Pröbsting, Eva; Kannenberg, Andreas; Zacharias, Britta
There are clear indications for benefits of stance control orthoses compared to locked knee ankle foot orthoses. However, stance control orthoses still have limited function compared with a sound human leg. The aim of this study was to evaluate the potential benefits of a microprocessor stance and swing control orthosis compared to stance control orthoses and locked knee ankle foot orthoses in activities of daily living. Survey of lower limb orthosis users before and after fitting of a microprocessor stance and swing control orthosis. Thirteen patients with various lower limb pareses completed a baseline survey for their current orthotic device (locked knee ankle foot orthosis or stance control orthosis) and a follow-up for the microprocessor stance and swing control orthosis with the Orthosis Evaluation Questionnaire, a new self-reported outcome measure devised by modifying the Prosthesis Evaluation Questionnaire for use in lower limb orthotics and the Activities of Daily Living Questionnaire. The Orthosis Evaluation Questionnaire results demonstrated significant improvements by microprocessor stance and swing control orthosis use in the total score and the domains of ambulation ( p = .001), paretic limb health ( p = .04), sounds ( p = .02), and well-being ( p = .01). Activities of Daily Living Questionnaire results showed significant improvements with the microprocessor stance and swing control orthosis with regard to perceived safety and difficulty of activities of daily living. The microprocessor stance and swing control orthosis may facilitate an easier, more physiological, and safer execution of many activities of daily living compared to traditional leg orthosis technologies. Clinical relevance This study compared patient-reported outcomes of a microprocessor stance and swing control orthosis (C-Brace) to those with traditional knee ankle foot orthosis and stance control orthosis devices. The C-Brace offers new functions including controlled
Pr?bsting, Eva; Kannenberg, Andreas; Zacharias, Britta
Background: There are clear indications for benefits of stance control orthoses compared to locked knee ankle foot orthoses. However, stance control orthoses still have limited function compared with a sound human leg. Objectives: The aim of this study was to evaluate the potential benefits of a microprocessor stance and swing control orthosis compared to stance control orthoses and locked knee ankle foot orthoses in activities of daily living. Study design: Survey of lower limb orthosis user...
Gordon Keith E
Full Text Available Abstract Background We studied human locomotor adaptation to powered ankle-foot orthoses with the intent of identifying differences between two different orthosis control methods. The first orthosis control method used a footswitch to provide bang-bang control (a kinematic control and the second orthosis control method used a proportional myoelectric signal from the soleus (a physiological control. Both controllers activated an artificial pneumatic muscle providing plantar flexion torque. Methods Subjects walked on a treadmill for two thirty-minute sessions spaced three days apart under either footswitch control (n = 6 or myoelectric control (n = 6. We recorded lower limb electromyography (EMG, joint kinematics, and orthosis kinetics. We compared stance phase EMG amplitudes, correlation of joint angle patterns, and mechanical work performed by the powered orthosis between the two controllers over time. Results During steady state at the end of the second session, subjects using proportional myoelectric control had much lower soleus and gastrocnemius activation than the subjects using footswitch control. The substantial decrease in triceps surae recruitment allowed the proportional myoelectric control subjects to walk with ankle kinematics close to normal and reduce negative work performed by the orthosis. The footswitch control subjects walked with substantially perturbed ankle kinematics and performed more negative work with the orthosis. Conclusion These results provide evidence that the choice of orthosis control method can greatly alter how humans adapt to powered orthosis assistance during walking. Specifically, proportional myoelectric control results in larger reductions in muscle activation and gait kinematics more similar to normal compared to footswitch control.
Full Text Available Robotic technology is gradually becoming commonplace in the medical sector and in the service of patients. Medical conditions that have benefited from significant technological development include stroke, for which rehabilitation with robotic devices is administered, and surgery assisted by robots. Robotic devices have also been proposed for assistance of movement disorders. Pathological tremor, among the most common movement disorders, is such one example. In practice, the dissemination and availability of tremor suppression robotic systems has been limited. Devices in the marketplace tend to either be non-ambulatory or to target specific functions such as eating and drinking.We have developed a one degree-of-freedom (DOF elbow orthosis that could be worn by an individual with tremor. A speed controlled voluntary driven suppression approach is implemented with the orthosis. Typically tremor suppression methods estimate the tremor component of the signal and produce a canceling counterpart signal. The suggested approach, instead estimates the voluntary component of the motion. A controller then actuates the orthosis based on the voluntary signal while simultaneously rejecting the tremorous motion.In this work, we tested the suppressive orthosis using a 1 DOF robotic system that simulates the human arm. The suggested suppression approach does not require a model of the human arm. Moreover, the human input along with the orthosis forearm gravitational forces, of nonlinear nature, are considered as part of the disturbance to the suppression system. Therefore, the suppression system can be modeled linearly. Nevertheless, the orthosis forearm gravitational forces can be compensated by the suppression system.The electromechanical design of the orthosis is presented, and data from an Essential Tremor patient is used as the human input. Velocity tracking results demonstrate an RMS error of 0.31 rad/s, and a power spectral density shows a reduction of
Arazpour, Mokhtar; Chitsazan, Ahmad; Bani, Monireh Ahmadi; Rouhi, Gholamreza; Ghomshe, Farhad Tabatabai; Hutchins, Stephen W
The aim of this case study was to identify the effect of a powered stance control knee ankle foot orthosis on the kinematics and temporospatial parameters of walking by a person with poliomyelitis when compared to a knee ankle foot orthosis. A knee ankle foot orthosis was initially manufactured by incorporating drop lock knee joints and custom molded ankle foot orthoses and fitted to a person with poliomyelitis. The orthosis was then adapted by adding electrically activated powered knee joints to provide knee extension torque during stance and also flexion torque in swing phase. Lower limb kinematic and kinetic data plus data for temporospatial parameters were acquired from three test walks using each orthosis. Walking speed, step length, and vertical and horizontal displacement of the pelvis decreased when walking with the powered stance control knee ankle foot orthosis compared to the knee ankle foot orthosis. When using the powered stance control knee ankle foot orthosis, the knee flexion achieved during swing and also the overall pattern of walking more closely matched that of normal human walking. The reduced walking speed may have caused the smaller compensatory motions detected when the powered stance control knee ankle foot orthosis was used. The new powered SCKAFO facilitated controlled knee flexion and extension during ambulation for a volunteer poliomyelitis person.
Ozdemir, Recep A; Contreras-Vidal, Jose L; Paloski, William H
This study examined differences between young and elderly volunteers in cortical involvement to human posture control during quiet stance with normal and altered sensory stimulation (Experiment-1), and biomechanical perturbations (Experiment-2). The primary focus of the first part was to monitor changes in cortical activity when unexpectedly altering the sensory conditions of upright stance, such as switching from stable (eyes open, fixed support surface) to less-stable (eyes closed, sway-referenced support surface) conditions. Our results demonstrate increased cortical activations in delta (0.2-4 Hz) and gamma (30-50 Hz) oscillations, primarily over central-frontal, central, and central parietal cortices during challenging postural conditions. While increased delta rhythms were observed in both groups during challenging sensory conditions, elderly individuals also showed increased gamma band activity over sensorimotor and parietal cortices, when compared to the younger group. To our knowledge, this study is the first to show age differences in balance related cortical activations during continuous postural tasks with challenging sensory conditions. Preliminary correlations also suggest that increased cerebral activity became more relevant to the control of Center of Mass (COM) dynamics when upright stance is threatened. The results of Experiment-2 also showed for the first time that oscillatory rhythms of the cortex are coherent with muscle firing characteristics suggesting increased corticospinal drive from leg motor cortex to lower limb motoneurons following postural perturbations. Finally, perturbation evoked potential (PEP) analyses suggest that, rather than motor system malfunctioning, impairments in perceptual processing of sensory afference forms the basis of prolonged muscle response delays during perturbed balance in the elderly. Copyright © 2017 Elsevier B.V. All rights reserved.
Full Text Available The ankle foot orthosis (AFO is as an assistive device used in foot disability for gait improvement. The objective of this paper was to design a neuro fuzzy controller for an AFO. Adaptive neuro fuzzy inference system (ANFIS was selected after a detailed study of existing neuro-fuzzy architectures. Data of gait pattern was collected with the help of analog gyro sensors. This data was fed to the ANFIS and a fuzzy rule base was created to complete the neuro-fuzzy system which was used to control the gait pattern. Angular velocity and angle of feet served as inputs to the controller and the output was actuation. The results obtained showed sigmoidal membership functions for the various inputs and outputs due to their close resemblance with the normal human gait. Output of the ANFIS showcased the initial data which was fed to the system; the modified data; changed membership functions and error after training.
Peterka, Robert J
There is considerable recent interest in developing humanoid robots. An important substrate for many motor actions in both humans and biped robots is the ability to maintain a statically or dynamically stable posture. Given the success of the human design, one would expect there are lessons to be learned in formulating a postural control mechanism for robots. In this study we limit ourselves to considering the problem of maintaining upright stance. Human stance control is compared to a suggested method for robot stance control called zero moment point (ZMP) compensation. Results from experimental and modeling studies suggest there are two important subsystems that account for the low- and mid-frequency (DC to approximately 1Hz) dynamic characteristics of human stance control. These subsystems are (1) a "sensory integration" mechanism whereby orientation information from multiple sensory systems encoding body kinematics (i.e. position, velocity) is flexibly combined to provide an overall estimate of body orientation while allowing adjustments (sensory re-weighting) that compensate for changing environmental conditions and (2) an "effort control" mechanism that uses kinetic-related (i.e., force-related) sensory information to reduce the mean deviation of body orientation from upright. Functionally, ZMP compensation is directly analogous to how humans appear to use kinetic feedback to modify the main sensory integration feedback loop controlling body orientation. However, a flexible sensory integration mechanism is missing from robot control leaving the robot vulnerable to instability in conditions where humans are able to maintain stance. We suggest the addition of a simple form of sensory integration to improve robot stance control. We also investigate how the biological constraint of feedback time delay influences the human stance control design. The human system may serve as a guide for improved robot control, but should not be directly copied because the
Mohd Azuwan Mat Dzahir
Full Text Available This paper introduces the body weight support gait training system known as the AIRGAIT exoskeleton and delves into the design and evaluation of its leg orthosis control algorithm. The implementation of the mono- and biarticular pneumatic muscle actuators (PMAs as the actuation system was initiated to generate more power and precisely control the leg orthosis. This research proposes a simple paradigm for controlling the mono- and bi-articular actuator movements cocontractively by introducing a cocontraction model. Three tests were performed. The first test involved control of the orthosis with monoarticular actuators alone without a subject (WO/S; the second involved control of the orthosis with mono- and bi-articular actuators tested WO/S; and the third test involved control of the orthosis with mono- and bi-articular actuators tested with a subject (W/S. Full body weight support (BWS was implemented in this study during the test W/S as the load supported by the orthosis was at its maximum capacity. This assessment will optimize the control system strategy so that the system operates to its full capacity. The results revealed that the proposed control strategy was able to co-contractively actuate the mono- and bi-articular actuators simultaneously and increase stiffness at both hip and knee joints.
Allison, Kim; Bennell, Kim L; Grimaldi, Alison; Vicenzino, Bill; Wrigley, Tim V; Hodges, Paul W
Lateral hip pain during single leg loading, and hip abductor muscle weakness, are associated with gluteal tendinopathy, but it has not been shown how or whether kinematics in single leg stance differ in those with gluteal tendinopathy. To compare kinematics in preparation for, and during, single leg stance between individuals with and without gluteal tendinopathy, and the effect of hip abductor muscle strength on kinematics. Twenty individuals with gluteal tendinopathy and 20 age-matched pain-free controls underwent three-dimensional kinematic analysis of single leg stance and maximum isometric hip abductor strength testing. Maximum values of hip adduction, pelvic obliquity (contralateral pelvis rise/drop), lateral pelvic translation (ipsilateral/contralateral shift) and ipsilateral trunk lean during preparation for leg lift and average values in steady single leg stance, were compared between groups using an analysis of covariance, with and without anthropometric characteristics and strength as covariates. Individuals with gluteal tendinopathy demonstrated greater hip adduction (standardized mean difference (SMD)=0.70, P=0.04) and ipsilateral pelvic shift (SMD=1.1, P=0.002) in preparation for leg lift, and greater hip adduction (SMD=1.2, P=0.002) and less contralateral pelvic rise (SMD=0.86, P=0.02) in steady single leg stance than controls. When including strength as a covariate, only between-group differences in lateral pelvic shift persisted (SMD=1.7, P=0.01). Individuals with gluteal tendinopathy use different frontal plane kinematics of the hip and pelvis during single leg stance than pain-free controls. This finding is not influenced by pelvic dimension or the potentially modifiable factor of body mass index, but is by hip abductor muscle weakness. Copyright © 2016 Elsevier B.V. All rights reserved.
Ryser, Franziska; Butzer, Tobias; Held, Jeremia P; Lambercy, Olivier; Gassert, Roger
To prevent learned non-use of the affected hand in chronic stroke survivors, rehabilitative training should be continued after discharge from the hospital. Robotic hand orthoses are a promising approach for home rehabilitation. When combined with intuitive control based on electromyography, the therapy outcome can be improved. However, such systems often require extensive cabling, experience in electrode placement and connection to external computers. This paper presents the framework for a stand-alone, fully wearable and real-time myoelectric intention detection system based on the Myo armband. The hard and software for real-time gesture classification were developed and combined with a routine to train and customize the classifier, leading to a unique ease of use. The system including training of the classifier can be set up within less than one minute. Results demonstrated that: (1) the proposed algorithm can classify five gestures with an accuracy of 98%, (2) the final system can online classify three gestures with an accuracy of 94.3% and, in a preliminary test, (3) classify three gestures from data acquired from mildly to severely impaired stroke survivors with an accuracy of over 78.8%. These results highlight the potential of the presented system for electromyography-based intention detection for stroke survivors and, with the integration of the system into a robotic hand orthosis, the potential for a wearable platform for all day robot-assisted home rehabilitation.
Herrnstadt, Gil; Menon, Carlo
Robotic technology is gradually becoming commonplace in the medical sector and in the service of patients. Medical conditions that have benefited from significant technological development include stroke, for which rehabilitation with robotic devices is administered, and surgery assisted by robots. Robotic devices have also been proposed for assistance of movement disorders. Pathological tremor, among the most common movement disorders, is one such example. In practice, the dissemination and availability of tremor suppression robotic systems has been limited. Devices in the marketplace tend to either be non-ambulatory or to target specific functions, such as eating and drinking. We have developed a one degree-of-freedom (DOF) elbow orthosis that could be worn by an individual with tremor. A speed-controlled, voluntary-driven suppression approach is implemented with the orthosis. Typically tremor suppression methods estimate the tremor component of the signal and produce a canceling counterpart signal. The suggested approach instead estimates the voluntary component of the motion. A controller then actuates the orthosis based on the voluntary signal, while simultaneously rejecting the tremorous motion. In this work, we tested the suppressive orthosis using a one DOF robotic system that simulates the human arm. The suggested suppression approach does not require a model of the human arm. Moreover, the human input along with the orthosis forearm gravitational forces, of non-linear nature, are considered as part of the disturbance to the suppression system. Therefore, the suppression system can be modeled linearly. Nevertheless, the orthosis forearm gravitational forces can be compensated by the suppression system. The electromechanical design of the orthosis is presented, and data from an essential tremor patient is used as the human input. Velocity tracking results demonstrate an RMS error of 0.31 rad/s, and a power spectral density shows a reduction of the tremor
Herrnstadt, Gil; Menon, Carlo
Robotic technology is gradually becoming commonplace in the medical sector and in the service of patients. Medical conditions that have benefited from significant technological development include stroke, for which rehabilitation with robotic devices is administered, and surgery assisted by robots. Robotic devices have also been proposed for assistance of movement disorders. Pathological tremor, among the most common movement disorders, is one such example. In practice, the dissemination and availability of tremor suppression robotic systems has been limited. Devices in the marketplace tend to either be non-ambulatory or to target specific functions, such as eating and drinking. We have developed a one degree-of-freedom (DOF) elbow orthosis that could be worn by an individual with tremor. A speed-controlled, voluntary-driven suppression approach is implemented with the orthosis. Typically tremor suppression methods estimate the tremor component of the signal and produce a canceling counterpart signal. The suggested approach instead estimates the voluntary component of the motion. A controller then actuates the orthosis based on the voluntary signal, while simultaneously rejecting the tremorous motion. In this work, we tested the suppressive orthosis using a one DOF robotic system that simulates the human arm. The suggested suppression approach does not require a model of the human arm. Moreover, the human input along with the orthosis forearm gravitational forces, of non-linear nature, are considered as part of the disturbance to the suppression system. Therefore, the suppression system can be modeled linearly. Nevertheless, the orthosis forearm gravitational forces can be compensated by the suppression system. The electromechanical design of the orthosis is presented, and data from an essential tremor patient is used as the human input. Velocity tracking results demonstrate an RMS error of 0.31 rad/s, and a power spectral density shows a reduction of the tremor
van der Kooij, H; Jacobs, R; Koopman, B; Grootenboer, H
A model is presented to study and quantify the contribution of all available sensory information to human standing based on optimal estimation theory. In the model, delayed sensory information is integrated in such a way that a best estimate of body orientation is obtained. The model approach agrees with the present theory of the goal of human balance control. The model is not based on purely inverted pendulum body dynamics, but rather on a three-link segment model of a standing human on a movable support base. In addition, the model is non-linear and explicitly addresses the problem of multisensory integration and neural time delays. A predictive element is included in the controller to compensate for time delays, necessary to maintain erect body orientation. Model results of sensory perturbations on total body sway closely resemble experimental results. Despite internal and external perturbations, the controller is able to stabilise the model of an inherently unstable standing human with neural time delays of 100 ms. It is concluded, that the model is capable of studying and quantifying multisensory integration in human stance control. We aim to apply the model in (1) the design and development of prostheses and orthoses and (2) the diagnosis of neurological balance disorders.
Full Text Available Rehabilitation robots are designed to help patients improve their recovery from injury by supporting them to perform repetitive and systematic training sessions. These robots are not only able to guide the subjects’ lower-limb to a designate trajectory, but also estimate their disability and adapt the compliance accordingly. In this research, a new control strategy for a high compliant lower-limb rehabilitation orthosis system named AIRGAIT is developed. The AIRGAIT orthosis is powered by pneumatic artificial muscle actuators. The trajectory tracking controller based on a modified computed torque control which employs a fractional derivative is proposed for the tracking purpose. In addition, a new method is proposed for compliance control of the robotic orthosis which results in the successful implementation of the assist-as-needed training strategy. Finally, various subject-based experiments are carried out to verify the effectiveness of the developed control system.
Jackman, Michelle; Novak, Iona; Lannin, Natasha; Galea, Claire
Two-group randomized controlled trial. Upper limb orthoses worn during functional tasks are commonly used in pediatric neurologic rehabilitation, despite a paucity of high-level evidence. The purpose of this study was to investigate if a customized functional wrist orthosis, when placed on the limb, leads to an immediate improvement in hand function for children with cerebral palsy or brain injury. A 2-group randomized controlled trial involving 30 children was conducted. Participants were randomized to either receive a customized functional wrist orthosis (experimental, n = 15) or not receive an orthosis (control, n = 15). The box and blocks test was administered at baseline and repeated 1 hour after experimental intervention, with the orthosis on if randomized to the orthotic group. After intervention, there were no significant differences on the box and blocks test between the orthotic group (mean, 10.13; standard deviation, 11.476) and the no orthotic group (mean, 14.07; standard deviation, 11.106; t, -0.954; P = .348; and 95% confidence interval, -12.380 to 4.513). In contrast to the findings of previous studies, our results suggest that a functional wrist orthosis, when supporting the joint in a 'typical' position, may not lead to an immediate improvement in hand function. Wearing a functional wrist orthosis did not lead to an immediate improvement in the ability of children with cerebral palsy or brain injury to grasp and release. Further research is needed combining upper limb orthoses with task-specific training and measuring outcomes over the medium to long term. Copyright © 2017 Hanley & Belfus. All rights reserved.
Gordon, Keith E; Sawicki, Gregory S; Ferris, Daniel P
We developed a powered ankle-foot orthosis that uses artificial pneumatic muscles to produce active plantar flexor torque. The purpose of this study was to quantify the mechanical performance of the orthosis during human walking. Three subjects walked at a range of speeds wearing ankle-foot orthoses with either one or two artificial muscles working in parallel. The orthosis produced similar total peak plantar flexor torque and network across speeds independent of the number of muscles used. The orthosis generated approximately 57% of the peak ankle plantar flexor torque during stance and performed approximately 70% of the positive plantar flexor work done during normal walking. Artificial muscle bandwidth and force-length properties were the two primary factors limiting torque production. The lack of peak force and work differences between single and double muscle conditions can be explained by force-length properties. Subjects altered their ankle kinematics between conditions resulting in changes in artificial muscle length. In the double muscle condition greater plantar flexion yielded shorter artificial muscles lengths and decreased muscle forces. This finding emphasizes the importance of human testing in the design and development of robotic exoskeleton devices for assisting human movement. The results of this study outline the mechanical performance limitations of an ankle-foot orthosis powered by artificial pneumatic muscles. This orthosis could be valuable for gait rehabilitation and for studies investigating neuromechanical control of human walking.
Suberbiola, Aaron; Zulueta, Ekaitz; Lopez-Guede, Jose Manuel; Etxeberria-Agiriano, Ismael; Graña, Manuel
This paper shows experimental results on electromyography (EMG)-based system control applied to motorized orthoses. Biceps and triceps EMG signals are captured through two biometrical sensors, which are then filtered and processed by an acquisition system. Finally an output/control signal is produced and sent to the actuators, which will then perform the actual movement, using algorithms based on autoregressive (AR) models and neural networks, among others. The research goal is to predict the desired movement of the lower arm through the analysis of EMG signals, so that the movement can be reproduced by an arm orthosis, powered by two linear actuators. In this experiment, best accuracy has achieved values up to 91%, using a fourth-order AR-model and 100ms block length.
Yang, Mingliang; Li, Jianjun; Guan, Xinyu; Gao, Lianjun; Gao, Feng; Du, Liangjie; Zhao, Hongmei; Yang, Degang; Yu, Yan; Wang, Qimin; Wang, Rencheng; Ji, Linhong
The high energy cost of paraplegic walking using a reciprocating gait orthosis (RGO) is attributed to limited hip motion and excessive upper limb loading for support. To address the limitation, we designed the hip energy storage walking orthosis (HESWO) which uses a spring assembly on the pelvic shell to store energy from the movements of the healthy upper limbs and flexion-extension of the lumbar spine and hip and returns this energy to lift the pelvis and lower limb to assist with the swing and stance components of a stride. Our aim was to evaluate gait and energy cost indices for the HESWO compared to the RGO in patients with paraplegia. The cross-over design was used in the pilot study. Twelve patients with a complete T4-L5 chronic spinal cord injury underwent gait training using the HESWO and RGO. Gait performance (continuous walking distance, as well as the maximum and comfortable walking speeds) and energy expenditure (at a walking speed of 3.3m/min on a treadmill) were measured at the end of the 4-week training session. Compared to the RGO, the HESWO increased continuous walking distance by 24.7% (Penergy expenditure by 13.9% (Puse of the HESWO as an alternative support for paraplegic walking. Copyright © 2017. Published by Elsevier B.V.
Full Text Available In developed countries, falls in older people represent a rising problem. As effective prevention should start before the risk becomes evident, an early predictor is needed. Single stance instability would appear as a major risk factor. Aims of the study were to describe single stance stability, its sensory components, and their correlation with age and gender. A random sample of 597 older adults (319 men, 278 women living at home, aged 65–84, was studied. Stability tests were performed with an electronic postural station. The single stance test showed the impairment of single stance stability in older individuals (75–84 yrs. The significant decline of stability in the older subjects may be explained by the impairment of proprioceptive control together with the decrease in compensatory visual stabilization and emergency responses. Younger subjects (65–74 yrs exhibited better, but still inadequate, proprioceptive control with compensatory visual stabilization. Gender differences appeared in older subjects: women were significantly less stable than men. The measurement of the sensory components of single stance stability could aid in the early detection of a decay in antigravity movements many years before the risk of falling becomes evident. Adequate proprioceptive control could mitigate the effects of all other risks of falling.
Delafontaine, Arnaud; Gagey, Olivier; Colnaghi, Silvia; Do, Manh-Cuong; Honeine, Jean-Louis
Rigid ankle-foot orthoses (AFO) are commonly used for impeding foot drop during the swing phase of gait. They also reduce pain and improve gait kinematics in patients with weakness or loss of integrity of ankle-foot complex structures due to various pathological conditions. However, this comes at the price of constraining ankle joint mobility, which might affect propulsive force generation and balance control. The present study examined the effects of wearing an AFO on biomechanical variables and electromyographic activity of tibialis anterior (TA) and soleus muscles during gait initiation (GI). Nineteen healthy adults participated in the study. They initiated gait at a self-paced speed with no ankle constraint as well as wearing an AFO on the stance leg, or bilaterally. Constraining the stance leg ankle decreased TA activity ipsilaterally during the anticipatory postural adjustment (APA) of GI, and ipsilateral soleus activity during step execution. In the sagittal plane, the decrease in the stance leg TA activity reduced the backward displacement of the center of pressure (CoP) resulting in a reduction of the forward velocity of the center of mass (CoM) measured at foot contact (FC). In the frontal plane, wearing the AFO reduced the displacement of the CoP in the direction of the swing leg during the APA phase. The mediolateral velocity of the CoM increased during single-stance prompting a larger step width to recover balance. During step execution, the CoM vertical downward velocity is normally reduced in order to lessen the impact of the swing leg with the floor and facilitates the rise of the CoM that occurs during the subsequent double-support phase. The reduction in stance leg soleus activity caused by constraining the ankle weakened the vertical braking of the CoM during step execution. This caused the absolute instantaneous vertical velocity of the CoM at FC to be greater in the constrained conditions with respect to the control condition. From a
Full Text Available Rigid ankle-foot orthoses (AFO are commonly used for impeding foot drop during the swing phase of gait. They also reduce pain and improve gait kinematics in patients with weakness or loss of integrity of ankle-foot complex structures due to various pathological conditions. However, this comes at the price of constraining ankle joint mobility, which might affect propulsive force generation and balance control. The present study examined the effects of wearing an AFO on biomechanical variables and electromyographic activity of tibialis anterior (TA and soleus muscles during gait initiation (GI. Nineteen healthy adults participated in the study. They initiated gait at a self-paced speed with no ankle constraint as well as wearing an AFO on the stance leg, or bilaterally. Constraining the stance leg ankle decreased TA activity ipsilaterally during the anticipatory postural adjustment (APA of GI, and ipsilateral soleus activity during step execution. In the sagittal plane, the decrease in the stance leg TA activity reduced the backward displacement of the center of pressure (CoP resulting in a reduction of the forward velocity of the center of mass (CoM measured at foot contact (FC. In the frontal plane, wearing the AFO reduced the displacement of the CoP in the direction of the swing leg during the APA phase. The mediolateral velocity of the CoM increased during single-stance prompting a larger step width to recover balance. During step execution, the CoM vertical downward velocity is normally reduced in order to lessen the impact of the swing leg with the floor and facilitates the rise of the CoM that occurs during the subsequent double-support phase. The reduction in stance leg soleus activity caused by constraining the ankle weakened the vertical braking of the CoM during step execution. This caused the absolute instantaneous vertical velocity of the CoM at FC to be greater in the constrained conditions with respect to the control condition. From
Buckon, C E; Thomas, S S; Jakobson-Huston, S; Sussman, M; Aiona, M
The purpose of this study was to examine the effectiveness of the hinged ankle-foot orthosis (HAFO), posterior leaf spring (PLS), and solid ankle-foot orthosis (SAFO), in preventing contracture, improving efficiency of gait, and enhancing performance of functional motor skills in 30 children (21 male, 9 female; mean age 9 years 4 months; age range 4 to 18 years,) with spastic hemiplegia. Following a 3-month baseline period of no ankle-foot orthosis (AFO) use, each AFO was worn for 3 months after which ankle range of motion, gait analysis, energy consumption, and functional motor skills were assessed. The HAFO and PLS increased passive ankle dorsiflexion and normalization of ankle rocker function during gait. Normalization of knee motion in stance was dependent upon the knee abnormality present and AFO configuration. The HAFO was the most effective in controlling knee hyperextension in stance, while PLS was the most effective in promoting knee extension in children with >10 degree knee flexion in stance. Energy efficiency was improved in 21 of the children, with 13 of these children demonstrating the greatest improvement in HAFO and PLS. Improvements in functional mobility were greatest in the HAFO and PLS.
Guerra Padilla, M; Molina Rueda, F; Alguacil Diego, I M
Stroke is currently the main cause of permanent disability in adults. The impairments are a combination of sensory, motor, cognitive and emotional changes that result in restrictions on the ability to perform basic activities of daily living (BADL). Postural control is affected and causes problems with static and dynamic balance, thus increasing the risk of falls and secondary injuries. The purpose of this review was to compile the literature to date, and assess the impact of ankle-foot orthosis (AFO) on postural control and gait in individuals who have suffered a stroke. The review included randomised and controlled trials that examined the effects of AFO in stroke patients between 18 and 80 years old, with acute or chronic evolution. No search limits on the date of the studies were included, and the search lasted until April 2011. The following databases were used: Pubmed, Trip Database, Cochrane library, Embase, ISI Web Knowledge, CINHAL and PEDro. Intervention succeeded in improving some gait parameters, such as speed and cadence. However it is not clear if there was improvement in the symmetry, postural sway or balance. Because of the limitations of this systematic review, due to the clinical diversity of the studies and the methodological limitations, 0these results should be considered with caution. Copyright © 2011 Sociedad Española de Neurología. Published by Elsevier Espana. All rights reserved.
Balance control involves the contribution of neural, muscular and sensory systems, which work together via complex feedback pathways in a closed loop. With age or disease, the underlying systems in balance control can deteriorate; e.g. muscle strength decreases, the sensory systems become less
Doherty, Cailbhe; Bleakley, Chris; Hertel, Jay; Caulfield, Brian; Ryan, John; Delahunt, Eamonn
Single-limb stance is maintained via the integration of visual, vestibular and somatosensory afferents. Musculoskeletal injury challenges the somatosensory system to reweight distorted sensory afferents. This investigation supplements kinetic analysis of eyes-open and eyes-closed single-limb stance tasks with a kinematic profile of lower limb postural orientation in an acute lateral ankle sprain group to assess the adaptive capacity of the sensorimotor system to injury. Sixty-six participants with first-time acute lateral ankle sprain completed a 20-second eyes-open single-limb stance task on their injured and non-injured limbs (task 1). Twenty-three of these participants successfully completed the same 20-second single-limb stance task with their eyes closed (task 2). A non-injured control group of 19 participants completed task 1, with 16 completing task 2. 3-dimensional kinematics of the hip, knee and ankle joints, as well as associated fractal dimension of the center-of-pressure path were determined for each limb during these tasks. Between trial analyses revealed significant differences in stance limb kinematics and fractal dimension of the center-of-pressure path for task 2 only. The control group bilaterally assumed a position of greater hip flexion compared to injured participants on their side-matched "involved"(7.41 [6.1°] vs 1.44 [4.8]°; η(2)=.34) and "uninvolved" (9.59 [8.5°] vs 2.16 [5.6°]; η(2)=.31) limbs, with a greater fractal dimension of the center-of-pressure path (involved limb=1.39 [0.16°] vs 1.25 [0.14°]; uninvolved limb=1.37 [0.21°] vs 1.23 [0.14°]). Bilateral impairment in postural control strategies present following a first time acute lateral ankle sprain. Copyright © 2014 Elsevier Ltd. All rights reserved.
Full Text Available This paper presents a novel approach to the design of a motorized rehabilitation device – active elbow orthosis (AEO – inspired by the principles of robotic exoskeletons. The device is currently designed for the elbow joint, but can be easily modified for other joints as well. AEO determines the motion activity of the patient using a strain gauge and utilizes this measurement to control the actuator that drives the forearm part of the orthosis. Patient activity level is related to a free arm measurement obtained via a calibration procedure prior to the exercise. A high-level control module offers several types of exercises mimicking the physiotherapist. The device was successfully verified by tests on a number of patients, resulting in extended range of elbow-joint motion.
