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Deficits in locomotor function, including impairments in walking speed and balance, are major problems for many individuals with incomplete spinal cord injury (iSCI). However, it remains unclear which type of training paradigms are more effective in improving balance, particularly dynamic balance, in individuals with iSCI. The purpose of this study was to determine whether anodal transcutaneous spinal direct current stimulation (tsDCS) can facilitate learning of balance control during walking in individuals with iSCI. Fifteen individuals with iSCI participated in this study and were tested in two sessions (i.e., tsDCS and sham conditions). Each session consisted of 1 min of treadmill walking without stimulation or perturbation (baseline), 10 min of walking with either anodal tsDCS or sham stimulation, paired with bilateral pelvis perturbation (adaptation), and finally 2 min of walking without stimulation and perturbation (post-adaptation). The outcome measures were the dynamic balance, assessed using the minimal margin of stability (MoS), and electromyography of leg muscles. Participants demonstrated a smaller MoS during the late adaptation period for the anodal tsDCS condition compared to sham (p = 0.041), and this MoS intended to retain during the early post-adaptation period (p = 0.05). In addition, muscle activity of hip abductors was greater for the anodal tsDCS condition compared to sham during the late adaptation period and post-adaptation period (p 0.05). Results from this study suggest that anodal tsDCS may modulate motor adaptation to pelvis perturbation and facilitate learning of dynamic balance control in individuals with iSCI.

The purpose of this study was to determine whether applying "varied" versus constant pelvis assistance force mediolaterally toward the paretic side of stroke survivors during walking would result in short-term improvement in weight shift toward the paretic side. Twelve individuals post-stroke (60.4 ± 6.2 years; gait speed: 0.53 ± 0.19 m/s) were tested under two conditions (varied vs. constant). Each condition was conducted in a single separate session, which consisted of (a) treadmill walking with no assistance force for 1 min (baseline), pelvis assistance toward the paretic side for 9 min (adaptation), and then no force for additional 1 min (post-adaptation), and (b) overground walking. In the "varied" condition, the magnitude of force was randomly changed across steps between 30% and 100% of the predetermined amount. In the abrupt condition, the magnitude of force was kept constant at 100% of the predetermined amount. Participants exhibited greater improvements in weight shift toward the paretic side (p

The purpose of this study was to determine whether activation of muscles in the paretic leg, particularly contributing to propulsion, and gait symmetry can be improved by applying a targeted resistance force to the pelvis in the backward direction during stance phase while walking in individuals post-stroke. Thirteen individuals post-stroke participated in two experimental sessions, which consisted of treadmill walking, with either targeted or constant resistances, together with overground walking. For the targeted condition, a resistance force was applied to the pelvis during the stance phase of the paretic leg. For the constant condition, the resistance force was applied throughout the whole gait cycle. Participants showed greater increase in medial hamstring muscle activity in the paretic leg and improved step length symmetry after the removal of targeted resistance force, compared to effects of a constant resistance force (P < 0.03). In addition, treadmill walking with the targeted resistance induced more symmetrical step length during overground walking 10 min after the treadmill walking, compared to the result of the constant resistance force (P = 0.01). Applying a targeted resistance force to the pelvis during the stance phase of the paretic leg may induce an enhanced use of the paretic leg and an improvement in gait symmetry in individuals post-stroke. These results provide evidence showing that applying a targeted resistance to the pelvis may induce a forced use of the paretic leg during walking.

