Knee Bending Research Articles

Rehabilitation of a Patient with Knee Arthrofibrosis after Tibial Spine Fracture: a Case Report in Paediatrics

INTRODUCTION. Tibial spine fracture (TSF) is a rare injury, the incidence is higher among children. The common complication of treatment is arthrofibrosis. Early rehabilitation is important for its prevention. Guidelines haven’t been worked out. CASE REPORT. Patient A., 11 years old, was operated for TSF. When she had hospitalized in medical rehabilitation center after 4 months, knee arthrofibrosis was diagnosed. Examination: range of knee motion is 180–155°. Edema of periarticular tissues. The gait pattern is impaired. She couldn’t maintained balance in Trendelenburg test on affected leg. Psychological diagnostics: fear of knee flexion, decreased motivation. Rehabilitation aims: A. will begin to bend knee while walking after 10–14 procedures d450.3.2–d450.2.1, b7100.2–b7100.1. A. is not afraid to bend knee during exercises by the end of the rehabilitation d240.2.0–d240.1.0. Rehabilitation program: physical exercises, mechanotherapy (treadmill, ladder with ramp, continuous passive motion), electrical myostimulation, aquajet therapy, vibrotherapy, kinesiotaping, hardware massage, sessions with psychologist, magnetic laser. RESULTS AND DISCUSSION. Range of knee motion is 180–135°. Edema of tibia and hip has decreased. A. minimally bends knee when walking, hip flexion has appeared. A. can maintain balance in Trendelenburg test. The fear of bending knee has decreased according to self-assessment, but it is difficult for A. to cope with the situation of physical discomfort on her own. The aims have been partially achieved. Rehabilitation potential is low because of long period after surgery and personal characteristics. Life quality didn’t decrease, it made difficult setting rehabilitation aims. The team decided to focus on psychological work and improving motion. CONCLUSION. Teamwork and guidelines are important for rehabilitation due to variety and complexity the pathology.

Comparative study of Baduanjin and brisk walking on balance and stability in older adults.

To investigate the impact of practicing the health Qigong-Baduanjin exercise on lower limb balance among elderly individuals. Two intervention methods, Baduanjin and brisk walking, were applied to study the effect of exercise on senior balancing. Sixty elderly individuals aged 65 to 79 were selected and randomly divided into the Baduanjin group, the brisk walking group, and the control group that did not engage in exercise. There were a total of 20 individuals in each group, 10 males and 10 females. The first two groups participated in a 16-week exercise regimen. The balance tests for members of all three groups were conducted. (1) For the eyes-open two-legged standing posture, the center of pressure (COP) was more centralized in the Baduanjin group; the swaying range of the body, forward and backward displacement, and left and right displacement among the elderly individuals in this group were significantly lower than those of the other two groups. (2) In the tests for two-legged standing, one-legged standing, and tandem feet stance, the elderly in the Baduanjin group had significantly lower swaying trajectory of the center of gravity, body swaying ellipse area, and maximum vibration parameters than those in the brisk walking and control groups. (3) The 2nd pose of Baduanjin, which involves a considerable amount of knee bending and semi-squatting exercises for the lower limbs, proved to be beneficial for the lower limb joints and body balance among the elderly. Long-term practice of health Qigong-Baduanjin can exert a beneficial impact on improving the muscle strength of the lower limb joints and ankle joint flexibility, improving the static balance ability of the elderly, and consequently reducing their risk of falling.

Evaluation Tibia Rotation in Total Knee Arthroplasty Designed for Deep Knee Flexion Using Knee Kinematics Motion Simulator