Allum, John H J; Honegger, Flurin
Acute unilateral peripheral vestibular deficit (aUPVD) patients have balance deficits that can improve after several weeks. Determining differences in vestibulo-spinal reflex (VSR) influences on balance control and vestibular ocular reflex (VOR) responses with peripheral recovery and central compensation would provide insights into CNS plasticity mechanisms. Also, clinically, knowing when balance control is approximately normal again should contribute to decisions about working ability after aUPVD. Usually VORs are employed for this purpose, despite a lack of knowledge about correlations with balance control. Given this background, we examined whether balance and VOR measures improve similarly and are correlated. Further whether balance improvements are different for stance and gait. 26 patients were examined at onset of aUPVD, and 3, 6 and 13 weeks later. To measure balance control and thereby assess the contribution of VSR influences during stance and gait, body-worn gyroscopes mounted at lumbar 1-3 recorded the angular velocity of the lower trunk in the roll (lateral) and pitch (anterior-posterior) directions. These signals were integrated to yield angle deviations. To measure VOR function, rotating chair (ROT) tests were performed with triangular velocity profiles with accelerations of 20°/s(2) and 5°/s(2), and caloric tests with bithermal (44 and 30°C) water irrigation of the external auditory meatus. Changes in average balance and VOR measures at the 4 examination time points were modelled with exponential decays. Improvements were assumed to plateau when model values were to within 10% of steady state. Balance improvement rates were task and direction dependent, ranging from 3-9 weeks post aUPVD, similar to the range of ROT VOR improvement rates. Stance balance control improved similarly in the pitch and roll directions. Both reached steady state at 7.5 weeks. However, changes in visual and proprioceptive influences on stance sway velocities continued to
Mat Dzahir, M A; Nobutomo, T; Yamamoto, S I
Recently, robot assisted therapy devices are increasingly used for spinal cord injury (SCI) rehabilitation in assisting handicapped patients to regain their impaired movements. Assistive robotic systems may not be able to cure or fully compensate impairments, but it should be able to assist certain impaired functions and ease movements. In this study, the control system of lower extremity orthosis for the body weight support gait training system which implements pneumatic artificial muscle (PAM) is proposed. The hip and knee joint angles of the gait orthosis system are controlled based on the PAM coordinates information from the simulation. This information provides the contraction data for the mono- and bi-articular PAMs that are arranged as posterior and anterior actuators to simulate the human walking motion. The proposed control system estimates the actuators' contraction as a function of hip and knee joint angles. Based on the contraction model obtained, input pressures for each actuators are measured. The control system are performed at different gait cycles and two PMA settings for the mono- and bi-articular actuators are evaluated in this research. The results showed that the system was able to achieve the maximum muscle moment at the joints, and able to perform the heel contact movement. This explained that the antagonistic mono- and bi-articular actuators worked effectively.
Jiang, Ping; Chiba, Ryosuke; Takakusaki, Kaoru; Ota, Jun
The development of a physiologically plausible computational model of a neural controller that can realize a human-like biped stance is important for a large number of potential applications, such as assisting device development and designing robotic control systems. In this paper, we develop a computational model of a neural controller that can maintain a musculoskeletal model in a standing position, while incorporating a 120-ms neurological time delay. Unlike previous studies that have used an inverted pendulum model, a musculoskeletal model with seven joints and 70 muscular-tendon actuators is adopted to represent the human anatomy. Our proposed neural controller is composed of both feed-forward and feedback controls. The feed-forward control corresponds to the constant activation input necessary for the musculoskeletal model to maintain a standing posture. This compensates for gravity and regulates stiffness. The developed neural controller model can replicate two salient features of the human biped stance: (1) physiologically plausible muscle activations for quiet standing; and (2) selection of a low active stiffness for low energy consumption. PMID:27655271
Mohd Azuwan Mat Dzahir
Full Text Available It is a general assumption that pneumatic muscle-type actuators will play an important role in the development of an assistive rehabilitation robotics system. In the last decade, the development of a pneumatic muscle actuated lower-limb leg orthosis has been rather slow compared to other types of actuated leg orthoses that use AC motors, DC motors, pneumatic cylinders, linear actuators, series elastic actuators (SEA and brushless servomotors. However, recent years have shown that the interest in this field has grown exponentially, mainly due to the demand for a more compliant and interactive human-robotics system. This paper presents a survey of existing lower-limb leg orthoses for rehabilitation, which implement pneumatic muscle-type actuators, such as McKibben artificial muscles, rubbertuators, air muscles, pneumatic artificial muscles (PAM or pneumatic muscle actuators (PMA. It reviews all the currently existing lower-limb rehabilitation orthosis systems in terms of comparison and evaluation of the design, as well as the control scheme and strategy, with the aim of clarifying the current and on-going research in the lower-limb robotic rehabilitation field.
Raymond K. Chong
Full Text Available Achieving a soft landing during walking can be quantified by analyzing changes in the vertical velocity of the body center of mass (CoM just prior to the landing of the swing limb. Previous research suggests that walking speed and step length may predictably influence the extent of this CoM control. Here we ask how stable this control is. We altered treadmill walking speed by systematically increasing or decreasing it at fixed intervals. We then reversed direction. We hypothesized that the control of the CoM vertical velocity during the late stance of the walking gait may serve as an order parameter which has an attribute of hysteresis. The presence of hysteresis implies that the CoM control is not based on simply knowing the current input conditions to predict the output response. Instead, there is also the influence of previous speed conditions on the ongoing responses. We found that the magnitudes of CoM control were different depending on whether the treadmill speed (as the control parameter was ramped up or down. Changes in step length also influenced CoM control. A stronger effect was observed when the treadmill speed was speeded up compared to down. However, the effect of speed direction remained significant after controlling for step length. The hysteresis effect of CoM control as a function of speed history demonstrated in the current study suggests that the regulation of CoM vertical velocity during late stance is influenced by previous external conditions and constraints which combine to influence the desired behavioral outcome.
Arazpour, Mokhtar; Moradi, Alireza; Samadian, Mohammad; Bahramizadeh, Mahmood; Joghtaei, Mahmoud; Ahmadi Bani, Monireh; Hutchins, Stephen W; Mardani, Mohammad A
Traditionally, the anatomical knee joint is locked in extension when walking with a conventional knee-ankle-foot orthosis. A powered knee-ankle-foot orthosis was developed to provide restriction of knee flexion during stance phase and active flexion and extension of the knee during swing phase of gait. The purpose of this study was to determine differences of the powered knee-ankle-foot orthosis compared to a locked knee-ankle-foot orthosis in kinematic data and temporospatial parameters during ambulation. Quasi-experimental design. Subjects with poliomyelitis (n = 7) volunteered for this study and undertook gait analysis with both the powered and the conventional knee-ankle-foot orthoses. Three trials per orthosis were collected while each subject walked along a 6-m walkway using a calibrated six-camera three-dimensional video-based motion analysis system. Walking with the powered knee-ankle-foot orthosis resulted in a significant reduction in both walking speed and step length (both 18%), but a significant increase in stance phase percentage compared to walking with the conventional knee-ankle-foot orthosis. Cadence was not significantly different between the two test conditions (p = 0.751). There was significantly higher knee flexion during swing phase and increased hip hiking when using the powered orthosis. The new powered orthosis permitted improved knee joint kinematic for knee-ankle-foot orthosis users while providing knee support in stance and active knee motion in swing in the gait cycle. Therefore, the new powered orthosis provided more natural knee flexion during swing for orthosis users compared to the locked knee-ankle-foot orthosis. This orthosis has the potential to improve knee joint kinematics and gait pattern in poliomyelitis subjects during walking activities. © The International Society for Prosthetics and Orthotics 2015.
Wu, Jianhua; McKay, Sandra; Angulo-Barroso, Rosa
This study aimed to apply an uncontrolled manifold (UCM) approach to investigate how children utilize the variability of multiple body segment movement to facilitate the center of mass (COM) control during quiet stance. Three groups of participants were included in this study: younger children (YC, mean age 6.3 years), older children (OC, mean age 10.3 years), and young adults (YA, mean age 20.5 years). Participants stood on a force platform with their hands on the iliac crests for 40 s in each trial. Two visual conditions were examined including eyes-open and eyes-closed and three trials were collected for each condition. Results showed that all three groups partitioned more variability of multi-segment movement into the UCM subspace (maintaining the mean COM position) than into the ORT subspace (a subspace orthogonal to the UCM subspace, causing the deviation of the COM from its mean position) in both eyes-open and eyes-closed conditions. Furthermore, both the YC and OC groups partitioned a significantly higher percentage of variability into the UCM subspace than the YA group regardless of visual condition. In addition, results of conventional COM variables indicated that only the YC group produced significantly faster sway velocity and greater standard deviation than the YA group. All the results together suggest that children at 6-10 years of age use a similar variability-partitioning strategy (a greater V(UCM) and a smaller V(ORT)) like young adults in quiet stance to facilitate the COM control, but it takes more than 10 years for children to refine this strategy and achieve an adult-like variability-partitioning capability (i.e., UCM ratio). It also suggests that postural development may include two phases in which children learn to regulate the position and movement of multiple body segments and the COM first and gain an adult-like variability-partitioning capability later.
Chen, Xingyu; Qu, Xingda
The main purpose of this study was to examine the effects of affective auditory stimuli on balance control during static stance. Twelve female and 12 male participants were recruited. Each participant completed four upright standing trials including three auditory stimuli trials and one baseline trial (ie no auditory stimuli). The three auditory stimuli trials corresponded to the pleasant, neutral and unpleasant sound conditions. Center of pressure (COP) measures were used to quantify balance control performance. It was found that unpleasant auditory stimuli were associated with larger COP amplitude in the AP direction compared to the rest testing conditions. There were no significant interaction effects between 'auditory stimuli' and gender. These findings suggested that some specificities presented by auditory stimuli are important for balance control, and the effects of auditory stimuli on balance control were dependent on their affective components. Practitioner Summary: Findings from this study can aid in better understanding of the relationship between auditory stimuli and balance control. In particular, unpleasant auditory stimuli were found to result in poorer balance control and higher fall risks. Therefore, to prevent fall accidents, interventions should be developed to reduce exposures to unpleasant sound.
Danna-Dos-Santos, A.; Degani, A.M.; Boonstra, T.W.; Mochizuki, L.; Harney, A.M.; Schmeckpeper, M.M; Tabor, L.C.; Leonard, C.T.
Standing upright requires the coordination of neural drives to a large set of muscles involved in controlling human bipedal stance (i.e., postural muscles). The coordination may deteriorate in situations where standing is performed under more challenging circumstances, such as standing on a smaller
Ferris, Daniel P; Czerniecki, Joseph M; Hannaford, Blake
We developed a pneumatically powered orthosis for the human ankle joint. The orthosis consisted of a carbon fiber shell, hinge joint, and two artificial pneumatic muscles. One artificial pneumatic muscle provided plantar flexion torque and the second one provided dorsiflexion torque. Computer software adjusted air pressure in each artificial muscle independently so that artificial muscle force was proportional to rectified low-pass-filtered electromyography (EMG) amplitude (i.e., proportional myoelectric control). Tibialis anterior EMG activated the artificial dorsiflexor and soleus EMG activated the artificial plantar flexor. We collected joint kinematic and artificial muscle force data as one healthy participant walked on a treadmill with the orthosis. Peak plantar flexor torque provided by the orthosis was 70 Nm, and peak dorsiflexor torque provided by the orthosis was 38 Nm. The orthosis could be useful for basic science studies on human locomotion or possibly for gait rehabilitation after neurological injury.
Arazpour, Mokhtar; Ahmadi, Fardin; Bahramizadeh, Mahmood; Samadian, Mohammad; Mousavi, Mohammad Ebrahim; Bani, Monireh Ahmadi; Hutchins, Stephen W
Compared to able-bodied subjects, subjects with post-polio syndrome and poliomyelitis demonstrate a preference for weight-bearing on the non-paretic limb, causing gait asymmetry. The purpose of this study was to evaluate the gait symmetry of the poliomyelitis subjects when ambulating with either a drop-locked knee-ankle-foot orthosis or a newly developed powered knee-ankle-foot orthosis. Quasi experimental study. Seven subjects with poliomyelitis who routinely wore conventional knee-ankle-foot orthoses participated in this study and received training to enable them to ambulate with the powered knee-ankle-foot orthosis on level ground, prior to gait analysis. There were no significant differences in the gait symmetry index of step length (p = 0.085), stance time (p = 0.082), double-limb support time (p = 0.929), or speed of walking (p = 0.325) between the two test conditions. However, using the new powered knee-ankle-foot orthosis improved the symmetry index in step width (p = 0.037), swing time (p = 0.014), stance phase percentage (p = 0.008), and knee flexion during swing phase (p ⩽ 0.001) compared to wearing the drop-locked knee-ankle-foot orthosis. The use of a powered knee-ankle-foot orthosis for ambulation by poliomyelitis subjects affects gait symmetry in the base of support, swing time, stance phase percentage, and knee flexion during swing phase. A new powered knee-ankle-foot orthosis can improve gait symmetry for poliomyelitis subjects by influencing step width, swing time, stance time percentage, and knee flexion during swing phase when compared to ambulating with a drop-locked knee-ankle-foot orthosis. © The International Society for Prosthetics and Orthotics 2015.
Baumgart, Christian; Hoppe, Matthias Wilhelm; Freiwald, Jürgen
The authors aimed to evaluate the differences in postural control during stance and gait between train conductors and controls. Twenty-one train conductors and 21 office workers performed 6 unilateral and bilateral balance tests on stable and unstable surfaces as well as a gait analysis. In the balance tests, the mean velocity of the center of pressure and unstable surface was measured. In the bilateral balance tests the selected stance width was measured. During gait the length, width, frequency, and velocity of the steps were calculated from the ground reaction forces. Train conductors showed a significantly greater step width during gait (15.4 ± 4.7 vs. 13.0 ± 3.4 cm; p = .035) and stance width during the bilateral stance on the unstable surface (21.0 ± 5.1 vs. 17.8 ± 3.7 cm; p = .026) than the office workers, while no differences were revealed in balance variables. The revealed differences between train conductors and office workers may represent task-specific feedforward control strategies, which increase the base of support and may be helpful to resist unexpected perturbations in trains.
Houck, Jeff; Neville, Christopher; Tome, Josh; Flemister, Adolph
The value of strengthening and stretching exercises combined with orthosis treatment in a home-based program has not been evaluated. The purpose of this study was to compare the effects of augmenting orthosis treatment with either stretching or a combination of stretching and strengthening in participants with stage II tibialis posterior tendon dysfunction (TPTD). Participants included 39 patients with stage II TPTD who were recruited from a medical center and then randomly assigned to a strengthening or stretching treatment group. Excluding 3 dropouts, there were 19 participants in the strengthening group and 17 in the stretching group. The stretching treatment consisted of a prefabricated orthosis used in conjunction with stretching exercises. The strengthening treatment consisted of a prefabricated orthosis used in conjunction with the stretching and strengthening exercises. The main outcome measures were self-report (ie, Foot Function Index and Short Musculoskeletal Function Assessment) and isometric deep posterior compartment strength. Two-way analysis of variance was used to test for differences between groups at 6 and 12 weeks after starting the exercise programs. Both groups significantly improved in pain and function over the 12-week trial period. The self-report measures showed minimal differences between the treatment groups. There were no differences in isometric deep posterior compartment strength. A moderate-intensity, home-based exercise program was minimally effective in augmenting orthosis wear alone in participants with stage II TPTD. Level I, prospective randomized study. © The Author(s) 2015.
de Wit, D.C.M.; Buurke, Jaap; Nijlant, J.M.M.; IJzerman, Maarten Joost; Hermens, Hermanus J.
Objective: Regaining walking ability is a major goal during the rehabilitation of stroke patients. To support this process an ankle-foot orthosis (AFO) is often prescribed. The aim of this study is to investigate the effect of an AFO on walking ability in chronic stroke patients. Design: Cross-over
Kilroy, Elisabeth A; Crabtree, Olivia M; Crosby, Brittany; Parker, Amanda; Barfield, William R
The purpose of this study was to compare kinetic differences of static balance between female dancers (D) with at least seven years of dance experience and female non-dancers (ND) who were typical college students. Participants were tested in single-leg stance. Both the dominant leg (DL) and non-dominant leg (NDL) were tested with the participants shod (S) and barefoot (BF). Kinetic variables (vertical, medio-lateral [ML], antero-posterior [AP] maximum ground reaction forces (GRF), and center of pressure (COP) ML and AP) were measured by a Bertec force platform at 1000 Hz with participants S and BF. Each subject's stance was measured over 3 × 30-second intervals. No significant differences (p≥0.05) existed between groups for height, body mass, or age. Significant differences existed between groups for balance time, AP GRF in both BF and S conditions for both DL and NDL, and ML GRF in BF NDL and S DL and NDL conditions. D and ND in BF and S conditions with DL and NDL static stance demonstrate different AP and ML GRF when balancing over a 30-second time interval. Data may suggest that ND are more prone to lose their balance. Further investigation is warranted to understand whether individuals in the rehabilitative field and athletic populations can use dance therapy for injury prevention and rehabilitation.
Fernando, Malindu E; Crowther, Robert G; Lazzarini, Peter A; Sangla, Kunwarjit S; Wearing, Scott; Buttner, Petra; Golledge, Jonathan
Current international guidelines advocate achieving at least a 30 % reduction in maximum plantar pressure to reduce the risk of foot ulcers in people with diabetes. However, whether plantar pressures differ in cases with foot ulcers to controls without ulcers is not clear. The aim of this study was to assess if plantar pressures were higher in patients with active plantar diabetic foot ulcers (cases) compared to patients with diabetes without a foot ulcer history (diabetes controls) and people without diabetes or a foot ulcer history (healthy controls). Twenty-one cases with diabetic foot ulcers, 69 diabetes controls and 56 healthy controls were recruited for this case-control study. Plantar pressures at ten sites on both feet and stance phase duration were measured using a pre-established protocol. Primary outcomes were mean peak plantar pressure, pressure-time integral and stance phase duration. Non-parametric analyses were used with Holm's correction to correct for multiple testing. Binary logistic regression models were used to adjust outcomes for age, sex and body mass index. Median differences with 95 % confidence intervals and Cohen's d values (standardised mean difference) were reported for all significant outcomes. The majority of ulcers were located on the plantar surface of the hallux and toes. When adjusted for age, sex and body mass index, the mean peak plantar pressure and pressure-time integral of toes and the mid-foot were significantly higher in cases compared to diabetes and healthy controls (p diabetic foot ulcers despite having a longer stance phase duration which would be expected to lower plantar pressure. Whether plantar pressure changes can predict ulcer healing should be the focus of future research. These results highlight the importance of offloading feet during active ulceration in addition to before ulceration.
Taube, Wolfgang; Leukel, Christian; Gollhofer, Albert
The present study assessed the influence of visual feedback on stance stability and soleus H-reflex excitability. The centre of pressure (COP) displacement was measured in upright stance on a rigid surface (stable surface) and on a spinning top (unstable surface) while subjects either received "normal" visual feedback (without laser pointer = WLP) or pointed with a laser pointer on a target on the wall (LP). In order to verify that laser pointing influenced visual feedback, two additional experiments were conducted: (1) Subjects performed a finger reaction task which was thought to increase attention and cognitive demands without alteration of the visual feedback. (2) The effect of laser pointing on the wall was compared with pointing at a board, which was attached to the subjects themselves. In this case, the laser point could not serve as a reference for sway because the board moved in synchrony with the body. On stable and unstable surface, COP displacement was reduced in the LP compared to the WLP task (-17 cm +/- 6, P < 0.05; -14 cm +/- 6, P < 0.05). Conversely, H-reflexes were greater in the LP condition (stable: +20 microV +/- 30, not significant; unstable +115 microV +/- 40, P < 0.05). Stance stability and H-reflex modulation were negatively correlated (R(2) = -0.5; P < 0.001). The finger reaction task did neither influence COP displacement nor H-reflexes. Pointing at the body-fixed target did not alter COP displacement. These findings suggest that postural sway can be reduced by a handheld laser pointer targeting on an external reference point. It is argued that altered visual input was responsible for modulating the H-reflex.
do Nascimento, Breno Gontijo; Vimieiro, Claysson Bruno Santos; Nagem, Danilo Alves Pinto; Pinotti, Marcos
Powered orthosis is a special class of gait assist device that employs a mechanical or electromechanical actuator to enhance movement of hip, knee, or ankle articulations. Pneumatic artificial muscle (PAM) has been suggested as a pneumatic actuator because its performance is similar to biological muscle. The electromyography (EMG) signal interpretation is the most popular and simplest method to establish the patient voluntary control of the orthosis. However, this technique is not suitable for patients presenting neurological lesions causing absence or very low quality of EMG signal. For those cases, an alternative control strategy should be provided. The aim of the present study is to develop a gait assistance orthosis for lower limb powered by PAMs controlled by a voluntary activation method based on the angular behavior of hip joint. In the present study, an orthosis that has been molded in a patient was employed and, by taking her anthropometric parameters and movement constraints, the adaptation of the existing orthosis to the powered orthosis was planned. A control system was devised allowing voluntary control of a powered orthosis suitable for patients presenting neurological lesions causing absence or very low quality of EMG signal. A pilot clinical study was reported where a patient, victim of poliovirus, successfully tested a hip orthosis especially modified for the gait test evaluation in the parallel bar system. The hip orthosis design and the control circuitry parameters were able to be set to provide satisfactory and comfortable use of the orthosis during the gait cycle.
Meeker, Cassie; Park, Sangwoo; Bishop, Lauri; Stein, Joel; Ciocarlie, Matei
Wearable orthoses can function both as assistive devices, which allow the user to live independently, and as rehabilitation devices, which allow the user to regain use of an impaired limb. To be fully wearable, such devices must have intuitive controls, and to improve quality of life, the device should enable the user to perform Activities of Daily Living. In this context, we explore the feasibility of using electromyography (EMG) signals to control a wearable exotendon device to enable pick ...
Meeker, Cassie; Park, Sangwoo; Bishop, Lauri; Stein, Joel; Ciocarlie, Matei
Wearable orthoses can function both as assistive devices, which allow the user to live independently, and as rehabilitation devices, which allow the user to regain use of an impaired limb. To be fully wearable, such devices must have intuitive controls, and to improve quality of life, the device should enable the user to perform Activities of Daily Living. In this context, we explore the feasibility of using electromyography (EMG) signals to control a wearable exotendon device to enable pick and place tasks. We use an easy to don, commodity forearm EMG band with 8 sensors to create an EMG pattern classification control for an exotendon device. With this control, we are able to detect a user's intent to open, and can thus enable extension and pick and place tasks. In experiments with stroke survivors, we explore the accuracy of this control in both non-functional and functional tasks. Our results support the feasibility of developing wearable devices with intuitive controls which provide a functional context for rehabilitation.
Full Text Available By analysing the dynamic principles of the human gait, an economic gait-control analysis is performed, and passive elements are included to increase the energy efficiency in the motion control of active orthoses. Traditional orthoses use position patterns from the clinical gait analyses (CGAs of healthy people, which are then de-normalized and adjusted to each user. These orthoses maintain a very rigid gait, and their energy cost is very high, reducing the autonomy of the user. First, to take advantage of the inherent dynamics of the legs, a state machine pattern with different gains in each state is applied to reduce the actuator energy consumption. Next, different passive elements, such as springs and brakes in the joints, are analysed to further reduce energy consumption. After an off-line parameter optimization and a heuristic improvement with genetic algorithms, a reduction in energy consumption of 16.8% is obtained by applying a state machine control pattern, and a reduction of 18.9% is obtained by using passive elements. Finally, by combining both strategies, a more natural gait is obtained, and energy consumption is reduced by 24.6% compared with a pure CGA pattern.
Bill, M; McIntosh, R; Myers, P
This paper reports on a series of case studies where improvements were sought in muscle tone and gait in children with cerebral palsy. A Midfoot Control Ankle Foot Orthosis (AFO) was developed to control foot position in a cohort of patients with cerebral palsy (CP). The concept of controlling midfoot and hindfoot with an encapsulated internal Supra-Malleolar AFO that fitted into an external AFO was shown to be effective in ambulant children with CP. Some initial problems of compliance were noted and postulated to be due to difficulties associated with previous orthotic devices. Evidence from the case studies suggest that the developed Supra-Malleolar AFO orthoses enables children with CP to maintain mobility without skin tissue damage, delays the need for surgery and at the same time maintains the length of the Triceps Surae (Gastrocnemius and Soleus) complex. Plans for further research are discussed which will contribute to the evidence base for this particular orthotic device.
Desloovere, Kaat; Molenaers, Guy; Van Gestel, Leen; Huenaerts, Catherine; Van Campenhout, Anja; Callewaert, Barbara; Van de Walle, Patricia; Seyler, J
Several studies indicated that walking with an ankle foot orthosis (AFO) impaired third rocker. The purpose of this study was to evaluate the effects of two types of orthoses, with similar goal settings, on gait, in a homogeneous group of children, using both barefoot and shoe walking as control conditions. Fifteen children with hemiplegia, aged between 4 and 10 years, received two types of individually tuned AFOs: common posterior leaf-spring (PLS) and Dual Carbon Fiber Spring AFO (CFO) (with carbon fibre at the dorsal part of the orthosis). Both orthoses were expected to prevent plantar flexion, thus improving first rocker, allowing dorsiflexion to improve second rocker, absorbing energy during second rocker, and returning it during the third rocker. The effect of the AFOs was studied using objective gait analysis, including 3D kinematics, and kinetics in four conditions: barefoot, shoes without AFO, and PLS and CFO combined with shoes. Several gait parameters significantly changed in shoe walking compared to barefoot walking (cadence, ankle ROM and velocity, knee shock absorption, and knee angle in swing). The CFO produced a significantly larger ankle ROM and ankle velocity during push-off, and an increased plantar flexion moment and power generation at pre-swing compared to the PLS (<0.01). The results of this study further support the findings of previous studies indicating that orthoses improve specific gait parameters compared to barefoot walking (velocity, step length, first and second ankle rocker, sagittal knee and hip ROM). However, compared to shoes, not all improvements were statistically significant.
Arazpour, Mokhtar; Ahmadi Bani, Monireh; Samadian, Mohammad; Mousavi, Mohammad E; Hutchins, Stephen W; Bahramizadeh, Mahmood; Curran, Sarah; Mardani, Mohammad A
A powered knee-ankle-foot orthosis was developed to provide restriction of knee flexion during stance phase and active flexion and extension of the knee during swing phase of gait. The purpose of this study was to determine its effect on the physiological cost index, walking speed and the distance walked in people with poliomyelitis compared to when walking with a knee-ankle-foot orthosis with drop lock knee joints. Quasi experimental study. Seven subjects with poliomyelitis volunteered for the study and undertook gait analysis with both types of knee-ankle-foot orthosis. Walking with the powered knee-ankle-foot orthosis significantly reduced walking speed (p = 0.015) and the distance walked (p = 0.004), and also, it did not improve physiological cost index values (p = 0.009) compared to walking with the locked knee-ankle-foot orthosis. Using a powered knee-ankle-foot orthosis did not significantly improve any of the primary outcome measures during walking for poliomyelitis subjects. This powered knee-ankle-foot orthosis design did not improve the physiological cost index of walking for people with poliomyelitis when compared to walking with a knee-ankle-foot orthosis with drop lock knee joints. This may have been due to the short training period used or the bulky design and additional weight of the powered orthosis. Further research is therefore warranted. © The International Society for Prosthetics and Orthotics 2015.
Horlings, C.G.; Kung, U.M.; Bloem, B.R.; Honegger, F.; Alfen, N. van; Engelen, B.G.M. van; Allum, J.H.
OBJECTIVE: To distinguish between normal and deficient balance control due to vestibular loss (VL) or proprioceptive loss (PL) using pelvis and shoulder sway measures. METHODS: Body-worn gyroscopes measured pelvis and shoulder sway in pitch (anterior-posterior) and roll (side-to-side) directions in
Jantsje H. Pasma
Full Text Available The Independent Channel (IC model is a commonly used linear balance control model in the frequency domain to analyze human balance control using system identification and parameter estimation. The IC model is a rudimentary and noise-free description of balance behavior in the frequency domain, where a stable model representation is not guaranteed. In this study, we conducted firstly time-domain simulations with added noise, and secondly robot experiments by implementing the IC model in a real-world robot (PostuRob II to test the validity and stability of the model in the time domain and for real world situations. Balance behavior of seven healthy participants was measured during upright stance by applying pseudorandom continuous support surface rotations. System identification and parameter estimation were used to describe the balance behavior with the IC model in the frequency domain. The IC model with the estimated parameters from human experiments was implemented in Simulink for computer simulations including noise in the time domain and robot experiments using the humanoid robot PostuRob II. Again, system identification and parameter estimation were used to describe the simulated balance behavior. Time series, Frequency Response Functions, and estimated parameters from human experiments, computer simulations, and robot experiments were compared with each other. The computer simulations showed similar balance behavior and estimated control parameters compared to the human experiments, in the time and frequency domain. Also, the IC model was able to control the humanoid robot by keeping it upright, but showed small differences compared to the human experiments in the time and frequency domain, especially at high frequencies. We conclude that the IC model, a descriptive model in the frequency domain, can imitate human balance behavior also in the time domain, both in computer simulations with added noise and real world situations with a
Full Text Available Balance disorders are commonly observed during the course of multiple sclerosis (MS. The aim of this study is to report characteristics of MS patient stance control disorders, measured by means of posturography and related to the brainstem lesions. Thirty-eight patients affected by MS, mildly to moderately disable according to Kurtzke’s Expanded Disability Status Scale, underwent a complete clinical neurological and vestibular evaluation and brain MRI scanning. All patients were then tested on a static posturography platform (Tetrax, Israel in four conditions: eyes open and eyes closed standing on a firm surface and on a foam pad. Clinical and/or magnetic resonance imaging evidence of brainstem involvement was observed in 55.3% of patients. When brainstem lesion was detected, Fourier analysis showed a typical pattern characterized by inversion of the 0- 0.1 Hz and 0.1-0.25 Hz frequency bands. In conclusion, MS leads to pervasive postural disturbances in the majority of subjects, including the visuo-vestibular loops and proprioception involving vestibulospinal pathways in at least 55.3% of patients. Our results may also suggest the presence of Fourier inversion in patients with brainstem lesions.
Full Text Available The purpose of this study was to evaluate the effect of a continuous and a discretized Visual Biofeedback (VBF on balance performance in upright stance. The coordinates of the Centre of Pressure (CoP, extracted from a force plate, were processed in real-time to implement the two VBFs, administered to two groups of 12 healthy participants. In the first group, a representation of the CoP was continuously shown, while in the second group, the discretized VBF was provided at an irregular frequency (that depended on the subject's performance by displaying one out of a set of five different emoticons, each corresponding to a specific area covered by the current position of the CoP. In the first case, participants were asked to maintain a white spot within a given square area, whereas in the second case they were asked to keep the smiling emoticon on. Trials with no VBF were administered as control. The effect of the two VBFs on balance was studied through classical postural parameters and a subset of stabilogram diffusion coefficients. To quantify the amount of time spent in stable conditions, the percentage of time during which the CoP was inside the stability area was calculated. Both VBFs improved balance maintainance as compared to the absence of any VBF. As compared to the continuous VBF, in the discretized VBF a significant decrease of sway path, diffusion and Hurst coefficients was found. These results seem to indicate that a discretized VBF favours a more natural postural behaviour by promoting a natural intermittent postural control strategy.
D'Anna, Carmen; Schmid, Maurizio; Bibbo, Daniele; Bertollo, Maurizio; Comani, Silvia; Conforto, Silvia
The purpose of this study was to evaluate the effect of a continuous and a discretized Visual Biofeedback (VBF) on balance performance in upright stance. The coordinates of the Centre of Pressure (CoP), extracted from a force plate, were processed in real-time to implement the two VBFs, administered to two groups of 12 healthy participants. In the first group, a representation of the CoP was continuously shown, while in the second group, the discretized VBF was provided at an irregular frequency (that depended on the subject's performance) by displaying one out of a set of five different emoticons, each corresponding to a specific area covered by the current position of the CoP. In the first case, participants were asked to maintain a white spot within a given square area, whereas in the second case they were asked to keep the smiling emoticon on. Trials with no VBF were administered as control. The effect of the two VBFs on balance was studied through classical postural parameters and a subset of stabilogram diffusion coefficients. To quantify the amount of time spent in stable conditions, the percentage of time during which the CoP was inside the stability area was calculated. Both VBFs improved balance maintainance as compared to the absence of any VBF. As compared to the continuous VBF, in the discretized VBF a significant decrease of sway path, diffusion and Hurst coefficients was found. These results seem to indicate that a discretized VBF favours a more natural postural behaviour by promoting a natural intermittent postural control strategy.
... PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3475 Limb orthosis. (a) Identification. A limb orthosis (brace) is a device intended for medical purposes that is worn on the upper or lower... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Limb orthosis. 890.3475 Section 890.3475 Food and...
Saeedi, Hassan; Mousavi, Mohammad E; Majddoleslam, Basir; Rahgozar, Mehdi; Aminian, Gholamreza; Tabatabai Ghomshe, Farhad; Movahedi Yeganeh, Mohsen
Due to blocking of pronation/dorsiflexion in flexible flat foot and restriction of these movements in using the University of California Berkeley Laboratory orthosis, provided pressures in sole by the orthosis were increased. Therefore, this article describes the evaluation of modified foot orthosis with flexible structure in the management of individuals with flexible flat foot. CASE DESCRIPTION AND METHOD: The patient was a 21-year-old male who had symptomatic flat foot. The modified foot orthosis included movable surface and the outside structure. The modified foot orthosis was evaluated by standing foot X-ray, comfort rate, electromyography of leg muscle and vertical ground reaction force during walking. The modified foot orthosis improved the foot alignment and decreased the symptoms of flat foot with more comfort. Subtalar position by sub-maximum supination had higher position than neutral in sagittal plane. It may increase the muscle activity of peroneus longus by 7% compared to barefoot, and there was a decrease of 11% ground reaction force in mid stance. The result of this single case evaluation only proposed the feasibility of this modified insole as the orthotic treatment in flexible flat foot. Clinical relevance The modified foot orthosis, which is mobile in the midfoot, is an orthosis for walking and standing in subjects with flexible flat foot.
Full Text Available Background: Back pain caused by lumbar region pathologies is a condition that leads to loss of productivity and physical disability, with high costs of diagnosis and treatment. This study was planned to investigate the effect of taping and soft orthosis application on the pain and functional disability in the pathology of lumbar region without neurological deficit. Methods: This study is randomized controlled trial. Sixty-three volunteer patients were randomly divided into three groups of 21 people. Group I, soft orthotics and stabilization exercise program; Group II, Kinesio taping and stabilization exercise program; Group III, stabilization exercise program was applied. After obtaining demographic data of the participants; patients were evaluated in terms of range of motion and muscle strength. We used visual analog scale for pain level assessment, sit and reach test for flexibility assessment, timed up and go test (TUG for functional ambulation and balance, modified Schober test for lumbar spine flexibility, Oswestry Disability Index in the assessment of functional disability. They were assessed at the pretreatment, third (post treatment and six week (home programs and follow-up. Results: The results showed that significant differences (p<0.05 occurred over time in the study parameters such as functional ambulation, flexibility, lumbar flexibility, functional disability, pain, strength, range of motion in all groups. In comparisons between groups, there was a difference mainly in favor of Group II (p<0.05. Conclusions: We have concluded that in lumbar region pathologies without neurological deficits, stabilization exercises combined with orthotics and Kinesio taping applications reduces pain and functional disability.
Fournier Belley, Amélie; Bouffard, Jason; Brochu, Karine; Mercier, Catherine; Roy, Jean-Sébastien; Bouyer, Laurent
Proprioception is important for proper motor control. As the central nervous system modulates how sensory information is processed during movement (sensory gating), proprioceptive tests performed at rest do not correlate well with performance during dynamic tasks such as walking. Proprioception therefore needs to be assessed during movement execution. 1) To develop a test evaluating the ability to detect movement errors during walking, and its test-retest reliability; 2) to quantify the relationship between proprioceptive threshold (obtained with this new test) and performance in a standardized dynamic balance task. Thirty healthy subjects walked on a treadmill while wearing a robotized ankle-foot orthosis (rAFO) for 2 bouts of 6min on 2 evaluation sessions (test-retest reliability). Force perturbations resisting ankle dorsiflexion during swing were applied to the ankle via the rAFO (150ms duration, variable amplitude). Participants pushed a button when they detected the perturbations. The Star Excursion Balance Test (SEBT) was used to evaluate dynamic balance. Angular differences between perturbed and non-perturbed gait cycles were used to quantify movement error. Detection threshold was defined as the minimal movement error at which 50% of the perturbations were perceived. Intraclass correlation coefficients (ICCs) estimated test-retest reliability, and Pearson coefficients were used to determine the correlation between detection threshold and SEBT. Detection threshold was 5.31±2.12°. Good reliability (ICC=0.70) and a moderate to strong correlation to SEBT (r=-0.57 to -0.76) were found. Force perturbations produced by the robotized AFO provides a reliable way of evaluating proprioception during walking. Copyright © 2016 Elsevier B.V. All rights reserved.
van der Kooij, Herman; Peterka, Robert J
We developed a theory of human stance control that predicted (1) how subjects re-weight their utilization of proprioceptive and graviceptive orientation information in experiments where eyes closed stance was perturbed by surface-tilt stimuli with different amplitudes, (2) the experimentally observed increase in body sway variability (i.e. the "remnant" body sway that could not be attributed to the stimulus) with increasing surface-tilt amplitude, (3) neural controller feedback gains that determine the amount of corrective torque generated in relation to sensory cues signaling body orientation, and (4) the magnitude and structure of spontaneous body sway. Responses to surface-tilt perturbations with different amplitudes were interpreted using a feedback control model to determine control parameters and changes in these parameters with stimulus amplitude. Different combinations of internal sensory and/or motor noise sources were added to the model to identify the properties of noise sources that were able to account for the experimental remnant sway characteristics. Various behavioral criteria were investigated to determine if optimization of these criteria could predict the identified model parameters and amplitude-dependent parameter changes. Robust findings were that remnant sway characteristics were best predicted by models that included both sensory and motor noise, the graviceptive noise magnitude was about ten times larger than the proprioceptive noise, and noise sources with signal-dependent properties provided better explanations of remnant sway. Overall results indicate that humans dynamically weight sensory system contributions to stance control and tune their corrective responses to minimize the energetic effects of sensory noise and external stimuli.
Park, KwangYong; Seo, KyoChul
[Purpose] The purpose of this study was to examine the effects of a functional foot orthosis on the knee angle in the sagittal plane of college students in their 20s who had flatfoot. [Subjects and Methods] The subjects of this study were 20 college students diagnosed as having flatfoot. The variations of their knee angle (Q-angle) in the sagittal plane during the stance phase were measured using the VICON Motion System (Vicon, Hansung, Korea) before and while wearing a foot orthosis. The experimental data were analyzed using SPSS 12.0 for Windows. [Results] The Q-angle in the test group during the stance phase showed statistically significant declines on the right and left sides while wearing the foot orthosis during the gait-phases of loading response and midstance. During initial contact, terminal stance, and preswing, the Q-angle also decreased on the right and left sides after wearing the foot orthosis, but the changes were not statistically significant. [Conclusion] The college students with flatfoot exhibited declines in the Q-angle in the sagittal plane while wearing a foot orthosis. In this regard, the application of active gait training using orthotic shoes for long hours is likely to help individuals with flatfoot to achieve normal gait.
Wahid, Ferdous; Begg, Rezaul; Sangeux, Morgan; Halgamuge, Saman; Ackland, David C
The aim of this study was twofold. Firstly, to develop a multiple regression normalization (MR) strategy to decorrelate physical properties and walking speed from spatiotemporal gait data in healthy children; and secondly, to use this MR approach to identify the effect of a solid ankle foot orthosis (AFO) on gait in children with cerebral palsy (CP). Spatiotemporal gait data during self-selected walking were obtained from 51 children with diplegic CP and 34 aged-matched healthy controls. Data were normalized using standard dimensionless equations (DS) and a MR approach. Stride length, stance time, swing time, and double support time were significantly different between children with CP and healthy controls using DS (pchildren with CP walked with and without an AFO. Normalizing gait data using DS demonstrated significant differences in cadence and step time in children with CP when wearing an AFO compared to the controls (pchildren with CP with and without an AFO, except double support time. After MR normalization, spatiotemporal parameters in children wearing an AFO became closer to those of the controls, except for double support time. The MR approach presented will assist in evaluating the effectiveness of conservative interventions such as AFOs in children with CP, as well as in surgery, and may be useful in gait classification using machine learning.
Musalimov, V.; Monahov, Y.; Tamre, M.; Rõbak, D.; Sivitski, A.; Aryassov, G.; Penkov, I.
The article discusses motion of a healthy knee joint in the sagittal plane and motion of an injured knee joint supported by an active orthosis. A kinematic scheme of a mechanism for the simulation of a knee joint motion is developed and motion of healthy and injured knee joints are modelled in Matlab. Angles between links, which simulate the femur and tibia are controlled by Simulink block of Model predictive control (MPC). The results of simulation have been compared with several samples of real motion of the human knee joint obtained from motion capture systems. On the basis of these analyses and also of the analysis of the forces in human lower limbs created at motion, an active smart orthosis is developed. The orthosis design was optimized to achieve an energy saving system with sufficient anatomy, necessary reliability, easy exploitation and low cost. With the orthosis it is possible to unload the knee joint, and also partially or fully compensate muscle forces required for the bending of the lower limb.
Full Text Available The article discusses motion of a healthy knee joint in the sagittal plane and motion of an injured knee joint supported by an active orthosis. A kinematic scheme of a mechanism for the simulation of a knee joint motion is developed and motion of healthy and injured knee joints are modelled in Matlab. Angles between links, which simulate the femur and tibia are controlled by Simulink block of Model predictive control (MPC. The results of simulation have been compared with several samples of real motion of the human knee joint obtained from motion capture systems. On the basis of these analyses and also of the analysis of the forces in human lower limbs created at motion, an active smart orthosis is developed. The orthosis design was optimized to achieve an energy saving system with sufficient anatomy, necessary reliability, easy exploitation and low cost. With the orthosis it is possible to unload the knee joint, and also partially or fully compensate muscle forces required for the bending of the lower limb.
Kerkum, Y.L.; Brehm, M.A.; Buizer, A.I.; van den Noort, J.C.; Becher, J.G.; Harlaar, J.
A rigid ventral shelf ankle foot orthosis (AFO) may improve gait in children with spastic cerebral palsy (SCP) whose gait is characterized by excessive knee flexion in stance. However, these AFOs can also impede ankle range of motion (ROM) and thereby inhibit push-off power. A more spring-like AFO
Kerkum, Yvette L.; Brehm, Merel-Anne; Buizer, Annemieke I.; van den Noort, Josien C.; Becher, Jules G.; Harlaar, Jaap
A rigid ventral shelf ankle foot orthosis (AFO) may improve gait in children with spastic cerebral palsy (SCP) whose gait is characterized by excessive knee flexion in stance. However, these AFOs can also impede ankle range of motion (ROM) and thereby inhibit push-off power. A more spring-like AFO
Burnfield, Judith M; Eberly, Valerie J; Gronely, Joanne K; Perry, Jacquelin; Yule, William Jared; Mulroy, Sara J
Microprocessor controlled prosthetic knees (MPK) offer opportunities for improved walking stability and function, but some devices' swing phase features may exceed needs of users with invariable cadence. One MPK offers computerized control of only stance (C-Leg Compact). To assess Medicare Functional Classification Level K2 walkers' ramp negotiation performance, function and balance while using a non-MPK (NMPK) compared to the C-Leg Compact. Crossover. Gait while ascending and descending a ramp (stride characteristics, kinematics, electromyography) and function were assessed in participant's existing NMPK and again in the C-Leg Compact following accommodation. Ramp ascent and descent were markedly faster in the C-Leg Compact compared to the NMPK (p ≤ 0.006), owing to increases in stride length (p ≤ 0.020) and cadence (p ≤ 0.020). Residual limb peak knee flexion and ankle dorsiflexion were significantly greater (12.9° and 4.9° more, respectively) during single limb support while using the C-Leg Compact to descend ramps. Electromyography (mean, peak) did not differ significantly between prosthesis. Function improved in the C-Leg Compact as evidenced by a significantly faster Timed Up and Go and higher functional questionnaire scores. Transfemoral K2 walkers exhibited significantly improved function and balance while using the stance-phase only MPK compared to their traditional NMPK.
Full Text Available In this work, the development of a human arm active orthosis is presented. The orthosis is designed primarily for training and rehabilitation in virtual environments.The orthosis system is intended for embodiment in virtual reality where it is allowing human to perceive forces at different body parts or the weight of lifted objects. In the paper the choice of a mechanical structure is shown equivalent to the structure of the human arm. A mechanical model of the orthosis arm as haptic device is built, where kinematic and dynamic parameters are evaluated. Impedance control scheme is selected as the most suitable for force refection at the hand or arm. An open-loop impedance controller is presented in the paper. Computer experiments are carried out using the dimensions of a real arm orthosis. Computer experiments have been carried out to provide force reflection by VR, according to virtual scenario. The conducted simulations show the range of the forces on the operator hand, orthosis can provide. The results of additional measurements and experimental evaluations of physical quantities in the interaction in a virtual environment are revealed in the paper.
Danino, Barry; Erel, Snir; Kfir, Meital; Khamis, Sam; Batt, Reuven; Hemo, Yoram; Wientroub, Shlomo; Hayek, Shlomo
We retrospectively assessed the effect of ankle-foot orthosis (AFO) on the foot progression angle (FPA) of 97 children with spastic cerebral palsy (CP) who had undergone comprehensive computer-based gait analysis both barefoot and with their orthosis, during the same session. The physical examination results and the gait study temporal and kinematic parameters comprise the study data. We focused on the peak FPA reached during stance and swing phases and at mid-stance and mid-swing, and also measured the transverse rotations of the pelvis, the femur and the tibia. AFOs improved gait, as reflected by improved temporal parameters, but they also increased internal rotation of the feet in diplegic CP children by 4.29 degrees for mid-stance, and by 3.72 degrees for mid-swing. The correlation between components of the rotational profile and FPA was significant for the diplegic group. AFOs did not produce any noteworthy differences between walking barefoot and walking with the brace in the hemiplegic group in what concerns FPA. Children with diplegic CP who use AFOs walk with increased internal FPAs in their orthoses. These findings might be explained by anatomical attributes as well as dynamic features during gait. Copyright © 2015 Elsevier B.V. All rights reserved.
Eberly, Valerie J; Mulroy, Sara J; Gronley, JoAnne K; Perry, Jacquelin; Yule, William J; Burnfield, Judith M
For individuals with transfemoral amputation, walking with a prosthesis presents challenges to stability and increases the demand on the hip of the prosthetic limb. Increasing age or comorbidities magnify these challenges. Computerized prosthetic knee joints improve stability and efficiency of gait, but are seldom prescribed for less physically capable walkers who may benefit from them. To compare level walking function while wearing a microprocessor-controlled knee (C-Leg Compact) prosthesis to a traditionally prescribed non-microprocessor-controlled knee prosthesis for Medicare Functional Classification Level K-2 walkers. Crossover. Stride characteristics, kinematics, kinetics, and electromyographic activity were recorded in 10 participants while walking with non-microprocessor-controlled knee and Compact prostheses. Walking with the Compact produced significant increase in velocity, cadence, stride length, single-limb support, and heel-rise timing compared to walking with the non-microprocessor-controlled knee prosthesis. Hip and thigh extension during late stance improved bilaterally. Ankle dorsiflexion, knee extension, and hip flexion moments of the prosthetic limb were significantly improved. Improvements in walking function and stability on the prosthetic limb were demonstrated by the K-2 level walkers when using the C-Leg Compact prosthesis. Understanding the impact of new prosthetic designs on gait mechanics is essential to improve prescription guidelines for deconditioned or older persons with transfemoral amputation. Prosthetic designs that improve stability for safety and walking function have the potential to improve community participation and quality of life. © The International Society for Prosthetics and Orthotics 2013.
Full Text Available People affected by Cerebral Palsy suffer from physical disabilities due to irreversible neural impairment since the very beginning of their life. Difficulties in motor control and coordination often relegate these patients to the use of a wheelchair and to the unavoidable upcoming of disuse syndromes. As pointed out in recent literature Damiano  physical exercise, especially in young ages, can have a deep impact on the patient health and quality of life. For training purposes is very important to keep an upright position, although in some severe cases this is not trivial. Many commercial mobile orthoses are designed to facilitate the standing, but not all the patients are able to deploy them. ARGO, the Active Reciprocated Gait Orthosis we developed, is a device that overcomes some of the limitations of these devices. It is an active device that is realized starting from a commercial reciprocated Gait Orthosis applying sensors and actuators to it. With ARGO we aim to develop a device for helping limbs in a non-coercive way accordingly to user’s intention. In this way patients can drive the orthosis by themselves, deploying augmented biofeedback over movements. In fact Cerebral Palsy patients usually have weak biofeedback mechanisms and consequently are hardly inclined to learn movements. To achieve this behavior ARGO deploys a torque planning algorithm and a force control system. Data collected from a single case of study shows benefits of the orthosis. We will show that our test patient reaches complete autonomous walking after few hour of training with prototype.
Full Text Available This paper presents a simulation of bipedal locomotion to generate stimulation pulses for activating muscles for paraplegic walking with wheel walker using functional electrical stimulation (FES with spring brake orthosis (SBO. A new methodology for paraplegic gait, based on exploiting natural dynamics of human gait, is introduced. The work is a first effort towards restoring natural like swing phase in paraplegic gait through a new hybrid orthosis, referred to as spring brake orthosis (SBO. This mechanism simplifies the control task and results in smooth motion and more-natural like trajectory produced by the flexion reflex for gait in spinal cord injured subjects. SBO can eliminate reliance on the withdrawal reflex and foot-ground clearance without extra upper body effort. The stored energy in the spring of SBO is used to replace stimulation pulses in knee flexion and reduce total required torque for the paraplegic walking with wheel walker. The study is carried out with a model of humanoid with wheel walker using the Visual Nastran (Vn4D dynamic simulation software. Stimulated muscle model of quadriceps is developed for knee extension. Fuzzy logic control (FLC is developed in Matlab/Simulink to regulate the muscle stimulation pulse-width required to drive FES-assisted walking gait and the computed motion is visualised in graphic animation from Vn4D. The simulation results show that SBO can be successfully used with FES for paraplegic walking with wheel walker with all the advantages discussed over the current hybrid orthoses available.
Full Text Available Purpose: consists in studying the relationships between the system of equilibrium regulation in upright stance and voluntary motion control in athletes-shooters during ready position and target shooting. Material: 19 highly skilled athletes specialized in pistol shooting were studied. Physiological and biomechanical characteristics of posture and voluntary motions were assessed by methods of stabilography, electromyography and tremorometry; besides, accuracy of target shooting was registered. Results: high degree of shooting accuracy dependence on posture somatic parameters has been revealed, of which the greatest impact upon the result is exerted by low-frequency vibrations of the body general centre of mass, subjected to voluntary control. Prognostic models of shooting accuracy dependence upon the character of posture regulation during ready position and the shot have been developed. Conclusions: obtained results reveal the mechanisms of functioning and interacting of two systems of management - posture and voluntary motion. Elaborated regression models permit to model and predict posture stability and shooting accuracy during ready position and the shot.
Sawicki, Gregory S; Ferris, Daniel P
Background The goal of this study was to test the mechanical performance of a prototype knee-ankle-foot orthosis (KAFO) powered by artificial pneumatic muscles during human walking. We had previously built a powered ankle-foot orthosis (AFO) and used it effectively in studies on human motor adaptation, locomotion energetics, and gait rehabilitation. Extending the previous AFO to a KAFO presented additional challenges related to the force-length properties of the artificial pneumatic muscles and the presence of multiple antagonistic artificial pneumatic muscle pairs. Methods Three healthy males were fitted with custom KAFOs equipped with artificial pneumatic muscles to power ankle plantar flexion/dorsiflexion and knee extension/flexion. Subjects walked over ground at 1.25 m/s under four conditions without extensive practice: 1) without wearing the orthosis, 2) wearing the orthosis with artificial muscles turned off, 3) wearing the orthosis activated under direct proportional myoelectric control, and 4) wearing the orthosis activated under proportional myoelectric control with flexor inhibition produced by leg extensor muscle activation. We collected joint kinematics, ground reaction forces, electromyography, and orthosis kinetics. Results The KAFO produced ~22%–33% of the peak knee flexor moment, ~15%–33% of the peak extensor moment, ~42%–46% of the peak plantar flexor moment, and ~83%–129% of the peak dorsiflexor moment during normal walking. With flexor inhibition produced by leg extensor muscle activation, ankle (Pearson r-value = 0.74 ± 0.04) and knee ( r = 0.95 ± 0.04) joint kinematic profiles were more similar to the without orthosis condition compared to when there was no flexor inhibition (r = 0.49 ± 0.13 for ankle, p = 0.05, and r = 0.90 ± 0.03 for knee, p = 0.17). Conclusion The proportional myoelectric control with flexor inhibition allowed for a more normal gait than direct proportional myoelectric control. The current orthosis design
Ferris Daniel P
Full Text Available Abstract Background The goal of this study was to test the mechanical performance of a prototype knee-ankle-foot orthosis (KAFO powered by artificial pneumatic muscles during human walking. We had previously built a powered ankle-foot orthosis (AFO and used it effectively in studies on human motor adaptation, locomotion energetics, and gait rehabilitation. Extending the previous AFO to a KAFO presented additional challenges related to the force-length properties of the artificial pneumatic muscles and the presence of multiple antagonistic artificial pneumatic muscle pairs. Methods Three healthy males were fitted with custom KAFOs equipped with artificial pneumatic muscles to power ankle plantar flexion/dorsiflexion and knee extension/flexion. Subjects walked over ground at 1.25 m/s under four conditions without extensive practice: 1 without wearing the orthosis, 2 wearing the orthosis with artificial muscles turned off, 3 wearing the orthosis activated under direct proportional myoelectric control, and 4 wearing the orthosis activated under proportional myoelectric control with flexor inhibition produced by leg extensor muscle activation. We collected joint kinematics, ground reaction forces, electromyography, and orthosis kinetics. Results The KAFO produced ~22%–33% of the peak knee flexor moment, ~15%–33% of the peak extensor moment, ~42%–46% of the peak plantar flexor moment, and ~83%–129% of the peak dorsiflexor moment during normal walking. With flexor inhibition produced by leg extensor muscle activation, ankle (Pearson r-value = 0.74 ± 0.04 and knee ( r = 0.95 ± 0.04 joint kinematic profiles were more similar to the without orthosis condition compared to when there was no flexor inhibition (r = 0.49 ± 0.13 for ankle, p = 0.05, and r = 0.90 ± 0.03 for knee, p = 0.17. Conclusion The proportional myoelectric control with flexor inhibition allowed for a more normal gait than direct proportional myoelectric control. The current
Balaban, Birol; Yasar, Evren; Dal, Ugur; Yazicioglu, Kamil; Mohur, Haydar; Kalyon, Tunc Alp
To assess the effectiveness of a hinged ankle-foot orthoses on gait impairments and energy expenditure in children with hemiplegic cerebral palsy (CP) whom orthoses were indicated to control equines. Eleven children (seven males, four females) who had a diagnosis of hemiplegic cerebral palsy were included in the study. Each child underwent gait analysis and energy consumption studies with and without ankle-foot orthosis (AFO). The AFOs were all custom-made for the individual child and had plantarflexion stop at 0 degrees with no dorsoflexion stop. The Vicon 512 Motion analysis system was used for gait analysis. Walking energy expenditure measurements were done with breath by breath method using an open-circuit indirect calorimeter (Vmax 29c, Sensormedics, USA). All tests were carried out on the same day with enough resting period. AFO application, as compared with the barefoot condition improved walking speed, stride length and single support time. Double support time was decreased significantly with AFOs and no change in cadance. Ankle dorsiflexion at initial contact, midstance and midswing showed significiant increase. Knee flexion at initial contact was decreased and no significant change in maximum knee extension at stance and maximum knee flexion at swing was obtained. The oxygen consumption was significantly reduced during AFO walking. The hinged AFO is useful in controlling dynamic equinus deformity and reducing the energy expenditure of gait in children with hemiplegic spastic cerebral palsy.
Chong, Raymond K. Y.; Mills, Bradley; Dailey, Leanna; Lane, Elizabeth; Smith, Sarah; Lee, Kyoung-Hyun
We tested the hypothesis that a computational overload results when two activities, one motor and the other cognitive that draw on the same neural processing pathways, are performed concurrently. Healthy young adult subjects carried out two seemingly distinct tasks of maintaining standing balance control under conditions of low (eyes closed),…
Full Text Available The present study was designed to assess the relative contribution of each leg to unperturbed bipedal posture in lower limb amputees. To achieve this goal, eight unilateral traumatic trans-femoral amputees (TFA were asked to stand as still as possible on a plantar pressure data acquisition system with their eyes closed. Four dependent variables were computed to describe the subject's postural behavior: (1 body weight distribution, (2 amplitude, (3 velocity and (4 regularity of centre of foot pressure (CoP trajectories under the amputated (A leg and the non-amputated (NA leg. Results showed a larger body weight distribution applied to the NA leg than to the A leg and a more regular CoP profiles (lower sample entropy values with greater amplitude and velocity under the NA leg than under the A leg. Taken together, these findings suggest that the NA leg and the A leg do not equally contribute to the control of unperturbed bipedal posture in TFA. The observation that TFA do actively control unperturbed bipedal posture with their NA leg could be viewed as an adaptive process to the loss of the lower leg afferents and efferents because of the unilateral lower-limb amputation. From a methodological point of view, these results demonstrate the suitability of computing bilateral CoP trajectories regularity for the assessment of lateralized postural control under pathological conditions.
Chin, T; Sawamura, S; Shiba, R; Oyabu, H; Nagakura, Y; Nakagawa, A
We have compared the energy expenditure during walking in three patients, aged between 51 and 55 years, with unilateral disarticulation of the hip when using the mechanical-controlled stance-phase control knee (Otto Bock 3R15) and the microprocessor-controlled pneumatic swing-phase control knee (Intelligent Prosthesis, IP). All had an endoskeletal hip disarticulation prosthesis with an Otto Bock 7E7 hip and a single-axis foot. The energy expenditure was measured when walking at speeds of 30, 50, and 70 m/min. Two patients showed a decreased uptake of oxygen (energy expenditure per unit time, ml/kg/min) of between 10.3% and 39.6% when using the IP compared with the Otto Bock 3R15 at the same speeds. One did not show any significant difference in the uptake of oxygen at 30 m/min, but at 50 and 70 m/min, a decrease in uptake of between 10.5% and 11.6% was found when using the IP. The use of the IP decreased the energy expenditure of walking in these patients.
Full Text Available Developmental Coordination Disorder (DCD is a leading movement disorder in children that commonly involves poor postural control. Multisensory integration deficit, especially the inability to adaptively reweight to changing sensory conditions, has been proposed as a possible mechanism but with insufficient characterization. Empirical quantification of reweighting significantly advances our understanding of its developmental onset and improves the characterization of its difference in children with DCD compared to their typically developing (TD peers.Twenty children with DCD (6.6 to 11.8 years were tested with a protocol in which visual scene and touch bar simultaneously oscillateded medio-laterally at different frequencies and various amplitudes. Their data were compared to data on TD children (4.2 to 10.8 years from a previous study. Gains and phases were calculated for medio-lateral responses of the head and center of mass to both sensory stimuli. Gains and phases were simultaneously fitted by linear functions of age for each amplitude condition, segment, modality and group. Fitted gains and phases at two comparison ages (6.6 and 10.8 years were tested for reweighting within each group and for group differences. Children with DCD reweight touch and vision at a later age (10.8 years than their TD peers (4.2 years. Children with DCD demonstrate a weak visual reweighting, no advanced multisensory fusion and phase lags larger than those of TD children in response to both touch and vision.Two developmental perspectives, postural body scheme and dorsal stream development, are provided to explain the weak vision reweighting. The lack of multisensory fusion supports the notion that optimal multisensory integration is a slow developmental process and is vulnerable in children with DCD.
Full Text Available To investigate efficacy of a contoured sandal being marketed for plantar heel pain with comparison to a flat flip-flop and contoured in-shoe insert/orthosis.150 volunteers aged 50 (SD: 12 years with plantar heel pain (>4 weeks were enrolled after responding to advertisements and eligibility determined by telephone and at first visit. Participants were randomly allocated to receive commercially available contoured sandals (n = 49, flat flip-flops (n = 50 or over the counter, pre-fabricated full-length foot orthotics (n = 51. Primary outcomes were a 15-point Global Rating of Change scale (GROC: 1 = a very great deal worse, 15 = a very great deal better, 13 to 15 representing an improvement and the 20-item Lower Extremity Function Scale (LEFS on which participants rate 20 common weight bearing activities and activities of daily living on a 5-point scale (0 = extreme difficulty, 4 = no difficulty. Secondary outcomes were worst level of heel pain in the preceding week, and the foot and ankle ability measure. Outcomes were collected blind to allocation. Analyses were done on an intention to treat basis with 12 weeks being the primary outcome time of interest.The contoured sandal was 68% more likely to report improvement in terms of GROC compared to flat flip-flop. On the LEFS the contoured sandal was 61% more likely than flat flip-flop to report improvement. The secondary outcomes in the main reflected the primary outcomes, and there were no differences between contoured sandal and shoe insert.Physicians can have confidence in supporting a patient's decision to wear contoured sandals or in-shoe orthoses as one of the first and simple strategies to manage their heel pain.The Australian New Zealand Clinical Trials Registry ACTRN12612000463875.
Nolan, Karen J; Yarossi, Mathew
Identifying and understanding the changes in transfer of momentum that are directly affected by orthotic intervention are significant factors related to the improvement of mobility in individuals with hemiplegia. The purpose of this investigation was to use a novel analysis technique to objectively measure weight transfer during double support (DS) in healthy individuals and individuals with hemiplegia secondary to stroke with and without an ankle foot orthosis. Prospective, Repeated measures, case-controlled trial. Participants included 25 adults with stroke-related hemiplegia >6 months using a prescribed ankle foot orthosis and 12 age-matched healthy controls. Main outcome measures included the weight transfer point timing (WTP, %DS), maximum total force timing (MTF, %DS), timing difference between WTP and MTF (MTF-WTP, %DS) and the linearity of loading (LOL, R(2)) during the DS phase of the gait cycle. The WTP and LOL were significantly different between conditions with and without the ankle foot orthosis for the affected and unaffected limb in post-stroke individuals, p ≤ 0.01. The MTF and difference in timing between MTF-WTP were significantly different during affected limb loading with and without the ankle foot orthosis in the stroke group, p ≤ 0.0001 and p = 0.03, respectively. MTF, MTF-WTP and LOL were significantly different between individuals with stroke (during affected limb loading) and healthy controls (during right limb loading). This research established a systematic method for analysing weight transfer during walking to evaluate the effect of an ankle foot orthosis on loading during double support in hemiplegic gait. This novel method can be used to elucidate biomechanical mechanisms behind orthosis-mediated changes in gait patterns and quantify functional mobility outcomes in rehabilitation. This novel approach to orthotic assessment will provide the clinician with needed objective evidence to select the most effective orthotic
Wood, Scott J.; Tyler, Mitchell E.; Bach-y-Rita, Paul; MacDougall, Hamish G.; Moore, Steven T.; Stallings, Valerie L.; Paloski, William H.; Black, F. Owen
Integration of multi-sensory inputs to detect tilts relative to gravity is critical for sensorimotor control of upright orientation. Displaying body orientation using electrotactile feedback to the tongue has been developed by Bach-y-Rita and colleagues as a sensory aid to maintain upright stance with impaired vestibular feedback. MacDougall et al. (2006) recently demonstrated that unpredictably varying Galvanic vestibular stimulation (GVS) significantly increased anterior-posterior (AP) sway during rotational sway referencing with eyes closed. The purpose of this study was to assess the influence of electrotactile feedback on postural control performance with pseudorandom binaural bipolar GVS. Postural equilibrium was measured with a computerized hydraulic platform in 10 healthy adults (6M, 4F, 24-65 y). Tactile feedback (TF) of pitch and roll body orientation was derived from a two-axis linear accelerometer mounted on a torso belt and displayed on a 144-point electrotactile array held against the anterior dorsal tongue (BrainPort, Wicab, Inc., Middleton, WI). Subjects were trained to use TF by voluntarily swaying to draw figures on their tongue, both with and without GVS. Subjects were required to keep the intraoral display in their mouths on all trials, including those that did not provide TF. Subjects performed 24 randomized trials (20 s duration with eyes closed) including four support surface conditions (fixed, rotational sway-referenced, translating the support surface proportional to AP sway, and combined rotational-translational sway-referencing), each repeated twice with and without GVS, and with combined GVS and TF. Postural performance was assessed using deviations from upright (peak-to-peak and RMS sway) and convergence toward stability limits (time and distance to base of support boundaries). Postural stability was impaired with GVS in all platform conditions, with larger decrements in performance during trials with rotation sway
Mortensen, Sune Sønderberg; Mortensen, Janus
The oral examination of defendants and witnesses is a cornerstone in most criminal trials, where the weight and credibility of what is said and the certainty with which testimony is delivered will often be decisive for the ruling of the court. This chapter presents a case study of the linguistic...... construction of certainty and uncertainty – or epistemic stance taking – in Danish courtroom interaction. Based on transcribed audio recordings from a criminal trial in Denmark in 2014, we examine the ways in which the defendant, the alleged victim and an eyewitness construct epistemic stances during...