Background Little research has examined how psychosocial factors change over time and influence rehabilitation outcomes following meniscectomy. This information can inform the need to assess and address psychosocial factors in meniscectomy rehabilitation. Hypothesis/purpose The purpose of this study was to examine changes in fear-avoidance and self-efficacy psychosocial factors from pre-surgery to one year after meniscectomy and their associations with rehabilitation outcomes. The hypothesis was that psychosocial factors would improve following meniscectomy, and less improvement in psychosocial factors would be associated with less improvement in rehabilitation outcomes. Study design Prospective cohort. Methods Twenty-five patients with partial meniscectomy participated. Testing time points were pre-surgery, after post-surgical rehabilitation, and one-year post-surgery. Fear avoidance (pain catastrophizing and kinesiophobia) and self-efficacy (knee-related activity) psychosocial factors were assessed with the Pain Catastrophizing Scale (PCS), the Tampa Scale for Kinesiophobia (TSK-11), and Knee Activity Self-efficacy (KASE) questionnaires; respectively. Rehabilitation outcomes were quadriceps strength, evaluated with isokinetic testing at 60 °/sec; knee pain, measured with the Numeric Pain Rating Scale (NPRS); and self-reported knee function, measured with the International Knee Documentation Committee Subjective Knee Form (IKDC-SKF). Results PCS scores improved from pre-surgery to after post-surgical rehabilitation, while TSK-11 and KASE scores improved from pre-surgery to after post-surgical rehabilitation and from after post-surgical rehabilitation to 1-year post-surgery. Pre-surgery PCS and KASE scores were associated with 1-year post-surgery NPRS score (r = 0.50) and quadriceps peak torque (r = 0.48), respectively. From pre-surgery to 1-year post-surgery, change in TSK-11 score was associated with change in NPRS score (r = 0.65), and change in KASE score was associated with change in IKDC-SKF score (r = 0.44). From pre-surgery to after post-surgical rehabilitation, changes in TSK-11 and KASE scores were associated with changes in NPRS (TSK-11, r = 0.47; KASE, r = -0.50) and IKDC-SKF scores (TSK-11, r = -0.39; KASE, r = 0.71). From after post-surgical rehabilitation to 1-year post-surgery, changes in KASE score was associated with changes in IKDC-SKF score (r = 0.59). Conclusions Assessment of pain catastrophizing and knee activity self-efficacy pre-surgery might help to identify patients at risk for sustained knee pain and quadriceps muscle weakness. Decreasing kinesiophobia and increasing knee activity self-efficacy were associated with improved knee pain and function. Level of evidence 2b.

The purpose of this study was to examine the effects of combined pelvic corrective force and visual feedback during treadmill walking on paretic leg muscle activity and gait characteristics in individuals with post-stroke hemiparesis. Fifteen chronic stroke participants completed visual feedback only and combined pelvic corrective force and visual feedback conditions during treadmill walking. Each condition included: 1-minute baseline, 7-minute training with visual feedback only or additional pelvic corrective force, 1-minute post training, 1- minute standing break, and another 5-minute training. EMGs from the paretic leg muscles and step length were measured. Overground walking was evaluated before treadmill walking, immediately and 10 minutes after treadmill walking. Greater increases in integrated EMG of all muscles, except vastus medialis and tibialis anterior, were observed with the application of additional pelvic corrective force compared to visual feedback only during treadmill walking. Overground walking speed significantly increased after treadmill training with combined pelvic correction force and visual feedback, but was not significant for the visual feedback only condition. Voluntary weight shifting with additional pelvic corrective force enhanced paretic leg muscle activities and improved gait characteristics during walking. Individuals with post-stroke hemiparesis could adapt feedforward control and generalize the adaptation to overground walking.

The purpose of this study was to determine whether the application of lateral pelvis pulling force toward the non-paretic side during the stance phase of the paretic leg would enhance forced use of the paretic leg and increase weight shift toward the paretic side in stroke survivors. Eleven chronic stroke survivors participated in two experimental sessions, which consisted of (1) treadmill walking with the application of “pelvis resistance” or “pelvis assistance” and (2) overground walking. During the treadmill walking, the laterally pulling force was applied during the stance phase of the paretic leg toward the non-paretic side for the “pelvis resistance” condition or toward the paretic side for the “pelvis assistance” condition during the stance phase of the paretic leg. After force release, the “pelvis resistance” condition exhibited greater enhancement in muscle activation of hip ABD, ADD, and SOL and greater improvement in lateral weight shift toward the paretic side, compared with the effect of the “pelvis assistance” condition (P

People with incomplete spinal cord injury (iSCI) usually show impairments in lateral balance control during walking. Effective interventions for improving balance control are still lacking, probably due to limited understanding of motor learning mechanisms. The objective of this study was to determine how error size and error variability impact the motor learning of lateral balance control during walking in people with iSCI. Fifteen people with iSCI were recruited. A controlled assistance force was applied to the pelvis in the medial-lateral direction using a customized cable-driven robotic system. Participants were tested using 3 conditions, including abrupt, gradual, and varied forces. In each condition, participants walked on a treadmill with no force for 1 minute (baseline), with force for 9 minutes (adaptation), and then with no force for additional 2 minutes (post-adaptation). The margin of stability at heel contact (MoS_HC) and minimum value moment (MoS_Min) were calculated to compare the learning effect across different conditions. Electromyogram signals from the weaker leg were also collected. Participants showed an increase in MoS_Min (after effect) following force release during the post-adaptation period for all three conditions. Participants showed a faster adaptation and a shorter lasting of after effect in MoS_Min for the varied condition in comparison with the gradual and abrupt force conditions. Increased error variability may facilitate motor learning in lateral balance control during walking in people with iSCI, although a faster learning may induce a shorter lasting of after effect. Error size did not show an impact on the lasting of after effect.

