Biomechanical Characteristics Research Articles

Trunk biomechanical changes between the sit-to-stand and stand-to-sit performed at self-selected and fast speeds in stroke survivors

Purpose To compare the trunk biomechanical characteristics between the sit-to-stand and stand-to-sit performed at self-selected and fast speeds in stroke survivors and healthy-matched controls. Methods Thirty individuals (15 stroke survivors and 15 healthy-matched controls) were included. The following biomechanical characteristics were determined: peak of trunk forward flexion and time until the peak of trunk forward flexion, total duration, phase I (sit-to-stand: time spent from the beginning to seat-off; stand-to-sit: time spent from the beginning to seat-on) and II durations (sit-to-stand: time spent from seat-off to the end of the task; stand-to-sit: time spent from the seat-on to the end of the task). Two-way repeated measures ANOVA was used (α = 5%). Results The maximum angle of trunk forward flexion and time spent until the maximum angle of trunk forward flexion in both tasks were significantly higher in stroke survivors. For both groups and speeds, phase I duration and peak of trunk forward flexion of the stand-to-sit were significantly higher than that of the sit-to-stand (11.41≤F ≤ 33.60; 0.001 ≤ p ≤ 0.002) and, phase II duration was significantly higher during the sit-to-stand than that of the stand-to-sit (21.27 ≤ F ≤ 65.10; p ≤ 0.001). Conclusions These results confirm specific trunk biomechanical characteristics between sit-to-stand and stand-to-sit in stroke survivors and healthy-matched controls.

Теория мультифизического подобия гидробионтов

In the course of studying the biomechanical characteristics of hydrobionts there appears a need to apply the theory of similarity of living objects. Along with the theory of similarity, the theory of dimensions is observed. There is considered the multiphysical similarity of hydrobionts of the same species, based on the theory of physical similarity of A. A. Nedostup. One of the tasks of studying the mechanics and hydrodynamics of living systems (hydrobionts) in the aquatic environment is to automate the collection of statistics with subsequent visualization of the characteristics of hydrobionts using augmented reality technologies. Based on the similarity theory, the rules of physical similarity have been developed, similarity criteria have been obtained with respect to geometric, mechanical, hydroacoustic, hydrodynamic, thermodynamic, and optical characteristics of hydrobionts. An important component of similarity is to preserve the physical nature of the original phenomena in the model. Based on the scale of the multiphysical similarity of hydrobionts, the criteria for the similarity of hydrobionts are determined. There is considered the solution of the problems of describing the biomechanics of hydrobionts in recirculation aquaculture systems, where only one species of hydrobionts is grown at the same time. The importance of studies of biomechanics of aquatic organisms in certain habitat conditions, in our case in an artificial enclosed space, with artificial lighting, feeding, cleaning system, etc., is explained by the need to increase fish productivity and environmental friendliness of fish farming, which requires automation of the growing process. Automation tasks require a preliminary mathematical description of processes in order to build simulation models. In turn, for a mathematical description of the growth process of a growing object, it is necessary to derive mathematical dependencies linking the target characteristics of the hydrobionts with the initial data of breeding conditions and a set of characterizing parameters of the object itself, including behavioral ones.

Effect of vegetation growth on morphological traits of vegetation and biomechanical features of roots

Effect of vegetation growth on morphological traits of vegetation and biomechanical features of roots

Spatiotemporal and kinematic adjustments in master runners may be associated with the relative physiological effort during running.

Master runners maintain a similar running economy to young runners, despite displaying biomechanical characteristics that are associated with a worse running economy. This apparent paradox may be explained by a greater physiological effort-i.e., percentage of maximal oxygen uptake (VO2-max)-that master runners perform at a given speed. Moreover, age-related responses to non-exhaustive sustained running are yet underexplored. The aims of this study were, therefore, to examine if biomechanical adjustments in master runners are physiological-effort dependent, and to explore the age-related biomechanical changes during a non-exhaustive sustained run. Young (23.9 ± 6; n = 12) and master (47.3 ± 6.9; n = 12) runners performed a sustained 30-minute treadmill run matched for relative physiological effort (70% VO2-max), while spatiotemporal and lower-limb kinematic characteristics were collected during the 1st and 30th minute. Group differences were observed in step/stride length, knee touch-down angle, and knee stiffness. However, both groups of runners had a similar step frequency, vertical center of mass oscillation, and knee range of motion. Age-related adjustment in these latter characteristics may thus not be an inevitable result of the aging process but rather a strategy to maintain running economy. The relative physiological effort of runners should, therefore, be considered when examining age-related adjustments in running biomechanics.