Ates, Serdar; Lobo-Prat, Joan; Lammertse, Piet; van der Kooij, Herman; Stienen, Arno H A
In this paper, a new hand and wrist exoskeleton design, the SCRIPT Passive Orthosis (SPO), for the rehabilitation after stroke is presented. The SPO is a wrist, hand, and finger orthosis that assists individuals after stroke that suffer from impairments caused by spasticity and abnormal synergies. These impairments are characterized in the wrist and hand by excessive involuntary flexion torques that make the hand unable to be used for many activities in daily life. The SPO can passively offset these undesired torques, but it cannot actively generate or control movements. The user needs to use voluntary muscle activation to perform movements and thus needs to have some residual muscle control to successfully use the SPO. The SPO offsets the excessive internal flexion by applying external extension torques to the joints of the wrist and fingers. The SPO physically interacts with the users using the forearm shell, the hand plate and the digit caps from the Saebo Flex, but is otherwise a completely novel design. It applies the external extension torques via passive leaf springs and elastic tension cords. The amount of this support can be adjusted to provide more or less offset force to wrist, finger, or thumb extension, manually. The SPO is equipped with sensors that can give a rough estimate of the joint rotations and applied torques, sufficient to make the orthosis interact with our interactive gaming environment. Integrated inertial and gyroscopic sensors provide limited information on the user's forearm posture. The first home-based patient experiences have already let to several issues being resolved, but have also made it clear that many improvement are still to be made.
NEVILLE, CHRISTOPHER; BUCKLIN, MARY; ORDWAY, NATHANIEL; LEMLEY, FREDERICK
STUDY DESIGN Controlled laboratory, repeated measures. BACKGROUND Posterior tibial tendon dysfunction is a common musculoskeletal problem that includes tendon degeneration and collapse of the medial arch of the foot (flatfoot deformity). Ankle-foot orthoses (AFOs) typically are used to correct flatfoot deformity. Correction of flatfoot deformity involves increasing forefoot adduction, forefoot plantar flexion, and hindfoot inversion. OBJECTIVES To test whether a foot orthosis with a lateral extension reduces forefoot abduction in patients with stage II posterior tibial tendon dysfunction while walking. METHODS The gait of 15 participants with stage II posterior tibial tendon dysfunction was evaluated under 3 conditions: a standard AFO, an AFO with a lateral extension, and a shoe-only control condition. Kinematic variables of interest were evaluated at designated time points in the gait cycle and included hindfoot inversion/eversion, forefoot plantar flexion/dorsiflexion, and forefoot abduction/adduction. A 3-by-4, repeated-measures analysis of variance (brace condition by gait phase) was used to compare variables across conditions. RESULTS The AFO with a lateral extension resulted in a significantly greater change in forefoot adduction compared to the standard AFO (2.6°, P = .02) and shoe-only conditions (4.1°, P<.01) across all phases of stance. Forefoot plantar flexion was significantly increased when comparing the standard AFO and AFO with a lateral extension to the shoe-only condition. The AFO with the lateral extension also demonstrated significantly increased hindfoot inversion during the loading response and terminal stance phases. CONCLUSION Off-the-shelf and standard AFOs have been shown to improve forefoot plantar flexion and hindfoot eversion, but not forefoot adduction. A lateral extension added to a standard AFO along the forefoot significantly improved forefoot adduction in participants with posterior tibial tendon dysfunction while walking. PMID
Kawamura, T; Takanaka, K; Nakamura, T; Osumi, H
In recent years, there is an increase in the number of people that require support during walking as a result of a decrease in the leg muscle strength accompanying aging. An important index for evaluating walking ability is step length. A key cause for a decrease in step length is the loss of muscle strength in the legs. Many researchers have designed and developed orthoses for walking assistance. In this study, we advanced the design of an orthosis for walking assistance that assists the forward swing of the leg to increase step length. We employed a pneumatic artificial muscle as the actuator so that flexible assistance with low rigidity can be achieved. To evaluate the performance of the system, we measured the effect of assistance quantitatively. In this study, we constructed a prototype of the orthosis and measure EMG and step length on fitting it to a healthy subject so as to determine the effect of assistance, noting the increase in the obtained step length. Although there was an increase in EMG stemming from the need to maintain body balance during the stance phase, we observed that the EMG of the sartorius muscle, which helps swing the leg forward, decreased, and the strength of the semitendinosus muscle, which restrains the leg against over-assistance, did not increase but decreased. Our experiments showed that the assistance force provided by the developed orthosis is not adequate for the intended task, and the development of a mechanism that provides appropriate assistance is required in the future.
Full Text Available Infantile tibia vara (ITV is an acquired form of tibial deformity associated with tibial varus and internal torsion. As there is currently insufficient data available on the effects of orthotics on gait parameters, this study aimed to document the influence of orthosis on walking. A male infant with bilateral tibia vara used orthoses for five months. Gait evaluations were performed pre- and posttreatment for both legs. The kinematic parameters were collected by using a motion analysis system. The orthotic design principle was used to correct the femur and tibia. Posttreatment gait parameters were improved compared to pretreatment parameters. After 5 months, there was remarkable change in the stance-phase degrees of frontal plane hip joint abduction and knee joint varus. We found that orthoses were an effective treatment for the infantile tibia vara gait characteristics in this patient. Full-time use of single, upright knee-ankle-foot orthosis with a drop lock knee joint and application of corrective forces at five points along the full length of the limb were effective.
A valuable step towards news veracity assessment is to understand stance from different information sources, and the process is known as the stance detection. Specifically, the stance detection is to detect four kinds of stances (
Casabona, Antonino; Leonardi, Giuseppa; Aimola, Ettore; La Grua, Giovanni; Polizzi, Cristina Maria; Cioni, Matteo; Valle, Maria Stella
Learning highly specialized upright postures may be of benefit for more common as well as for novel stances. In this study, we asked whether this generalization occurs with foot configurations previously trained or depends on a generic increase in balance difficulty. We also explored the possibility that the benefit may concern not only the level of postural performance but also the structural organization of the upright standing. Ten elite professional ballet dancers were compared to ten untrained subjects, measuring the motion of the center of pressure (COP) across a set of five stances with different foot configurations. The balance stability was measured computing the area, the sway path, and the root mean square of the COP motion, whereas the structure of the postural control was assessed by compute approximate entropy, fractal dimension and the mean power frequency. The foot position included common and challenging stances, with the level of difficulty changed across the configurations. Among these conditions, only one foot configuration was familiar to the dancers. Statistically significant differences between the two groups, for all the parameters, were observed only for the stance with the foot position familiar to the dancers. Stability and structural parameters exhibited comparable differences. We concluded that the benefit from classical ballet is limited to a specific foot configuration, regardless of the level of stance difficulty or the component of postural control. Copyright © 2016 Elsevier B.V. All rights reserved.
Gerschutz, Maria J; Phillips, Chandler A; Reynolds, David B; Repperger, Daniel W
High-force pneumatic muscle actuators (PMAs) are used for force assistance with minimal displacement applications. However, poor control due to dynamic nonlinearities has limited PMA applications. A simulated control system is developed consisting of: (1) a controller relating an input position angle to an output proportional pressure regulator voltage, (2) a phenomenological model of the PMA with an internal dynamic force loop (system time constant information), (3) a physical model of a human sit-to-stand task and (4) an external position angle feed-back loop. The results indicate that PMA assistance regarding the human sit-to-stand task is feasible within a specified PMA operational pressure range.
Huurnink, Arnold; Fransz, Duncan P; Kingma, Idsart; van Dieën, Jaap H
Training and testing of balance have potential applications in sports and medicine. Laboratory grade force plates (FP) are considered the gold standard for the measurement of balance performance. Measurements in these systems are based on the parameterization of center of pressure (CoP) trajectories. Previous research validated the inexpensive, widely available and portable Nintendo Wii Balance Board (WBB). The novelty of the present study is that FP and WBB are compared on CoP data that was collected simultaneously, by placing the WBB on the FP. Fourteen healthy participants performed ten sequences of single-leg stance tasks with eyes open (EO), eyes closed (EC) and after a sideways hop (HOP). Within trial comparison of the two systems showed small root-mean-square differences for the CoP trajectories in the x and y direction during the three tasks (mean±SD; EO: 0.33±0.10 and 0.31±0.16 mm; EC: 0.58±0.17 and 0.63±0.19 mm; HOP: 0.74±0.34 and 0.74±0.27 mm, respectively). Additionally, during all 420 trials, comparison of FP and WBB revealed very high Pearson's correlation coefficients (r) of the CoP trajectories (x: 0.999±0.002; y: 0.998±0.003). A general overestimation was found on the WBB compared to the FP for 'CoP path velocity' (EO: 5.3±1.9%; EC: 4.0±1.4%; HOP: 4.6±1.6%) and 'mean absolute CoP sway' (EO: 3.5±0.7%; EC: 3.7±0.5%; HOP: 3.6±1.0%). This overestimation was highly consistent over the 140 trials per task (r>0.996). The present findings demonstrate that WBB is sufficiently accurate in quantifying CoP trajectory, and overall amplitude and velocity during single-leg stance balance tasks. Copyright © 2013 Elsevier Ltd. All rights reserved.
Michael, John Andrew
In this paper, I propose a developmental explanation of the reliability of the intentional stance as an interpretive strategy, and by doing so counter an objection to Dennett’s intentional stance theory (i.e.the ‘If it isn’t true, why does it work?’ objection). Specifically, young children’s use...... of the intentional stance enables them to learn from and thereby to become more similar to the adults in their culture. Asa result, they themselves become increasingly intelligible to other people taking the intentional stance.Thus, the intentional stance and cultural learning constitute a feedback loop...... that (partially) explainsthe reliability of the intentional stance, and does so – contra Dennett’s realist critics – without appealing to a realist interpretation of the descriptions speakers attach to intentional terms. However, I also suggest that this developmental perspective provides grist to the mill...
Andrysek, Jan; Wright, F Virginia; Rotter, Karin; Garcia, Daniela; Valdebenito, Rebeca; Mitchell, Carlos Alvarez; Rozbaczylo, Claudio; Cubillos, Rafael
The purpose of this study was to clinically evaluate the automatic stance-phase lock (ASPL) knee mechanism against participants' existing weight-activated braking (WAB) prosthetic knee joint. This prospective crossover study involved 10 young adults with an above-knee amputation. Primary measurements consisted of tests of walking speeds and capacity. Heart rate was measured during the six-minute walk test and the Physiological Cost Index (PCI) which was calculated from heart rate estimated energy expenditure. Activity was measured with a pedometer. User function and quality of life were assessed using the Lower Limb Function Questionnaire (LLFQ) and Prosthetic Evaluation Questionnaire (PEQ). Long-term follow-up over 12 months were completed. Walking speeds were the same for WAB and APSL knees. Energy expenditure (PCI) was lower for the ASPL knees (p = 0.007). Step counts were the same for both knees, and questionnaires indicated ASPL knee preference attributed primarily to knee stability and improved walking, while limitations included terminal impact noise. Nine of 10 participants chose to keep using the ASPL knee as part of the long-term follow-up. Potential benefits of the ASPL knee were identified in this study by functional measures, questionnaires and user feedback, but not changes in activity or the PEQ.
Nizamis, Kostas; Ganseij, Maarten; Koopman, H.F.J.M.
Duchenne Muscular Dystrophy (DMD) is a progressive muscular disease. Active hand orthoses can greatly improve the quality of life of people with DMD. Surface Electromyography (sEMG) is commonly used for the control of active devices. The interfacing between the human and the sensor is regularly done
Nizamis, Kostas; Ganseij, Maarten; Koopman, Hubertus F.J.M.
Duchenne Muscular Dystrophy (DMD) is a progressive muscular disease. Active hand orthoses can greatly improve the quality of life of people with DMD. Surface Electromyography (sEMG) is commonly used for the control of active devices. The interfacing between the human and the sensor is regularly done
Luis Manuel Vaca Benitez
Full Text Available The rehabilitation of patients should not only be limited to the first phases during intense hospital care but also support and therapy should be guaranteed in later stages, especially during daily life activities if the patient’s state requires this. However, aid should only be given to the patient if needed and as much as it is required. To allow this, automatic self-initiated movement support and patient-cooperative control strategies have to be developed and integrated into assistive systems. In this work, we first give an overview of different kinds of neuromuscular diseases, review different forms of therapy, and explain possible fields of rehabilitation and benefits of robotic aided rehabilitation. Next, the mechanical design and control scheme of an upper limb orthosis for rehabilitation are presented. Two control models for the orthosis are explained which compute the triggering function and the level of assistance provided by the device. As input to the model fused sensor data from the orthosis and physiology data in terms of electromyography (EMG signals are used.
Kannan Megalingam, Rajesh; Apuroop, K. G. S.; Boddupalli, Sricharan
Many stroke and spinal cord injury patients suffer from paralysis which range from severe to nominal. Some of them, after therapy, could regain most of the motor control, particularly in hands if the severity level is not so high. In this paper we propose a hand orthosis for such patients whose stroke and spinal cord injury severity is nominal and the motor control in hands can be regained by therapy as part of their rehabilitation process. The patients can wear this orthosis and the therapy can be done with simple Human Computer Interface. The physicians, the physiotherapists and the patients themselves can carry out the therapy with the help of this device. The tests conducted in the lab and the results obtained are very promising that this can be an effective mechanism for stroke and spinal cord injury patients in their rehabilitation process. The hand orthosis is designed and fabricated locally so that it can be made available to such patients at an affordable cost.
Full Text Available The paper presents design and manufacturing process of an individualized ankle orthosis using additive manufacturing technologies and reverse engineering. Conventional processes of manufacturing of orthosesareexpensive and time consuming -an alternative method was proposed. The patient’s leg was 3D scanned and the orthosis was designed using a CAD system. It was then manufactured using the Fused Deposition Modelling technology, assembled and fully tested. Positive results were obtained.
Aboutorabi, Atefeh; Saeedi, Hassan; Kamali, Mohammad; Farahmand, Behshid; Eshraghi, Arezoo; Dolagh, Roghaye S
Flat foot in children is a common deformity in which the medial longitudinal arch is reduced or eliminated. The objective of this article was to compare flat foot and healthy children on the displacement of the center of pressure and walking parameters in children with two common orthoses (functional foot orthosis and medical shoe). Comparative study. This study included 30 children with flat foot and 20 healthy children as a control group. The step length and width, walking velocity, symmetry, and center of pressure (CoP) displacements were recorded and compared for three conditions: functional foot orthosis and regular shoe, a medical shoe and barefoot. The results from the CoP displacements showed that the regular shoe with functional foot orthosis caused a significant decrease in the level of displacement of the CoP in flat foot children. The findings indicated a significant improvement in symmetry of steps and walking speed with the functional foot orthosis in comparison to the medical shoe in flat foot children. The CoP displacement was decreased and the percentage of gait symmetry and walking speed were increased by the use of regular shoes with a functional foot orthosis in comparison to the medical shoes. An orthopaedic shoe can be expensive, and in particular heavy with most children reluctant to wear it. This study focussed on the CoP displacement and selected gait parameters with an orthopaedic shoe and functional foot orthosis, and showed that a combined prescription of a functional foot orthosis and with regular shoes may be a useful alternative for children with moderate flat foot. © The International Society for Prosthetics and Orthotics 2013.
Yang, Bing-Shiang; Chen, Yen-Wan; Tong, Ji-Rou
If an assistive device is not acceptable to the user, it will not achieve efficacy and would be resource-wasting. This study employed in-depth interviews to understand what users' individual activities of daily living, problems of using orthoses, and considerations for selecting orthoses are. We conducted qualitative interviews with 35 lower-limb orthosis users, and semi-structured interviews were applied in this study. We analyzed the interview data from transcripts, through coding and concepts, to theories based on grounded theory. The results showed that problems of using orthoses are mostly related to activities of daily living of the user and user's expectation. Therefore, in order to enhance its efficacy and use intention, the design and prescribing process of orthoses need to address the problems in the light of activities of daily living and user education.
Full Text Available Background: Foot pronation is a series of movements which is intended to absorb shock by decelerating and cushioning the foot as it comes in contact with surface. When this motion is exaggerated, the ankle rolls too far inward and the arch is flattened causing overpronation. It is seen that with an abnormal pronation, navicular drop occurs. Navicular drop causes pain in ankle and knee, fatigue, difficulty in walking. The purpose of the study was to determine the effect of intrinsic muscle strengthening with orthosis over conventional physiotherapy exercises with orthosis for correction of navicular drop and Pain Disability in prolong standing workers. Method: An Experimental study design, seventy industrial workers were tested for navicular drop test out of which fifty tested positive. The subjects were divided into two groups Group A (N=25 and Group B (N=25. Group-A subjects received intrinsic muscle strengthening exercises with orthosis and Group-B received conventional physiotherapy exercises with orthosis. The duration of treatment continued was given for 8 weeks and outcome measurements were measured at 0 day, 4th week and 8th week using the Navicular drop (ND test and Pain Disability Questionnaire (PDQ. Results: Comparative analysis using Independent t-test was carried out separately for ND and PDQ. For ND, t =-5.01 which is highly significant (p=0.00. It has been inferred that ND decreases more when intrinsic muscle strengthening with orthosis was applied. To see the difference of means of PDQ, t = -1.97 which is significant (p = 0.049 implying that PDQ decrease more when intrinsic muscle strengthening was applied as compared to conventional physiotherapy with orthosis. Conclusion: It is concluded that 8 weeks of intrinsic muscle strengthening exercise with orthosis is more effective than conventional physiotherapy exercises with orthosis in reducing navicular drop and improving Pain Disability in prolong standing workers.
Almonroeder, Thomas G; Benson, Lauren C; O'Connor, Kristian M
Study Design Controlled laboratory study, cross-sectional. Background Orthotic prescription is often based on the premise that the mechanical effects will be more prominent in individuals with greater calcaneal eversion. Objective To compare the effects of a prefabricated foot orthosis on lower extremity kinematics and kinetics between recreational athletes with high and low calcaneal eversion during running. Methods Thirty-one recreational athletes were included in this study. Three-dimensional kinematic and kinetic data were collected while running with and without a foot orthosis. Participants were grouped based on the degree of calcaneal eversion during the running trials relative to a standing trial (dynamic foot motion). The effects of the orthosis on the frontal and transverse plane angles and moments of the hip and knee were compared between the 10 participants with the greatest and least amount of dynamic foot motion. Results There were no significant interactions (group by orthotic condition) for any of the kinematic or kinetic variables of interest. Conclusion The effects of an orthosis on the mechanics of the hip and knee do not appear to be dependent on an individual's dynamic foot motion. J Orthop Sports Phys Ther 2016;46(9):749-755. Epub 5 Aug 2016. doi:10.2519/jospt.2016.6253.
Ohnishi, Kengo; Saito, Yukio; Oshima, Toru; Higashihara, Takanori
This paper discusses the developments and control strategies of exoskeleton-type robot systems for the application of an upper limb powered orthosis and an attachable power-assist device for care-givers. Hydraulic Bilateral Servo System, which consist of a computer controlled motor, parallel connected hydraulic actuators, position sensors, and pressure sensors, are installed in the system to derive the joint motion of the exoskeleton arm. The types of hydraulic component structure and the control strategy are discussed in relation to the design philosophy and target joints motions.
Full Text Available Background and objective: Iliopsoas stiffness and restricted hip extension ROM affect muscle balance and lumbopelvic alignment. The purpose of this research is study of iliopsoas tightness’ effect on electromyographic activity of hip extensor synergists during gait. Methods: In this case-control study 15 adolescents with iliopsoas tightness as experimental group, and 15 healthy adolescents which matched based on age, height, weight, BMI, dominant leg, and sport experience participated voluntarily as control group. Surface electromyographic (sEMG activity of the gluteus maximus, adductor magnus, and biceps femoris, were measured between groups during stance phase of gait. Results: Individuals with restricted hip flexor muscle length demonstrated more gluteus maximus activation during terminal stance (p=0.001, more biceps femoris activation during mid stance (p=0.002 and late stance (p=0.001 and more adductor magnus activation during mid stance (p=0.04 and late stance (p=0.001. Discussion and conclusion: Adolescent soccer athletes with hip flexor muscle tightness exhibit more biceps femoris and adductor magnus and gluteus maximus activation during stance phase of gait. Thus, individuals with hip flexor muscle tightness appear to utilize different neuromuscular strategies to control lower extremity motion.
Conclusion Considering the importance of maintaining a proper posture to optimize the muscles activity in preventing deformity and orthosis with a bio-feedback mechanism may be the solution. The long-term effect of using a bio-feedback orthosis indicated that kypho-remainder orthosis can significantly improve the kyphosis curve in individuals with postural hyper-kyphosis.
Undisturbed stance control in healthy adults is achieved differently along anteroposterior and mediolateral axes: evidence from visual feedback of various signals from center of pressure trajectories.
Rougier, Patrice R
Provided through the screen of a monitor, the participant's resultant center of pressure (CPRes) movements from a force platform device, modified the postural performance of a healthy individual. However, these effects could largely vary with the axis that researchers consider (mediolateral [ML] or anteroposterior [AP]), because they know these controls are involved in 2 distinct ankle and hip mechanisms. To demonstrate this organization, the author tested a group of healthy adults in several conditions that gave the whole or some part of the information in the CPRes displacements. Compared with the CPRes feedback, left and right plantar CP or body weight distribution feedback deteriorated the control of the vertically projected center of gravity (CGv) along the ML and AP axes, whose amplitudes increased, respectively. These data highlight the primary role of loading or unloading and pressure variations in the achievement of postural control along each ML or AP axis, respectively. It is interesting that merging these 2 pieces of information (CPRes displacements) helped participants optimize their postural performance.
Buckon, Cathleen E; Thomas, Susan Sienko; Jakobson-Huston, Sabrina; Moor, Michael; Sussman, Michael; Aiona, Michael
This study compared the functional efficacy of three commonly prescribed ankle-foot orthosis (AFO) configurations (solid [SAFO], hinged [HAFO], and posterior leaf spring [PLS]). Sixteen independently ambulatory children (10 males, six females; mean age 8 years 4 months, SD 2 years 4 months; range 4 years 4 months to 11 years 6 months) with spastic diplegia participated in this study. Four children were classified at level I of the Gross Motor Function Classification System (GMFCS; Palisano et al. 1997); the remaining 12 were at level II. Children were assessed barefoot (BF) at baseline (baseline assessment of energy consumption was performed with shoes on, no AFO) and in each orthotic configuration after three months of use, using gait analysis, oxygen consumption, and functional outcome measures. AFO use did not markedly alter joint kinematics or kinetics at the pelvis, hip, or knee. All AFO configurations normalized ankle kinematics in stance, increased step/stride length, decreased cadence, and decreased energy cost of walking. Functionally, all AFO configurations improved the execution of walking/running/jumping skills, upper extremity coordination, and fine motor speed/dexterity. However, the quality of gross motor skill performance and independence in mobility were unchanged. These results suggest that most children with spastic diplegia benefit functionally from AFO use. However, some children at GMFCS level II demonstrated a subtle but detrimental effect on function with HAFO use, shown by an increase in peak knee extensor moment in early stance, excessive ankle dorsiflexion, decreased walking velocity, and greater energy cost. Therefore, constraining ankle motion by using a PLS or SAFO should be considered for most, but not all, children with spastic diplegia.
Full Text Available Biological seed treatment promotes to save the environment from toxic chemicals in the agricultural practices. Schizophyllum commune is one of the important seedborne pathogenic fungi causing brown germ and seed rot of oil palm which required effective and efficient treat -ment based on environmental friendly approaches. Anti-microbial substances are extracted from antagonistic bacteria of B. multivorans and M. testaceum after mass production in the liquid media. Application method of anti-microbial substances for the control of Schizophylllum commune was done by seed dipping for 30 minutes and vacuum infiltration at 400 mm Hg. vac. for 2 min. in supernatant of anti-microbial substances diluted in sterilized distilled water with concentra -tion ratio of 1:4. Application method using anti-microbial substances from antagonistic bacteria inhibited the growth of pathogenic fungus, enhanced seed germination, and without causing any abnormal growth of oil palm seedlings.
Organizational Institutionalism is gradually embracing a more situated, actor-centered stance that is prompting empirical inquiry into how embedded actors respond to institutional complexity. French Pragmatist Sociology can contribute to this endeavor because it provides a situated, relational......, and practice-oriented framework for studying how actors negotiate and justify actions through shared moral “worlds” that are akin to institutional logics. French Pragmatist Sociology can help illuminate three questions that are key to a situated stance in Organizational Institutionalism: (a) How free...
Jang, John; Hsiao, Katherine T; Hsiao-Wecksler, Elizabeth T
Pregnant women often remark that their balance degrades during pregnancy; however, it appears that no studies have documented the gravida's perception of her balance nor measured direction-specific changes in balance throughout pregnancy or after delivery. Thirty women, fifteen pregnant and fifteen non-pregnant controls, were tested monthly and through 6-month postpartum. For each session, perceived degradation in sense of balance, laboratory-based balance measures, stance width, and the number of falls since the previous session were recorded. Laboratory-based balance measures, quantified by direction-specific measures of postural sway, were computed from ten 30s quiet-standing trials on a stationary force platform. Repeated-measures analysis of variance, paired t-tests, and Pearson correlations were use to examine group and time effects. For the pregnant group, perceived balance degradation and stance width were highly correlated (r = 0.94). Both increased during pregnancy (P r > 0.72) and also decreased significantly between the third trimester and postpartum (P pregnancy, but increased after delivery. Contrary to recent work suggesting fall rates of 25%, only 13% of our subjects (n = 2) fell during pregnancy. Perceived degradation in balance during pregnancy was strongly related to increasing postural sway instability in the anterior-posterior direction. Lateral stability was maintained during pregnancy and likely accomplished by increasing stance width.
In this work we focus on the dynamics of the conflict that often arises in a police interview between suspects and police officers. Police interviews are a special type of social encounter, primarily because of the authority role of the police interviewer and the often uncooperative stance that the
Schmidt, K; Hübscher, M; Vogt, L; Klinkmüller, U; Hildebrandt, H D; Fink, M; Banzer, W
Osteoporosis is a widespread chronic bone disease leading to an increased risk of bone fractures. The most common clinical consequences are back pain, hyperkyphosis, limitations of physical functioning and activities of daily living as well as reduced quality of life. Furthermore, osteoporosis is associated with decreased strength and deficits of gait and balance, all together resulting in an increased risk of falls and a subsequent aggravation of fracture risk. Besides pharmaceutical and exercise therapy, back orthoses are increasingly being used in the therapy of osteoporosis and rehabilitation after vertebral fractures. Previous studies have shown that wearing a spinal orthosis results in a reduction of pain as well as improvements of posture and back extensor strength. To date there is no study that has evaluated the effects of a spinal orthosis on gait stability and physical functioning in patients with osteoporosis. Therefore the purpose of the present study was to assess the effects of a spinal orthosis on gait and pain-induced limitations of activities of daily living (ADL) in women with osteoporosis. A total of 69 postmenopausal osteoporotic women with and without vertebral fractures were randomly assigned to receive either a spinal orthosis (Thämert Osteo-med intervention group n=35; average age 74 ± 8.3 years, height 158.3 ± 6.3 cm, weight 62.8 ± 9.6 kg, t-score -2.6 ± 1.0, number of vertebral fractures 1.4 ± 2.0) or to a waiting list control group (n= 34, age 74.1 ± 7.7 years, height 159.6 ± 5.9 cm, weight 65.4 ± 11.3 kg, t-score -2.9± 0.8, number of vertebral fractures: 0.9 ± 1.2). The following outcome measures were collected at baseline and at 3 and 6 months follow-up: gait parameters including gait analysis: velocity, stride length and width, double support time (% of gait cycle) and perceived limitations in activities of daily living (numeric rating scale 1-10; 1=best, 10= worst situation). The ANCOVA indicated a
Lv, Ge; Gregg, Robert D
Body-weight support (i.e., gravity compensation) is an effective clinical tool for gait rehabilitation after neurological impairment. Body-weight supported training systems have been developed to help patients regain mobility and confidence during walking, but conventional systems constrain the patient's treatment in clinical environments. We propose that this challenge could be addressed by virtually providing patients with bodyweight support through the actuators of a powered orthosis (or exoskeleton) utilizing potential energy shaping control. However, the changing contact conditions and degrees of underactuation encountered during human walking present significant challenges to consistently matching a desired potential energy for the human in closed loop. We therefore derive a generalized matching condition for shaping Lagrangian systems with holonomic contact constraints. By satisfying this matching condition for four phases of gait, we derive passivity-based control laws to achieve virtual body-weight support through a powered knee-ankle orthosis. We demonstrate beneficial effects of virtual body-weight support in simulations of a human-like biped model, indicating the potential clinical value of this proposed control approach.
Full Text Available Background and aim: Cerebral palsy is a non progressive brain disorder and, cerebral plasy is the most common type of spastic paralysis which can be the cause of motor and postural deficits during child development. The purpose of this study was to investigate the effect of using Anti spastic Orthosis on the Reduction of Spasticity and in diplegic spastic children between 2 – 5 years in Tehran.Materials & Methods: 20 diplegic spastic children between 2- 5 years were selected randomly and divided into two groups. The first lower limb spasticity was assessed by a neurologist, and then by an experienced occupational therapist whitout being aware of research process before the intervention, The experimental group went under treatment using positioning therapeutic intervention and neurodevelopmental treatment, while the control group was treated and only with NDT. The research Instrument used was the Modified Ashworth scale (MAS and the H-Reflex and, H/M ratio in the lower limb spasticity was assessed, Utilizing Experimental pretest - post test with control group design. The data of this study was analyzed using t Test k square test and the findings showed meaningful differences between the two groups.Result: The findings of this study reveraled meaningful differences between the two groups, scores of mean spasticity in interference group was significantly less than control group (p=0/003 Conclusion: Application of Anti spastic Orthosis before rehabilitation exercises is recommended for diplegic spastic children.
Veale, Allan J.; Anderson, Iain A.; Xie, Shane Q.
Robotic orthoses have the potential to provide effective rehabilitation while overcoming the availability and cost constraints of therapists. These orthoses must be characterized by the naturally safe, reliable, and controlled motion of a human therapist's muscles. Such characteristics are only possible in the natural kingdom through the pain sensing realized by the interaction of an intelligent nervous system and muscles' embedded sensing organs. McKibben fluidic muscles or pneumatic muscle actuators (PMAs) are a popular orthosis actuator because of their inherent compliance, high force, and muscle-like load-displacement characteristics. However, the circular cross-section of PMA increases their profile. PMA are also notoriously unreliable and difficult to control, lacking the intelligent pain sensing systems of their biological muscle counterparts. Here the Peano fluidic muscle, a new low profile yet high-force soft actuator is introduced. This muscle is smart, featuring bioinspired embedded pressure and soft capacitive strain sensors. Given this pressure and strain feedback, experimental validation shows that a lumped parameter model based on the muscle geometry and material parameters can be used to predict its force for quasistatic motion with an average error of 10 - 15N. Combining this with a force threshold pain sensing algorithm sets a precedent for flexible orthosis actuation that uses embedded sensors to prevent damage to the actuator and its environment.