The purpose of this study was to determine whether applying repetitive constraint forces to the non-paretic leg during walking would induce motor learning of enhanced use of the paretic leg in individuals post-stroke. Sixteen individuals post chronic (>6months) stroke were recruited in this study. Each subject was tested in two conditions, i.e., applying a constraint force to the non-paretic leg during treadmill walking and treadmill walking only. For the constraint condition, subjects walked on a treadmill with no force for 1 minute (baseline), with force for 7 minutes (adaptation), and then without force for 1 minute (post-adaptation). For the treadmill only condition, a similar protocol was used but no force was applied. EMGs from muscles of the paretic leg and ankle kinematic data were recorded. Spatial-temporal gait parameters during overground walking pre and post treadmill walking were also collected. Integrated EMGs of ankle plantarflexors and hip extensors during stance phase significantly increased during the early adaptation period, and partially retained (15–21% increase) during the post-adaptation period for the constraint force condition, which were significantly greater than that for the treadmill only (3–5%) condition. The symmetry of step length during overground walking significantly improved (p = 0.04) after treadmill walking with the constraint condition, but had no significant change after treadmill walking only. Repetitively applying constraint force to the non-paretic leg during treadmill walking may lead to a motor learning of enhanced use of the paretic leg in individuals post-stroke, which may transfer to overground walking.

BACKGROUND: Little research has examined how psychosocial factors change over time and influence rehabilitation outcomes following meniscectomy. This information can inform the need to assess and address psychosocial factors in meniscectomy rehabilitation. HYPOTHESIS/PURPOSE: The purpose of this study was to examine changes in fear-avoidance and self-efficacy psychosocial factors from pre-surgery to one year after meniscectomy and their associations with rehabilitation outcomes. The hypothesis was that psychosocial factors would improve following meniscectomy, and less improvement in psychosocial factors would be associated with less improvement in rehabilitation outcomes. STUDY DESIGN: Prospective cohort. METHODS: Twenty-five patients with partial meniscectomy participated. Testing time points were pre-surgery, after post-surgical rehabilitation, and one-year post-surgery. Fear avoidance (pain catastrophizing and kinesiophobia) and self-efficacy (knee-related activity) psychosocial factors were assessed with the Pain Catastrophizing Scale (PCS), the Tampa Scale for Kinesiophobia (TSK-11), and Knee Activity Self-efficacy (KASE) questionnaires; respectively. Rehabilitation outcomes were quadriceps strength, evaluated with isokinetic testing at 60 °/sec; knee pain, measured with the Numeric Pain Rating Scale (NPRS); and self-reported knee function, measured with the International Knee Documentation Committee Subjective Knee Form (IKDC-SKF). RESULTS: PCS scores improved from pre-surgery to after post-surgical rehabilitation, while TSK-11 and KASE scores improved from pre-surgery to after post-surgical rehabilitation and from after post-surgical rehabilitation to 1-year post-surgery. Pre-surgery PCS and KASE scores were associated with 1-year post-surgery NPRS score (r = 0.50) and quadriceps peak torque (r = 0.48), respectively. From pre-surgery to 1-year post-surgery, change in TSK-11 score was associated with change in NPRS score (r = 0.65), and change in KASE score was associated with change in IKDC-SKF score (r = 0.44). From pre-surgery to after post-surgical rehabilitation, changes in TSK-11 and KASE scores were associated with changes in NPRS (TSK-11, r = 0.47; KASE, r = -0.50) and IKDC-SKF scores (TSK-11, r = -0.39; KASE, r = 0.71). From after post-surgical rehabilitation to 1-year post-surgery, changes in KASE score was associated with changes in IKDC-SKF score (r = 0.59). CONCLUSIONS: Assessment of pain catastrophizing and knee activity self-efficacy pre-surgery might help to identify patients at risk for sustained knee pain and quadriceps muscle weakness. Decreasing kinesiophobia and increasing knee activity self-efficacy were associated with improved knee pain and function. LEVEL OF EVIDENCE: 2b

