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The impact of cognitive tasks on human movement is of practical significance; we hereby aim to demonstrate that a significant relationship exists between the dual task's cognitive demand and the disruption caused in hand movement, with the hope to extend this experiment to subjects with disorders (MS, CP, stroke patients) in future studies. By doing so, we hope to be able to develop a metric for evaluating their disease levels using our method and minimize clinical interventions. While previous research has predominantly focused on lower body activities, this study explores the effect of dual tasks on hand movements in healthy individuals. A simulated finger-to-nose test combined with a standard reverse counting task, featuring four difficulty levels, was conducted. Utilizing SVM and decision tree classifiers, we analyzed various features to discern the impact of cognitive tasks on hand movements, including completed cycles and idle time at markers. Our findings reveal that features such as entropy and kurtosis effectively distinguish between task difficulty levels and hand movement disruption. The classifiers achieved accuracies of 70% and 74% for decision tree and SVM, respectively. We hope extending this research to diseased subjects could potentially provide a more accurate assessment of disease severity through the measurement of hand movements during cognitive tasks, offering a non-clinical alternative for disease evaluation. [ABSTRACT FROM AUTHOR]

Objectives: The current study assessed the intrasession and intersession reliability of the knee flexion–extension Lyapunov exponent in patients with anterior cruciate ligament deficiency and healthy individuals. Study Design: University research laboratory. Methods: Kinematic data were collected in 14 patients with anterior cruciate ligament deficiency and 14 healthy individuals walked on a treadmill at a self-selected, low, and high speed, with and without cognitive load. The intraclass correlation coefficient, standard error of measurement, minimal metrically detectable change, and percentage of coefficient of variation were calculated to assess the reliability. Results: The knee flexion–extension Lyapunov exponent had high intrasession reliability, with intraclass correlation coefficients ranging from.83 to.98. In addition, the intersession intraclass correlation coefficient values of these measurements ranged from.35 to.85 regardless of group, gait speed, and dual tasking. In general, relative and absolute reliability were higher in the patients with anterior cruciate ligament deficiency than in the healthy individuals. Conclusions: Although knee flexion–extension Lyapunov exponent demonstrates good intrasession reliability, its low intersession reliability indicates that changes of these measurements between different days should be interpreted with caution. [ABSTRACT FROM AUTHOR]

Static and dynamic behaviors of the human spine in response to internal and external loads may be useful in future building design. The new structure was made by simplification in structure parts more than the previous validated material simplifications of Finite Element (FE) of one motion segment of the human lumbar spine (L3/L4). The study showed the anatomical and mechanical properties of this model were adapted to validated previously models by having fewer materials and stress amount. This validated simplified structure by having the natural process may be useful to achieve adaptable, sustainable, and sensible future structures for several disciplines. Simplification of human lumbar spine structure more than material simplifications. Simplified lumbar structure for prosthesis, implants, building joints & structures. Having fewer materials, less stress & simple form by simplifying lumbar structure. Simplified lumbar structure by being resistant against internal & external response. Sustainable, sensible & adaptable structure by inspiration of the natural process. [ABSTRACT FROM AUTHOR]

Background: Hand tremor is one of the consequences of MS disease degrading quality of patient's life. Recently DBS is used as a prominent treatment to reduce this effect. Evaluation of this approach has significant importance because of the prevalence rate of disease. Objective: The purpose of this study was the nonlinear analysis of tremor signal in order to evaluate the quantitative effect of DBS on reducing MS tremor and differentiating between them using pattern recognition algorithms. Material and Methods: In this analytical study, nine features were extracted from the tremor signal. Through statistical analysis, the significance level of each feature was examined. Finally, tremor signals were categorized by SVM, weighted KNN and NN classifiers. The performance of methods was compared with an ROC graph. Results: The results have demonstrated that dominant frequency, maximum amplitude and energy of the first IMF, deviation of the direct path, sample entropy and fuzzy entropy have the potential to create a significant difference between the tremor signals. The classification accuracy rate of tremor signals in three groups for Weighted KNN, NN and SVM with Gaussian and Quadratic kernels resulted in 95.1%, 93.2%, 91.3% and 88.3%, respectively. Conclusion: Generally, nonlinear and nonstationary analyses have a high potential for a quantitative and objective measure of MS tremor. Weighted KNN has shown the best performance of classification with the accuracy of more than 95%. It has been indicated that DBS has a positive influence on reducing the MS tremor. Therefore, DBS can be used in the objective improvement of tremor in MS patients. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine an average quasi-linear viscoelastic model for the mechanical behavior of rat cervix. The average model is applicable at defined displacement rates for virgin and pregnant tissues in the last trimester of pregnancy. After preconditioning, the displacement of 2 mm was applied to the distal halves of five pregnant rat's cervices and 1 mm to the five virgin samples circumferentially. Uniaxial tension tests were employed at the displacement rates of 0.01, 0.1 and 1 mm/s randomly and were held for 10 min while the tissues were relaxed. Tensile and load-relaxation curves were well described by a quasi-linear viscoelastic model. Two average quasi-linear viscoelastic models were fitted to all 30 curves obtained from experiments for virgin and pregnant tissues. The average quasi-linear viscoelastic model coefficients were extracted using the average model equations. Cervical tissue is strongly viscoelastic. Determination of an average viscoelastic model of rat cervix may lead to a more precise description of the mechanical behavior of the virgin and pregnant tissues in the assessment of cervical insufficiency. [ABSTRACT FROM AUTHOR]