Dingenen, Bart; Janssens, Luc; Luyckx, Thomas; Claes, Steven; Bellemans, Johan; Staes, Filip F
An anterior cruciate ligament injury may lead to deteriorations in postural stability. The goal of this study was to evaluate postural stability during the transition from double-leg stance to single-leg stance of both legs in anterior cruciate ligament injured subjects and non-injured control subjects with a standardized methodology. Fifteen control subjects and 15 anterior cruciate ligament injured subjects (time after injury: mean (SD)=1.4 (0.7) months) participated in the study. Both groups were similar for age, gender, height, weight and body mass index. Spatiotemporal center of pressure outcomes of both legs of each subject were measured during the transition from double-leg stance to single-leg stance in eyes open and eyes closed conditions. Movement speed was standardized. The center of pressure displacement after a new stability point was reached during the single-leg stance phase was significantly increased in the anterior cruciate ligament injured group compared to the control group in the eyes closed condition (Plegs within both groups (P>.05). No significant differences were found during the transition itself (P>.05). The anterior cruciate ligament injured group showed postural stability deficits during the single-leg stance phase compared to the non-injured control group in the eyes closed condition. Using the non-injured leg as a normal reference when evaluating postural stability of the injured leg may lead to misinterpretations, as no significant differences were found between the injured and non-injured leg of the anterior cruciate ligament injured group. Copyright © 2015 Elsevier Ltd. All rights reserved.
Lee, Winson C C; Kobayashi, Toshiki; Choy, Barton T S; Leung, Aaron K L
A custom moulded ankle orthosis with hinged joints potentially offers a better control over the subtalar joint and the ankle joint during lateral cutting movements, due to total contact design and increase in material strength. To test the above hypothesis by comparing it to three other available orthoses. Repeated measures. Eight subjects with a history of ankle sprains (Grade 2), and 11 subjects without such history performed lateral cutting movements in four test conditions: 1) non-orthotic, 2) custom-moulded ankle orthosis with hinges, 3) Sport-Stirrup, and 4) elastic ankle sleeve with plastic support. A VICON motion analysis system was used to study the motions at the ankle and subtalar joints. The custom-moulded ankle orthosis significantly lowered the inversion angle at initial contact (p = 0.006) and the peak inversion angle (p = 0.000) during lateral cutting movements in comparison to non-orthotic condition, while the other two orthoses did not. The three orthoses did not affect the plantarflexion motions, which had been suggested by previous studies to be important in shock wave attenuation. The custom-moulded ankle orthosis with hinges could better control inversion and thus expected to better prevent ankle sprain in lateral cutting movements. Custom-moulded ankle orthoses are not commonly used in preventing ankle sprains. This study raises the awareness of the use of custom-moulded ankle orthoses which are expected to better prevent ankle sprains.
Dingenen, Bart; Janssens, Luc; Claes, Steven; Bellemans, Johan; Staes, Filip F
Previous studies mainly focused on muscles at the operated knee after anterior cruciate ligament reconstruction, less on muscles around other joints of the operated and non-operated leg. The aim of this study was to investigate muscle activation onset times during the transition from double-leg stance to single-leg stance in anterior cruciate ligament reconstructed subjects. Lower extremity muscle activation onset times of both legs of 20 fully returned to sport anterior cruciate ligament reconstructed subjects and 20 non-injured control subjects were measured during the transition from double-leg stance to single-leg stance in eyes open and eyes closed conditions. Analysis of covariance (ANCOVA) was used to evaluate differences between groups and differences between legs within both groups, while controlling for peak center of pressure velocity. Significantly delayed muscle activation onset times were found in the anterior cruciate ligament reconstructed group compared to the control group for gluteus maximus, gluteus medius, vastus medialis obliquus, medial hamstrings, lateral hamstrings and gastrocnemius in both eyes open and eyes closed conditions (Panterior cruciate ligament reconstructed group, no significant different muscle activation onset times were found between the operated and non-operated leg (P>.05). Despite completion of rehabilitation and full return to sport, the anterior cruciate ligament reconstructed group showed neuromuscular control deficits that were not limited to the operated knee joint. Clinicians should focus on relearning multi-segmental anticipatory neuromuscular control strategies after anterior cruciate ligament reconstruction. Copyright © 2016 Elsevier Ltd. All rights reserved.
Sung, Youn-Bum; Lee, Jun-Cheol; Kim, Kyoung
[Purpose] The purpose of this study was to investigate the effects of taping and proprioceptive neuromuscular facilitation in stroke patients. [Subjects and Methods] Thirty patients who were diagnosed with hemiparalysis due to stroke were selected as subjects of study. Experiment group 1 patients had Kinesio taping applied before applying the PNF, while experiment group 2 patients had McConell taping applied before applying the PNF. The control group had only the PNF applied. The dartfish program was used to evaluate the stance phase of stroke patients. [Results] Experiment group 1 and experiment group 2 showed a significantly longer stance phase duration of the affected side than the control group in week 6. [Conclusion] Application of Kinesio taping has a more positive effect on the stance phase duration than McConell taping in the patients with stroke.
Full Text Available A review study was conducted on existing lower-limb orthosis systems for rehabilitation which implemented pneumatic muscle type of actuators with the aim to clarify the current and on-going research in this field. The implementation of pneumatic artificial muscle will play an important role for the development of the advanced robotic system. In this research a derivation model for the antagonistic mono- and bi-articular muscles using pneumatic artificial muscles of a lower limb orthosis will be verified with actual human’s muscle activities models. A healthy and young male 29 years old subject with height 174cm and weight 68kg was used as a test subject. Two mono-articular muscles Vastus Medialis (VM and Vastus Lateralis (VL were selected to verify the mono-articular muscle models and muscle synergy between anterior muscles. Two biarticular muscles Rectus Femoris (RF and Bicep Femoris (BF were selected to verify the bi-articular muscle models and muscle co-contraction between anterior-posterior muscles. The test was carried out on a treadmill with a speed of 4.0 km/h, which approximately around 1.25 m/s for completing one cycle of walking motion. The data was collected for about one minute on a treadmill and 20 complete cycles of walking motion were successfully recorded. For the evaluations, the mathematical model obtained from the derivation and the actual human muscle activation patterns obtained using the surface electromyography (sEMG system were compared and analysed. The results shown that, high correlation values ranging from 0.83 up to 0.93 were obtained in between the derivation model and the actual human muscle’s model for both mono- and biarticular muscles. As a conclusion, based on the verification with the sEMG muscle activities data and its correlation values, the proposed derivation models of the antagonistic mono- and bi-articular muscles were suitable to simulate and controls the pneumatic muscles actuated lower limb
Kim, Ha Jeong; Chun, Min Ho; Kim, Hong Min; Kim, Bo Ryun
To evaluate the effects of heel-opened ankle foot orthosis (HOAFO) on hemiparetic gait after stroke, especially on external foot rotation, and to compare the effects of HOAFO with conventional plastic-AFO (pAFO) and barefoot during gait. This cross-over observational study involved 15 hemiparetic patients with external rotation of the affected foot. All subjects were able to walk independently, regardless of their usual use of a single cane, and had a less than fair-grade in ankle dorsiflexion power. Each patient was asked to walk in three conditions with randomized sequences: 1) barefoot, 2) with a pAFO, and 3) with an HOAFO. Their gait patterns were analyzed using a motion analysis system. Fifteen patients consisted of nine males and six females. On gait analysis, hip and foot external rotation were significantly greater in pAFO (-3.35° and -23.68°) than in barefoot and HOAFO conditions (pexternal rotation compared with pAFO; although there was no significant difference between HOAFO and barefoot walking. Walking speed and percentage of single limb support were significantly greater for HOAFO than in barefoot walking. HOAFO was superior to pAFO in reducing hip and foot external rotation during the stance phase in patients with post-stroke hemiparesis. HOAFO may, therefore, be useful in patients with excessive external rotation of the foot during conventional pAFO.
Methods: Ten subjects without any neuromuscular disease participated in this study. New orhosis with the same structure of Scottish rite orthosis was designed. Qualysis system analyses with seven cameras as well as a Kistler force plate were used to measure the kinematics and kinetics variables during the gait with and without orthosis. For statistical analysis independent student-t test was used. The significance level was set at p0.05. There was significant difference between peak medio-lateral forces applied on knee during walking with and without orthosis (p<0.05. Conclusion: The new orthosis decreases the adductor moment on knee joint therefore, it can decrease the forces applied on medial compartment of the knee joint. This orthosis improves walking because it does not let inferior transition. This orthosis can improve femur alignment. It is recommended that physiotherapist prescribe this orthosis in order to decrease pain in patients with OA.
Delvert, Céline; Rippert, Pascal; Margirier, Françoise; Vadot, Jean-Pierre; Bérard, Carole; Poirot, Isabelle; Vuillerot, Carole
Transverse-plane foot deformities are a frequently encountered issue in children with neurological disorders. They are the source of many symptoms, such as pain and walking difficulties, making their prevention very important. We aim to describe the use and tolerability of a side pole static ankle foot orthosis used to prevent transverse-plane foot deformities in children with neurologic disorders. Monocentric, retrospective, observational study. Medical data were collected from 103 children with transverse-plane foot deformities in one or both feet caused by a neurological impairment. All children were braced between 2001 and 2010. Unilateral orthosis was prescribed for 32 children and bilateral orthosis for 71. Transverse-plane foot deformities were varus in 66% of the cases and an equinus was associated in 59.2% of the cases. Mean age for the first prescription was 8.6 years. For the 23 patients present at the 4-year visit, 84.8% still wore the orthosis daily, and 64.7% wore the orthosis more than 6 h per day. The rate of permanent discontinuation of wearing the orthosis was 14.7%. The side pole static ankle foot orthosis is well tolerated with very few side effects, which promotes regular wearing and observance. Clinical relevance Side pole static ankle foot orthoses are well tolerated and can be safely used for children with foot abnormalities in the frontal plane that have a neurological pathology origin.
Forogh, Bijan; Khalighi, Mohsen; Javanshir, Mohammad Ali; Ghoseiri, Kamiar; Kamali, Mohammad; Raissi, Gholamreza
This paper reports on the design and testing of a new designed forearm orthosis and explores its efficacious in comparison to the standard counterforce orthosis in patients with lateral epicondylitis. Twenty-four patients were enrolled in this assessor-blinded clinical trial and randomly assigned to two parallel treatment groups. The measures of pain and function, the pain threshold and grip strength were compared using patient rated tennis elbow evaluation (PRTEE) form, algometer and dynamometer respectively at baseline and 4 weeks after treatment. Paired and independent t-test statistical methods recruited for within and between groups comparisons respectively. The both orthoses, counterforce and new-designed, significantly relieved pain, and improved function, pain threshold and grip strength of all patients after 4 weeks application. The new-designed orthosis seemed to be more effective than the counterforce orthosis in pain relief, but there was not any significant difference in efficacious of two types of orthoses regarding function. The new-designed orthosis can significantly relieve pain, improve function, increase pain threshold and grip strength after application. This orthosis seemed to be more effective than counterforce orthosis in relieving pain and increasing the pain threshold probably due to the limitation of forearm supination.
Gallagher, Helen; Jack, Anthony I.; Roepstorff, Andreas
The "intentional stance" is the disposition to treat an entity as a rational agent, possessing particular beliefs, desires, and intentions, in order to interpret and predict it's behavior. The intentional stance is a component of a broader social cognitive function, mentalizing. Here we report a ...
Herrin, Kinsey; Geil, Mark
Orthotic treatment of idiopathic toe walking is complicated by the lack of a known etiology. This study compared control of toe walking using an articulated ankle-foot orthosis versus a rigid carbon fiber footplate attached to a foot orthosis. Ascertain differences between two orthoses in the control of idiopathic toe walking. Randomized controlled trial. A total of 18 children with idiopathic toe walking were randomized to either the ankle-foot orthosis or foot orthosis treatment group in a Parallel Randomized Controlled Trial with no blinding. Prior to and after 6 weeks of treatment, participants completed three-dimensional gait assessment and the L-test of Functional Mobility. Parents completed a satisfaction survey and a subset of the Orthotic and Prosthetic User Survey after treatment. Nine participants were analyzed in each group. Both groups showed significant improvement in kinematics versus baseline with orthoses; however, when the orthoses were removed, the ankle-foot orthosis group did not immediately sustain this improvement, while the foot orthosis group did. Parents preferred the foot orthosis for donning and appearance. The ankle-foot orthosis controls idiopathic toe walking, but subjects may revert to earlier patterns following treatment. The foot orthosis does not control idiopathic toe walking as well but is less restrictive and more accepted by children and their parents, with similar out-of-brace effects. This study suggests that sequential orthotic treatment for children with idiopathic toe walking (ITW) may be beneficial. Initial treatment could include a less restrictive orthosis like a foot orthosis (FO); if this is unsuccessful within a set time frame, then the patient may require a more restrictive form of treatment such as an ankle-foot orthosis (AFO). © The International Society for Prosthetics and Orthotics 2015.
Tehran J. Davis
Full Text Available Successfully meeting a shared goal usually requires co-actors to adopt complementary roles. However, in many cases, who adopts what role is not explicitly predetermined, but instead emerges as a consequence of the differences in the individual abilities and constraints imposed upon each actor. Perhaps the most basic of roles are leader and follower. Here, we investigated the emergence of “leader-follower” dynamics in inter-personal coordination using a joint supra-postural task paradigm (Ramenzoni et al., 2011; Athreya et al., 2014. Pairs of actors were tasked with holding two objects in alignment (each actor manually controlled one of the objects as they faced different demands for stance (stable vs. difficult and control (which actor controlled the larger or smaller object. Our results indicate that when actors were in identical stances, neither led the inter-personal (between actors coordination by any systematic fashion. Alternatively, when asymmetries in postural demands were introduced, the actor with the more difficult stance led the coordination (as determined using cross-recurrence quantification analysis. Moreover, changes in individual stance difficulty resulted in similar changes in the structure of both intra-personal (individual and inter-personal (dyadic coordination, suggesting a scale invariance of the task dynamics. Implications for the study of interpersonal coordination are discussed.
Full Text Available Abstract Background The design of foot and ankle orthoses is currently limited by the methods used to fabricate the devices, particularly in terms of geometric freedom and potential to include innovative new features. Additive manufacturing (AM technologies, where objects are constructed via a series of sub-millimetre layers of a substrate material, may present the opportunity to overcome these limitations and allow novel devices to be produced that are highly personalised for the individual, both in terms of fit and functionality. Two novel devices, a foot orthosis (FO designed to include adjustable elements to relieve pressure at the metatarsal heads, and an ankle foot orthosis (AFO designed to have adjustable stiffness levels in the sagittal plane, were developed and fabricated using AM. The devices were then tested on a healthy participant to determine if the intended biomechanical modes of action were achieved. Results The adjustable, pressure relieving FO was found to be able to significantly reduce pressure under the targeted metatarsal heads. The AFO was shown to have distinct effects on ankle kinematics which could be varied by adjusting the stiffness level of the device. Conclusions The results presented here demonstrate the potential design freedom made available by AM, and suggest that it may allow novel personalised orthotic devices to be produced which are beyond the current state of the art.
Lv, Ge; Zhu, Hanqi; Elery, Toby; Li, Luwei; Gregg, Robert D
Traditional control methodologies of rehabilitation orthoses/exoskeletons aim at replicating normal kinematics and thus fall into the category of kinematic control . This control paradigm depends on pre-defined reference trajectories, which can be difficult to adjust between different locomotor tasks and human subjects. An alternative control category, kinetic control , enforces kinetic goals (e.g., torques or energy) instead of kinematic trajectories, which could provide a flexible learning environment for the user while freeing up therapists to make corrections. We propose that the theory of underactuated potential energy shaping, which falls into the category of kinetic control, could be used to generate virtual body-weight support for stroke gait rehabilitation. After deriving the nonlinear control law and simulating it on a human-like biped model, we implemented this controller on a powered ankle-foot orthosis that was designed specifically for testing torque control strategies. Experimental results with an able-bodied human subject demonstrate the feasibility of the control approach for both positive and negative virtual body-weight augmentation.
Zhang, Chao; Zhu, Yanhe; Fan, Jizhuang; Zhao, Jie; Yu, Hongying
Muscular rigidity and atrophy caused by long-term underactivity usually lead to foot drop, strephenopodia, foot extorsion or some other complications for the lower limb movement disorders or lower limb surgery sufferers. The ankle-foot orthosis can help patients conduct the right ankle motion mode training, inhibit spasm and prevent ankle complications. In this paper, a quasi-passive 3 DOFs ankle-foot wearable orthosis was designed on the basis of kinematics and dynamics analysis of the ankle joint. Ankle joint trajectory and dynamic characteristics similar to those of natural gait can be obtained by the combination of passive energy storage and additional power complement. In terms of function, the orthosis has shock absorption and low energy consumption. Given its excellent characteristics of comfortableness, lightweight, and anthropomorphic construction, the orthosis can be used in medical institutions for rehabilitation training or as a daily-walking auxiliary equipment for surgery sufferers.
Kashapova, R. M.; Kashapov, R. N.; Kashapova, R. S.
The possibility of using the built-in ultrasound physiotherapy system of the hand orthosis is explored in the work. The individual mesh orthosis from nylon 12 was manufactured by the 3D prototyping method on the installation of selective laser sintering SLS SPro 60HD. The applied technology of three-dimensional scanning made it possible to obtain a model of the patient’s hand and on the basis of it to build a virtual model of the mesh frame. In the course of the research, the developed system of ultrasound exposure was installed on the orthosis and its tests were carried out. As a result, the acceleration of the healing process and the reduction in the time of wearing orthosis were found.
Leal-Junior, Arnaldo G.; Frizera, Anselmo; Marques, Carlos; Sánchez, Manuel R. A.; Botelho, Thomaz R.; Segatto, Marcelo V.; Pontes, Maria José
This paper presents the development of a polymer optical fiber (POF) strain gauge based on the light coupling principle, which the power attenuation is created by the misalignment between two POFs. The misalignment, in this case, is proportional to the strain on the structure that the fibers are attached. This principle has the advantages of low cost, ease of implementation, temperature insensitiveness, electromagnetic fields immunity and simplicity on the sensor interrogation and signal processing. Such advantages make the proposed solution an interesting alternative to the electronic strain gauges. For this reason, an analytical model for the POF strain gauge is proposed and validated. Furthermore, the proposed POF sensor is applied on an active orthosis for knee rehabilitation exercises through flexion/extension cycles. The controller of the orthosis provides 10 different levels of robotic assistance on the flexion/extension movement. The POF strain gauge is tested at each one of these levels. Results show good correlation between the optical and electronic strain gauges with root mean squared deviation (RMSD) of 1.87 Nm when all cycles are analyzed, which represents a deviation of less than 8%. For the application, the proposed sensor presented higher stability than the electronic one, which can provide advantages on the rehabilitation exercises and on the inner controller of the device.
Dafkin, Chloe; Green, Andrew; Olivier, Benita; McKinon, Warrick; Kerr, Samantha
To assess if there is a circadian variation in electromyographical (EMG) muscle activity during gait in restless legs syndrome (RLS) patients and healthy control participants. Gait assessment was done in 14 RLS patients and 13 healthy control participants in the evening (PM) and the morning (AM). Muscle activity was recorded bilaterally from the tibialis anterior (TA), lateral gastrocnemius (GL), rectus femoris (RF) and biceps femoris (BF) muscles. A circadian variation during the stance phase in only TA (PM > AM, p Controls, p < 0.05) during early stance and decreased GL activity (RLS < Controls, p < 0.01) during terminal stance in comparison to control participants in the evening. No other significant differences were noted between RLS patients and control participants. Activation of GL during the swing phase was noted in 79% of RLS patients and in 23% of control participants in the morning compared to 71% and 38% in the evening, respectively. EMG muscle activity shows no circadian variation in RLS patients. Evening differences in gait muscle activation patterns between RLS patients and control participants are evident. These results extend our knowledge about alterations in spinal processing during gait in RLS. A possible explanation for these findings is central pattern generator sensitization caused by increased sensitivity in cutaneous afferents in RLS patients. Copyright © 2018 Elsevier B.V. All rights reserved.
Doherty, Cailbhe; Bleakley, Chris; Hertel, Jay; Caulfield, Brian; Ryan, John; Sweeney, Kevin; Delahunt, Eamonn
This investigation combined measures of inter-joint coordination and stabilometry to evaluate eyes-open (condition 1) and eyes-closed (condition 2) static unilateral stance performance in a group of participants with an acute, first-time lateral ankle sprain injury in comparison to a control group. Sixty-six participants with an acute first-time lateral ankle sprain and 19 non-injured controls completed three 20-second unilateral stance task trials in conditions 1 and 2. An adjusted coefficient of multiple determination statistic was used to compare stance limb 3-D kinematic data for similarity in the aim of establishing patterns of inter-joint coordination for these groups. Between-group analyses revealed significant differences in stance limb inter-joint coordination strategies for conditions 1 and 2. Injured participants displayed increases in ankle-hip linked coordination compared to controls in condition 1 (sagittal/frontal plane: 0.12 [0.09] vs 0.06 [0.04]; η(2)=.16) and condition 2 (sagittal/frontal plane: 0.18 [0.13] vs 0.08 [0.06]; η(2)=0.37). Participants with acute first-time lateral ankle sprain exhibit a hip-dominant coordination strategy for static unilateral stance compared to non-injured controls. Copyright © 2015 Elsevier Ltd. All rights reserved.
Chong, R; Berl, B; Cook, B; Turner, P; Walker, K
The visual, somatosensory, and vestibular systems are critical for establishing a sensorimotor set for postural control and orientation. The goal of this study was to assess how individuals with a vestibular-related disorder keep their balance following prolonged stance on an inclined surface. We hypothesize that subjects will show greater reliance on the somatosensory system than age-matched controls as inferred by the presence of a forward postural lean aftereffect following the inclined stance (i.e., a positive response). The results revealed an underlying somatosensory-dominant strategy for postural control in the vestibular group: 100% of the subjects tested positive compared to 58% in the control group (P=.006). Individuals with a vestibular-related disorder use a somatosensory-dominant strategy for postural orientation following prolonged inclined stance. The implications for the management of this population are discussed. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Neubauer, Brett C; Nath, Jonathan; Durfee, William K
Small-scale hydraulics is ideal for powered human assistive devices including powered ankle foot orthoses because a large torque can be generated with an actuator that is small and light. A portable hydraulic ankle foot orthosis has been designed and is undergoing preliminary prototyping and engineering bench test evaluation. The device provides 90 Nm of ankle torque and has an operating pressure of 138 bar (2,000 psi). The battery-operated hydraulic power supply weighs about 3 kg and is worn at the waist. The ankle component weighs about 1.2 Kg and connects to the power supply with two hoses. Performance simulation and preliminary bench testing suggests that the device could be useful in certain rehabilitation applications.
Ayad Murad Takhakh, Hassanein Salih Hussain
This study includes two main parts: The first part includes the process of manufacturing and testing partial foot orthosis for a patient suffering from partial foot amputation. The orthosis was manufactured from lamination Perlon-Carbon-Perlon(4-2-4) and then tested with Force plate and F-Socket. The patientwas tested in two cases: the first without wearing the orthosis and the second after wearing the orthosis. The results of gait cycle testshow that the gait cycle of the patient was improve...
Terada, Kazunori; Ono, Kouhei; Ito, Akira
Whether or not humans can construe the behaviors of entities depends on their psychological stance. The philosopher Dennett proposed human cognitive strategies (three stances) in which humans construe the behavior of other animated objects, including other humans, artifacts, and physical phenomena:‘intentional’, ‘design’ and ‘physical’ stances. Detecting the psychological stance taken toward entities is difficult, because such mental state attribution is a subjective cognitive process and hard to measure. In the present study, we proposed a novel method for detecting underlying stance adopted when human construe behavior of entities. In our method the subject was asked to select the most suitable action sequence shown in three movies each of which representing Dennett’s three stances. To valid our method we have conducted an experiment in which the subjects were presented thirty short videos and asked to compare them to the three movies. The result indicated that the subjects did not focused on prior knowledge about the entity but could focused on motion characteristics per se, owing to simple and typical motion of an abstract shaped object.
Karimi, Mohammad Taghi; Amiri, Pouya; Esrafilian, Amir; Sedigh, Jafar; Fatoye, Francis
Most patients with spinal cord injury use a wheelchair to transfer from place to place, however they need to stand and walk with orthosis to improve their health status. Although many orthoses have been designed for paraplegic patients, they have experienced various problems while in use. A new type of reciprocal gait orthosis was designed in the Bioengineering Unit of Strathclyde University to solve the problems of the available orthoses. Since there was no research undertaken regarding testing of the new orthosis on paraplegic subjects, this study was aimed to evaluate the new orthosis during standing of paraplegic subjects. Five paraplegic patients with lesion level between T12 and L1 and aged matched normal subjects were recruited into this study. The stability of subjects was evaluated during quiet standing and while undertaking hand tasks during standing with the new orthosis and the knee ankle foot orthosis (KAFO). The difference between the performances of paraplegic subjects while standing with both orthoses, and between the function of normal and paraplegic subjects were compared using the paired t test and independent sample t test, respectively. The stability of paraplegic subjects in standing with the new orthosis was better than that of the KAFO orthosis (p < 0.05). Moreover, the force applied on the crutch differed between the orthoses. The functional performance of paraplegic subjects was better with the new orthosis compared with normal subjects. The performance of paraplegic subjects while standing with the new orthosis was better than the KAFO. Therefore, the new orthosis may be useful to improve standing and walking in patients with paraplegia.
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Background. Balance disorders are commonly evidenced during the course of multiple sclerosis (MS. The aim of this study is to report characteristics of MS patient stance control disorders, measured by means of posturography and related to the brainstem lesions.
Methods. Thirty-eight patients affected by MS, mildly to moderately disable according to Kurtzke’s Expanded Disability Status Scale, underwent a complete clinical neurological and vestibular evaluation and brain MRI scanning. All patients were then tested on a static posturography platform (Tetrax, Israel in four conditions: eyes open and closed standing on a firm surface and on a foam pad.
Results. Clinical and/or MRI evidence of brainstem involvement was observed in 55.3 % of patients. When brainstem lesion was detected, Fourier analysis showed a typical pattern characterized by inversion of the 0- 0.1 Hz and 0.1 - 0.25 Hz. frequency bands.
Conclusions. MS leads to pervasive postural disturbances in the majority of subjects, including the visuo-vestibular loops and proprioception involving vestibulo-spinal pathways in at least 55.3 % of patients. Our results may also suggest the presence of Fourier inversion in patients with brainstem lesions.
Full Text Available Background: Scoliosis is a three-dimensional spinal deformity characterized by lateral curvature and rotational deformity of the spine. Various methods have been used to investigate the performance of the subjects during walking with an orthosis, but nobody study the biomechanics of orthotic use by understanding the length of the muscles and the force produced by them. Therefore, the aim of this research is to test the effect of the orthosis on the muscular force, tendon length during walking with and without orthosis. Materials and Methods: A 12-year-old scoliosis subject was recruited in this study. The forces produced by trunk musculature, joint reaction force, length of trunk musculature were some parameters selected in this study. Open SIMM and Visual 3D software were used to model the subject. Results: The results of this research showed that the length of erector spine muscles increased follow the use of orthosis. Moreover, the force produced by trunk muscles differed during walking with and without orthosis and also between right and left sides. Discussion: It seems that Open SIMM software can be used to predict the length of muscles, active-passive forces produced by muscles in scoliotic subjects. Therefore, it is recommended this research be done on more number of subjects.
Karimi, Mohammad; Kavyani, Mahsa
Scoliosis is a three-dimensional spinal deformity characterized by lateral curvature and rotational deformity of the spine. Various methods have been used to investigate the performance of the subjects during walking with an orthosis, but nobody study the biomechanics of orthotic use by understanding the length of the muscles and the force produced by them. Therefore, the aim of this research is to test the effect of the orthosis on the muscular force, tendon length during walking with and without orthosis. A 12-year-old scoliosis subject was recruited in this study. The forces produced by trunk musculature, joint reaction force, length of trunk musculature were some parameters selected in this study. Open SIMM and Visual 3D software were used to model the subject. The results of this research showed that the length of erector spine muscles increased follow the use of orthosis. Moreover, the force produced by trunk muscles differed during walking with and without orthosis and also between right and left sides. It seems that Open SIMM software can be used to predict the length of muscles, active-passive forces produced by muscles in scoliotic subjects. Therefore, it is recommended this research be done on more number of subjects.
Andrysek, Jan; Klejman, Susan; Torres-Moreno, Ricardo; Heim, Winfried; Steinnagel, Bryan; Glasford, Shane
There is a need for a prosthetic knee joint design that is technologically and functionally appropriate for use in developing countries. To develop and clinically evaluate a new type of stance phase controlled prosthetic knee joint that provides stance phase stability without inhibiting swing phase flexion. A crossover repeated measures study design comparing the new knee joint to the participant's conventional low- or high-end prosthetic knee joint. The new knee joint was fitted to fourteen individuals aged 15 to 67 years with unilateral lower limb amputations. Walk tests were performed to measure walking speed. Energy expenditure was estimated using the physiological cost index (PCI). Walking speeds with the new knee joint were on average 0.14 m/s faster than conventional low-end knees (p < 0.0001), but 0.07 m/s slower than conventional high-end prosthetic knees (p = 0.008). The PCI was similar across all three knee joint technologies (p = 0.276). Mobility function with the new knee joint, in terms of walking speed, was more closely matched to high-end than low-end prosthetic knee joints. Therefore, given its relatively simple design, the new stance phase control mechanism may offer a functional and cost effective solution for active transfemoral amputees. This paper describes a new type of prosthetic knee joint mechanism that is intended to be cost-effective while providing high-level stance phase function to active individuals with a transfemoral amputation. Initial clinical testing suggests that the new knee joint may have some functional advantages over existing technologies in this category.
Tashman, S; Zajac, F E; Perkash, I
We developed a three dimensional, four segment, eight-degree-of-freedom model for the analysis of paraplegic ambulation in a reciprocating gait orthosis (RGO). Model development was guided by experimental analysis of a spinal cord injured individual walking in an RGO with the additional assistance of arm crutches. Body forces and torques required to produce a dynamic simulation of the RGO gait swing phase were found by solving an optimal control problem to track the recorded kinematics and ground reaction forces. We found that high upper body forces are required, not only during swing but probably also during double support to compensate for the deceleration of the body during swing, which is due to the pelvic thrust necessary to swing the leg forward. Other stimulations showed that upper body forces and body deceleration during swing can be reduced substantially by producing a ballistic swing. Functional neuromuscular stimulation of the hip musculature during double support would then be required, however, to establish the initial conditions needed in a ballistic swing.
Full Text Available It is very important for quadruped walking machine to keep its stability in high speed walking. It has been indicated that moment around the supporting diagonal line of quadruped in trotting gait largely influences walking stability. In this paper, moment around the supporting diagonal line of quadruped in trotting gait is modeled and its effects on body attitude are analyzed. The degree of influence varies with different initial stances of quadruped and we get the optimal initial stance of quadruped in trotting gait with maximal walking stability. Simulation results are presented.
Neuhaus, Peter D; Noorden, Jerryll H; Craig, Travis J; Torres, Tecalote; Kirschbaum, Justin; Pratt, Jerry E
Mobility options for persons suffering from paraplegia or paraparesis are limited to mainly wheeled devices. There are significant health, psychological, and social consequences related to being confined to a wheelchair. We present the Mina, a robotic orthosis for assisting mobility, which offers a legged mobility option for these persons. Mina is an overground robotic device that is worn on the back and around the legs to provide mobility assistance for people suffering from paraplegia or paraparesis. Mina uses compliant actuation to power the hip and knee joints. For paralyzed users, balance is provided with the assistance of forearm crutches. This paper presents the evaluation of Mina with two paraplegics (SCI ASIA-A). We confirmed that with a few hours of training and practice, Mina is currently able to provide paraplegics walking mobility at speeds of up to 0.20 m/s. We further confirmed that using Mina is not physically taxing and requires little cognitive effort, allowing the user to converse and maintain eye contact while walking. © 2011 IEEE
Full Text Available Abstract Introduction Immobilization in a hip spica cast is required in surgical and nonsurgical treatments for children aged three months to four years diagnosed with developmental dysplasia of the hip. Skin complications are associated with the use of the spica cast in 30% of the cases. This research explores the use of photogrammetry and rapid prototyping for the production of a lighter, shower friendly and hygienic hip orthosis that could replace the hip spica cast. Methods Digitalized data of a plastic dool was used for design and fabrication of a customised hip orthosis following four steps: 1 Digitalization of the external anatomical structure by photogrammetry using a smartphone and open source software; 2 Idealization and 3D modeling of the hip orthosis; 3 Rapid prototyping of a low cost orthosis in polymer polylact acid; 4 Evaluation tests. Results Photogrammetry provided a good 3D reconstruction of the dool's hip and legs. The manufacture method to produce the hip orthosis was accurate in fitting the hip orthosis to the contours of the doll. The orthosis could be easily placed on the doll ensuring mechanical strength to immobilize the region of the hip. Conclusion A new approach and the feasibility of both techniques for hip orthosis fabrication were described. It represents an exciting advance for the development of hip orthosis that could be used in orthopedics. To test the effectiveness of this orthosis for developmental dysplasia of the hip treatment in newborns, material and mechanical tests, design optimization and physical tests with patients should be carried.