Total knee arthroplasty is a successful procedure for treating chronic degenerative knee pathologies, many patients are dissatisfied with the results of the standard design. Improper tibia rotation of the implant is suspected to contribute to post-operative pain, polyethylene wears, aseptic loosening, and instability. Many factors can influence the alteration of knee kinematics after surgery including differences in implant design. Using magnetic resonance imaging, tibia rotation in a normal knee has -15.0º and -2.5º in weight-bearing males neutral tibia rotation, and tibia rotation in postoperative patients has 2.1º and 9.5º using computer tomography. In this study, a knee joint implant was developed to facilitate a high range of motion. Tibia rotation was observed with the axes of knee motion joint implants varied from 0°, 2°, 3° to 5° and knee bend measurements at 30°, 60°, 90°, 120°, and 150° of knee flexion using the knee kinematic motion simulator and the results will be compared with the results from magnetic resonance imaging and computer tomography. Using statistical analysis resulted for 0° and 2° kinematics alignment, the p-value of the development product is 0.072 and 0.054 (p > 0.05), for 3° and 5° kinematics alignment, the p-value of the development product is 0.039 and 0.031 (p ˂ 0.05). Thus, the kinematics development product at 0° and 2° kinematics alignment are similar to a normal human knee joint. Evaluation of knee kinematics implant using a knee motion simulator is expected to become a standard procedure before performing total knee arthroplasty surgery. This similarity in kinematics knee implant with a normal knee is to be expected to reduce postoperative pain, polyethylene wears, aseptic loosening, and instability during deep knee flexion and minimize the risk of implant failure.

Extraction and incorporation of cellulose microfibers from textile wastes into MXene-enhanced PVA-borax hydrogel for multifunctional wearable sensors.

Conductive hydrogel has drawn great concern in wearable sensors, human-machine interfaces, artificial intelligence (AI), health monitoring, et al. But it still remains challenge to develop hydrogel through facile and sustainable methods. In this work, a conductive, flexible, bendable, and self-healing hydrogel (PBCM) composed of polyvinyl alcohol (PVA), borax, cellulose microfibers (CMFs), and MXene nanosheet was fabricated by a simple and efficient strategy. The carboxylated CMFs were extracted from waste ramie fibers via a one-pot ammonium persulfate oxidation method. The crystallinity and tensile strength were increased 70 % and 4 times due to the addition of CMFs and MXene compared to the pristine PVA-borax hydrogel. The incorporation of MXene nanosheets acts as multifunctional cross-linkers and energy transfer platform, promoting the electrical conductivity, stretchability, and bendability of hydrogel remarkably. The PBCM-2 hydrogel exhibited the maximum electrical conductivity of 0.81 S/cm. Additionally, the dynamic borate ester linkage imparts self-healing ability to the hydrogel. The resulting PBCM hydrogel demonstrated excellent resistance to fire and pH response properties. Moreover, it showed sensitivity in monitoring various human physiological movements, including finger, wrist, elbow, knee bending, and drinking water, indicating its potential for wearable sensing applications like health care and sports training.

Ultrafast self-healing zwitterionic hydrogels reinforced by carboxymethyl chitosan-oxidized hyaluronic acid and graphene oxide toward high-performance strain sensors

Inspired by the inherent recuperative ability of organisms in nature, researchers have dedicated significant efforts towards developing self-healing hydrogel sensors. Although the works on self-healing hydrogels have made great progress, achieving hydrogel sensors combining with rapid and efficient healing capability, excellent mechanical properties and high sensing sensitivity remains a challenging task. In this study, we proposed a novel approach for fabricating a self-healing conductive zwitterionic hydrogel sensor by adding carboxymethyl chitosan (CMCs) and oxidized hyaluronic acid (OHA) to induce dynamic Schiff base reaction, and nano-reinforced by adding with graphene oxide (GO) nanosheets. This zwitterionic hydrogel exhibited a high tensile strength of 133 kPa and elongation at break of 878 %. By leveraging various dynamic interactions within the system, the hydrogel exhibited ultra-fast and efficient healing property, achieving a self-healing efficiency of 98.9 % within just 15 min. The hydrogel demonstrated exceptional adhesion to diverse substrates especially to glass with a maximum adhesion strength reaching up to 53.7 kPa. The hydrogel exhibited a high gauge factor (GF) value of 23.2, which showed clear and stable monitoring and sensing capabilities across various human movements ranging from swallowing to bending knees. Notably, the hydrogel could also be employed as a Morse code transmitter and flexible tablet. The zwitterionic hydrogel demonstrates its great potential applications in the field of high-performance flexible sensors as well as human-computer interaction.

Flexible and Stable GaN Piezoelectric Sensor for Motion Monitoring and Fall Warning.