Hyaluronic Acid-Based Injective Medical Devices: In Vitro Characterization of Novel Formulations Containing Biofermentative Unsulfated Chondroitin or Extractive Sulfated One with Cyclodextrins.

Currently, chondroitin sulfate (CS) and hyaluronic acid (HA) pharma-grade forms are used for osteoarthritis (OA) management, CS as an oral formulations component, and HA as intra-articular injective medical devices. Recently, unsulfated chondroitin, obtained through biofermentative (BC) manufacturing, has been proposed for thermally stabilized injective preparation with HA. This study aimed to highlight the specific properties of two commercial injective medical devices, one based on HA/BC complexes and the other containing HA, extractive CS, and cyclodextrins, in order to provide valuable information for joint disease treatments. Their biophysical and biomechanical features were assayed; in addition, biological tests were performed on human pathological chondrocytes. Rheological measurements displayed similar behavior, with a slightly higher G' for HA/BC, which also proved superior stability to the hyaluronidase attack. Both samples reduced the expression of specific OA-related biomarkers such as NF-kB, interleukin 6 (IL-6), and metalloprotease-13 (MMP-13). Moreover, HA/BC better ensured chondrocyte phenotype maintenance by up-regulating collagen type 2A1 (COLII) and aggrecan (AGN). Notwithstanding, the similarity of biomolecule components, the manufacturing process, raw materials characteristics, and specific concentration resulted in affecting the biomechanical and, more interestingly, the biochemical properties, suggesting potential better performances of HA/BC in joint disease treatment.

Chimpanzees select comfortable nesting tree species

Every evening, chimpanzees build sleeping “nests” in trees. In some studied communities, individuals appear to be selective about the tree species used, which has led researchers to hypothesize whether chimpanzees prefer trees that repel troublesome insects or/and that provide comfortable and stable structures. We investigate these hypotheses, or a trade-off between both, though study of tree species preference based on their biomechanical and/or biochemical properties in the Sebitoli chimpanzee community in Kibale National Park, Uganda. The ten tree species most frequently used for nesting were compared with ten abundant in their environment but not preferred for nesting. For these 20 tree species, we determined their biomechanical and morphological characteristics such as foliar density, foliar units form (shape and size) and branch rigidity. Their spatial repellent activity, previously tested against Anopheles gambiae was incorporated into the analysis. Chimpanzees chose tree species with medium-sized and elongated foliar units, high foliar density and branch with stiffer wood. In addition, most tree species with such mechanical and morphological properties also have mosquito repellent activity. These tree properties may provide a comfortable sleeping environment enhancing sleep quality. Finally, a comparison across chimpanzee communities would be relevant to understand whether these choices are not only ecological but also cultural.

Cortical activity and spatiotemporal parameters during gait termination and walking: A preliminary study