Case, J Brad; Palmer, Ross; Valdes-Martinez, Alex; Egger, Erick L; Haussler, Kevin K
To report clinical findings and outcome in a dog with gastrocnemius tendon strain treated with autologous mesenchymal stem cells and a custom orthosis. Clinical report. A 4-year-old spayed female Border Collie. Bone-marrow derived, autologous mesenchymal stem cells were transplanted into the tendon core lesion. A custom, progressive, dynamic orthosis was fit to the tarsus. Serial orthopedic examinations and ultrasonography as well as long-term force-plate gait analysis were utilized for follow up. Lameness subjectively resolved and peak vertical force increased from 43% to 92% of the contralateral pelvic limb. Serial ultrasonographic examinations revealed improved but incomplete restoration of normal linear fiber pattern of the gastrocnemius tendon. Findings suggest that autologous mesenchymal stem cell transplantation with custom, progressive, dynamic orthosis may be a viable, minimally invasive technique for treatment of calcaneal tendon injuries in dogs. © Copyright 2013 by The American College of Veterinary Surgeons.
Pegah Saddat Hosseini
Full Text Available Background: During speech, larynx is higher in the neck for high-pitched sounds and lower for low-pitched sounds. Patients with different problems in cervical and cervicothoracic spine use cervical orthosis to limit cervical motion. This study aimed to evaluate the effects of Minerva orthosis on larynx height in young, healthy volunteers. Subjects and methods: This study included 18 subjects. Acoustic measurement of frequency variability has been assessed in 3 brace conditions: (1 without brace, (2 with brace, and (3 30 minutes after wearing the brace. Results: Several statistically significant differences were found in the comparison between Minerva and 30 minutes after Minerva. Conclusion: When planning cervical orthosis treatment, it is important to consider the reduction in larynx height that may result from bracing for those who are already at risk of developing dysphagia and dysphonia.
Valentin, Gitte Hoff; Pedersen, Louise Nymann; Maribo, Thomas
extensor strength can result in decreased kyphosis and thus a decreased risk of falls and fractures.Objectives:The aim was to examine the effects of an active spinal orthosis - Spinomed III - on back extensor strength, back pain and physical functioning in women with osteoporotic vertebral fractures.......Study design:Experimental follow-up.Methods:The women used the active spinal orthosis for 3 months. Outcomes were changes in isometric back extensor strength, changes in back pain and changes in physical functioning.Results:A total of 13 women were included in the trial. Wearing the orthosis during a 3-month...... period was associated with an increase in back extensor strength of 50% (p = 0.01). The study demonstrated a 33% reduction in back pain and a 6.5-point improvement in physical functioning. The differences in pain and physical functioning were borderline significant.Conclusion:The women demonstrated...
Rouse, Elliott J.; Hargrove, Levi J.; Perreault, Eric J.; Kuiken, Todd A.
Human joint impedance is the dynamic relationship between the differential change in the position of a perturbed joint and the corresponding response torque; it is a fundamental property that governs how humans interact with their environments. It is critical to characterize ankle impedance during the stance phase of walking to elucidate how ankle impedance is regulated during locomotion, as well as provide the foundation for future development of natural, biomimetic powered prostheses and their control systems. In this study, ankle impedance was estimated using a model consisting of stiffness, damping and inertia. Ankle torque was well described by the model, accounting for 98 ± 1.2% of the variance. When averaged across subjects, the stiffness component of impedance was found to increase linearly from 1.5 Nm/rad/kg to 6.5 Nm/rad/kg between 20% and 70% of stance phase. The damping component was found to be statistically greater than zero only for the estimate at 70% of stance phase, with a value of 0.03 Nms/rad/kg. The slope of the ankle’s torque-angle curve—known as the quasi-stiffness—was not statistically different from the ankle stiffness values, and showed remarkable similarity. Finally, using the estimated impedance, the specifications for a biomimetic powered ankle prosthesis were introduced that would accurately emulate human ankle impedance during locomotion. PMID:24760937
Kerkum, Yvette L; Brehm, Merel-Anne; Buizer, Annemieke I; van den Noort, Josien C; Becher, Jules G; Harlaar, Jaap
A rigid ventral shelf ankle foot orthosis (AFO) may improve gait in children with spastic cerebral palsy (SCP) whose gait is characterized by excessive knee flexion in stance. However, these AFOs can also impede ankle range of motion (ROM) and thereby inhibit push-off power. A more spring-like AFO can enhance push-off and may potentially reduce walking energy cost. The recent development of an adjustable spring-hinged AFO now allows adjustment of AFO stiffness, enabling tuning toward optimal gait performance. This study aims to quantify the mechanical properties of this spring-hinged AFO for each of its springs and settings. Using an AFO stiffness tester, two AFO hinges and their accompanying springs were measured. The springs showed a stiffness range of 0.01-1.82 N · m · deg(-1). The moment-threshold increased with increasing stiffness (1.13-12.1 N · m), while ROM decreased (4.91-16.5°). Energy was returned by all springs (11.5-116.3 J). These results suggest that the two stiffest available springs should improve joint kinematics and enhance push-off in children with SCP walking with excessive knee flexion.
The connection of what we claim to know (ontology) and how do we claim to know (epistemology) will be addressed in this paper. Some mapping tools will be used to make understanding easier. It should be understood that making a choice of a certain epistemic stance is not the end of the journey. The critical aspect is to ...
Dingenen, Bart; Janssens, Luc; Claes, Steven; Bellemans, Johan; Staes, Filip F
The goal of this study was to evaluate postural stability during the transition from double-leg stance (DLS) to single-leg stance (SLS) in anterior cruciate ligament reconstructed (ACLR) (n=20) and non-injured control subjects (n=20). All ACLR subjects had fully returned to their pre-injury sport participation. Both groups were similar for age, gender, height, weight, body mass index and activity level. Spatiotemporal center of pressure outcomes of both legs of each subject were measured during the transition from DLS to SLS in eyes open and eyes closed conditions. Movement speed was standardized. The center of pressure displacement after a new stability point was reached during the SLS phase was significantly increased in the ACLR group compared to the control group in the eyes closed condition (P=.001). No significant different postural stability outcomes were found between the operated and non-operated legs. In conclusion, the ACLR group showed postural stability deficits, indicating that these persons may have a decreased ability to stabilize their body after the internal postural perturbation created by the transition from DLS to SLS. The non-operated leg may not be the best reference when evaluating postural stability of the operated leg after ACLR, as no differences were found between legs. Copyright © 2015 Elsevier B.V. All rights reserved.
Li, Meng; Law, Sheung-wai; Cheng, Jack; Kee, Ho-man; Wong, Man Sang
Osteoporosis is one of the major health problems in aging population and may lead to osteoporotic vertebral fracture that causes severe back pain and reduced functional independency. To compare the efficacy of SpinoMed® and soft lumbar orthosis at the subacute stage (the second and third weeks of disease onset) of the patients with osteoporotic vertebral fracture. Prospective randomized trial, pilot trial. A total of 51 female subjects aged 55 years or above with osteoporotic vertebral fracture were randomly distributed to the soft lumbar orthosis (control group, n = 24) and SpinoMed® (test group, n = 27) groups after the acute stage (the first week of disease onset). The pain level was assessed by obtaining verbally feedback in 10-point scale scoring, while functional mobility level was estimated with Functional Independence Measure-motor Scores, Elderly Mobility Scale, and Modified Functional Ambulation Category. The thoracic kyphosis angle was measured from standing X-ray on 10 out of 51 subjects. Both groups showed significant reduction in the patients' pain level and limitations of daily life (p 0.05) at the subacute stage. In this study, SpinoMed® could not provide additional treatment benefits to patients with osteoporotic vertebral fracture regarding pain relief and functional independence improvement at the subacute stage. The effects of SpinoMed® in muscle-strengthening and thoracic kyphotic angle reduction for patients with osteoporotic vertebral fracture need to be further verified in a more intensive and longer-term training program. © The International Society for Prosthetics and Orthotics 2014.
Sukumar, Chand; Ramachandran, K. I.
Leg amputation is a major consequence of aggregated foot ulceration in diabetic patients. A common sense based treatment approach for diabetic foot ulceration is foot offloading where the patient is required to wear a foot offloading orthosis during the entire treatment course. Removable walker is an excellent foot offloading modality compared to the golden standard solution - total contact cast and felt padding. Commercially available foot offloaders are generally customized with huge cost and less patient compliance. This work suggests an optimized 3D model of a new type light weight removable foot offloading orthosis for diabetic patients. The device has simple adjustable features which make this suitable for wide range of patients with weight of 35 to 74 kg and height of 137 to 180 cm. Foot plate of this orthosis is unisexual, with a size adjustability of (US size) 6 to 10. Materials like Aluminum alloy 6061-T6, Acrylonitrile Butadiene Styrene (ABS) and Polyurethane acted as the key player in reducing weight of the device to 0.804 kg. Static analysis of this device indicated that maximum stress developed in this device under a load of 1000 N is only 37.8 MPa, with a small deflection of 0.150 cm and factor of safety of 3.28, keeping the safety limits, whereas dynamic analysis results assures the load bearing capacity of this device. Thus, the proposed device can be safely used as an orthosis for offloading diabetic ulcerated foot.
Cerebral palsy (CP) is a heterogeneous group of permanent, non-progressive motor disorders of movement and posture. Ankle–foot orthoses (AFOs) are frequently prescribed to correct skeletal misalignments in spastic CP. The present study aims to evaluate the effect of the three side support ankle–foot orthosis on ...
Cheung, Jason Tak-Man; Zhang, Ming
Custom-molded foot orthoses are frequently prescribed in routine clinical practice to prevent or treat plantar ulcers in diabetes by reducing the peak plantar pressure. However, the design and fabrication of foot orthosis vary among clinical practitioners and manufacturers. Moreover, little information about the parametric effect of different combinations of design factors is available. As an alternative to the experimental approach, therefore, computational models of the foot and footwear can provide efficient evaluations of different combinations of structural and material design factors on plantar pressure distribution. In this study, a combined finite element and Taguchi method was used to identify the sensitivity of five design factors (arch type, insole and midsole thickness, insole and midsole stiffness) of foot orthosis on peak plantar pressure relief. From the FE predictions, the custom-molded shape was found to be the most important design factor in reducing peak plantar pressure. Besides the use of an arch-conforming foot orthosis, the insole stiffness was found to be the second most important factor for peak pressure reduction. Other design factors, such as insole thickness, midsole stiffness and midsole thickness, contributed to less important roles in peak pressure reduction in the given order. The statistics-based FE method was found to be an effective approach in evaluating and optimizing the design of foot orthosis.
Full Text Available To investigate sensory reweighting as a fundamental property of sensor fusion during standing, we probed postural control with simultaneous rotations of the visual scene and surface of support. Nineteen subjects were presented with pseudo-random pitch rotations of visual scene and platform at the ankle to test for amplitude dependencies in the following conditions: low amplitude vision: high amplitude platform, low amplitude vision: low amplitude platform, and high amplitude vision: low amplitude platform. Gain and phase of frequency response functions (FRFs to each stimulus were computed for two body sway angles and a single weighted EMG signal recorded from seven muscles. When platform stimulus amplitude was increased while visual stimulus amplitude remained constant, gain to vision increased, providing strong evidence for inter-modal reweighting between vision and somatosensation during standing. Intra-modal reweighting of vision was also observed as gains to vision decreased as visual stimulus amplitude increased. Such intra-modal and inter-modal amplitude dependent changes in gain were also observed in muscular activity. Gains of leg segment angle and muscular activity relative to the platform, on the other hand, showed only intra-modal reweighting. That is, changing platform motion amplitude altered the responses to both visual and support surface motion whereas changing visual scene motion amplitude did not significantly affect responses to support surface motion, indicating that the sensory integration scheme between somatosensation (at the support surface and vision is asymmetric.
In this paper, I present and discuss two key findings from a recent study on disciplinary literacy in the literature classroom in L1 Danish (Kabel, 2016). In particular, I explore students’ choices of resources for stance-taking in their written interpretations of literature and I relate these ch...... these choices to students’ reflections on the discipline and to aspects of the pedagogical context, namely which resources the students are encouraged to apply in writing.......In this paper, I present and discuss two key findings from a recent study on disciplinary literacy in the literature classroom in L1 Danish (Kabel, 2016). In particular, I explore students’ choices of resources for stance-taking in their written interpretations of literature and I relate...
Jarociński, Marek; Smets, Frank
This paper estimates a Bayesian VAR for the US economy which includes a housing sector and addresses the following questions. Can developments in the housing sector be explained on the basis of developments in real and nominal GDP and interest rates? What are the effects of housing demand shocks on the economy? How does monetary policy affect the housing market? What are the implications of house price developments for the stance of monetary policy? Regarding the latter question, we implement...
Petrovska, Magdalena; Georgievska, Ljupka
This paper applies a SVAR model which combines different monetary policy instruments to construct an alternative indicator of monetary policy stance in Macedonia. It employs the approach introduced by Bernanke and Mihov (1998) of isolating monetary policy shocks from the whole set of monetary policy instruments that otherwise react to real developments. The residuals from such VAR are cleaned from the central bank's reaction function and represent true monetary policy innovations. Furthermore...
Full Text Available Orientation of posture relative to the environment depends on the contributions from the somatosensory, vestibular, and visual systems mixed in varying proportions to produce a sensorimotor set. Here, we probed the sensorimotor set composition using a postural adaptation task in which healthy adults stood on an inclined surface for 3 min. Upon returning to a horizontal surface, participants displayed a range of postural orientations – from an aftereffect that consisted of a large forward postural lean to an upright stance with little or no aftereffect. It has been hypothesized that the post-incline postural change depends on each individual’s sensorimotor set: whether the set was dominated by the somatosensory or vestibular system: Somatosensory dominance would cause the lean aftereffect whereas vestibular dominance should steer stance posture toward upright orientation. We investigated the individuals who displayed somatosensory dominance by manipulating their attention to spatial orientation. We introduced a distraction condition in which subjects concurrently performed a difficult arithmetic subtraction task. This manipulation altered the time course of their post-incline aftereffect. When not distracted, participants returned to upright stance within the 3-min period. However, they continued leaning forward when distracted. These results suggest that the mechanism of sensorimotor set adaptation to inclined stance comprises at least two components. The first component reflects the dominant contribution from the somatosensory system. Since the postural lean was observed among these subjects even when they were not distracted, it suggests that the aftereffect is difficult to overcome. The second component includes a covert attentional component which manifests as the dissipation of the aftereffect and the return of posture to upright orientation.
Grčar, Miha; Cherepnalkoski, Darko; Mozetič, Igor; Kralj Novak, Petra
Social media are an important source of information about the political issues, reflecting, as well as influencing, public mood. We present an analysis of Twitter data, collected over 6 weeks before the Brexit referendum, held in the UK in June 2016. We address two questions: what is the relation between the Twitter mood and the referendum outcome, and who were the most influential Twitter users in the pro- and contra-Brexit camps? First, we construct a stance classification model by machine learning methods, and are then able to predict the stance of about one million UK-based Twitter users. The demography of Twitter users is, however, very different from the demography of the voters. By applying a simple age-adjusted mapping to the overall Twitter stance, the results show the prevalence of the pro-Brexit voters, something unexpected by most of the opinion polls. Second, we apply the Hirsch index to estimate the influence, and rank the Twitter users from both camps. We find that the most productive Twitter users are not the most influential, that the pro-Brexit camp was four times more influential, and had considerably larger impact on the campaign than the opponents. Third, we find that the top pro-Brexit communities are considerably more polarized than the contra-Brexit camp. These results show that social media provide a rich resource of data to be exploited, but accumulated knowledge and lessons learned from the opinion polls have to be adapted to the new data sources.
Garros, Danielle dos Santos Cutrim; Gagliardi, Rubens José; Guzzo, Regina Aparecida Rossetto
The performance and the satisfaction of the patient were quantitatively compared with the use of the volar dorsal orthosis in order to position the spastic hand. Thirty patients wearing the orthosis for eight hours daily were evaluated by the Canadian Occupational Performance Measure and the box and blocks test, for a three-month period. Five activities were selected (among daily life activities, productive activities, and leisure activities) by the patients, which were impaired by spasticity. There was an improvement related to performance after use of orthosis, with an average of 1.4 + or - 0.5 to 6.3 + or - 0.8 (pPatient satisfaction average after wearing the orthosis was of 1.7 + or - 0.4 to 6.3 + or - 0.6 (ppatient satisfaction.
Macpherson, J. M.; Ye, Y.; Peterson, B. W. (Principal Investigator)
This study examined the configuration of the vertebral column of the cat during independent stance and in various flexed positions. The range of motion in the sagittal plane is similar across most thoracic and lumbar joints, with the exception of a lesser range at the transition region from thoracic-type to lumbar-type vertebrae. The upper thoracic column exhibits most of its range in dorsiflexion and the lower thoracic and lumbar in ventroflexion. Lateral flexion is limited to less than 5 degrees at all segments. The range in torsion is almost 180 degrees and occurs primarily in the midthoracic region, T4-T11. Contrary to the depiction in most atlases, the standing cat exhibits several curvatures, including a mild dorsiflexion in the lower lumbar segments, a marked ventroflexion in the lower thoracic and upper lumbar segments, and a profound dorsiflexion in the upper thoracic (above T9) and cervical segments. The curvatures are not significantly changed by altering stance distance but are affected by head posture. During stance, the top of the scapula lies well above the spines of the thoracic vertebrae, and the glenohumeral joint is just below the bodies of vertebrae T3-T5. Using a simple static model of the vertebral column in the sagittal plane, it was estimated that the bending moment due to gravity is bimodal with a dorsiflexion moment in the lower thoracic and lumbar region and a ventroflexion moment in the upper thoracic and cervical region. Given the bending moments and the position of the scapula during stance, it is proposed that two groups of scapular muscles provide the major antigravity support for the head and anterior trunk. Levator scapulae and serratus ventralis form the lateral group, inserting on the lateral processes of cervical vertebrae and on the ribs. The major and minor rhomboids form the medial group, inserting on the spinous tips of vertebrae from C4 to T4. It is also proposed that the hypaxial muscles, psoas major, minor, and quadratus
Doherty, Cailbhe; Bleakley, Chris; Hertel, Jay; Caulfield, Brian; Ryan, John; Sweeney, Kevin; Delahunt, Eamonn
Longitudinal analyses of participants with a history of lateral ankle sprain are lacking. This investigation combined measures of inter-joint coordination and stabilometry to evaluate eyes-open (condition 1) and eyes-closed (condition 2) static unilateral stance performance in a group of participants, 6-months after they sustained an acute, first-time lateral ankle sprain in comparison to a control group. Sixty-nine participants with a 6-month history of first-time lateral ankle sprain and 20 non-injured controls completed three 20-second unilateral stance task trials in conditions 1 and 2. An adjusted coefficient of multiple determination statistic was used to compare stance limb 3-dimensional kinematic data for similarity in the aim of establishing patterns of lower-limb inter-joint coordination. The fractal dimension of the stance limb centre of pressure path was also calculated. Between-group analyses revealed significant differences in stance limb inter-joint coordination strategies for conditions 1 and 2, and in the fractal dimension of the centre-of-pressure path for condition 2 only. Injured participants displayed increases in ankle-hip linked coordination compared to controls in condition 1 (sagittal/frontal plane: 0.15 [0.14] vs 0.06 [0.04]; η(2)=.19; sagittal/transverse plane: 0.14 [0.11] vs 0.09 [0.05]; η(2)=0.14) and condition 2 (sagittal/frontal plane: 0.15 [0.12] vs 0.08 [0.06]; η(2)=0.23), with an associated decrease in the fractal dimension of the centre-of-pressure path (injured limb: 1.23 [0.13] vs 1.36 [0.13]; η(2)=0.20). Participants with a 6-month history of first-time lateral ankle sprain exhibit a hip-dominant coordination strategy for static unilateral stance compared to non-injured controls. Copyright © 2014 Elsevier Ltd. All rights reserved.
Full Text Available Somatosensory input is known to be essential for postural control. The present study examined the effects on postural sway of sensory input delivered via transcutaneous electrical nerve stimulation (TENS applied to the knees during stance. Electrodes from a dual-channel portable TENS unit were adhered to the skin overlying the lateral and medial aspect of both knees of 20 young healthy volunteers (mean age 24.0 years, standard deviation 4.0. Postural sway parameters were obtained during static bipedal stance with an AMTI force platform. Four stimulation conditions were tested with eyes open and with eyes closed: no TENS; TENS applied bilaterally; and TENS applied to either the right or the left knee. Participants underwent two eight-trial blocks, with each trial lasting 30 seconds. The order of conditions was randomized for each participant. Stimulation consisted of a biphasic symmetrical stimulus delivered at the sensory detection level, with a pulse duration of 200μsec and a pulse frequency of 100Hz. The application of TENS induced significant reductions in mean sway velocity and in the medio-lateral dispersion of the center of pressure, with no corresponding effect on the anterior-posterior dispersion. These findings suggest that electrical stimulation delivered at the sensory detection level to the lateral aspects of the knees may be effective in improving balance control, and that this effect may be directionally specific.
Sonobe, M.; Yamaguchi, H.; Hino, J.
Standing ride type vehicles like electric skateboards have been developed in recent years. Although these vehicles have advantages as being compact and low cost due to their simple structure, it is necessary to improve the riding quality. Therefore, the system aiding riders to keep their balance on a skateboard by feedback control or feedforward control has been required. To achieve it, a human balance model should be built as simple as possible. In this study, we focus on the human balance modelling during standing when the support surface moves largely. We restricted the model on frontal plane and narrow stance because the restrictions allow us to assume single-degree-of-freedom model. The balance control system is generally assumed as a delayed feedback control system. The model was identified through impulse response test and frequency response test. As a result, we found the phase between acceleration of the skateboard and posture angle become opposite phase in low frequency range.
Diane M. Vetter
Full Text Available In this paper the author presents the argument that through the use of rich classroom talk, students can be motivated to take a critical stance on issues of citizenship, such as social justice, equity and environmental concern. Suggesting that students who are not part of the solution are, indeed, part of the problem, the author advocates giving young children a voice through the integration of citizenship education and critical literacy across the curriculum to promote student awareness and to empower students to become pro active global citizens.
Peixoto, J.; Flores, P.; Souto, A. P.
This paper concerns the development of a new approach for orthopaedic footwear to apply in KAFO orthosis (acronym for Knee Ankle Foot Orthosis). This procedure starts with full characterization of the problem with the purpose to characterize a plantar of a patient’s foot with polio. A 3D Scanner was used to collect their feet’s data to produce an anatomic insole. After this step, the patient performs a study of his gait using a static and dynamic study with the aim of characterizing the parameters to improve quality in the footwear. The insole was produced using a 3D printing technology. It was essential to optimize manufacturing processes and it was developed a footwear prototype with innovative characteristics, which is 25% lighter, allowing the user to consume less energy in daily routines.
Belokar, R. M.; Banga, H. K.; Kumar, R.
This study presents a novel approach for testing mechanical properties of medical orthosis developed by three dimensional (3D) technologies. A hand-held type 3D laser scanner is used for generating 3D mesh geometry directly from patient’s limb. Subsequently 3D printable orthotic design is produced from crude input model by means of Computer Aided Design (CAD) software. Fused Deposition Modelling (FDM) method in Additive Manufacturing (AM) technologies is used to fabricate the 3D printable Ankle Foot Orthosis (AFO) prototype in order to test the mechanical properties on printout. According to test results, printed Acrylonitrile Butadiene Styrene (ABS) AFO prototype has sufficient elasticity modulus and durability for patient-specific medical device manufactured by the 3D technologies.
Ishak N.Z.; Mohamaddan S.; Kamaruddin A.M.N.A; Khamis H.; Yamamoto S.; Dawal S.Z.M.
Ankle foot orthosis (AFO) are commonly used to correct the instabilities and joint weakness of lower limb. In this research, AFO was developed by using pneumatic artificial muscle (PAM) to prevent plantarflexion to occur and also to correct the foot from the inversion syndrome. The research started with designing the AFO by using SolidWorks software based on anthropometry measurement data (n=5, age=12 years old). The mechanical simulation was conducted by using Autodesk Inventor software to o...
Full Text Available The possibility to realize highly customized orthoses is receiving boost thanks to the widespread diffusion of low-cost 3D printing technologies. However, rapid prototyping (RP with 3D printers is only the final stage of patient personalized orthotics processes. A reverse engineering (RE process is in fact essential before RP, to digitize the 3D anatomy of interest and to process the obtained surface with suitable modeling software, in order to produce the virtual solid model of the orthosis to be printed. In this paper, we focus on the specific and demanding case of the customized production of hand orthosis. We design and test the essential steps of the entire production process with particular emphasis on the accurate acquisition of the forearm geometry and on the subsequent production of a printable model of the orthosis. The choice of the various hardware and software tools (3D scanner, modeling software, and FDM printer is aimed at the mitigation of the design and production costs while guaranteeing suitable levels of data accuracy, process efficiency, and design versatility. Eventually, the proposed method is critically analyzed so that the residual issues and critical aspects are highlighted in order to discuss possible alternative approaches and to derive insightful observations that could guide future research activities.
Saharan, Lokesh; de Andrade, Monica Jung; Saleem, Wahaj; Baughman, Ray H.; Tadesse, Yonas
Several works have been reported in powered hand orthosis in the last ten years for assistive or rehabilitative purposes. However, most of these approaches uses conventional actuators such as servo motors to power orthosis. In this work, we demonstrate the recently reported twisted and coiled polymeric (TCP) muscles to drive a compact, light, inexpensive and wearable upper extremity device, iGrab. A 3D printed orthotic hand module was designed, developed and tested for the performance. The device has six 2-ply muscles of diameter 1.35 mm with a length of 380 mm. We used a single 2-ply muscle for each finger and two 2-ply muscles for the thumb. Pulsed actuation of the muscles at 1.8 A current for 25 s with 7% duty cycle under natural cooling showed full flexion of the fingers within 2 s. Modeling and simulation were performed on the device using standard Euler-Lagrangian equations. Our artificial muscles powered hand orthosis demonstrated the capability of pinching and picking objects of different shapes, weights, and sizes.
Geller, Josie; Iyar, Megumi; Srikameswaran, Suja; Zelichowska, Joanna; Zhou, Yuan; Dunn, Erin C
Collaborative support provided by carers (family and friends) of individuals with eating disorders has been shown to be integral to patient motivation and clinical outcome. Little is known about factors that contribute to carers' use of collaborative, as opposed to directive, support stance. This exploratory research investigated associations between patient characteristics and carers' support beliefs and behaviors. Eating disorder patients (n = 72) completed measures of readiness for change, eating disorder, and psychiatric symptom severity, and interpersonal functioning. Their carers (n = 72) completed measures of collaborative and directive support. Patient demographic variables, readiness for change, and psychiatric symptom severity were not associated with carer beliefs or behaviors. However, some patient interpersonal functioning scores were; higher Domineering/Controlling scores were associated with carers viewing directive support as more helpful, and with their use of more directive support behaviors. Higher Vindictive/Self-Centered and Intrusive/Needy scores in patients were also associated with carers viewing directive support as more helpful. This exploratory study suggests that carers may be more prone to utilizing a directive, rather than a collaborative, support stance with patients experiencing higher levels of threat, anger, and hostility, and lower levels of safety, closeness, and trust. © 2017 Wiley Periodicals, Inc.
Davis, Boyd H; Pope, Charlene; Mason, Peyton R; Magwood, Gayenell; Jenkins, Carolyn M
This mixed methods study uses a unique approach from social science and linguistics methodologies, a combination of positioning theory and stance analysis, to examine how 20 African Americans with type 2 diabetes make sense of the practices that led to recurrent emergency department visits to identify needs for more effective intervention. In a purposive sample of postemergency department visit interviews with a same-race interviewer, people responded to open-ended questions reflecting on the decision to seek emergency department care. As applied to diabetes education, positioning theory explains that people use their language to position themselves toward their disease, their medications, and the changes in their lives. Transcriptions were coded using discourse analysis to categorize themes. As a form of triangulation, stance analysis measured language patterns using factor analysis to see when and how speakers revealed affect, attitude, and agentive choices for action. Final analysis revealed that one third of the sample exhibited high scores for positive agency or capacity for decision-making and self-management, while the rest expressed less control and more negative emotions and fears that may preclude self-management. This approach suggests a means to tailor diabetes education considering alternative approaches focused on communication for those facing barriers.
Peters, Heather T; Page, Stephen J; Persch, Andrew
To determine the immediate effect of a portable, myoelectric elbow-wrist-hand orthosis on paretic upper extremity (UE) impairment in chronic, stable, moderately impaired stroke survivors. Observational cohort study. Outpatient rehabilitation clinic. Participants exhibiting chronic, moderate, stable, poststroke, UE hemiparesis (N=18). Subjects were administered a battery of measures testing UE impairment and function. They then donned a fabricated myoelectric elbow-wrist-hand orthosis and were again tested on the same battery of measures while wearing the device. The primary outcome measure was the UE Section of the Fugl-Meyer Scale. Subjects were also administered a battery of functional tasks and the Box and Block (BB) test. Subjects exhibited significantly reduced UE impairment while wearing the myoelectric elbow-wrist-hand orthosis (FM: t 17 =8.56, Phand orthosis, with 3 subtasks showing significant increases (feeding [grasp]: z=2.251, P=.024; feeding [elbow]: z=2.966, P=.003; drinking [grasp]: z=3.187, P=.001). Additionally, subjects showed significant decreases in time taken to grasp a cup (z=1.286, P=.016) and increased gross manual dexterity while wearing a myoelectric elbow-wrist-hand orthosis (BB test: z=3.42, Phand orthosis, and these changes exceeded the Fugl-Meyer Scale's clinically important difference threshold. Further, utilization of a myoelectric elbow-wrist-hand orthosis significantly increased gross manual dexterity and performance of certain functional tasks. Future work will integrate education sessions to increase subjects' ability to perform multijoint functional movements and attain consistent functional changes. Copyright © 2017. Published by Elsevier Inc.
Zumbrunn, Thomas; MacWilliams, Bruce A; Johnson, Barbara A
Balance is a major determinate of gait. In high functioning individuals without significant vestibular or vision impairments, a ceiling effect may be present when using a double limb support protocol to assess balance function. For these populations, a single leg stance protocol may be more suitable. 47 typically developing (TD) subjects and 10 patients with CEV performed a single leg stance test on a force plate. The center of pressure (COP) was determined and several COP derived variables were calculated. Included measurements were: standard deviation, maximum excursion, area, average radial displacement, path velocity and frequency of the COP. Directional components of suitable variables were used to analyze anterior/posterior and medial/lateral contributions. Correlations with age of TD subjects indicated that all balance variables except frequency were significantly correlated. Most parameters were highly inter-correlated. Age adjusted COP balance variables also correlated to the Bruininks-Oseretsky balance subtest. Highest correlations were determined by the maximum excursion and velocity of the COP in the anterior/posterior direction. Statistical comparisons between the CEV group and a 4-6 TD group indicated significant differences between groups for most COP balance parameters. These results indicated that a single limb balance assessment may be a useful assessment for determining balance impairments in higher functioning children with orthopedic impairments. Copyright © 2011 Elsevier B.V. All rights reserved.
Meijer, J.W.; Voerman, G.E.; Santegoets, K.M.; Geurts, A.C.H.