Wearable devices have potential applications in health monitoring and personalized healthcare due to their portability, conformability, and excellent mechanical flexibility. However, their performance is often limited by instability in acidic or basic environments. In this study, a flexible sensor with excellent stability based on a GaN nanoplate was developed through a simple and controllable fabrication process, where the linearity and stability remained at almost 99% of the original performance for 40 days in an air atmosphere. Moreover, perfect stability was also demonstrated in acid-base environments, with pH values ranging from 1 to 13. Based on its excellent stability and piezotronic performance, a flexible device for motion monitoring was developed, capable of detecting motions such as finger, knee, and wrist bending, as well as swallowing. Furthermore, gesture recognition and intelligent fall monitoring were explored based on the bending properties. In addition, an intelligent fall warning system was proposed for the personalized healthcare application of elders by applying machine learning to analyze data collected from typical activities. Our research provides a path for stable and flexible electronics and personalized healthcare applications.

Can Cadaver Testing Replicate In Vivo Kinematics of Total Knee Arthroplasty?

Whether the kinematics of cadaveric knees recreate those of the patient's knees after total knee arthroplasty (TKA) remains unknown. This study compared in vivo and in vitro fluoroscopic kinematics of knees after TKA during knee bending using the same implant design. Patients who had undergone cruciate-retaining and cruciate-substituting total knee arthroplasty (CR-TKA and CS-TKA) did squatting motions. Fresh-frozen human cadaveric knees were tested under dynamic closed-chain knee extension in an Oxford knee rig. Fluoroscopic kinematics were measured in vivo and in vitro using a 2-dimensional to 3-dimensional registration technique. The axial rotation angle and anterior-posterior translation of medial and lateral contact points of the femoral implant relative to the tibial implant was evaluated in each flexion angle. No notable differences in the axial rotation angles were found between in vivo and in vitro measurements in both CR-TKA and CS-TKA. In early flexion, the medial and lateral contact points in cadaver knees were located more posterior than those in in vivo after CR-TKA. From early flexion to high flexion, the medial and lateral contact points in cadaver knees were located more posterior than those in in vivo after CS-TKA. The axial rotation angle of cadaveric knees in the Oxford knee rig was similar to that measured in vivo after TKA. However, the anterior-posterior location of the femoral implant in cadaver knee was more posterior than that in in vivo knees after TKA.

Flame-induced performance enhancement of MXene-based nanocomposite sponge for infrared stealth and strain sensing

Assembling MXene nanofillers on a macroscopic carrier via the non-covalent bonding forces is one of the most efficient paths for preparing the MXene-based nanocomposites with multi functions and hierarchical structure. However, the frequently-used substrates, such as cotton fabric, synthetic textile, and polymer sponge are highly flammable, severely restricting the practical applications in some highly integrated scenarios. Herein, we report a facile design strategy that enables us to readily achieve the flame retardant MXene-based nanocomposites for highly efficient infrared stealth and strain sensing even when used in high-temperature environments. In particular, a phosphorus-nitrogen rich compound (HPTCP) was intercalated into the laminates of Ti3C2Tx-MXene to construct a hybrid flame retardant that was coated on the skeletons of melamine sponge by repeated dip-coating procedures. As a result of the synergistic effect among multicomponent, the Ti3C2Tx-HPTCP coated sponge displays excellent structural stability in real fire. In this case, flame treatment was adopted to create micro-/nano-scale cracks in the coated sponge and skeletons, significantly enhancing the sensitivity (∼0.20 kPa−1) and shortening the response time (69 ms) to strain. The burned sponge sensor can be employed for monitoring various human motions, from tiny throat vibrations and facial expressions to large-scale finger and knee bending. Besides, the burned sample still maintains the superior infrared stealth performance with a wide stealth temperature range, a large reduction in radiation temperature of 154 °C for the object temperature of 300 °C, and long-term working stability at high temperatures. Given the simple fabrication process, multilevel structural design, and stable performance, this work provides a promising strategy for addressing the flammability issue of template-based composite materials

Development of a Knee Orthosis to Prevent Falling Due to Buckling among Elderlies

The number of elderlies increases over the years and has triggered concerns on healthcare system, the community and the family. Elderly could experience knee buckle and fall due knee osteoarthritis (OA), a common syndrome of weakness due to aging degeneration. It may cause pain and injuries and hence fears to stay mobile. As a result, this would give a negative effect to mental and physical health. It is common that elderlies attempt to wear an assistive knee device in hope of providing security in walking. The aim of this project is to survey the faith of elderlies in knee braces, to investigate the stiffness of sampled market knee braces/orthoses again sudden knee buckling and to propose a novelty design of a mechatronic knee orthosis. From the survey, the elderlies are general having faith in wearing a knee brace / orthosis to provide walking security. Secondly, from the experimental load test, the findings revealed that these sampled knee brace or orthoses do not feature on delayed bending when knee buckling occurred. Finally, the proposed design has revealed improved knee stiffness and prolong delayed knee bending.