Gait termination requires an interaction between the biomechanical and neuromuscular systems to arrest forward momentum. Currently, the biomechanical characteristics of gait termination have been demonstrated; however, the neural mechanism of gait termination remains unclear. This study aimed to investigate cortical activity during gait termination using functional near-infrared spectroscopy (fNIRS). Thirteen healthy younger adults (mean age:24.0 ± 1.7) participated in this study. All participants performed three experimental sessions: planned gait termination (PGT), unplanned gait termination (UGT), and walking. Each experimental session comprised a block paradigm design (three cycles; 20 s resting, 45 s task). Cortical activity in the dorsolateral prefrontal cortex (DLPFC), supplementary motor area (SMA), and primary motor cortex (M1) and spatiotemporal parameters were measured. We compared the cortical activities and spatiotemporal parameters among PGT, UGT, and walking sessions. In addition, we performed Pearson correlations between hemodynamic responses and spatiotemporal parameters. The PGT was activated in the right DLPFC, whereas the UGT and walking were activated in the left SMA (p < 0.05). Comparing cortical activation between sessions, both the PGT and UGT showed significantly higher activation in the right DLPFC than during walking (p < 0.05). There were no significant differences in cortical activity between PGT and UGT (p > 0.05). In addition, the gait termination time revealed moderate positive correlation with hemodynamic responses in the right DLPFC (p < 0.05). Our results indicate that the right DLPFC is associated with gait termination, regardless of gait termination type. Our findings provide the potential implication that the hemodynamic response in the right DLPFC would be a biomarker to evaluate the ability of gait termination.

The Effects of Structural Characteristics of the Rollator on the Elderly’s Gait Strategies in Various Walking Environments

A rollator, one of the most widely used among walking assistance devices, can assist the elderly with stable walking in their daily lives. In this study, we investigated how the structural characteristics of two types of rollators affect the upper and lower extremity muscle activity and plantar pressure of the elderly in various walking environments. We quantified muscle activity (upper and lower limbs) and plantar pressure (mean force, peak pressure, and contact area) of 11 older adults walking in various environments (flat, obstacle, uneven, and sloped terrain) using two types of rollators. Upper extremity muscle activity was highest in the obstacle terrain and the uneven terrain, and a significant difference was found due to the structural differences of the rollator. Additionally, it was observed that lower extremity muscle activity and plantar pressure patterns appeared in accordance with the gait strategy to maintain stability in an unstable or inclined walking environment. In other words, it was confirmed that the weight of the rollator, the size of the wheel, grip type, and the auxiliary tools had a great effect on the upper and lower extremity muscle activity and plantar pressure of the elderly during walking. From the results of this study, it can be suggested that it is absolutely necessary to consider the biomechanical characteristics of the elderly and the structure of the rollator, which appear differently depending on the walking environment, in the development of walking aids. In the future, more clinical data will be collected, and based on this a rollator that can safely assist the elderly in various walking environments will be developed.

Effects of 56-Kilogram Kettlebell Swing Endpoint on Total Body Mechanics.

Ross, JA, Keogh, JWL, Lorenzen, C, and Lake, J. Effects of 56-kilogram kettlebell swing endpoint on total body mechanics. J Strength Cond Res 37(12): 2333-2338, 2023-In the past 2 decades, kettlebell training popularity has increased and the range of kettlebells has expanded to 2-92 kg. However, commercially available kettlebells above 56 kg have 12 kg increments, so alternatives to load are required to provide a suitable way of increasing training stimulus until the athlete is strong enough for a load increase. This study aimed to determine the differences in the force plate-derived biomechanical characteristics of heavy kettlebell swings to 3 different heights, as altering the height of the kettlebell swing may be one way to alter the mechanical demands with the same kettlebell mass. Fifteen resistance-trained men performed the kettlebell swing to acromion process height (AH), acromion process height + 20% (AH+20), and acromion process height-20% (AH-20). Swing height significantly affected vertical braking and propulsion phase net impulse and displacement, vertical braking velocity, and braking and propulsion work but not braking and propulsion duration. Altering kettlebell swing trajectory endpoint is a method to regress/progress the demands of kettlebell training. Coaches may be able to alter the acute demands and likely chronic adaptations of kettlebell training by prescribing different swing heights and kettlebell masses to their athletes.