OBJECTIVE: To associate the short-term effects of the Handmaster orthosis on disabling symptoms of the affected upper extremity with long-term Handmaster orthosis use after stroke. DESIGN: Historic cohort study. PATIENTS: Patients with chronic stroke. METHODS: The Modified Ashworth Scale (0-5) for
Rougier, Patrice; Genthon, Nicolas; Gallois-Montbrun, Thibault; Brugiere, Steve; Bouvat, Eric
To highlight the capacity of one- and two-legged standing protocols when assessing postural behavior induced by a rigid ankle orthosis, 14 healthy individuals stood upright barefoot and wore either an elastic stocking on the preferred leg or a rigid orthosis with or without additional taping in one- or two-legged (TL) conditions. Traditional…
Weber, Nicholas J; McPoil, Thomas G
Rheumatoid arthritis is a chronic inflammatory condition characterized by joint pain, stiffness, and functional disability. Approximately 90% of patients will report symptoms in the foot or ankle during the course of their disease. A case of a 40-year-old woman with a 12-year history of rheumatoid arthritis referred to outpatient physical therapy with a chief complaint of pain in the lateral rearfoot and forefoot is presented. At the time of the initial examination, the patient reported persistent pain ranging from 3 to 9/10, aggravated when standing and walking during activities of daily living. Treatment consisted of the fabrication of a supramalleolar orthosis that incorporated an in-shoe foot orthosis to address functional limitations and abnormal foot and ankle posture. A home exercise program was prescribed to address potential balance deficits and strength loss following the application of the orthosis. Clinically significant improvements were seen in pain, gait speed, and on the Foot Function Index following the implementation of the orthotic device. The patient returned to standing and walking with minimal symptom limitations. This case report highlights the short-term clinical outcomes when using a supramalleolar orthosis in conjunction with an in-shoe foot orthosis to manage lateral rearfoot and forefoot pain in a patient with rheumatoid arthritis. Copyright © 2015 Elsevier Ltd. All rights reserved.
Seo, Kyo Chul; Park, Kwang Yong
[Purpose] This study examined the effects of foot orthosis on the gait ability of college students in their 20s with flat feet. [Subjects and Methods] The subjects were 20 college students who had been diagnosed with flat feet. The subjects' step time, step length, stride time, stride length, and gait velocity were measured using the VICON Motion System (Vicon, Oxford, UK) prior to and while wearing foot orthoses. The resulting data were analyzed using SPSS v. 12.0. [Results] The subject's step time and stride time significantly decreased for both feet after they began using foot orthosis, and stride length and gait velocity significantly increased in both feet orthosis; however, step length did not significantly increase on either side. [Conclusions] College students with flat feet saw an improvement in elements of their gait while using the foot orthosis. The results of this study verified that students with flat feet might walk more efficiently if they received active gait training via long-term use of foot orthosis.
How to improve walking, balance and social participation following stroke: a comparison of the long term effects of two walking aids--canes and an orthosis TheraTogs--on the recovery of gait following acute stroke. A study protocol for a multi-centre, single blind, randomised control trial
Full Text Available Abstract Background Annually, some 9000 people in Switzerland suffer a first time stroke. Of these 60% are left with moderate to severe walking disability. Evidence shows that rehabilitation techniques which emphasise activity of the hemiplegic side increase ipsilesional cortical plasticity and improve functional outcomes. Canes are commonly used in gait rehabilitation although they significantly reduce hemiplegic muscle activity. We have shown that an orthosis "TheraTogs" (a corset with elasticated strapping significantly increases hemiplegic muscle activity during gait. The aim of the present study is to investigate the long term effects on the recovery of gait, balance and social participation of gait rehabilitation with TheraTogs compared to gait rehabilitation with a cane following first time acute stroke. Methods/Design Multi-centre, single blind, randomised trial with 120 patients after first stroke. When subjects have reached Functional Ambulation Category 3 they will be randomly allocated into TheraTogs or cane group. TheraTogs will be applied to support hip extensor and abductor musculature according to a standardised procedure. Cane walking held at the level of the radial styloid of the sound wrist. Subjects will walk throughout the day with only the assigned walking aid. Standard therapy treatments and usual care will remain unchanged and documented. The intervention will continue for five weeks or until patients have reached Functional Ambulation category 5. Outcome measures will be assessed the day before begin of intervention, the day after completion, 3 months, 6 months and 2 years. Primary outcome: Timed "up and go" test, secondary outcomes: peak surface EMG of gluteus maximus and gluteus medius, activation patterns of hemiplegic leg musculature, temporo-spatial gait parameters, hemiplegic hip kinematics in the frontal and sagittal planes, dynamic balance, daily activity measured by accelerometry, Stroke Impact Scale
Making aspects of privileged ways of participating visible is central to support students’ literacy development within different educational disciplines (Hasan, 1996, 2011). In my doctoral work I focus on the discipline of literature in lower secondary school in the school subject of Danish......, exploring students’ resources for stance-taking in their written literary response texts. In my presentation on Friday I will outline the theoretical grounding of the study and the preliminary findings. Drawing on the appraisal system within SFL (Hood, 2011; Martin & White, 2005) and the dimension...... of specialization within LCT (Maton, 2007, 2010), my analyses show a variation in students’ interpersonal meaning-making choices, linking their literary response texts within the same task to either primarily a knower or a knowledge code. This variation suggests a tension in the literature education at this time...
Kobayashi, Toshiki; Leung, Aaron K L; Akazawa, Yasushi; Naito, Hisashi; Tanaka, Masao; Hutchins, Stephen W
The purpose of this study was to design a new automated stiffness measurement device which could perform a simultaneous measurement of both dorsi- and plantarflexion angles and the corresponding resistive torque around the rotational centre of an articulated ankle-foot orthosis (AAFO). This was achieved by controlling angular velocities and range of motion in the sagittal plane. The device consisted of a hydraulic servo fatigue testing machine, a torque meter, a potentiometer, a rotary plate and an upright supporter to enable an AAFO to be attached to the device via a surrogate shank. The accuracy of the device in reproducing the range of motion and angular velocity was within 4% and 1% respectively in the range of motion of 30° (15° plantarflexion to 15° dorsiflexion) at the angular velocity of 10°/s, while that in the measurement of AAFO torque was within 8% at the 0° position. The device should prove useful to assist an orthotist or a manufacturer to quantify the stiffness of an AAFO and inform its clinical use.
Pinter, I.J.; van Swigchem, R.; van Soest, A.J.; Rozendaal, L.A.
Research on unperturbed stance is largely based on a one-segment inverted pendulum model. Recently, an increasing number of studies report a contribution of other major joints to postural control. Therefore this study evaluates whether the conclusions originating from the research based on a
Formolo, Daniel; Bosse, Tibor
© 2017, Springer International Publishing AG. This paper presents an algorithm to automatically detect interpersonal stance in vocal signals. The focus is on two stances (referred to as ‘Dominant’ and ‘Empathic’) that play a crucial role in aggression de-escalation. To develop the algorithm, first a
Dobbs, Christina L.
Effective academic writing is accessible to readers because writers follow shared conventions for organization and signal their stance on particular topics; however, few specifics are known about how middle graders might develop knowledge of and use these academic language forms and functions to signal their organization and stance in persuasive…
Aull, Laura L.; Lancaster, Zak
This article uses corpus methods to examine linguistic expressions of stance in over 4,000 argumentative essays written by incoming first-year university students in comparison with the writing of upper-level undergraduate students and published academics. The findings reveal linguistic stance markers shared across the first-year essays despite…
Drawing on the appraisal framework from systemic functional linguistics (SFL), this article examines patterns of stance in a corpus of 92 high- and low-graded argumentative papers written in the context of an upper-level course in economics. It interprets differential patterns of stance in students' texts in light of interview commentaries…
Full Text Available Research on the texts of apprentice academic writers has found that they often exhibit weaknesses related to presenting an authoritative argumentative stance. This study rendered explicit linguistic resources for stance-taking and engaged advanced L2 writers in exploring stance expressions in published research. Both linguistic and language learning theories informed this study. Seven Mandarin-speaking learners of English from fields in social sciences engaged in three writing sessions in which they consulted a concordance tool organized and created to present genre moves (Swales 1990; 2004 and engagement strategies (Martin & White, 2005 used by academic authors in research introductions. Analysis of their drafts showed improvement in rhetorical move structure and stance deployment after using the tool. They were found to be more accurate in applying and identifying stances that present assertive claims and factual statements than moderately assertive stance expressions that present expansive meanings. Despite some success in learning, close text analysis reveals that more help is needed to support students in deploying appropriately assertive claims, substantiating strong claims, and managing their stance expression across several clauses. Overall, this study found that an explicit approach to learning about authorial stance has the potential to raise L2 writers’ consciousness and improve their writing.
Liu, Lian; Stevenson, Marie
This study examines stance in cross-cultural media discourse by comparing disaster news reports on the Sichuan earthquake of May 2008 in a Chinese, an Australian Chinese, and an Australian newspaper. The stance taken in the news reports is examined using the Attitude sub-system of Martin and White's (2005) Appraisal framework. The analysis…
Full Text Available Abstract Background The maintenance of postural control is fundamental for different types of physical activity. This can be measured by having subjects stand on one leg on a force plate. Many studies assessing standing balance have previously been carried out in patients with ankle ligament injuries but not in patients with ankle fractures. The aim of this study was to evaluate whether patients operated on because of an ankle fracture had impaired postural control compared to an uninjured age- and gender-matched control group. Methods Fifty-four individuals (patients operated on because of an ankle fracture were examined 14 months postoperatively. Muscle strength, ankle mobility, and single-limb stance on a force-platform were measured. Average speed of centre of pressure movements and number of movements exceeding 10 mm from the mean value of centre of pressure were registered in the frontal and sagittal planes on a force-platform. Fifty-four age- and gender-matched uninjured individuals (controls were examined in the single-limb stance test only. The paired Student t-test was used for comparisons between patients' injured and uninjured legs and between side-matched legs within the controls. The independent Student t-test was used for comparisons between patients and controls. The Chi-square test, and when applicable, Fisher's exact test were used for comparisons between groups. Multiple logistic regression was performed to identify factors associated with belonging to the group unable to complete the single-limb stance test on the force-platform. Results Fourteen of the 54 patients (26% did not manage to complete the single-limb stance test on the force-platform, whereas all controls managed this (p Conclusion One in four patients operated on because of an ankle fracture had impaired postural control compared to an age- and gender-matched control group. Age over 45 years and decreased strength in the ankle plantar flexors and dorsiflexors
Full Text Available In boxing, athletes choose between two strategies: the orthodox stance characteristic of right handed competitors, or the southpaw stance characteristic of left-handers. Despite a conviction popular among the practitioners of this sport that fighting against a southpaw opponent constitutes a handicap, the effectiveness of the type of stance has so far not been examined. We extracted the statistics of the top twenty active male professionals boxing in each of the seventeen weight divisions. Out of the 340 boxers who composed our group, 75% used the orthodox stance and 25% were southpaw. Generally, we found that boxing stance had no effect on the percentage of 340 top professional boxers’ victories. However, both the southpaw and the orthodox athletes had a higher percentage of victories against orthodox boxers than against southpaws.
Conclusion This study showed that the AFOs based on the models (static or dynamic had a paradoxical effect on balance, kinetic and kinematic parameters of gait in the stroke patients. AFOs had a significant improvement in balance, kinetic and kinematic parameters of gait compared to those without orthosis situation in the stroke patients. According to the result of this study, depending on the patient's needs and situation, the best and the most suitable ankle foot orthoses should be designed and custom molded for them.
Kurz, Eduard; Faude, Oliver; Roth, Ralf; Zahner, Lukas; Donath, Lars
Incomplete maturation and aging-induced declines of the neuromuscular system affect postural control both in children and older adults and lead to high fall rates. Age-specific comparisons of the modulation of ankle muscle activation and behavioral center of pressure (COP) indices during upright stance have been rarely conducted. The objective of the present study was to quantify aging effects on a neuromuscular level. Thus, surface electromyography (SEMG) modulation and co-activity of ankle muscles during single-leg standing was compared in healthy children, young adults and seniors. Postural steadiness (velocity and mean sway frequency of COP), relative muscle activation (SEMG modulation) and co-activation of two ankle muscles (tibialis anterior, TA; soleus, SO) were examined during single-leg stance in 19 children [age, 9.7 (SD 0.5) years], 30 adults [23.3 (1.5) years] and 29 seniors [62.7 (6.1) years]. Velocity of COP in medio-lateral and anterior-posterior directions, mean sway frequency in anterior-posterior direction, relative muscle activation (TA and SO) and co-activation revealed large age effects (P 0.14). Post-hoc comparisons indicated higher COP velocities, anterior-posterior frequencies, relative SO activation and co-activation in children and seniors when compared with adults. Relative TA activation was higher in children and adults compared with seniors (P modulation. However, TA modulation is higher in children and adults, whereas seniors' TA modulation capacity is diminished. An aging-induced decline of TA motor units might account for deteriorations of TA modulation in seniors.
Kim, Eun Sil; Yoon, Yong-Soon; Sohn, Min Kyun; Kwak, Soo-Hyun; Choi, Jong Ho; Oh, Ji Sun
To evaluate the feasibility and effectiveness of a knee-ankle-foot orthosis powered by artificial pneumatic muscles (PKAFO). Twenty-three hemiplegic patients (age, 59.6±13.7 years) were assessed 19.7±36.6 months after brain lesion. The 10-m walking time was measured as a gait parameter while the individual walked on a treadmill. Walking speed (m/s), step cycle (cycle/s), and step length (m) were also measured on a treadmill with and without PKAFO, and before and after gait training. Clinical parameters measured before and after gait training included Korean version of Modified Bathel Index (K-MBI), manual muscle test (MMT), and Modified Ashworth Scale (MAS) of hemiplegic ankle. Gait training comprised treadmill walking for 20 minutes, 5 days a week for 3 weeks at a comfortable speed. The 10-m walking time, walking speed, step length, and step cycle were significantly greater with PKAFO than without PKAFO, and after gait training (both p<0.05). K-MBI was improved after gait training (p<0.05), but MMT and MAS were not. PKAFO may improve gait function in hemiplegic patients. It can be a useful orthosis for gait training in hemiplegic patients.
Solanki, Punita Vasant; Sheth, Binoti Arun; Poduval, Murali; Sams, Stephen Brian Austin
The aim of this study was to study the effectiveness of modified ankle foot orthosis fabricated from low-temperature thermoplastics, as an alternative orthosis for the maintenance of correction in idiopathic congenital talipes equino varus (CTEV) deformity. The study was conducted in infants after the completion of the Ponseti serial manipulation and cast treatment, with or without, percutaneous Achilles tenotomy. Both male and female infants with unilateral or bilateral CTEV deformity were included in our study. A custom-made modified ankle foot orthosis was fabricated on the day of the removal of the last plaster of Paris cast. Initial clinical assessment, including medical history, Pirani score, modified Dimeglio score, clinical method of evaluating tibial torsion, ankle and foot range of motion were carried out on the day of the fabrication of the orthosis. Follow-up assessments were carried out at regular intervals for a duration of 6 months. All infants were provided with a set of exercises in the outpatient department three to five times per week, and other sessions were carried out by the caregivers in the form of home exercise programmes, daily every 2 h. In our study, we had 40 infants. Of these, 12 were lost to follow-up. The remaining 28 infants (22 males and six females) were included in the study. Of the 28 infants, six were left sided, seven were right sided and 15 were bilateral cases. The age at which cast treatment was initiated ranged from 1 week to 8 months, and the age at which modified ankle foot orthosis was given ranged from 1 month 1 week to 15 months. The average number of plaster of Paris casts given was six. Sixteen infants required tenotomy. We found that there was a significant reduction in the Pirani and modified Dimeglio scores from baseline to the third and to the sixth months, that is, improvement and/or maintenance of the baseline scores of Pirani and modified Dimeglio was observed (P0.05). The difference was independent of the
Kubinski, Samantha N; McQueen, Christina A; Sittloh, Keir A; Dean, Jesse C
Increases in step width have been reported for several clinical populations, including older adults and stroke survivors. These populations often also exhibit decreased hip abductor strength, suggesting that walking with wider steps may be an adaptive response in order to reduce the mechanical demands on the hip abductors. The purpose of this study was to quantify the relationship between step width and gluteus medius (GM) activity during walking. Fourteen young, uninjured adults walked on a treadmill at 1.25 m/s for four step width conditions (Normal, Narrow, Medium, and Wide) while step width and stance phase GM electromyographic (EMG) activity were quantified. We also measured hip abduction torque and GM activity during maximum voluntary isometric contractions (MVICs) at three hip angles (neutral, abducted 10°, and abducted 20°). During walking trials, GM activity was significantly (p < 0.0001) influenced by step width; compared to Normal walking, GM activity was 47% higher with Wide steps and 24% lower with Narrow steps. We also observed a weak positive correlation (r = 0.18 ± 0.14) between step width and GM activity during Normal walking, as GM activity was higher with wider steps. These results cannot be attributed to changes in GM conformation under the recording electrode, as GM activity was not influenced by hip angle during MVICs. The increased GM activity with wider steps does not support the proposal that increasing step width would be a beneficial adaptation to weakened hip abductors. A likely alternative explanation is that increased step width is a response to decreased gait balance. Published by Elsevier B.V.
Full Text Available Abstract Objective the aim of this study was to assess whether reduced balance capacity in obese subjects is secondary to altered sensory information. Design cross sectional study. Subjects 44 obese (BMI = 40.6 ± 4.6 kg/m2 , age = 34.2 ± 10.8 years, body weight: 114,0 ± 16,0 Kg, body height 167,5 ± 9,8 cm and 20 healthy controls (10 females, 10 males, BMI: 21.6 ± 2.2 kg/m2, age: 30.5 ± 5.5 years, body weight: 62,9 ± 9,3 Kg, body height 170,1 ± 5,8 cm were enrolled. Measurements center of pressure (CoP displacements were evaluated during quiet stance on a force platform with eyes open (EO and closed (EC. The Romberg quotient (EC/EO was computed and compared between groups. Results we found statistically significant differences between obese and controls in CoP displacements (p 0.08. Conclusion the increased CoP displacements in obese subjects do not need an hypothesis about altered sensory information. The integration of different sensory inputs appears similar in controls and obese. In the latter, the increased mass, ankle torque and muscle activity may probably account for the higher CoP displacements.
Serrao Mariano; Ranavolo Alberto; Andersen Ole; Conte Carmela; Don Romildo; Cortese Francesca; Mari Silvia; Draicchio Francesco; Padua Luca; Sandrini Giorgio; Pierelli Francesco
Abstract Background Modulation of nociceptive withdrawal reflex (NWR) excitability was evaluated during gait initiation in 10 healthy subjects to investigate how load- and movement-related joint inputs activate lower spinal centres in the transition from quiet stance to walking. A motion analysis system integrated with a surface EMG device was used to acquire kinematic, kinetic and EMG variables. Starting from a quiet stance, subjects were asked to walk forward, at their natural speed. The su...
Zuur, Abraham T; Christensen, Mark Schram; Sinkjær, Thomas
Abstract A rapid plantar flexion perturbation in the early stance phase of walking elicits a large stretch reflex in tibialis anterior (TA). In this study we use repetitive Transcranial Magnetic Stimulation (rTMS) to test if this response is mediated through a transcortical pathway. TA stretch...... reflexes were elicited in the early stance phase of the step cycle during treadmill walking. 20 minutes of 1 Hz rTMS at 115% resting motor threshold (MTr) significantly decreased (p
Balderas-Rosas, G.C. (Gloria del Carmen)
Neuroscientist Maxwell Bennett and philosopher Peter Hacker defend the need to eradicate the mereological fallacy of cognitive neuroscience. This fallacy attributes to the parts of an animal psychological predicates that make sense only when applied to the whole animal. In contrast, philosopher Daniel Dennett argues that it is possible to explain behavior and cognitive abilities by applying the Intentional Stance (IS) to the brain, a stance that attributes increasingly simple psychological ca...
King, Adam C; Wang, Zheng
The motor control properties of the right and left legs are dependent on the stabilization and mobilization features of the motor tasks. The current investigation examined the right and left leg control differences - interlateral asymmetries - during static single leg stance and dynamic goal directed kicking with an emphasis of the asymmetrical stabilization and mobilization components of movements. Ten young, healthy, right-leg preferred individuals with minimal kicking experience completed both tests on each limb. During static single leg stance, participants were requested to stand as still as possible with one leg in contact with a force platform. Interlateral asymmetries of the standing leg were quantified using postural variability measures of the center of pressure (COP) standard deviation in the anterior-posterior (SD-COP AP ) and medial-lateral (SD-COP ML ) directions, resultant COP length and velocity, and 95% COP elliptical area. During dynamic goal directed kicking, participants stood on two adjacent force platforms in a side-by-side foot position and kicked a soccer ball toward three different directions as soon as they received an auditory cue of kicking. Three targets were located -30°, 0° or 30° in front and 3.05 m away from the participants' midline. Participants kicked the ball toward the targets with each of their feet. The vertical ground reaction force (vGRF) of the kicking leg was used to define the preparation (from above two standard deviations of vGRF baseline to toe-off) and swing (from toe-off to toe-return) phases of dynamic kicking. To determine the presence of interlateral asymmetries during dynamic kicking, the magnitude and timing of the anticipatory postural adjustments (APA) during the preparation phase of kicking were quantified using the lateral net COP (COPnet-ML) time series derived from both force platforms. Postural variability measures of the support leg and the kinematic joint range of motion (JROM) trajectories of the
Farmani, Farzad; Mohseni Bandpei, Mohammad Ali; Bahramizadeh, Mahmood; Aminian, Gholamreza; Nikoo, Mohammad Reza; Sadeghi-Goghari, Mohammad
Ankle-foot orthoses could be utilized both with and without shoes. While several studies have shown that ankle-foot orthoses improve gait abilities in hemiplegic patients, it remains unclear whether they should be used with shoes or without. The study purpose was to compare the effect of standard shoes and rocker shoes on functional mobility in post-stroke hemiplegic patients utilizing ankle-foot orthosis. Randomized clinical study. Thirty post-stroke hemiplegic patients participated in this study randomly assigned to two groups. Group I received standard shoes + ankle-foot orthosis and group II were provided with rocker shoes + ankle-foot orthosis. Their functional mobility and energy expenditure parameters including timed up and go, timed up stairs, timed down stairs, preferred walking speed, and oxygen (O2) cost (mL/kg/m) were measured. In group I, no significant changes were seen in outcome measures after wearing standard shoes. While in group II, O2 cost and timed up and go time significantly decreased, and preferred walking speed increased when patients wore rocker shoes. Also, there was a significant difference between rocker shoes and standard shoes in improvement of timed up and go, preferred walking speed, and O2 cost. When patients using ankle-foot orthosis wore rocker shoes, their functional mobility improved and oxygen cost diminished. Also, rocker shoes was significantly more effective than standard shoes in improving functional mobility parameters. This study suggests that in post-stroke hemiplegic patients using ankle-foot orthosis, wearing rocker shoes can lead to much more improved functional mobility and decreased energy expenditure compared to ankle-foot orthosis only. Thus, in stroke patients, the combination of ankle-foot orthosis-rocker shoes is recommended for both rehabilitation programs and ankle-foot orthosis efficacy investigations. © The International Society for Prosthetics and Orthotics 2015.
Quek, Francis; Ehrich, Roger; Lockhart, Thurmon
The estimation of the direction of visual attention is critical to a large number of interactive systems. This paper investigates the cross-modal relation of the position of one's feet (or standing stance) to the focus of gaze. The intuition is that while one CAN have a range of attentional foci from a particular stance, one may be MORE LIKELY to look in specific directions given an approach vector and stance. We posit that the cross-modal relationship is constrained by biomechanics and personal style. We define a stance vector that models the approach direction before stopping and the pose of a subject's feet. We present a study where the subjects' feet and approach vector are tracked. The subjects read aloud contents of note cards in 4 locations. The order of `visits' to the cards were randomized. Ten subjects read 40 lines of text each, yielding 400 stance vectors and gaze directions. We divided our data into 4 sets of 300 training and 100 test vectors and trained a neural net to estimate the gaze direction given the stance vector. Our results show that 31% our gaze orientation estimates were within 5°, 51% of our estimates were within 10°, and 60% were within 15°. Given the ability to track foot position, the procedure is minimally invasive. PMID:20830212
Zari Sadat Seyyedrezaie
Full Text Available The present study aimed at investigating gender identity through the expression of interpersonal metadiscourse stance marking. The current study investigated male and female authors' pattern of stance markers utilization, focusing on totally 60 English and Persian articles, and English articles written by Persian speakers. Based on Xu and Longs'(2008 classification, five categories of stance markers (textual, epistemic, attitudinal, deontic and causation were identified and the frequencies of their occurrences were computed. The differences in each group were investigated separately through running chi-square tests. Regarding English articles, it was found that both male and female writers used the same pattern of stance taking except the epistemic markers. Another finding of this study was that both male and female writers followed the same pattern of stance taking in Persian articles except the deontic ones. In English articles written by Persian speakers, female writers used the same pattern as their native counterparts, while male ones were affected mostly by their native language. Attending to stance taking patterns, this article provides an informative picture which illustrates the common preferences of disciplinary community especially between male and female writers. Hence, the implications of this study can be helpful in academic writing, in assessment, and textbooks.
Tajul Arifin Muhamad
Full Text Available Background: Nowadays tennis is becoming faster and players are able to hit powerful from virtually anywhere on the tennis court. Training programmers and effective planning will help in designing safe, effective, and productive programs designed to help optimize the tennis performance of players. Objective: This research examine the effectiveness of open and closed stance forehand strokes in terms of percentage of success, accuracy and also to investigate whether there is a relation between level of accuracy and the choice of forehand strokes used by tennis player. Method: Participants were divided into two groups, namely, male and female who learned forehand strokes for one month. The participants were tested by using a two skill test for percentage of success and level of accuracy. Result: Founding showed that the closed stance forehand stroke has far better percentage of success and accuracy among the intermediate tennis players, but the difference was not significant. In addition, male players showed more accuracy and success in this research. And also accuracy did not have any influence to choice of forehand stroke among the intermediate tennis players. Conclusion: This research could improve the training protocol design for teaching the closed stance and open stance strokes. Keywords: Forehand stroke, open stance, closed stance, tennis accuracy, percentage of success
Geller, Josie; Iyar, Megumi; Srikameswaran, Suja; Zelichowska, Joanna; Dunn, Erin C
Although the role of social support is clearly established in the recovery of youth with eating disorders, little is known about factors that contribute to support satisfaction and improved treatment outcome in adults. This study examined the contribution of patient factors and perceived support stance used by family and friends in determining social support satisfaction. Individuals meeting DSM-IV criteria for an eating disorder (n = 182) completed measures of eating disorder and psychiatric severity, interpersonal functioning, perceived support stance used by family and friends, and social support satisfaction. Correlations indicated that both patient factors (lower psychiatric distress and fewer interpersonal difficulties) and perceived support stance (higher concerned and lower directive support) were associated with patient support satisfaction. Multiple regression analyses indicated that perceived support stance accounted for greater variance in social support satisfaction than did patient factors. Patient age was associated with differences in preferred support stance: expressions of caring were most critical for younger patients, whereas not being criticized or told what to do was most significant for older patients. This research suggests that the stance used when offering support is vital to the care of individuals with eating disorders. © 2017 Wiley Periodicals, Inc.
Tavernese, E; Petrarca, M; Rosellini, G; Di Stanislao, E; Pisano, A; Di Rosa, G; Castelli, E
Hemiplegic Celebral Palsy (CP) children commonly use AFO orthoses as walking aids. It is known that AFOs may have a detrimental effect on gait. To enhance mechanical properties of AFOs we developed an innovative, custom-made, carbon, ankle-foot orthosis (Ca.M.O) which offers the opportunity to tune its response to the patient's gait characteristics and/or functional maturity. To assess the efficacy of Ca.M.O. in improving gait in a group of hemiplegic CP children and to compare its performances with those of commonly prescribed AFO. A clinical and instrumental gait analysis was performed on a group of 15 spastic hemiplegic children (WINTERS-GAGE type I-II) walking barefoot, with commonly prescribed AFOs and with Ca.M.O.Temporal, kinematic and kinetic data were collected with an 8 cameras optoelectronic system and 2 force plates. Studied variables were comparable walking with Ca.M.O. and with the commonly prescribed AFO and are significantly different (p < 0.01) with respect to barefoot condition. Both types of orthoses normalize the kinematics of the first and second ankle rocker. The main advantage of Ca.M.O. is its modularity that allows to tune its effect on gait in relationship with the progress or involution of the child's functional development.
Kim, Daehan; Unger, Janelle; Lanovaz, Joel L; Oates, Alison R
The knee abduction moment in a weight-bearing limb is an important risk factor of conditions such as patellofemoral pain and knee osteoarthritis. Excessive pelvic drop in single-leg stance can increase the knee abduction moment. The gluteus medius muscle is crucial to prevent pelvic drop and must be activated in anticipation of the transition from double-leg to single-leg stance. To examine the relationship of anticipatory activity of the gluteus medius to pelvic drop and knee abduction moment. Observational, cross-sectional correlational study. Research laboratory. Twenty female adults (mean age 22.6 years, standard deviation 2.5) were recruited and fully participated. Participant selection was limited to healthy women who did not have a history of knee and ankle ligament injuries, any indication of knee, hip, and/or low back pain, and/or knowledge of the proper squat technique. Participants performed 16 single-leg mini squats on their nondominant leg. The onset and magnitude of anticipatory gluteus medius activity were measured in relation to toe-off of the dominant leg during the transition from double-leg to single-leg stance. Preplanned correlations between anticipatory gluteus medius onset and its activation magnitude, pelvic obliquity, and knee abduction moment were examined. The magnitude of anticipatory gluteus medius activity was significantly correlated with the knee abduction moment (rs (18) = -0.303, P pelvic obliquity (rs (18) = 0.361, P pelvic obliquity. The amount of gluteus medius activity is more important for controlling knee and pelvic stability in the frontal plane than the onset of activation. Copyright © 2016 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.
Fukaya, Takashi; Mutsuzaki, Hirotaka; Wadano, Yasuyoshi
The purposes of this study were to understand the kinematics changes in the frontal and horizontal planes with severe medial knee OA at the stance phase and to examine the relationship between varus and rotational movements. The OA group comprised 18 knees in 12 subjects (five men, seven women) with a Kellgren-Lawrence grade of three or four in at least one knee. From the results of gait analysis, we calculated Spearman rank-correlation coefficients for the following items: varus angle at initial contact (IC); varus angle at loading response (LR); amount of varus thrust from IC to LR; rotational angle at IC; rotational angle at LR and amount of rotational angle change from IC to LR. The results indicated that, as the external rotation angle at IC and internal rotational movement from IC to LR increased, the maximum varus angle to LR showed a tendency to become large. In addition, varus thrust showed a tendency to become larger as the external rotation angles increased at IC and LR. The subjects with severe knee OA showed a strong correlation between the knee varus angle at IC and at LR. Furthermore, an increase in movement to internal rotation of the knee during the initial stance phase increased the knee varus angle at LR. The control of the rotational movement according to the extent of varus thrust during the initial stance phase may have possible effects to decrease the load on the medial compartment of the knee. Copyright © 2015 Elsevier B.V. All rights reserved.
Farzadi, Maede; Safaeepour, Zahra; Mousavi, Mohammad E; Saeedi, Hassan
Higher plantar pressures at the medial forefoot are reported in hallux valgus. Foot orthoses with medial arch support are considered as an intervention in this pathology. However, little is known about the effect of foot orthoses on plantar pressure distribution in hallux valgus. To investigate the effect of a foot orthosis with medial arch support on pressure distribution in females with mild-to-moderate hallux valgus. Quasi-experimental. Sixteen female volunteers with mild-to-moderate hallux valgus participated in this study and used a medial arch support foot orthosis for 4 weeks. Plantar pressure for each participant was assessed using the Pedar-X(®) in-shoe system in four conditions including shoe-only and foot orthosis before and after the intervention. The use of the foot orthosis for 1 month led to a decrease in peak pressure and maximum force under the hallux, first metatarsal, and metatarsals 3-5 (p hallux and the first metatarsal head by transferring the load to the other regions. It would appear that this type of foot orthosis can be an effective method of intervention in this pathology. Findings of this study will improve the clinical knowledge about the effect of the medial arch support foot orthosis used on plantar pressure distribution in hallux valgus pathology. © The International Society for Prosthetics and Orthotics 2014.
Jensen, Erik Føge; Raunsbæk, Joakim; Lund, Jan Nørgaard
Introduction People who are born with arthrogryposis multiplex congenita are typically not able to perform activities of daily living (ADL) due to decreased muscle mass, joint contractures and unnatural upper extremity positioning. They are, therefore, potential users of an assistive device capable....... Results For a given configuration using a mono- and a bi-articular spring, the simulations showed that spring stiffnesses of 400?Nm?1 and of 1029?Nm?1, respectively, were able to lower the maximal muscle activity estimated by the musculoskeletal model to a level in which the 10 postures can be realized....... Conclusion By augmenting residual muscle strength with a partially gravity-balanced passive orthosis, ADLs may be achievable for people with arthrogryposis multiplex congenita....