Impact of Surgical Alignment, Bone Properties, Anterior-Posterior Translation, and Implant Design Factors on Fixation in Cementless Unicompartmental Knee Arthroplasty.

Micromotion exceeding 150 μm at the implant-bone interface may prevent bone formation and limit fixation after cementless knee arthroplasty. Understanding the critical parameters impacting micromotion is required for optimal implant design and clinical performance. However, few studies have focused on unicompartmental knee arthroplasty (UKA). This study assessed the impacts of alignment, surgical, and design factors on implant-bone micromotions for a novel cementless UKA design during a series of simulated daily activities. Three finite element models that were validated for predicting micromotion of cementless total knee arthroplasty (TKA) were loaded with design-specific kinematics/loading to simulate gait (GT), deep knee bending (DKB), and stair descent (SD). The implant-bone micromotion and the porous surface area ideal for bone ingrowth were estimated and compared to quantify the impact of each factor. Overall, the peak tray-bone micromotions were consistently found at the lateral aspect of the tibial baseplate and were consistently higher than the femoral micromotions. The femoral micromotion was insensitive to almost all the factors studied, and the porous area favorable for bone ingrowth was no less than 93%. For a medial uni, implanting the tray 1 mm medially or the femoral component 1 mm laterally reduced the tibial micromotion by 19.3% and 26.3%, respectively. Differences in tray-bone micromotion due to bone moduli were up to 59.8%. A 5 mm more posterior femoral translation increased the tray-bone micromotion by 35.8%. The presence of the tray keel prevented the spread of the micromotion and increased the overall porous surface area, but also increased peak micromotion. The tray peg and the femoral anterior peg had little impact on the micromotion of their respective implants. In conclusion, centralizing the load transfer to minimize tibial tray applied moment and optimizing the fixation features to minimize micromotion are consistent themes for improving cementless fixation in UKA. Perturbation of femoral-bone alignment may be preferred as it would not create under/overhang on the tibia.

CPoser: An Optimization-after-Parsing Approach for Text-to-Pose Generation Using Large Language Models

Text-to-pose generation is challenging due to the complexity of natural language and human posture semantics. Utilizing large language models (LLMs) for text-to-pose generation is appealing due to their strong capabilities in text understanding and reasoning. However, as LLMs are designed for general-purpose language processing and not specifically trained for pose generation, it remains nontrivial to generate precise articulation targets for the full body using LLMs directly. To this end, we propose CPoser, a novel approach to harness the power of LLMs for text-to-pose generation, featuring a prompt parsing stage and a pose optimization stage. The parsing stage utilizes LLMs to turn text prompts into pose intermediate representations (Pose-IRs) through a set of predefined structured queries. These Pose-IRs explicitly describe specific pose conditions, such as squatting depth and knee bending angle, naturally forming an objective function that a target pose should satisfy. The optimization stage solves for expressive poses and hand gestures based on the Pose-IR objective function via robust optimization in a quantized pose prior space. The results are further refined to enhance naturalness and incorporate facial expressions. Experiments show that our approach effectively understands diverse text prompts for pose generation, surpassing existing text-to-pose methods.

A deep learning-based comprehensive robotic system for lower limb rehabilitation

In the modern era, a significant percentage of people around the world suffer from knee pain-related problems. ‘Knee pain’ can be alleviated by performing knee rehabilitation exercises in the correct posture on a regular basis. In our research, an attention mechanism-based CNN-TLSTM (Convolution Neural Network-tanh Long Sort-Term Memory) network has been proposed for assessing the knee pain level of a person. Here, electroencephalogram (EEG) signals of the frontal, parietal, and temporal lobes, electromyography (EMG) signals of the hamstring and quadriceps muscles, and knee bending angle have been used for knee pain detection. First, the CNN network has been utilized for automated feature extraction from the EEG, knee bending angle, and EMG data, and subsequently, the TLSTM network has been used as a classifier. The trained CNN-TLSTM model can classify the knee pain level of a person into five categories, namely no pain, low pain, medium pain, moderate pain, and high pain, with an overall accuracy of 95.88 %. In the hardware part, a prototype of an automated robotic knee rehabilitation system has been designed to help a person perform three rehabilitation exercises, i.e., sitting knee bending, straight leg rise, and active knee bending, according to his/her pain level, without the presence of any physiotherapist. The novelty of our research lies in (i) designing a novel deep learning-based classifier model for broadly classifying knee pain into five categories, (ii) introducing attention mechanism into the TLSTM network to boost its classification performance, and (iii) developing a user-friendly rehabilitation device for knee rehabilitation.