BIOMECHANICAL ANALYSIS OF AN OPTIMIZED PATIENT-SPECIFIC DENTAL-IMPLANT SCREW IN THE POSTERIOR MANDIBLE

Implant design developed considerably with the advancement of restorative dentistry. Examining the stress distribution in the cancellous and cortical bones around custom-made implants with different thread-profile models is the study’s objective. The newly designed implants were made with a diameter and length of 4.5 mm and 11.5 mm. The implants were designed the same, but had different thread profiles. Model A is designed with a standard V-shape thread design, and it was compared with the remaining three dental implants (models B, C, and D) having different customized thread-profile designs. The biomechanical characteristics of the four implant models were compared with the use of biomechanical profiling to predict the mechanical performance of various dental-screw models, including the influence of physiological factors. The stress distribution in the D4 bone area of implants with different thread-profile designs under a vertical load of 100 N at 0° and an oblique load of 223.6 N at 25° was examined using ANSYS Workbench. The trabecular and cortical bones comprise the structure of the D4 bone area. Deformation and stress (von Mises) findings were found for the dental implants and bone. While implant models C and D showed less stress distribution in the cortical and cancellous bone, they nonetheless produced outcomes superior to those of the conventional model A underloading. According to the findings, the unique dental implant design lessens the stress concentration in the cortical bone’s neck area. The suggested model C increases the implant’s stability in that region by distributing a low stress over the D4 bone.

Biomechanical Comparison of 1.2-mm Suture Tape, 2.0-mm Suture Tape, and 0.5-mm Suture Using Various Arthroscopic Knot Techniques.

The biomechanical properties of the 1.2-mm suture tape have outperformed conventional sutures in previous studies. To compare the loop and knot security of 2 tape-type and 1 cord-type sutures using different arthroscopic knot techniques. Controlled laboratory study. The biomechanical characteristics of the 1.2-mm tape, 2.0-mm tape, and 0.5-mm No. 2 suture were compared using 4 different knot types: 2 sliding knots (Samsung Medical Center [SMC] and Tennessee) and 2 nonsliding knots (2-throw surgeon's and 2-throw square) with 2 and 3 additional reverse half-hitches on alternating posts (RHAPs) in a closed-loop system on a materials testing device. Each configuration was tested for loop security (maximal load applied between 0 and 3 mm of displacement), knot security (ultimate failure load), and failure mode with cyclical loading (30 N load for 20 cycles at 1 cycle per sec until failure). Loop and knot security among the configurations were compared using an analysis of variance. With 2 RHAPs, the 2.0-mm tape showed significantly greater loop security than the 1.2-mm tape and suture (P = .001). With 3 RHAPs, the loop security of the suture was significantly superior compared with the 1.2-mm tape (P = .010). Regarding knot security, with 2 RHAPs, the 2.0-mm tape was significantly better than the 1.2-mm tape and suture (P < .001), while with 3 RHAPs, the suture was significantly superior to the 1.2-mm tape (P = .012). Using a square knot with 2 RHAPs, the 2.0-mm tape had significantly greater loop security (P = .001) and better knot security (P = .001) to the 1.2-mm tape and suture. Using the Tennessee knot with 2 RHAPs, the 1.2-mm tape had less loop security (P = .011) and knot security (P = .005) than the suture. Using the SMC knot with 3 RHAPs, the 2.0-mm tape and suture were significantly superior in loop security (P = .001) and knot security (P < .001) to the 1.2-mm tape. There was no significant difference in the failure mode between tapes and sutures with 2 and 3 RHAPs. With 2 RHAPs, the 2.0-mm tape demonstrated greater resistance to suture loop displacement and better knot security compared with the 1.2-mm tape and suture. However, with 3 RHAPs, the 1.2-mm tape manifested weaker loop and knot security compared with the suture.

Biomechanics research on laterality effect between dominant and non-dominant during double roundhouse kick in the competitive taekwondo