The purpose of this study was to determine whether the gradual versus abrupt adaptation to lateral pelvis assistance force improves weight shift toward the paretic side and enhance forced use of the paretic leg during walking. Sixteen individuals who had sustained a hemispheric stroke participated in two experimental sessions, which consisted of 1) treadmill walking with the application of lateral pelvis assistance force (gradual vs. abrupt condition) and 2) overground walking. In the “gradual” condition, during treadmill walking, the assistance force was gradually increased from 0 to 100% of the predetermined force step by step. In the abrupt condition, the force was applied at 100% of the predetermined force throughout treadmill walking. Participants exhibited significant improvements in hip abductor and adductor, ankle dorsiflexor, and knee extensor muscle activities, weight shift toward the paretic side, and overground walking speed in the gradual condition (P0.20). Changes in weight shift toward the paretic side were statistically different between conditions (p0.11). In the gradual condition, the error amplitude was proportional to the improvement in weight shift during the late post-adaptation (R(2)=0.32, P=0.03), but not in the abrupt condition (R(2)=0.001, P=0.93). In conclusion, the “gradual adaptation” inducing “small errors” during constraint-induced walking may improve weight shift and enhance forced use of the paretic leg in individuals post-stroke. Applying gradual pelvis assistance force during walking may be used as an intervention strategy to improve walking in individuals post-stroke.

The purpose of this study was to determine whether the application of a varied pelvis perturbation force would improve dynamic balance control and gait stability of people with incomplete spinal cord injury (iSCI). Fourteen participants with iSCI completed the test in two conditions, i.e., walking paired with pelvis perturbation force and treadmill walking only, with one week interval in between. The order of the testing condition was randomized across participants. For the pelvis pertubation condition, subjects walked on a treadmill with no force for 1 minute, with a varied pelvis perturbation force that was bilaterally applied in the medial-lateral direction for 10 minutes, without force for 1 minute, and then with the perturbation for another 10 mintues after a sitting break. For the treadmill only condition, a protocol that was similar to the perturbation condition was used but no force was applied. Margin of stability (MoS), weight shifting, and other spatiotemporal gait parameters were calculated. Compared to treadmill training only, participants showed significant smaller MoS and double leg support time after treadmill walking with pelvis perturbation. In addition, participants showed significantly greater improvements in overground walking speed after treadmill walking with pelvis perturbation than treadmill only (p = 0.021). Results from this study suggest that applying a varied pelvis perturbation force during treadmill walking could improve dynamic balance control in people with iSCI, which could be transferred to overground walking. These findings may be used to develop a new intervention to improve balance and walking function in people with iSCI.

Objective To determine whether applying a mediolateral corrective force to the pelvis during treadmill walking would enhance muscle activity of the paretic leg and improve gait symmetry in individuals with post-stroke hemiparesis. Methods Fifteen subjects with post-stroke hemiparesis participated in this study. A customized cable-driven robotic system based over a treadmill generated a mediolateral corrective force to the pelvis toward the paretic side during early stance phase. Three different amounts of corrective force were applied. Electromyographic (EMG) activity of the paretic leg, spatiotemporal gait parameters and pelvis lateral displacement were collected. Results Significant increases in integrated EMG of hip abductor, medial hamstrings, soleus, rectus femoris, vastus medialis and tibialis anterior were observed when pelvic corrective force was applied, with pelvic corrective force at 9% of body weight inducing greater muscle activity than 3% or 6% of body weight. Pelvis lateral displacement was more symmetric with pelvic corrective force at 9% of body weight. Conclusions Applying a mediolateral pelvic corrective force toward the paretic side may enhance muscle activity of the paretic leg and improve pelvis displacement symmetry in individuals post-stroke. Significance Forceful weight shift to the paretic side could potentially force additional use of the paretic leg and improve the walking pattern.