A biomechanical analysis of four medial patellofemoral ligament reconstruction techniques

BackgroundImplant free medial patellofemoral ligament reconstruction is an increasingly popular technique to address patellar instability. There remains sparse literature on the biomechanical differences between the most common femoral attachment fixation points including Schottle's point, superficial medial collateral ligament, and adductor magnus tendon. This study compared these reconstruction techniques as well as a novel triangle reconstruction integrating both superficial medial collateral ligament and adductor magnus tendon. MethodsEight cadaveric knees were tested in a muscle activated knee simulator which mimicked a standing, shallow knee bend movement. Patella lateral displacement, external rotation and flexion were measured with and without a lateral load applied under the following conditions: 1) intact, 2) medial patellofemoral ligament cut, 3) Schottle's point reconstruction, 4) adductor magnus tendon reconstruction, 5) superficial medial collateral ligament reconstruction, 6) triangle reconstruction. Differences were analyzed using a repeated measures analysis of variance at 20, 30, 45 and 60 degrees of knee flexion. FindingsAll reconstruction techniques had significantly less lateral displacement compared to the cut condition when a lateral load was applied. Between reconstruction conditions, there was significantly less lateral displacement using Schottle's point and superficial medial collateral ligament as compared to adductor magnus tendon (p < 0.05). All reconstruction techniques had a trend towards medial constraint as compared to intact. InterpretationAn over constrained position of the patella through early flexion of the knee may increase the likelihood of secondary patellofemoral arthritis. Although there were differences in magnitude of displacement/constraint, further studies are needed to assess clinical differences regarding constraint.

Consequence of Orange Theory Fitness Training on Selected Health Related Physical Fitness Variables among Obese

Abstract The main task of the study was to find out Consequence of orange theory fitness training on Selected Health Related Physical Fitness Variables among Obese. To achieve the task of the study Forty class-I obese school boys were selected from various schools in Tuticorin were selected as subjects and their age ranged from 12-15 years only. The selected subjects were divided into two equal groups namely experimental group (20) and control group (20). The experimental group participated in orange theory fitness training. Pre and post-test method were followed. The experimental training was adopted for eight weeks on three days a week and control group was not exposed to experimental treatment. The selected variables namely flexibility, cardio respiratory endurance and muscular endurance. The above selected variables were tested through Flexibility (sit and reach in centimetre), Cardio Vascular Endurance (1.6 mile run in five minutes), and Muscular Endurance (bent knee sit-ups). The collected data were statistically analyses using dependent 't' test. The level of confidence was fixed at 0.05 for all cases. The result of the study showed that there was a significant improvement in flexibility, cardio respiratory endurance and muscular endurance among class -I obese school boys due to orange theory fitness training.

High-Performance Flexible Pressure Sensor with Micropyramid Structure for Human Motion Signal Detection and Electromagnetic Interference Shielding.

Flexible pressure sensors have a wide range of applications in the field of human motion signal detection, but the electromagnetic radiation generated during the monitoring process has become an unavoidable problem. Nowadays, it is still a challenge to develop high-performance pressure sensors with excellent electromagnetic interference (EMI) shielding performance. Herein, the Ti3C2TX MXene/carbon fiber/multiwalled carbon nanotube/polydimethylsiloxane (MXene/CMP) films with a micropyramidal structure were developed by the technology of vacuum high-temperature hot pressing and spray deposition. Benefiting from the dielectric loss of the conductive fillers and the presence of the microstructure, the MXene/CMP film exhibits excellent EMI shielding performance, and the EMI shielding efficiency (SE) can reach 49.37 dB. Besides, the introduction of CF effectively improves the mechanical properties of the MXene/CMP films, and the MXene nanosheets deposited on the surface of the film can reduce stress concentration, which in turn delays the expansion of cracks. Furthermore, the MXene/CMP sensor exhibits high sensitivity (89.76 kPa-1) and fast response/recovery time (61/60 ms). The deformation of microstructure and the construction of conductive networks enable the sensor to realize the monitoring of human motion signals (such as finger bending, knee bending, wrist bending, etc.). Meanwhile, the sensor maintains sensing stability even after 2000 pressure cycles, which can be attributed to the improvement in mechanical properties. In summary, the developed high-performance flexible pressure sensor with micropyramid structure has great application prospects in wearable devices and healthcare.