BackgroundThe Double Roundhouse Kick (DRK) is one of the major scoring tools and athletes employ the leg of the dominant side (DS) or the non-dominant side (NS) for always attacking in an alternating state. The purpose is to examine the discrepancies in the biomechanical characteristics of the DS and NS of the leg of the DRK skills of sub-elite taekwondo athletes. MethodsUsing the Vicon, Kistler, and Daedo brand Electronic Body Protector (EBP), collection of the DRK data (attack time, joint angle, joint angular velocity, joint moment, ground reaction force, etc.) of 12 sub-elite taekwondo athletes (19.6 ± 2.0 yr, 180 ± 7.3 cm, 70 ± 9.8 kg) with the DS leg and NS leg. The measured data analyses via Visual3D, and statistical methods using nonparametric tests paired with samples based on the Wilcoxon signed-rank test (The significance level is set as significant for P<0.05, and very significant for P<0.01). Results(i) There is no statistically significant discrepancy between the DS and NS at the time of hit (P>0.05) and shift of the center of gravity (P>0.05). (ii) Attacking leg (AL): the maximum knee flexion angle (Knee-MFA) (P<0.05) and the peak linear velocity of attack of the foot in the vertical hitting direction (P<0.01) on the DS was greater than that on the NS during the first hit phase (P1). (iii) Supporting leg (SL): the peak hip extension moment (P<0.05) on the DS was reported to be higher than that of the NS during the second hit phase (P2). (iv) Symmetry Index (SI): In the P1, the vertical ground reaction force (vGRF) of the SL leads to SI = 10.19 %, and in the P2, the vGRF of the SL results in SI = 18.48 %. ConclusionsThe DRK requires more and more symmetry between the DS and NS. The Knee-MFA of the AL and the line of attack speed of the foot in the vertical striking direction of the SL exhibited significant discrepancies. The DS has higher striking speed, athletes need to improve the striking speed of the NS leg in training, achieving more scoring opportunities in the game. Both the DS and NS revealed strong symmetry in the peak SI of the ground reaction force of the SL stirrup; however, weak symmetry was attained in the peak SI of the vGRF of the SL landing cushion.

Robust Imaging of Speed of Sound Using Virtual Source Transmission.

Speed of sound (SoS) is a novel imaging biomarker for assessing the biomechanical characteristics of soft tissues. SoS imaging in the pulse-echo mode using conventional ultrasound (US) systems with hand-held transducers has the potential to enable new clinical uses. Recent work demonstrated that diverging waves (DWs) from a single element (SE) transmit to outperform plane-wave sequences. However, SE transmits have severely limited power and hence produce a low signal-to-noise ratio (SNR) in echo data. We herein propose Walsh-Hadamard (WH) coded and virtual-source (VS) transmit sequences for the improved SNR in SoS imaging. We additionally present an iterative method of estimating beamforming (BF) SoS in the medium, which otherwise confounds SoS reconstructions due to beamforming inaccuracies in the images used for reconstruction. Through numerical simulations, phantom experiments, and in vivo imaging data, we show that WH is not robust against motion, which is often unavoidable in clinical imaging scenarios. Our proposed VS sequence is shown to provide the highest SoS reconstruction performance, especially robust to motion artifacts. In phantom experiments, despite having a comparable SoS root-mean-square error (RMSE) of 17.5-18.0 m/s at rest, with a minor axial probe motion of ≈ 0.67 mm/s the RMSE for SE, WH, and VS already deteriorate to 20.2, 105.4, and 19.0 m/s, respectively, showing that WH produces unacceptable results, not robust to motion. In the clinical data, the high SNR and motion resilience of VS sequences are seen to yield superior contrast compared to SE and WH sequences.

Comparison of foot measures on dynamic and static balance in children engaged in different sports disciplines

It is known that sports contribute to the development of children's anthropometric, biomechanical, postural and proprioceptive characteristics. By participating in a sport discipline in childhood, it is possible to gain sports-specific features. Comparing sports that require different motoric features and neuromuscular competencies raises the question of how these different requirements might also affect biomechanical and balance skills. The aim of this study is to compare the foot posture, foot function and dynamic-static balance in children who engaged sports in different sport disciplines. The study included totally 66 child athletes with the mean age of 13.19±2.11 from the box, basketball and swimming disciplines. 54.55% of the participating athletes were female and 45.45% were male. Demographic and sport-specific characteristics of the participants were questioned with an 11-question case form. The Foot Posture Index (FPI) and the Foot Function Index (FFI) were administered. Static balance assessment was performed with the Flamingo Balance Test and dynamic balance assessment was performed with the Y Balance Test. The data obtained for each sport branch were compared between groups. There was no statistically significant difference in terms of demographic characteristics among groups. A statistically significant difference was found between boxing, basketball, and swimming branches in terms of FPI score, right and left static balance results, and foot posture class parameters (p