Background Locomotor training has been used to improve walking function in people with incomplete spinal cord injury (iSCI), but functional gains are relatively small for some patients, which may be due to the lack of weight shifting training. Objective To determine whether applying a pelvis assistance force in the coronal plane during walking would improve weight shifting and stepping in people with iSCI. Design Repeated measures study. Setting Rehabilitation hospital. Participants Seventeen people with iSCI. Interventions A controlled assistance force was bilaterally applied to the pelvis in the medial-lateral direction to facilitate weight shifting, which gradually increased during the course of treadmill walking. Main outcome measures Weight shifting, step length, margin of stability, and muscle activities of the weaker leg were used to quantify gait performance. The spatial-temporal gait parameters during overground walking were collected pre, post, and 10 minutes after treadmill training. Results During treadmill walking, participants significantly improved weight shifting (ie, center of mass [CoM] lateral distance reduced from 0.16 ± 0.06 m to 0.12 ± 0.07 m, P = .012), and increased step length (from 0.35 ± 0.08 m to 0.37 ± 0.09 m, P = .037) on the stronger side when the force was applied, which were partially retained (ie, CoM distance was 0.14 ± 0.06, P = .019, and step length was 0.37 ± 0.09 m, P = .005) during the late postadaptation period when the force was removed. In addition, weight shifting and step length on the weaker side during overground walking also improved (support base reduced from 0.13 ± 0.06 m to 0.12 ± 0.06 m, P = .042, and step length increased from 0.48 ± 0.12 m to 0.51 ± 0.09 m, P = .045) after treadmill training. Conclusions Applying pelvis assistance during treadmill walking may facilitate weight shifting and improve step length in people with SCI, which may partially transfer to overground walking. Level of evidence III.

The goal of this study was to determine how individuals post-stroke response to the lateral assistance force applied to the pelvis during treadmill walking. Ten individuals post chronic (> 6 months) stroke were recruited to participate in this study. A controlled assistance force (∼10% of body weight) was applied to the pelvis in the lateral direction toward the paretic side during stance of the paretic leg. Kinematics of the pelvis and legs were recorded. Applying pelvis assistance force facilitated weight shifting toward the paretic side, resulting in a more symmetrical gait pattern but also inducing an enlarged range of motion of the pelvis during early adaptation period. The neural system of individuals post stroke adapted to the pelvis assistance force and showed an aftereffect consists of reduced range of motion of the pelvis following load release during post adaptation period.

Software is currently a key part of many safety-critical and life-critical application systems. People always need easy- and instinctive-to-use software, but the biggest challenge for software engineers is how to develop software with high reliability in a timely manner. To assure quality, and to assess the reliability of software products, many software reliability growth models (SRGMs) have been proposed in the past three decades. The practical problem is that sometimes these selected SRGMs by companies or software practitioners disagree in their reliability predictions, while no single model can be trusted to provide consistently accurate results across various applications. Consequently, some researchers have proposed to use combinational models for improving the prediction capability of software reliability. In this paper, three enhanced weighted-combinations, namely weighted arithmetic, weighted geometric, and weighted harmonic combinations, are proposed. To solve the problem of determining proper weights for model combinations, we further study how to incorporate enhanced genetic algorithms (EGAs) with several efficient operators into weighted assignments. Experiments are performed based on real software failure data, and numerical results show that our proposed models are flexible enough to depict various software development environments. Finally, some management metrics are presented to both assure software quality and determine the optimal release strategy of software products under development.

The rapid development of technology provides high performance and reliability for the hardware system; based on this, software engineers can focus their developed software on more convenience and ultra-high reliability. To reach this goal, the testing stage of software development life cycle usually takes more time and effort due to the growing complexity of the software. How to build software that can be tested efficiently has become an important topic in addition to enhancing and developing new testing methods. Thus, research on software testability has been conducted and various methods have been developed. In the past, a dynamic technique for estimating program testability was proposed and called propagation, infection and execution PIE analysis. Previous research studies have shown that PIE analysis can complement software testing. However, this method requires a lot of computational overhead in estimating the testability of software components. In this article, we propose an extended PIE EPIE method to accelerate the conventional PIE analysis, based on generating group testability as a substitute for statement testability. Our proposed method can be systematically separated into three steps: breaking a program into blocks, dividing the blocks into groups and marking target statements. Experiments and evaluations with the Siemens suite, together with cost-effectiveness analysis, clearly show that the number of analysed statements can be effectively decreased, and the calculated values of testability are still acceptable.