Foot Posture and Ankle Dorsiflexion as Risk Factors for Developing Achilles Tendinopathy and Plantar Fasciitis: A Case-Control Study.

Plantar fasciitis (PF) and Achilles tendinopathy (AT) are common injuries that primarily affect people engaged in sport or occupational weightbearing activities. Identifying modifiable risk factors is important for the treatment and prevention of these injuries. The purpose of this study was to evaluate whether foot posture or ankle dorsiflexion are risk factors for developing AT or PF, and if there were any differences between PF and AT patients. This was a case-control study of 108 patients with PF and 114 patients with AT, compared to the same number of referred patients in 2 control groups never having had these injuries, matched for sex, age, body mass index (BMI), sport, and occupational weightbearing activities. Included patients were 20-65 years with ultrasonographic-verified PF or midsubstance AT. Foot posture was assessed using Foot Posture Index (FPI) classifying the feet into 3 categories: FPI 0-5 normal foot, 6-12 hyperpronated, <0 hypopronated. Ankle dorsiflexion was measured with a goniometer in weightbearing with straight and bent knee. Abnormal foot posture was associated with an increased risk for sustaining both AT (odds ratio [OR] 3.4-4.1) and PF (OR 3.2-3.8). Hyperpronation being the major reason for this association with ORs 5.4-5.5 compared with hypopronation with ORs 2.6-2.9. However, decreased dorsiflexion was not a risk factor: instead, there was an increased ankle dorsiflexion in patients with AT or PF compared with their control groups. Comparison between PF and AT patients demonstrated that PF affected mostly women, and AT mostly men, PF patients were 2.4 years (CI 0.2-4.5) younger, and had 25% more occupational weightbearing than AT patients. However, no differences in BMI or weightbearing physical activity was demonstrated. Hypopronation and hyperpronation but not limited ankle dorsiflexion was associated with increased risk for AT or PF.

The MnAl-alloy nanoparticles incorporated PVDF-based piezoelectric nanogenerator as a self-powered real-time pedometer sensor

This study introduces a flexible, sensitive, and cost-effective hybrid piezoelectric nanogenerator (PENG) by integrating MnAl-alloy nanoparticles into a poly (vinylidene fluoride) (PVDF) nanocomposite film. The MnAl-alloy nanoparticles serve as a nucleating agent for promoting the formation of the electroactive β-phase. It is observed that the electroactive β-phase, dielectric permittivity, saturation polarization, and output performance of the device improve with the incorporation of the MnAl-alloy nanoparticles up to 7.5 wt. % in the PVDF matrix. Hence, in this work, we report a MnAl-alloy-based optimized piezoelectric nanogenerator device using a free-standing nanofiber mat (7.5 wt. % MnAl-alloy) prepared by the electrospinning technique. The as-fabricated piezoelectric nanogenerator effectively channels charges generated by mechanical stress to the electrodes, resulting in an impressive output voltage of approximately 16 V and an output current of around 7.1 μA, yielding a power of 47 μW across 4.5 MΩ resistor. Furthermore, energy harvesting from human movements such as jogging, knee bending, and walking is demonstrated for practical application. A piezo potential of approximately 8 V generated during walking showcases the development of a self-powered pedometer. Furthermore, tapping the PENG charges a capacitor of 0.1 μF up to approximately 1 V, demonstrating the potential application for the power up of small portable electronic devices.