Effect of Pin Holes Location of Unicompartmental Knee Arthroplasty on Postoperative Tibial Plateau Mechanical Properties

The purpose of this study is to explore the biomechanical characteristics of the tibia after unicompartmental knee arthroplasty with different distributions of two-pin holes, and to optimize the two-pin holes scheme to reduce the risk of tibial fractures after unicompartmental knee arthroplasty. Lower limbs model is segmented and reconstructed from computed tomography images. Four combinations of two pin holes created for tibial cutting guide placement are simulated with finite element analysis. In the third mode, the positioning hole at the proximal medial edge of the tibial plateau has the highest stress value, and the position of the positioning hole near the medial edge of the proximal tibial plateau appears stress concentration. The present study revealed that placing tibial cutting guide holding pins centrally would lower the risks of periprosthetic fracture of the medial tibial plateau.

Hot Topics of Molecular and Cellular Biomechanics in 2022

The analysis of biomechanical characteristics plays an important role in mastering the technical characteristics of athletes, providing guidance for the formulation and prevention of sports injury training plans and providing theoretical support for research on injury prevention and stability control in the sports field. With the importance of data analysis, the application scope of artificial intelligence methods is more extensive. For example, intelligent training systems can be used for athletes’ personalized and professional training, real-time monitoring and feedback of training data, and further reduce the risk of sports injury. However, deep learning methods process a large number of medical images to identify and predict diseases such as cancer.

Personalized intermittent pneumatic calf compression frequency for augmenting foot blood perfusion: The optimized effect and a personalized mode predicting method

Intermittent pneumatic compression (IPC) therapy has been adopted in prevention and treatment of ischemic-related peripheral vascular diseases. The aim of this study is to provide an approach to personalize the compression strategy of IPC therapy for maximizing foot skin blood flow. In this study, we presented a method to predict the optimized compression mode (OCM) for each subject based on biomechanical features extracted from experimental data tested with multiple IPC modes. First, to demonstrate the blood flow enhancing effect by applying the personalized OCM, four IPC modes of different frequency settings were tested on a total of 24 subjects. The frequency settings were adjusted by deflating-waiting time, which was defined as the total time length from the start of cuff deflation to the start of next compression. The foot skin blood perfusion and IPC air cuff pressure were monitored during the experiments. The personalized OCM was defined as the certain IPC mode that has the highest blood perfusion augmentation (BPA). Compared with the rest stage blood perfusion, the personalized OCM settings resulted in >50% of augmentation for 75% of healthy subjects (maximum augmentation at 244%) and >20% augmentation for 75% of patients with diabetes (maximum augmentation at 180%). Second, for predicting the OCM, we establish a random forest model based on the features extracted from the experimental data. The binary classification resulted in acceptable prediction performance (AUC > 0.7). This study might inspire new IPC strategies for improving foot microcirculation.

Effect of carbon-fiber-reinforced polyetheretherketone on stress distribution in a redesigned tumor-type knee prosthesis: a finite element analysis.