Context: A sports injury has both physical and psychological consequences for the athlete. A common postinjury psychological response is elevated fear of reinjury. Objective: To provide an overview of the implications of fear of reinjury on the rehabilitation of athletes, including clinical methods to measure fear of reinjury; the impact of fear of reinjury on rehabilitation outcomes, including physical impairments, function, and return to sports rate; and potential interventions to address fear of reinjury during rehabilitation. Evidence Acquisition: PubMed was searched for articles published in the past 16 years (1990-2016) relating to fear of reinjury in athletes. The reference lists of the retrieved articles were searched for additionally relevant articles. Study Design: Clinical review. Level of Evidence: Level 3. Results: Fear of reinjury after a sports injury can negatively affect the recovery of physical impairments, reduce self-report function, and prevent a successful return to sport. Athletes with high fear of reinjury might benefit from a psychologically informed practice approach to improve rehabilitation outcomes. The application of psychologically informed practice would be to measure fear of reinjury in the injured athletes and provide interventions to reduce fear of reinjury to optimize rehabilitation outcomes. Conclusion: Fear of reinjury after a sports injury can lead to poor rehabilitation outcomes. Incorporating principles of psychologically informed practice into sports injury rehabilitation could improve rehabilitation outcomes for athletes with high fear of reinjury.

With the growing size and complexity of software applications, traditional software reliability methods are insufficient to analyze inter-component interactions of modular software systems. The number of test cases may be extremely large for this application; therefore, it is hard for us to extensively test each software component given resource limitations. In this paper, we propose an adaptive framework of incorporating path testing into reliability estimation for modular software systems. Three estimated methods based on common program structures, namely, sequence, branch, and loop structures, are proposed to calculate the path reliability. Consequently, the derived path reliabilities can be applied to the estimates of software reliability. Some experiments are performed based on two real systems. In addition, the accuracy and correlation with respect to the experiments are investigated by simulation and sensitivity analysis. Experimental results show that the path reliability has a high correlation to the actual software reliability. For software with loop structures, a smaller loop number can be assigned to derive an acceptable estimation of path reliability. Further, the sensitivity analysis can be used to identify critical modules and paths for resource allocation. It can be concluded that the proposed methods are useful and helpful for estimating software reliability and can be adaptively used in the early stages of software development.

Over the past three decades, many software reliability models with different parameters, reflecting various testing characteristics, have been proposed for estimating the reliability growth of software products. We have noticed that one of the most important parameters controlling software reliability growth is the fault reduction factor (FRF) proposed by Musa. FRF is generally defined as the ratio of net fault reduction to failures experienced. During the software testing process, FRF could be influenced by many environmental factors, such as imperfect debugging, debugging time lag, etc. Thus, in this paper, we first analyze some real data to observe the trends of FRF, and consider FRF to be a time-variable function. We further study how to integrate time-variable FRF into software reliability growth modeling. Some experimental results show that the proposed models can improve the accuracy of software reliability estimation. Finally, sensitivity analyses of various optimal release times based on cost and reliability requirements are discussed. The analytic results indicate that adjusting the value of FRF may affect the release time as well as the development cost.

In recent years, grey relational analysis (GRA), a similarity-based method, has been proposed and used in many applications. However, we found that most traditional GRA methods only consider nonweighted similarity for predicting software development effort. In fact, nonweighted similarity may cause biased predictions, because each feature of a project may have a different degree of relevance to the development effort. Therefore, this paper proposes six weighted methods, including nonweighted, distance-based, correlative, linear, nonlinear, and maximal weights, to be integrated into GRA for software effort estimation. Numerical examples and sensitivity analyses based on four public datasets are used to show the performance of the proposed methods. The experimental results indicate that the weighted GRA can improve estimation accuracy and reliability from the nonweighted GRA. The results also demonstrate that the weighted GRA performs better than other estimation techniques and published results. In summary, we can conclude that weighted GRA can be a viable and alternative method for predicting software development effort.

