days, animals were sacrificed and 60 wound tissue samples were evaluated using histopathological and biomechanical methods to quantify the amount of collagen and wound tensile strength to feed the ANN and ANFIS developed models. Based on the results, both models have appropriate performance to predict the wound collagen content. However, the comparison of coefficient of determination ([Formula: see text]) and root mean square error (RMSE) for testing dataset revealed that ANN ([Formula: see text], [Formula: see text]) had more prediction capability than ANFIS ([Formula: see text], [Formula: see text]). As a decision support system, ANN model could assist in the evaluation of wound healing process with collagen values prediction.

A Review on Biomechanics and Development of Finite Element Models of Human Head Neck System

Abstract: The biomechanics of human head neck system could be better understood by creating finite element models of the same that accurately represents most of the components of head and neck. The initial geometry of the human head and neck was obtained using the computer tomography scans. The finite element models are created from these computed tomography scans and are further undergone through the various analysis procedures of finite element analysis. Thus, the developed finite element head neck models could be studied for various kinds of impacts acting on the head neck system during the time of any vehicle collisions, spaceflights etc. The development of these models and the various impact studies helps in the safety of the people. In this paper the concept of Finite element method, application of finite element method in biomechanics and various steps involved in this method are discussed in detail. Similarly, the finite element models of head and neck system developed by various researchers are also considered.

Novel uniplanar pedicle screw systems applied to thoracolumbar fractures: a biomechanical study.

Objective: In this study, the advantages of the internal fixation configuration composed of uniplanar pedicle screws in the treatment of thoracolumbar fractures were verified by biomechanical experimental methods, which provided the basis for subsequent clinical experiments and clinical applications. Methods: A total of 24 fresh cadaveric spine specimens (T12-L2) were utilized to conduct biomechanical experiments. Two different internal fixation configurations, namely, the 6-screw configuration and the 4-screw/2-NIS (new intermediate screws) configuration, were tested using fixed-axis pedicle screws (FAPS), uniplanar pedicle screws (UPPS), and polyaxial pedicle screws (PAPS) respectively. The spine specimens were uniformly loaded with 8NM pure force couples in the directions of anteflexion, extension, left bending, right bending, left rotation, and right rotation, and the range of motion (ROM) of the T12-L1 and L1-L2 segments of the spine was measured and recorded to access biomechanical stability. Results: No structural damage such as ligament rupture or fracture occurred during all experimental tests. In the 6-screw configuration, the ROM of the specimens in the UPPS group was significantly better than that of the PAPS group but weaker than those of the FAPS group (p < 0.01). In the 4-screw/2-NIS configuration, the results were identical to the biomechanical test results for the 6-screw configuration (p < 0.01). Conclusion: Biomechanical test results show that the internal fixation configuration with UPPS can maintain the stability of the spine well, and the results are better than that of PAPS. UPPS has both the biomechanical advantages of FAPS and the superiority of easy operation of PAPS. We believe it is an optional internal fixation device for minimally invasive treatment of thoracolumbar fractures.

The knee joint deformities in rheumatoid arthritis patients

Knee joints injury in rheumatoid arthritis patients appear in 70 % cases. This is the most common cause of loss of work capacity, the ability to self-care. Patients become severely disabled, in that the disease is accompanied by deformations with the development of discordant positions of the lower limbs, which lead to a partial or complete loss of the function of support and walking, so this problem needs to be studied. Objective. To make an analysis of orthopedic treatment of secondary arthrosis of knee joints in RA patients, complicated by deformities depending on the age and gender of the patient, stage, duration of the disease and activity of the inflammatory process. Methods. In this work we have analyzed the orthopedic treatment of 66 RA patients with secondary arthrosis with axial deformities, who underwent 75 total endoprosthetics between 2013 and 2020. Anamnestic data, clinical, biomechanical and statistical research methods were used. The obtained data were evaluated using the scale of Joseph J., Kaufman E. E. Results. The analysis of the results of knee joint replacement was followed in the period from 6 months to 5 years. The results were carried out according to the 100-point scale Joseph J., Kaufman E. E. (1990). Thus, the analysis of the results of total knee arthroplasty in patients with RA according to the scale of Joseph J., Kaufman E. E. showed that good results were obtained in 46 (79.31 %) patients, satisfactory results in 11 (18.97 %) and unsatisfactory results obtained in 1 (1.72 %) patients. The reliable relationship of the level of joint deformation with the level of disease activity and with the scale of Joseph J., Kaufman E. E. was researched. Other indicators are not reliably correlated with the level of joint deformation. As a result of pairwise comparisons of groups with each other using the Duncan test, a significant increase in the degree of joint deformation was found in the group with activity 3 compared to the group with activity 1. The use of basic or complex therapy does not reliably affect the degree of joint deformation. Conclusions. Total knee joint replacement need patients with II stage of the 2nd phase of the disease and higher. In our opinion, this is the most optimal time for surgical treatment, which allows patients with RA to fully use the possibilities of an implanted endoprosthesis.