BackgroundKnee braces and foot orthoses are commonly used to improve knee adduction moment, pain and function in subjects with knee osteoarthritis (OA). However, no literature review has been performed to compare the effects of foot orthoses and knee braces in this group of patients.PurposeThe aim of this review was to evaluate the effects of foot orthoses and knee braces on knee adduction moment, pain and function in individuals with knee OA.Study designLiterature review.MethodThe search strategy was based on the Population Intervention Comparison Outcome method. A search was performed in PubMed, Science Direct, Google Scholar and ISI web of knowledge databases using the PRISMA method and based on selected keywords. Thirty-one related articles were selected for final evaluation.ResultsThe results of the analysis of these studies demonstrated that orthotic devices reduce knee adduction moment and also improve pain and function in individuals with knee OA.ConclusionFoot orthoses may be more effective in improving pain and function in subjects with knee OA. Both knee braces and foot orthoses reduce the knee adduction moment in knee OA and consequently patients typically do not need to use knee braces for a long period of time. Also, foot orthoses and knee braces may be more effective for medial compartment knee OA patients due to the fact that this treatment helps improve pain and function.Implications for RehabilitationKnee braces and foot orthoses are commonly used for improving knee adduction moment, pain and function in subjects with knee osteoarthritis (OA).Orthotic devices can reduce knee adduction moment, pain and improve function in knee OA.The combined use of a knee braces and foot orthoses can provide more improvement in knee adduction moment, reduced pain and increased function. [ABSTRACT FROM PUBLISHER]

Background: It is known that general gait training improves lower extremity muscle strength and endurance in Diabetes Neuropathy (DN). But, it is still unknown whether Task-Oriented (TO) gait training would change gait biomechanics and the risk of falling in DN. TO gait training focuses on promoting timing and coordination of lower extremity movements through goal-directed practices with sufficient repetition. Methods: A group of 14 patients with DN participated in a time-series study. All subjects participated in four sessions of assessments (Initial, Pre, Post and Follow-Up). Training was twice a week for 12 weeks. Vertical and horizontal Ground Reaction Forces (GRF), Time Get up and Go (TGUG) and Fall Efficacy Scale-International (FES-I) were evaluated. Gait training started with stepping patterns that progressively changed to complicated patterns of walking. Then, training continued combining walking patterns with upper extremity activities and then ended with treadmill-paced practice. Results: DN patients significantly increased Second Vertical Peak Force and Horizontal Propulsive Force in addition decrease in Minimum Vertical Force. TGUG significantly decreased while FES-I reflected significant increase after gait training. Discussion: Conclusively, training not only improved gait performance, confidence in daily activities and attenuated risk of falling, but also helped DN patients to improve feet biomechanics, muscles timing and coordination. Conclusions: Gait training with respect to principles of motor learning allowed patients to effectively improve through sessions. [ABSTRACT FROM AUTHOR]

Background: Many studies have been conducted on the changes in the balance capabilities of stroke patients. However, results regarding the effects of dual-task activities on postural control in these patients have been variable. Objective: To evaluate the effects of a short-term memory task on the sway characteristics of stroke patients. Method: Center of pressure (COP) fluctuations were measured in three levels of postural difficulty (rigid surface with closed and open eyes and foamsurface with closed eyes), aswell as two levels of cognitive difficulty (easy and difficult). COP parameters included mean velocity, standard deviation of velocity in both medial-lateral (M.L) and anterior-posterior (A.P) directions, total phase plane portrait, area. Nineteen stroke patients and 19 gender, age, height, and weight matching healthy volunteers participated in this study. Results:Our findings indicate thatmean velocity (F=14.21, P=0.001), standard deviation of velocity in bothM.L (F=17.50, P=0.000) and A.P (F=11.03, P=0.002) directions, total phase plane portrait (F=44.12, P=0.001), and area (F=13.95, P=0.01) of center of pressure of patients were statistically greater than normal subjects, while significant interaction of group|postural difficulty and postural|cognitive difficulty were observed for all parameters of postural sway. Conclusions: Different measures of postural sway showed complex response to postural and cognitive difficulties between stroke patients and normals. Cognitive error was not affected by the main effects of group and postural difficulty, while greatly increased at more difficult cognitive task (F=75.73, P=0.000). [ABSTRACT FROM AUTHOR]

A considerable proportion of bone fractures show signs of delayed or impaired healing. A novel device that applies interfragmentary compressive forces to the fracture site was developed and evaluated for its effect on fracture healing. The midshafts of the right tibias of 16 rabbits were osteotomized, leaving a 2-mm gap. A 4-pin, double-bar external fixator was fixed to the tibias. Interfragmental compressive displacement of 0.5 mm with a frequency of 1 Hz was applied 15 minutes per day. Mechanical stimulation began 1 week postoperatively and continued for 2 and 3 weeks. Control animals received no stimulation. Callus quality and area were assessed by radiographs. Maximum force and total energy absorbed up to failure of the healed bones were determined using a standard 3-point bending test. Postmortem radiographic examinations showed that mean radiographic measures in both anteroposterior and mediolateral views was significantly larger in experimental groups than controls (P=.029). Mechanical measures of the healed bones demonstrated that mean values of maximum force and absorbed energy were significantly higher in the experimental groups than in the control groups (P=.029). Both radiographic and mechanical measures were significantly higher after 3 weeks compared to 2 weeks of receiving stimulation (P<.05). [ABSTRACT FROM AUTHOR]