Introduction/Background Locomotor training has been used to improve walking function of individuals post-stroke. However, the functional gains are relatively small, which may be due to the compensatory movements of the non-paretic leg during locomotor training. Our previous study indicated that applying a constraint force to the non-paretic leg could increase muscle activations of the paretic leg during treadmill walking. It is still unclear whether muscle responses in the paretic leg are acquired through feedback correction mechanisms or feedforward control mechanisms. The goal of this study was to examine electromyography (EMG) responses in the paretic leg to a repeated constraint force applied to the non-paretic leg during treadmill walking. Material and method Fifteen individuals with chronic stroke participated in this study. Subjects walked on a treadmill with no force for 1 minute, i.e., baseline. A controlled resistance force was then applied to the non-paretic leg starting from toe-off to mid-swing through a custom designed cable-driven robotic system for 7 minutes, i.e., adaptation period. The force was released and subjects continued walking on the treadmill for another 1 minute, i.e., post-adaptation period. The magnitude of resistance force was ∼18% of MVC of the hip flexion. EMG from 8 muscles of the paretic leg were recorded using electrodes and ankle movement of both legs were measured using position sensors. Results Integrated EMGs of ankle plantarflexors and hip extensors during stance phase significantly increased (33–50% increase, P Conclusion Our results suggest that both feedback correction and feedforward control mechanisms may be involved in response to the constraint force applied to the non-paretic leg. Results from this study may be used to develop a long-term training paradigm to induce a forced use of the paretic leg and improve walking function of individuals post-stroke.

The Technology Acceptance Model (TAM) has been considered to be fundamental in determining the acceptance of new technology in the past decades. The two beliefs, ease of use and usefulness, in the model may not, however, fully explain the consumers' behavior in an emerging environment, such as mobile commerce (m-commerce). This paper aims to develop a framework for m-commerce adoption in consumer decision-making processes. In this paper TAM has been adopted and extended to analyze successful m-commerce adoption. The key elements of the proposed confidence-based framework for B2C m-commerce adoption include psychological and behavioral factors. Psychological factors include history-based confidence, institution-based confidence and personality-based confidence. Behavioral factors include perceived ease of use and perceived usefulness of the mobile application and technology.

In recent years, web services (WS’s) have been widely used to support interoperable machine-to-machine interaction over a network. In order to ensure a reliable WS system, a number of fault tolerance designs have been proposed. It is known that network connection and hardware devices may fail. In addition, the acceptance test (AT) as well as the decision mechanism (DM), which are common in fault tolerance designs, could also fail unexpectedly. Such uncertainties may affect the reliability of a WS-based system but have not yet been carefully considered in reliability modeling. Therefore, we propose extended NVP (ENVP) and extended RB (ERB) for the reliability analysis. Various operations of ENVP and ERB are discussed, and a simulation procedure is implemented to evaluate the system reliability and the failure probability of fault-tolerant WS-based systems. The experimental results show a high degree of correlation between the numbers of AT’s and the reliability improvements. The proposed fault tolerance designs could improve the system reliability, and the simulation procedure could also help in exploring appropriate configurations of fault tolerance designs for practitioners.

Background: Clinicians use the single-leg hop test to assess readiness for return to sports after knee injury. Few studies have reported the results of single-leg hop testing after meniscectomy. Additionally, the contributions of impairments in quadriceps strength and psychosocial factors to single-leg hop performance are unknown. Purpose: To compare single-leg hop performance (distance and landing mechanics) between limbs and to examine the association of single-leg hop performance with quadriceps strength and psychosocial factors in patients with meniscectomy. Study Design: Descriptive laboratory study. Methods: A total of 22 subjects who underwent meniscectomy for traumatic meniscal tears received either standard rehabilitation alone or with additional quadriceps strengthening. Testing was conducted immediately postrehabilitation and at 1 year postsurgery. A single-leg hop test was performed bilaterally, and hop distance was used to create a hop symmetry index. Landing mechanics (peak knee flexion angle, knee extension moment, and peak vertical ground-reaction force) were analyzed with a motion-capture system and a force plate. An isokinetic dynamometer (60 deg/s) assessed knee extensor peak torque and rate of torque development (RTD0-200ms and RTD0–peak torque). Questionnaires assessed fear of reinjury (Tampa Scale for Kinesiophobia [TSK-11]) and self-efficacy (Knee Activity Self-Efficacy [KASE]). Results: Rehabilitation groups did not significantly differ in single-leg hop performance; therefore, groups were combined for further analyses. The mean hop symmetry index was 88.6% and 98.9% at postrehabilitation and 1 year postsurgery, respectively. Compared with the nonsurgical limb, the surgical limb showed decreased peak knee flexion angle at postrehabilitation and decreased knee extension moment at 1 year postsurgery. The hop symmetry index was positively associated with peak torque, RTD0-200ms, and the KASE score at postrehabilitation. Moreover, at postrehabilitation, the peak knee flexion angle was positively associated with peak torque and RTD0-200ms, and the knee extension moment was positively associated with RTD0-200ms. At 1 year postsurgery, peak knee flexion angle and knee extension moment were both positively associated with peak torque, RTD0-200ms, and RTD0–peak torque. Conclusion: Although the hop symmetry index could be considered satisfactory for returning to sports, asymmetries in landing mechanics still exist in the first year postmeniscectomy. Greater quadriceps strength was associated with greater single-leg hop distance and better landing mechanics at both postrehabilitation and 1 year postsurgery. Knee activity self-efficacy was the only psychosocial factor associated with single-leg hop performance and isolated to a positive association with single-leg hop distance at postrehabilitation. Clinical Relevance: Rate of development is not typically measured in the clinic but can be an additional quadriceps measure to monitor for single-leg hop performance. Quadriceps strength and psychosocial factors appear to have separate influence on single-leg hop performance after meniscectomy, which has implications for developing appropriate interventions for optimal single-leg hop performance.