Nanograting-assisted flexible Triboelectric Nanogenerator for active human motion detection

This manuscript presents the development of a nanograting assisted Triboelectric Nanogenerator (TENG) for improved performance. The TENG leverages a cost-effective and straightforward fabrication method, utilizing nano-gratings on a Polydimethylsiloxane (PDMS) layer to enhance the triboelectric effect. The device characteristics are evaluated by considering tapping force, separation distance, and load resistance. The experimental electrical characterization shows that the output voltage increases significantly with higher applied forces, with a 2N force generating voltage increases of over 584% compared to a 0.1N force. Conversely, the output voltage decreases as the separation distance is reduced. The charge storage capability of the proposed device is demonstrated by integrating a TENG with a full-wave bridge rectifier. Furthermore, the fabricated TENG demonstrates remarkable sensitivity in detecting various body motions. When strategically placed on the biceps, the TENG effectively tracks muscle contraction and expansion with a voltage range of +0.5V to -1V, exhibiting a sensitivity of 1.5V per cycle. Similarly, the TENG accurately detects bending movements in the knee and elbow joints. For knee bending, the voltage output ranges from +2.5V to -1V, resulting in a sensitivity of 3.5V per cycle. Elbow flexion generates voltages between +4V and -5V, corresponding to a sensitivity of 9V per cycle. This clear correlation between voltage and specific body movements makes the TENG a promising candidate for wearable health and motion monitoring systems.

Does Cruciate Ligament Substitution and Implant Asymmetry Make a Difference for Total Knee Arthroplasty Kinematics? A Multi-Implant Evaluation

BackgroundThe non-implanted knee differs in comparison to total knee arthroplasty (TKA) designs, with regard to asymmetry and functionality of the anterior cruciate ligament and the posterior cruciate ligament. While surgeons may choose to implant either posterior stabilized (PS) or bi-cruciate stabilized (BCS) TKAs, substituting for one or both cruciate ligaments, the effects of symmetry versus asymmetry in substituting TKA designs have not been widely analyzed to determine possible benefits. Therefore, the objective of this research study was to determine if either TKA asymmetry and/or anterior ligament stabilization can lead to more normal-like kinematics and clinical benefit for patients. MethodsIn vivo, femoro-tibial kinematics for 64 subjects were evaluated in this retrospective study. Overall, 10 subjects had a normal, nonimplanted knee, 20 had a BCS TKA, and 34 had one of two different PS TKAs. All three TKAs had varying degrees of symmetry incorporated into the design, and all were implanted by the same surgeon and were analyzed using fluoroscopy during a deep knee bend. ResultsAt full extension, the BCS TKA subjects demonstrated a statistically more anterior position of both condyles compared to both PS TKAs. The BCS TKA subjects also experienced more posterior femoral rollback (PFR) and axial rotation in early flexion and from full extension to maximum knee flexion. Additionally, the TKAs in this study having asymmetry experienced greater amounts of PFR and weight-bearing knee flexion. ConclusionsThe results from this study indicated that in early flexion, the anterior cam/post mechanism does pull the femoral component more anterior, and all TKAs experienced PFR when the posterior cam engaged the post. The asymmetric designs also achieved greater rollback and axial rotation compared to the symmetric designs.

Development of prediction model for risks of musculoskeletal chronic lumbopelvic pain in Indian women

Chronic lumbopelvic pain (CLPP) and its associated disabilities significantly affect women's social, professional, and personal lives. However, the specific factors contributing to CLPP in women remain unclear. To address this gap, this prospective cross-sectional study aims to identify the risk factors predicting CLPP in women and develop a prediction model that can predict CLPP in women. The study was conducted across Delhi, India, where free health camps were held, and 2400 women were assessed. Among the assessed individuals, the study revealed a high prevalence rate of CLPP among Indian women, standing at 70.4%. Seven risk factors namely, hamstring muscle tightness (> 20° on passive knee extension test), increased lumbar lordosis (> 11.5 cm of the lumbar lordotic index), reduced hip flexibility (> 15 cm on bent knee fallout test), altered foot posture (≥ 20 on foot posture index score), increased perception of psychological stress (> 25 on cohen’s perceived stress scale-10 score), reduced physical activity level (< 475 metabolic/minute on international physical activity questionnaire) and reduced performance of transversus abdominis muscle (≤ 5 on deep muscle contraction scale score) strongly predict the risks of CLPP in women. Identifying these risk factors is crucial for effectively preventing and managing CLPP symptoms, especially considering its high prevalence among Indian women. Health professionals should prioritize raising awareness about CLPP and its causative factors, as well as implementing strategies for early detection and intervention.