Background: Surgery for bone tumors around the knee often involves extensive resection, making the subsequent prosthetic reconstruction challenging. While carbon fiber-reinforced polyetheretherketone (CF-PEEK) has been widely used in orthopedic implants, its application in tumor-type prosthesis is limited. This study aims to evaluate the feasibility of using 30wt% and 60wt% carbon fiber-reinforced polyetheretherketone (CF30-PEEK and CF60-PEEK) as materials for a redesigned tumor-type knee prosthesis through numerical analysis. Methods: A knee joint model based on CT data was created, and the resection and prosthetic reconstruction were simulated. Three finite element models of the prostheses, representing the initial and updated designs with CoCrMo and CFR-PEEK components, were constructed. Loading conditions during standing and squatting were simulated with forces of 700N and 2800N, respectively. Finite element analysis was used to analyze the von Mises stress and stability of all components for each prosthesis type. Results: After improvements in both material and design, the new Type 3 prosthesis showed significantly lower overall stress with stress being evenly distributed. Compared with the initial design, the maximum von Mises stress in Type 3 was reduced by 53.9% during standing and 74.2% during squatting. In the standing position, the maximum stress in the CF30-PEEK femoral component decreased by 57.3% compared with the initial design which was composed of CoCrMo, while the stress in the CF60-PEEK cardan shaft remained consistent. In the squatting position, the maximum stress in the femoral component decreased by 81.9%, and the stress in the cardan shaft decreased by 46.5%. Conclusion: The incorporation of CF30-PEEK effectively transmits forces and reduces stress concentration on the femoral component, while CF60-PEEK in the redesigned cardan shaft significantly reduces stress while maintaining stiffness. The redesigned prosthesis effectively conducts loading force and demonstrates favorable biomechanical characteristics, indicating the promising potential of utilizing CF30-PEEK and CF60-PEEK materials for tumor-type knee prostheses. The findings of this study could provide novel insights for the design and development of tumor-type knee prostheses.

Effects of shoe collar types on ankle and knee biomechanics characteristics when performing the side-step cutting task

ABSTRACT This study aimed to examine the effect of football shoes with different collar types on ankle and knee kinematic and kinetics features during 45° and 135° side-step cutting tasks. Fifteen healthy college football players volunteered for the study. Each participant was instructed to perform side-step cutting tasks with high, low, and no collar football shoes. The kinematic and ground reaction force data were measured using a Vicon motion capture system and a Kistler force plate, respectively. Two-way MANOVAs with repeated measures were used to examine the effect of shoe collar type and task conditions. There were no interaction effects. The high collar football shoe showed decreased ankle range of motion in the sagittal plane (p = 0.010) and peak ankle external rotation moment (p = 0.009) compared to the no collar football shoe. The high (p = 0.025) and low (p = 0.029) collar football shoes presented greater peak ankle external rotation angles than the no collar football shoe. These results imply that football shoes with high collars made of high intensity knitted fabric could be used to restrict ankle joint movement, with potential implications for decreasing the risk of ankle sprain injuries in football players.

Footwear Design and Biomechanics Evaluation for Clinical Nurses

Epidemiological investigations have shown a higher prevalence of work-related musculoskeletal disorders, (WRMDs) among nursing professionals. More than most other occupational groups. Most nursing activities require long periods of standing and walking. These job requirements can cause WRMDs problems in the lower limbs, and there are few footwear products available specifically for use by clinical nurses. Therefore, improving the current clinical nurse shoes and improving the wearing comfort of clinical nurse shoes are the necessary conditions to reduce the lower limb discomfort of clinical nurses. The purpose of this study is :(1) to test and obtain the foot morphology and walking gait characteristics of nurses in standing state by using human foot scanning and sports biomechanics technology, and to design comfortable clinical nursing footwear products suitable for nurses through shoe last optimization and application of environmentally friendly materials. (2) Sports biomechanical testing technology was used to test and compare the developed clinical care shoes with other shoes in the market, and the biomechanical characteristics of participants wearing different shoes were measured and compared to verify the design effect of clinical care shoes and improve it. This research method is divided into three stages. First, field observations and exercise biomechanics tests of the participants were performed, and data acquisition included plantar pressure characteristics, a three-dimensional foot model, foot surface temperature distribution, walking speed, and proportions of walking, standing, and sitting. Secondly, the clinical nursing shoes were designed based on the test results and the sample shoes were made. Finally, the function of professional nursing was evaluated through the exercise biomechanical testing technique. Measurements included lower limb joint range of motion (ROM), foot Pressure, ground reaction force (GRF), and subjective discomfort ratings for the lower body and feet. To summarize the findings of this study, comfortable clinical care shoes should emphasize arch support at the sole, use three-dimensional vertical insoles, and design heel height below 5 cm to significantly reduce plantar pressure distribution and ground impact, increase ankle flexibility, and recommend the use of pressure socks to reduce the risk of varicose veins in the lower extremities.