Over the past three decades, many software reliability growth models (SRGMs) were proposed and they are aimed at predicting and estimating software reliability. One common assumption of these conventional SRGMs is that detected faults will be removed immediately. In reality, this assumption may not be reasonable and may not always occur. Developers need time to identify the root causes of detected faults and then fix them. Besides, during debugging the fault correction rate may not be a constant and could be changed at some certain points as time proceeds. Consequently, in this paper, we will explore and study how to apply queueing model to investigate the fault correction process during software development. We propose an extended infinite server queueing model with multiple change-points to predict and assess software reliability. Experimental results based on real failure data show that proposed model can depicts the change of fault correction rates and predict the behavior of software development more accurately than traditional SRGMs.

The aim of this study focuses solely on the customer’s perceptions of the m-commerce environment, rather than on trust in intermediaries or in third parties that might mediate between the customer and the store. The focus is on development of a framework to explain mcommerce acceptance in consumers’ decision-making process. The chapter further extends the technology acceptance model (TAM) in mobile commerce, particularly in the context of the consumer’s confidence level in the buying decision making process, rather than only focusing on the users’ acceptance of technology. The chapter provides a theoretical framework for mcommerce adoption and also suggests the importantrelationships between psychological and behavioral factors in the consumer decision-making process.

In this paper, we propose a modified genetic algorithm (MGA) with calibrating fitness functions, weighted bit mutation, and rebuilding mechanism for the parameter estimation of software reliability growth models (SRGMs). An example using a real failure data is given to demonstrate the performance of proposed method. Experimental result shows that MGA is effective for estimating the parameters of SRGM.

In this paper, we propose a new approach to calculate a pathpsilas reliability along three basic programming structures, which include sequential, branching, and looping structures. The pathpsilas reliability is then taken to approximate the systempsilas reliability, and an example is evaluated to validate and show the effectiveness of proposed method. The numerical example yields several findings. First, the proposed method can be effectively used in the early stages of testing. Second, the path reliability is highly relative to system reliability, and the estimated error of the proposed method is acceptable. Third, with higher test coverage on path testing, the accuracy of system reliability estimation can be further improved. Therefore, the proposed method is a viable alternative method for architecture-based software reliability modeling.

The goal of software project planning is to provide a framework that allows project manager to make reasonable estimates of the resources. In fact, software development is highly unpredictable - only 10% of projects on time and budget. Thus, it is very important for software project managers to accurately and precisely estimate software development effort since the resources are limited. One of the most widely used approaches of software effort estimation is the Analogy method. Since the method of Analogy is constructed on the foundation of distance-based similarity, there are still some drawbacks and restrictions for application. For example, the anomalistic and outlying values will influence the function to determine similarity. Contrarily, Grey Relational Analysis (GRA) is a distinct measurement from the traditional distance scale and can dig out the realistic law from small-sample data. In this paper, we will show how to apply GRA to evaluate the effort estimation results for different data sequences and to compare its accuracy with that of Analogy method. Experimental result shows that the GRA provides a better predictive performance than other methods. We can see that the GRA is more suitable for predicting software development effort with unbalanced dataset.