Oxygen-Glucose Deprivation in Organotypic Hippocampal Cultures Leads to Cytoskeleton Rearrangement and Immune Activation: Link to the Potential Pathomechanism of Ischaemic Stroke.

Ischaemic stroke is characterized by a sudden loss of blood circulation to an area of the brain, resulting in a corresponding loss of neurologic function. As a result of this process, neurons in the ischaemic core are deprived of oxygen and trophic substances and are consequently destroyed. Tissue damage in brain ischaemia results from a complex pathophysiological cascade comprising various distinct pathological events. Ischaemia leads to brain damage by stimulating many processes, such as excitotoxicity, oxidative stress, inflammation, acidotoxicity, and apoptosis. Nevertheless, less attention has been given to biophysical factors, including the organization of the cytoskeleton and the mechanical properties of cells. Therefore, in the present study, we sought to evaluate whether the oxygen-glucose deprivation (OGD) procedure, which is a commonly accepted experimental model of ischaemia, could affect cytoskeleton organization and the paracrine immune response. The abovementioned aspects were examined ex vivo in organotypic hippocampal cultures (OHCs) subjected to the OGD procedure. We measured cell death/viability, nitric oxide (NO) release, and hypoxia-inducible factor 1α (HIF-1α) levels. Next, the impact of the OGD procedure on cytoskeletal organization was evaluated using combined confocal fluorescence microscopy (CFM) and atomic force microscopy (AFM). Concurrently, to find whether there is a correlation between biophysical properties and the immune response, we examined the impact of OGD on the levels of crucial ischaemia cytokines (IL-1β, IL-6, IL-18, TNF-α, IL-10, IL-4) and chemokines (CCL3, CCL5, CXCL10) in OHCs and calculated Pearsons' and Spearman's rank correlation coefficients. The results of the current study demonstrated that the OGD procedure intensified cell death and nitric oxide release and led to the potentiation of HIF-1α release in OHCs. Moreover, we presented significant disturbances in the organization of the cytoskeleton (actin fibers, microtubular network) and cytoskeleton-associated protein 2 (MAP-2), which is a neuronal marker. Simultaneously, our study provided new evidence that the OGD procedure leads to the stiffening of OHCs and a malfunction in immune homeostasis. A negative linear correlation between tissue stiffness and branched IBA1 positive cells after the OGD procedure suggests the pro-inflammatory polarization of microglia. Moreover, the negative correlation of pro- and positive anti-inflammatory factors with actin fibers density indicates an opposing effect of the immune mediators on the rearrangement of cytoskeleton induced by OGD procedure in OHCs. Our study constitutes a basis for further research and provides a rationale for integrating biomechanical and biochemical methods in studying the pathomechanism of stroke-related brain damage. Furthermore, presented data pointed out the interesting direction of proof-of-concept studies, in which follow-up may establish new targets for brain ischemia therapy.

The Digital Twin: A Potential Solution for the Personalized Diagnosis and Treatment of Musculoskeletal System Diseases.

Due to the high prevalence and rates of disability associated with musculoskeletal system diseases, more thorough research into diagnosis, pathogenesis, and treatments is required. One of the key contributors to the emergence of diseases of the musculoskeletal system is thought to be changes in the biomechanics of the human musculoskeletal system. However, there are some defects concerning personal analysis or dynamic responses in current biomechanical research methodologies. Digital twin (DT) was initially an engineering concept that reflected the mirror image of a physical entity. With the application of medical image analysis and artificial intelligence (AI), it entered our lives and showed its potential to be further applied in the medical field. Consequently, we believe that DT can take a step towards personalized healthcare by guiding the design of industrial personalized healthcare systems. In this perspective article, we discuss the limitations of traditional biomechanical methods and the initial exploration of DT in musculoskeletal system diseases. We provide a new opinion that DT could be an effective solution for musculoskeletal system diseases in the future, which will help us analyze the real-time biomechanical properties of the musculoskeletal system and achieve personalized medicine.

Gait Training with Functional Electrical Stimulation Improves Mobility in People Post-Stroke

(1) Background: Stroke is one of the leading causes of disability. To identify the best treatment strategies for people with stroke (PwS), the aim of the current study was to compare the effects of training on a treadmill with functional electrical stimulation (TT-FES) with training on a treadmill (TT), and to analyze the effects of sequence of training on mobility and the parameters of walking ability. (2) Methods: Prospective, longitudinal, randomized and crossover study, in which 28 PwS were distributed into groups, namely the A-B Group (TT-FES followed by TT) and B-A Group (TT followed by TT-FES), using the foot drop stimulator, and were measured with functional tests. (3) Results: We found improved mobility, balance, non-paretic limb coordination, and endurance only in the group that started with TT-FES. However, sensorimotor function improved regardless of the order of training, and paretic limb coordination only improved in the B-A Group, but after TT-FES. These data indicate that the order of the protocols changed the results. (4) Conclusions: Although biomechanical evaluation methods were not used, which can be considered a limitation, our results showed that TT-FES was superior to isolated training on a treadmill with regard to balance, endurance capacity, and coordination of the non-paretic limb.

Research progress in multi-body system dynamics modeling in stomatology

The stomatognathic system is an organic combination of bone, dentition, joints, masticatory muscles and innervation nerves. It is an organ system for the human body to perform mastication, speech, swallowing and other important functions. Due to the complex anatomical structure of stomatognathic system and ethical limitations, it is difficult to directly measure the movement and force by using the biomechanical experimental methods. Multi-body system dynamics is an important tool to study the kinetics and force of a multi-body system, which consists of several objects with relative motion. We can use the method of multi-body system dynamics simulation in engineering to study the movement, soft tissue deformation and force transfer of this complex stomatognathic system. This paper briefly introduces the history and application methods of multi-body system dynamics and the commonly used modeling methods. The application and research progress of multi-body system dynamics modeling methods in the field of stomatology was emphatically summarized, development prospects of current research and difficulties were put forward.

A novel mathematical model of the badminton smash: simulation and modeling in biomechanics

Applied physics and computer methods in biomechanics have been extensively used in sports science research, including performance and biomechanics analysis. The Brachistochrone problem, which expresses the curve that an object draws quickly under gravitational forces in a vertical position, is one of the most widely used studies in classical mechanics. A similar problem arises when a badminton player intends to hit a smash with the shortest shot time. This paper aims to determine the optimal stroke trajectory for a shuttlecock smash in the shortest time. We simulate the badminton smash movement using a computer program after analyzing the shuttlecock smash analytically and numerically for several conditions. The modeling results show that a cycloid trajectory allows badminton players to smash the shuttlecock in the shortest time. Based on the experimental findings of Tsai, Huang, and Jih’s study and our models, the ratio of clear speed to smash speed is 0.75, which is still in the range of 0.71 to 0.76, and we find that a cycloid trajectory gives the shortest shuttlecock smash time. We concluded that the experimental data from this study’s literature supported our model. The novelty of this study is that we found the first powerful model and simulation of conventional Brachistochrone in the case of a badminton smash of badminton players. For badminton coaches and players, this model formulation is intended as a reference for optimizing shuttlecock shots. Furthermore, another novelty of this research is that it may lead to software that can be used to analyze the muscle strength of badminton players based on their cycloid hand trajectory and shuttlecock speed.

Wound healing activity of Salvia huberi ethanolic extract in streptozocin-induced diabetic rats

Objective: The aim of this study was to examine the in vivo wound healing potential of Salvia huberi Hedge (endemic to Turkey) on excision and incision wound models in diabetic rats. Method: Male Wistar albino rats, 3-4 months old and weighing 180-240g were used. The animals were randomly divided into five groups including Control, Vehicle and Fito reference, and two different concentrations (0.5% and 1% weight/weight (w/w)) of ethanol extract of Salvia huberi were investigated in both wound models on streptozocin-induced diabetic rats using macroscopic, biomechanical, biochemical, histopathological, genotoxic and gene expression methods over both seven and 14 days. Fito cream (Tripharma Drug Industry and Trade Inc., Turkey) was used as the reference drug. Results: A total of 60 rats were used in this study. Salvia huberi ointments at 0.5% and 1% (w/w) concentrations and Fito cream showed 99.3%, 99.4% and 99.1% contraction for excision wounds, and 99.9%, 97.0% and 99% contraction for incision wounds, respectively. In Salvia huberi ointments and Fito cream groups, re-epithelialisation increased dramatically by both day 7 and day 14 (p<0.05). By day 14, low hydroxyproline and malondialdehyde (MDA) levels, and high glutathione (GSH) levels were observed in the Salvia huberi ointment groups. After two application periods, damaged cell percent and genetic damage index values and micronucleus frequency of Salvia huberi ointment treatment groups were lower than Control and Vehicle groups (p<0.001). A growth factor expression reached a high level by day 7 in the Control group; in Salvia huberi-treated groups it was decreased. Conclusion: The study showed that application of Salvia huberi ointments ameliorated the healing process in diabetic rats with excisional and incisional wounds and may serve as a potent healing agent.

Key transition technology of ski jumping based on inertial motion unit, kinematics and dynamics

BackgroundThe development and innovation of biomechanical measurement methods provide a solution to the problems in ski jumping research. At present, research on ski jumping mostly focuses on the local technical characteristics of different phases, but studies on the technology transition process are less.ObjectivesThis study aims to evaluate a measurement system (i.e. the merging of 2D video recording, inertial measurement unit and wireless pressure insole) that can capture a wide range of sport performance and focus on the key transition technical characteristics.MethodsThe application validity of the Xsens motion capture system in ski jumping was verified under field conditions by comparing the lower limb joint angles of eight professional ski jumpers during the takeoff phase collected by different motion capture systems (Xsens and Simi high-speed camera). Subsequently, the key transition technical characteristics of eight ski jumpers were captured on the basis of the aforementioned measurement system.ResultsValidation results indicated that the joint angle point-by-point curve during the takeoff phase was highly correlated and had excellent agreement (0.966 ≤ r ≤ 0.998, P < 0.001). Joint root-mean-square error (RMSE) differences between model calculations were 5.967° for hip, 6.856° for knee and 4.009° for ankle.ConclusionsCompared with 2D video recording, the Xsens system shows excellent agreement to ski jumping. Furthermore, the established measurement system can effectively capture the key transition technical characteristics of athletes, particularly in the dynamic changes of straight turn into arc in inrun, the adjustment of body posture and ski movement during early flight and landing preparation.

Wound healing activity of Salvia huberi ethanolic extract in streptozocin-induced diabetic rats

Objective: The aim of this study was to examine the in vivo wound healing potential of Salvia huberi Hedge (endemic to Turkey) on excision and incision wound models in diabetic rats. Method: Male Wistar albino rats, 3-4 months old and weighing 180-240g were used. The animals were randomly divided into five groups including Control, Vehicle and Fito reference, and two different concentrations (0.5% and 1% weight/weight (w/w)) of ethanol extract of Salvia huberi were investigated in both wound models on streptozocin-induced diabetic rats using macroscopic, biomechanical, biochemical, histopathological, genotoxic and gene expression methods over both seven and 14 days. Fito cream (Tripharma Drug Industry and Trade Inc., Turkey) was used as the reference drug. Results: A total of 60 rats were used in this study. Salvia huberi ointments at 0.5% and 1% (w/w) concentrations and Fito cream showed 99.3%, 99.4% and 99.1% contraction for excision wounds, and 99.9%, 97.0% and 99% contraction for incision wounds, respectively. In Salvia huberi ointments and Fito cream groups, re-epithelialisation increased dramatically by both day 7 and day 14 (p<0.05). By day 14, low hydroxyproline and malondialdehyde (MDA) levels, and high glutathione (GSH) levels were observed in the Salvia huberi ointment groups. After two application periods, damaged cell percent and genetic damage index values and micronucleus frequency of Salvia huberi ointment treatment groups were lower than Control and Vehicle groups (p<0.001). A growth factor expression reached a high level by day 7 in the Control group; in Salvia huberi-treated groups it was decreased. Conclusion: The study showed that application of Salvia huberi ointments ameliorated the healing process in diabetic rats with excisional and incisional wounds and may serve as a potent healing agent.

Repeatability and Temporal Consistency of Lower Limb Biomechanical Variables Expressing Interlimb Coordination during the Double-Support Phase in People with and without Stroke Sequelae

Reliable biomechanical methods to assess interlimb coordination during the double-support phase in post-stroke subjects are needed for assessing movement dysfunction and related variability. The data obtained could provide a significant contribution for designing rehabilitation programs and for their monitorisation. The present study aimed to determine the minimum number of gait cycles needed to obtain adequate values of repeatability and temporal consistency of lower limb kinematic, kinetic, and electromyographic parameters during the double support of walking in people with and without stroke sequelae. Eleven post-stroke and thirteen healthy participants performed 20 gait trials at self-selected speed in two separate moments with an interval between 72 h and 7 days. The joint position, the external mechanical work on the centre of mass, and the surface electromyographic activity of the tibialis anterior, soleus, gastrocnemius medialis, rectus femoris, vastus medialis, biceps femoris, and gluteus maximus muscles were extracted for analysis. Both the contralesional and ipsilesional and dominant and non-dominant limbs of participants with and without stroke sequelae, respectively, were evaluated either in trailing or leading positions. The intraclass correlation coefficient was used for assessing intra-session and inter-session consistency analysis. For most of the kinematic and the kinetic variables studied in each session, two to three trials were required for both groups, limbs, and positions. The electromyographic variables presented higher variability, requiring, therefore, a number of trials ranging from 2 to >10. Globally, the number of trials required inter-session ranged from 1 to >10 for kinematic, from 1 to 9 for kinetic, and 1 to >10 for electromyographic variables. Thus, for the double support analysis, three gait trials were required in order to assess the kinematic and kinetic variables in cross-sectional studies, while for longitudinal studies, a higher number of trials (>10) were required for kinematic, kinetic, and electromyographic variables.