Thompson, N S; Taylor, T C; McCarthy, K R; Cosgrove, A P; Baker, R J
Eighteen children with hemiplegia, mean age 8 years 5 months, underwent gait analysis and musculoskeletal modelling using specially designed software. The maximum lengths of the hamstrings were determined for each child walking in and out of an ankle-foot orthosis (AFO). The muscles were deemed to be short if shorter than the normal average -1SD. In bare feet 8 participants had short medial hamstrings with a higher proportion of these in the less involved individuals. All participants showed an increase in maximum hamstring length when wearing an AFO. In all but one child this was sufficient to restore hamstring length to within normal limits. These finding suggest that hamstring pathology in hemiplegic gait is usually secondary to more distal lower limb pathology.
Full Text Available Ankle foot orthosis (AFO are commonly used to correct the instabilities and joint weakness of lower limb. In this research, AFO was developed by using pneumatic artificial muscle (PAM to prevent plantarflexion to occur and also to correct the foot from the inversion syndrome. The research started with designing the AFO by using SolidWorks software based on anthropometry measurement data (n=5, age=12 years old. The mechanical simulation was conducted by using Autodesk Inventor software to obtain a safety factor before the fabrication process was conducted. The AFO was fabricated using 3D printer and the thermoplastic elastomer (TPE rubber was selected as the material. PAM was tested by using test bed machine to generate the force and contraction by muscle. The result shows that the PAM was suitable for low speed as the displacement was greater. The AFO could be valuable for the gait rehabilitation.
Yuan, Kebin; Parri, Andrea; Yan, Tingfang; Wang, Long; Munih, Marko; Vitiello, Nicola; Wang, Qining
In this paper, we present a fuzzy-logic-based hybrid locomotion mode classification method for an active pelvis orthosis. Locomotion information measured by the onboard hip joint angle sensors and the pressure insoles is used to classify five locomotion modes, including two static modes (sitting, standing still), and three dynamic modes (level-ground walking, ascending stairs, and descending stairs). The proposed method classifies these two kinds of modes first by monitoring the variation of the relative hip joint angle between the two legs within a specific period. Static states are then classified by the time-based absolute hip joint angle. As for dynamic modes, a fuzzy-logic based method is proposed for the classification. Preliminary experimental results with three able-bodied subjects achieve an off-line classification accuracy higher than 99.49%.
Kawa, Jacek; Stępień, Paula; Kapko, Wojciech; Niedziela, Aleksandra; Derejczyk, Jarosław
Falls are a major risk in elder population. Early diagnosis is therefore an important step towards increasing the safety of elders. One of the common diagnostic tests is the Berg Balance Scale (BBS), consisting of 14 exercises arranged from the easiest (sitting-to-standing) to the most demanding (one-leg stance). In this study a novel approach to the automatic assessment of the time in which the patient can remain in the one-leg stance position without loosing balance is introduced. The data is collected using a regular video camera. No markers, special garments, or system calibration are required. Two groups are examined. The first group consists of 16 students: healthy, young adults (12 female, 4 male, avg. 20yrs±1). The second group consists of 50 elders (39 female, 11 male, avg. 78.8yrs±5.9). Data (short, one minute recordings) are collected in a controlled environment using a digital video recorder (50fps, 1920×1080) fixed to a tripod. Data are processed off-line. First, the region of interest is determined. Next, the Kanade-Lucas-Tomasi tracking is performed. Best tracks are selected based on the registered vertical movement and two tracks are obtained corresponding to the left and right leg movements. Tracks are later subjected to the sparse signal baseline estimation, denoising and thresholding to detect the raised leg. Results are compared frame-wise to the ground truth reference obtained in the manual processing procedure. Both legs are evaluated in the elder group (in all cases several attempts featuring both legs were registered), resulting in 89.18%±11.27% DICE, 93.07%±5.43% sensitivity and 96.94%±6.11% specificity values for both legs. The signal of a single leg is evaluated in the student group (in all cases only one attempt was needed to perform the full examination) resulting in 98.96%±1.2% DICE, 98.78%±1.65% sensitivity and 98.73%±2.69% specificity values. This is the first step towards a video-based system enabling the automatic
Fisher, D. K.; Leon, N.; Jackson, R.; Greene, M. P.
. Various recycling bins (glass, plastic, metal, and paper) are lined up on the left and right sides of the screen, with a trash bin at the bottom. As an item drops, the player must quickly decide what kind of material it is made of and whether it is recyclable, then guide it into the appropriate bin. As the rate of items entering play increases, any missed items fall into the trash and stay there for a length of time proportional to their decomposition time. If the trash bin gets full, the game is over. While enjoying the increasing challenge of the game, players learn to identify many items as recyclable that they may not have recognized as recyclable before. Another feature on Climate Kids is "Climate Tales," a slightly edgy animated cartoon series (two episodes so far) about the adventures of a blundering polar bear, a chirpy tamarin monkey, and a grumpy old fish as "accidental tourists" around the planet, observing and dealing with the environmental conditions they encounter. Fairly complex concepts (such as reasons and implications of the declining abundance of phytoplankton) are woven into the tales. Climate Kids is a fun site for kids, educational and realistic, and yet positive and hopeful-the only reasonable stance to present to this young audience.
Changes in joint kinematics in children with cerebral palsy while walking with and without a floor reaction ankle-foot orthosis Mudanças na cinemática articular em crianças com paralisia cerebral durante o andar com e sem órteses de reação ao solo
Paulo Roberto Garcia Lucareli
Full Text Available INTRODUCTION: The floor reaction ankle-foot orthosis is commonly prescribed in the attempt to decrease knee flexion during the stance phase in the cerebral palsy (CP gait. Reported information about this type of orthosis is insufficient. PURPOSE: The purpose of this study was to determine the effect of clinically prescribed floor reaction ankle-foot orthosis on kinematic parameters of the hip, knee and ankle in the stance phase of the gait cycle, compared to barefoot walking on children with cerebral palsy. METHODS: A retrospective chart review of 2200 patients revealed that 71 patients (142 limbs had a diagnosis of diplegia, with no contractures in hip, knee or ankle flexion. Their average age was 12.2 ± 3.9. All of them were wearing clinically prescribed hinged floor reaction ankle-foot orthosis undergoing a three dimensional gait analysis. We divided the patients in three groups: Group I, with limited extension (maximum knee extension less than 15º; Group II, with moderate limited extension (maximum knee extension between 15º and 30º and Group III Crouch (maximum knee extension in stance more than 30º. RESULTS: Results indicate the parameters maximum knee extension and ankle dorsiflexion were significant in Group II e III; no change was observed in Group I. The maximum hip extension was not significant in all three groups. Conclusion: when indicated to improve the extension of the knees and ankle in the stance of the CP patients floor reaction ankle-foot orthosis was effective.INTRODUÇÃO: A órtese de reação ao solo é freqüentemente prescrita com o objetivo de reduzir a flexão do joelho durante a fase de apoio na marcha de pacientes com paralisia cerebral. Não há informações suficientes relatadas na literature sobre este tipo de órteses. OBJETIVOS: O objetivo deste estudo foi determinar o efeito que a órtese de reação ao solo tem na cinamática angular das articulações do quadril, joelho e tornozelo durante a fase de
Full Text Available The pedunculopontine area (PPNa including the pedunculopontine and cuneiform nuclei, belongs to the mesencephalic locomotor region. Little is known about the oscillatory mechanisms underlying the function of this region in postural and gait control. We examined the modulations of the oscillatory activity of the PPNa and cortex during stepping, a surrogate of gait, and stance in seven Parkinson's disease patients who received bilateral PPNa implantation for disabling freezing of gait (FOG. In the days following the surgery, we recorded behavioural data together with the local field potentials of the PPNa during sitting, standing and stepping-in-place, under two dopaminergic medication conditions (OFF and ON levodopa. Our results showed that OFF levodopa, all subjects had FOG during step-in-place trials, while ON levodopa, stepping was effective (mean duration of FOG decreasing from 61.7±36.1% to 7.3±10.1% of trial duration. ON levodopa, there was an increase in PPNa alpha (5-12 Hz oscillatory activity and a decrease in beta (13-35 Hz and gamma (65-90 Hz bands activity. PPNa activity was not modulated during quiet standing and sitting. Our results confirm the role of the PPNa in the regulation of gait and suggest that, in Parkinson disease, gait difficulties could be related to an imbalance between low and higher frequencies.
Herbaut, Alexis; Simoneau-Buessinger, Emilie; Barbier, Franck; Gillet, Christophe; Roux, Maxime; Guéguen, Nils; Chavet, Pascale
Compared to traditional tennis shoes, using 0-drop shoes was shown to induce an immediate switch from rear- to forefoot strike pattern to perform an open stance tennis forehand for 30% of children tennis players. The purpose of the study was to examine the long-term effects of a gradual reduction in the shoe drop on the biomechanics of children tennis players performing open stance forehands. Thirty children tennis players participated in 2 laboratory biomechanical test sessions (intermediate: +4 months and final: +8 months) after an inclusion visit where they were randomly assigned to control (CON) or experimental (EXP) group. CON received 12-mm-drop shoes twice, whereas EXP received 8 mm then 4-mm-drop shoes. Strike index indicated that all CON were rearfoot strikers in intermediate and final test sessions. All EXP were rearfoot strikers in intermediate test session, but half the group switched towards a forefoot strike pattern in final test session. This switch resulted in a decreased loading rate of the ground reaction force (-73%, p = .005) but increased peak ankle plantarflexors moment (+47%, p = .050) and peak ankle power absorption (+107%, p = .005) for these participants compared with CON. Biomechanical changes associated with the long-term use of partial minimalist shoes suggest a reduction in heel compressive forces but an increase in Achilles tendon tensile forces.
Sankaranarayan, H.; Gupta, Anupam; Khanna, Meeka; Taly, Arun B.; Thennarasu, K.
Objective: To study role of ankle foot orthosis (AFO) in improving locomotion and functional recovery after stroke. Setting: Neurological Rehabilitation Department of a university research tertiary hospital. Patients and Methods: AFO and activity based rehabilitation. Main Outcome Measures: Distance (meters) covered during the 6-minute walk test (6MWT) and speed (meter/second) during the 10-meter walk test. Functional abilities assessed using Functional Independence Measure (FIM®). Results: ...
Sharma, Sheena; McMorland, Angus J C; Stinear, James W
Following stroke, little is known about ground reaction forces during gait initiation. To compare stroke patients' with healthy subjects' anterior, medial, and lateral ground reaction forces generated during gait initiation. Patients with left paresis, right paresis, and age-similar healthy subjects were recruited. During gait initiation the average peak anterior, medial, and lateral ground reaction forces acting on each lower limb were calculated when it was the stance limb. Anterior ground reaction forces acting on the right and left stance limbs of healthy subjects were greater than anterior forces acting on the nonparetic and paretic limbs of stroke patients. Medial ground reaction forces for the nonparetic and paretic limbs of stroke patients and for the right and left stance limbs of healthy subjects were equivalent. While lateral ground reaction forces acting on the nonparetic and paretic limbs were equivalent for left paretic patients, for right paretic patients lateral forces acting on the nonparetic limb were greater compared to the paretic limb and also greater compared to the left limb of healthy subjects. An effect of side-of-lesion was revealed in average peak lateral ground reaction force data. Larger lateral ground reaction forces acting on the left nonparetic stance limb of right paretic patients compared to the right nonparetic stance limb of left paretic patients during gait initiation may be an indication of differing adaptations that depend on the side-of-lesion. Copyright © 2015 Elsevier Ltd. All rights reserved.
Full Text Available For the purpose of enhancing organizational sustainability during a crisis, an organization takes a position in decision-making, how to respond toward its public, and that is supposed to determine which stance or tactic to employ. This study aims to examine whether publics’ perceptions of organizational crisis responsibility affect their expectations that an organization should choose certain stances and strategies toward the public in a crisis. To address these concerns, an experiment was conducted. As the specific public of this research, health journalists were selected, since they affect public perceptions significantly and public opinion can ultimately put pressure on an organization. Results from an analysis of the experimental data with health journalists confirm that they expect a more accommodative stance/strategy when they perceive that the organization is highly responsible for a health-related crisis. Conversely, when the journalists perceive that an organization has a low level of responsibility for a crisis, they expect a more advocative stance/strategy. By taking into account the health journalists’ expectations along with the needs of the organization, public relations practitioners are better able to make optimal decisions regarding their client organizations’ adopted stance and strategy, and finally, enhance organizational sustainability in a crisis.
Krishnamoorthy, Vijaya; Hsu, Wei-Li; Kesar, Trisha M; Benoit, Daniel L; Banala, Sai K; Perumal, Ramu; Sangwan, Vivek; Binder-Macleod, Stuart A; Agrawal, Sunil K; Scholz, John P
This case report describes the application of a novel gait retraining approach to an individual with poststroke hemiparesis. The rehabilitation protocol combined a specially designed leg orthosis (the gravity-balanced orthosis), treadmill walking, and functional electrical stimulation to the ankle muscles with the application of motor learning principles. The participant was a 58-year-old man who had a stroke more than three years before the intervention. He underwent gait retraining over a period of five weeks for a total of 15 sessions during which the gravity compensation provided by the gravity-balanced orthosis and visual feedback about walking performance was gradually reduced. At the end of five weeks, he decreased the time required to complete the Timed Up and Go test; his gait speed increased during overground walking; gait was more symmetrical; stride length, hip and knee joint excursions on the affected side increased. Except for gait symmetry, all other improvements were maintained one month post-intervention. This case report describes possible advantages of judiciously combining different treatment techniques in improving the gait of chronic stroke survivors. Further studies are planned to evaluate the effectiveness of different components of this training in both the subacute and chronic stages of stroke recovery.
Kim, Kyong; Yu, Chang-Ho; Kwon, Tae-Kyu; Hong, Chul-Un; Kim, Nam-Gyun
There developed a lower limb orthosis with a pneumatic rubber actuator, which can assist and improve the muscular activities in the lower limb of the elderly. For this purpose, the characteristics of the lower limbs muscle activities for various pressures in the pneumatic actuator for the lower limb orthosis was investigated. To find out the characteristics of the muscle activities for various pneumatic pressures, it analyzed the flexing and extending movement of the knees, and measured the lower limbs muscular power. The subjects wearing the lower limbs orthosis were instructed to perform flexing and extending movement of the knees. The variation in the air pressure of the pneumatic actuator was varies from one kgf/cm2 to four kgf/cm2. The muscular power was measured by monitoring electromyogram using MP100 (BIOPAC Systems, Inc.) and detailed three-dimensional motions of the lower limbs were collected by APAS 3D Motion Analysis system. Through this study, it expected to find the most suitable air pressure for the improvement of the muscular power of the aged.
Katsuhira, Junji; Matsudaira, Ko; Yasui, Tadashi; Iijima, Shinno; Ito, Akihiro
Postural alignment of elderly people becomes poor due to aging, possibly leading to low-back pain and spinal deformity. Although there are several interventions for treating these conditions, no previous study has reported the effectiveness of a spinal orthosis or lumbosacral orthosis (LSO) in healthy elderly people without specific spinal deformity. We therefore developed a trunk orthosis to decrease low-back muscle activity while training good postural alignment through resistive force provided by joints with springs (here, called the ORF, which stands for orthosis with joints providing resistive force) as a preventive method against abnormal posture and low-back pain in healthy elderly persons. Fifteen community-dwelling elderly men participated in this study. Participants stood freely for 10 seconds in a laboratory setting under three conditions: without an orthosis, with the ORF, and with an LSO. The Damen corset LSO was selected as it is frequently prescribed for patients with low-back pain. Postural alignment during static standing was recorded using a three-dimensional motion capture system employing infrared cameras. Two force plates were used to record center of pressure. Electromyograms were obtained for bilateral erector spinae (ES), left internal abdominal oblique, and right gluteus medius muscles. Pelvis forward tilt angle tended to increase while wearing the ORF and decrease while wearing the LSO, but these results were not significant compared to no orthosis. Thorax extension angle and thorax angle on pelvis coordinate system significantly increased while wearing the ORF compared to the other two conditions. ES activity significantly decreased while wearing the ORF compared to the other two conditions. Internal oblique activity was significantly smaller while wearing the LSO than with no orthosis. Center of pressure did not significantly differ among the conditions. The ORF significantly improved trunk alignment and decreased ES activity in healthy
Katsuhira, Junji; Matsudaira, Ko; Yasui, Tadashi; Iijima, Shinno; Ito, Akihiro
Purpose Postural alignment of elderly people becomes poor due to aging, possibly leading to low-back pain and spinal deformity. Although there are several interventions for treating these conditions, no previous study has reported the effectiveness of a spinal orthosis or lumbosacral orthosis (LSO) in healthy elderly people without specific spinal deformity. We therefore developed a trunk orthosis to decrease low-back muscle activity while training good postural alignment through resistive force provided by joints with springs (here, called the ORF, which stands for orthosis with joints providing resistive force) as a preventive method against abnormal posture and low-back pain in healthy elderly persons. Patients and methods Fifteen community-dwelling elderly men participated in this study. Participants stood freely for 10 seconds in a laboratory setting under three conditions: without an orthosis, with the ORF, and with an LSO. The Damen corset LSO was selected as it is frequently prescribed for patients with low-back pain. Postural alignment during static standing was recorded using a three-dimensional motion capture system employing infrared cameras. Two force plates were used to record center of pressure. Electromyograms were obtained for bilateral erector spinae (ES), left internal abdominal oblique, and right gluteus medius muscles. Results Pelvis forward tilt angle tended to increase while wearing the ORF and decrease while wearing the LSO, but these results were not significant compared to no orthosis. Thorax extension angle and thorax angle on pelvis coordinate system significantly increased while wearing the ORF compared to the other two conditions. ES activity significantly decreased while wearing the ORF compared to the other two conditions. Internal oblique activity was significantly smaller while wearing the LSO than with no orthosis. Center of pressure did not significantly differ among the conditions. Conclusion The ORF significantly improved trunk
Full Text Available Background: Efficacy of rehabilitation program for subjects with orthosis with objective measurement. The study aiming to objectively compare the PCI and walking speed of normal children with ambulatory spastic diaplegic. Also we aimed to analyze whether BMIhad impact on energy cost. Methods: 41 normal children and 41 community walking spastic diaplegic aged between 6 to 18 yrs. were assessed to compare the PCI. Speed of walking and heart rate were checked constantlyboth barefoot and in shoes in normal children and with and without conventional AFO in children with spastic diaplegic at their chosen velocities over four consecutive lengths of a 12.5m walkway i.e. total 50m.,Pre and Post readings are taken. Heart rate is affected by speed; PCI with speed of walking and heart rate was calculated for each child. Results: The mean PCI in shoes and barefoot was same in normal children i.e. 0.05 ±0.039beats/meter. The PCI for children with pathological gait i.e. spastic diaplegic without orthosis and with orthosis is 0.199 ±0.176 and 0.104± 0.093beats/meter appreciably greater than that for normal children(p less than 0.05. Conclusion: This study showed that walking with orthosis in spastic diplegic CP children showed higher costs of energy and slower walking speed compared normal children with age matched. The PCI of walking, with orthosis in children with spastic Diplegic cerebral palsy is less as compared to without orthosis i.e. gait is more energy efficient with orthosis. BMI doesn’t show any correlation with PCI further study may require.
Kim, Jwa-jun; Park, Se-yeon
[Purpose] The purpose of this study was to evaluate the immediate effect of stabilizing exercise using the PNF technique on standing balance in one-leg and double-leg stances. [Subjects and Methods] The present study recruited 34 healthy participants from a local university. The Participants performed four balance tests (double-leg stance with and without vision, one-leg stance with and without vision), before and after exercise. The exercise consisted of exercises performed using PNF techniq...
Dwi Noverini Djenar
Full Text Available This article examines representations of adolescent social media interaction in two Indonesian teen novels to show how adolescent communication styles are typified. It is argued that public discourse on the potential danger of social media interaction is resounded in the novels. The article demonstrates that the authors of both novels take a similar moral stance on the issue of social media but use different rhetorical strategies for indexing that stance. Both draw on the social values of registers to communicate the stance. In Online addicted, standard Indonesian is used in narration to convey an authoritative voice and a stern moral tone, while the gaul register indexes an alignment with favourable aspects of the protagonist’s character. In Jurnal Jo online, gaul is similarly given a positive value by virtue of its juxtaposition with the Alay register. In this novel, gaul is the preferred, standard register. In both novels, there is a strong orientation toward “standardness”.
In recent years, palliative care and related organizations have increasingly adopted a stance of "studied neutrality" on the question of whether euthanasia should be legalized as a bona fide medical regimen in palliative care contexts. This stance, however, has attracted criticism from both opponents and proponents of euthanasia. Pro-euthanasia activists see the stance as an official position of indecision that is fundamentally disrespectful of a patient's right to "choose death" when life has become unbearable. Some palliative care constituents, in turn, are opposed to the stance, contending that it reflects an attitude of "going soft" on euthanasia and as weakening the political resistance that has hitherto been successful in preventing euthanasia from becoming more widely legalized. In this article, attention is given to examining critically the notion and possible unintended consequences of adopting a stance of studied neutrality on euthanasia in palliative care. It is argued that although palliative care and related organizations have an obvious stake in the outcome of the euthanasia debate, it is neither unreasonable nor inconsistent for such organizations to be unwilling to take a definitive stance on the issue. It is further contended that, given the long-standing tenets of palliative care, palliative care organizations have both a right and a responsibility to defend the integrity of the principles and practice of palliative care and to resist demands for euthanasia to be positioned either as an integral part or logical extension of palliative care. Copyright © 2012 U.S. Cancer Pain Relief Committee. Published by Elsevier Inc. All rights reserved.
Bakker, Maaike; Allum, John H J; Visser, Jasper E; Grüneberg, Christian; van de Warrenburg, Bart P; Kremer, H P H; Bloem, Bastiaan R
Previous studies of patients with focal cerebellar damage underscored the importance of the cerebellum for balance control. These studies were restricted to postural control in the pitch plane, and focused mainly on leg muscle responses. Here, we examined the effect of degenerative cerebellar
Yong Ho Cha
Full Text Available We described 3D printing technique and automated design software and clinical results after the application of this AFO to a patient with a foot drop. After acquiring a 3D modelling file of a patient’s lower leg with peroneal neuropathy by a 3D scanner, we loaded this file on the automated orthosis software and created the “STL” file. The designed AFO was printed using a fused filament fabrication type 3D printer, and a mechanical stress test was performed. The patient alternated between the 3D-printed and conventional AFOs for 2 months. There was no crack or damage, and the shape and stiffness of the AFO did not change after the durability test. The gait speed increased after wearing the conventional AFO (56.5 cm/sec and 3D-printed AFO (56.5 cm/sec compared to that without an AFO (42.2 cm/sec. The patient was more satisfied with the 3D-printed AFO than the conventional AFO in terms of the weight and ease of use. The 3D-printed AFO exhibited similar functionality as the conventional AFO and considerably satisfied the patient in terms of the weight and ease of use. We suggest the possibility of the individualized AFO with 3D printing techniques and automated design software.
Gao, Fan; Carlton, William; Kapp, Susan
Articulated or hinged ankle-foot orthosis (AFO) allow more range of motion. However, quantitative investigation on articulated AFO is still sparse. The objective of the study was to quantitatively investigate effects of alignment and joint types on mechanical properties of the thermoplastic articulated AFO. Tamarack dorsiflexion assist flexure joints with three durometers (75, 85 and 95) and free motion joint were tested. The AFO joint was aligned with the center of the motor shaft (surrogate ankle joint), 10 mm superior, inferior, anterior and posterior with respect to the motor shaft center. The AFO was passively moved from 20° plantar flexion to 15° dorsiflexion at a speed of 10°/s using a motorized device. Mechanical properties including index of hysteresis, passive resistance torque and quasi-static stiffness (at neutral, 5°, 10° and 15° in plantar flexion) were quantified. Significant effects of joint types and joint alignment on the mechanical properties of an articulated thermoplastic AFO were revealed. Specifically, center alignment showed minimum resistance and stiffness while anterior and posterior alignment showed significantly higher resistance and stiffness. The dorsiflexion assist torques at neutral position ranged from 0.69 ± 0.09 to 1.88 ± 0.10 Nm. Anterior and posterior alignment should be avoided as much as possible. The current study suggested that anterior and posterior alignment be avoided as much as possible in clinical practice due to potential skin irritation and increase in stress around the ankle joint.
Roberts, R S; Price, C T; Riddick, M F
Forty-four consecutive patients with idiopathic scoliosis treated by posterior spinal fusion and Harrington rod instrumentation were immobilized after surgery with bivalved polypropylene orthoses. Immediate ambulation was allowed, and the patients wore the orthoses for a mean of 5.9 months. Brace removal was permitted with the patient recumbent for sponge bathing. These patients were followed up for a mean of 2.1 years (range, 1.0-4.3 years). The average final correction for all curves was 45%. The average loss of correction was 2.4 degrees (5.3%). Combined distraction and compression instrumentation was found to improve final correction in all curves by 3 degrees (6.2%) as compared with distraction instrumentation alone. There were no pseudarthroses and no rod breakage. Patients enjoyed the benefits of improved personal hygiene, pleasing cosmetic appearance, and increased life-style flexibility, especially swimming, which was not possible with the conventional Risser plaster cast. Use of the polypropylene orthosis offers significant advantages as compared with previous methods of postoperative management: it not only provides consistently good results but is enthusiastically accepted by patients as well.
Full Text Available In this paper, we demonstrate how a systematic taxonomy of stances can help elucidate two classic debates of the historical turn—the Lakatos–Feyerabend debate concerning theory rejection and the Feyerabend–Kuhn debate about pluralism during normal science. We contend that Kuhn, Feyerabend, and Lakatos were often talking at cross-purposes due to the lack of an agreed upon taxonomy of stances. Specifically, we provide three distinct stances that scientists take towards theories: acceptance of a theory as the best available description of its domain, use of a theory in practical applications, and pursuit (elaboration of a theory. We argue that in the Lakatos–Feyerabend debate, Lakatos was concerned with acceptance whereas Feyerabend was mainly concerned with pursuit. Additionally, we show how Feyerabend and Kuhn’s debate on the role of pluralism/monism in normal science involved a crucial conflation of all three stances. Finally, we outline a few general lessons concerning the process of scientific change.
Otsuka, Mitsuo; Kurihara, Toshiyuki; Isaka, Tadao
This study aimed to clarify the effect of widened stance width at the set position during the block start phase in sprint running on kinematics and kinetics at the hip joint and block-induced power. Fourteen male sprinters volunteered to participate in this study. They performed three block-start trials with a normal stance width (25 ± 1 cm, normal condition) and a widened stance width (45 ± 2 cm, widened condition) at the set position. The block start movements were recorded at 250 Hz with high-speed cameras and the ground reaction forces at 1250 Hz with force plates. During the block phase in the widened condition, the hip abduction and external rotation angles in both legs were significantly larger and smaller, respectively, than those in the normal condition. The positive peak value of the hip power in the rear leg was significantly greater in the widened condition than that in the normal condition. However, no significant difference was seen in the normalized block-induced power between the widened and normal conditions. We conclude that a widened stance width at the set position affects the hip-joint kinematics and rear hip power generation during the block start phase, but no effect on the block-induced power when considering sprinting performance during the whole block start phase.
Bernardo, Alejandro S.
This paper reports the results of a survey which involved College English teachers from three leading universities in the Philippines. The results point to one conclusion--College English teachers now have a changing and changed stance toward norm selection in Philippine Universities. The results give the impression that a good number of College…
Linssen, Johannes Maria; Theune, Mariet; Heylen, Dirk K.J.; Hindriks, K.; de Weerdt, M.; van Riemsdijk, B.; Warnier, M.
We propose a combination of theories about interpersonal stances and politeness to inform virtual agent behaviour in a serious game, aimed at social interaction training in the domain of law enforcement. A pilot study we conducted showed promising results based on which we will refine our model.
Horlings, Corinne G C; Carpenter, Mark G; Küng, Ursula M; Honegger, Flurin; Wiederhold, Brenda; Allum, John H J
Balance problems during virtual reality (VR) have been mentioned in the literature but seldom investigated despite the increased use of VR systems as a training or rehabilitation tool. We examined the influence of VR on body sway under different stance conditions. Seventeen young subjects performed four tasks (standing with feet close together or tandem stance on firm and foam surfaces for 60s) under three visual conditions: eyes open without VR, eyes closed, or while viewing a virtual reality scene which moved with body movements. Angular velocity transducers mounted on the shoulder provided measures of body sway in the roll and pitch plane. VR caused increased pitch and roll angles and angular velocities compared to EO. The effects of VR were, for the most part, indistinguishable from eyes closed conditions. Use of a foam surface increased sway compared to a firm surface under eyes closed and VR conditions. During the movements of quiet stance, VR causes an increase in postural sway in amplitude similar to that caused by closing the eyes. This increased sway was present irrespective of stance surface, but was greatest on foam.
McGrath, Lisa; Kuteeva, Maria
Recent ESP research into academic writing has shown how writers convey their stance and interact with readers across different disciplines. However, little research has been carried out into the disciplinary writing practices of the pure mathematics academic community from an ESP genre analysis perspective. This study begins to address this gap by…
Broughton, Mary A.; Fairbanks, Colleen M.
Describes how in the examination of a sixth-grade girl's participation in the language arts classroom that is driven by high-stakes testing and by a regimented classroom culture, the authors came to view students' approaches to literacy events as "stances" and their negotiation of their subjectivities in response to literacy events as…
Stančík, Juraj; Välilä, T.
Roč. 43, č. 1 (2012), s. 199-217 ISSN 0377-7332 Institutional research plan: CEZ:AV0Z70850503 Keywords : fiscal policy * public expenditure * fiscal stance Subject RIV: AH - Economics Impact factor: 0.614, year: 2012
Bruijnes, Merijn; op den Akker, Hendrikus J.A.; Spitters, Sophie; Sanders, Merijn; Fu, Quihua
This paper reports on judgement studies regarding the perception of interpersonal stances taken by humans playing the role of a suspect in a police interrogation setting. Our project aims at building believable embodied conversational characters to play the role of suspects in a serious game for
This study investigates how Turkish teachers take and give stances in the discourse on globalization and language by using linguistic resources. According to the findings obtained through the discourse analysis of the corpus that consisted of 36 h of recording of the discussion among 4 teachers with 5 to 10 years of teaching experience, the…
Roseano, Paolo; González, Montserrat; Borràs-Comes, Joan; Prieto, Pilar
This study investigates how epistemic stance is encoded and perceived in face-to-face communication when language is regarded as comprised by speech and gesture. Two studies were conducted with this goal in mind. The first study consisted of a production task in which participants performed opinion reports. Results showed that speakers communicate…
Simonsen, Erik B; Cappelen, Katrine L; Skorini, Ragnhild ί; Larsen, Peter K; Alkjær, Tine; Dyhre-Poulsen, Poul
A hip joint flexor moment in the last half of the stance phase during walking has repeatedly been reported. However, the purpose of this moment remains uncertain and it is unknown how it is generated. Nine male subjects were instructed to walk at 4.5 km/h with their upper body in three different positions: normal, inclined and reclined. Net joint moments were calculated about the hip, knee and ankle joint. The peak hip joint flexor moment during late stance was significantly lower during inclined walking than in the two other conditions. During normal walking the iliacus muscle showed no or very weak activity and first at the transition from stance to swing. When walking reclined, a clear but rather low activity level of the iliacus muscle was seen in the first half of the stance phase, which could contribute to the hip moment. In the inclined condition the iliacus showed much increased activity but only in the swing phase. It is concluded that the hip flexor moment in question is largely generated by passive structures in the form of ligaments resisting hip joint extension.
Chang, Peichin; Tsai, Chin-Chung
Taking an effective authorial stance in research argumentation has been designated as both vitally important and challenging. The study investigated English as a foreign language (EFL) doctoral students' conceptions of authorial stance, the role of domains in affecting their conceptions, and the ties of the conceptions to the participants'…
This article explores the practices and pedagogies of six literacy teacher educators with a critical stance. In this qualitative research study, three semi-structured interviews were conducted with each participant over a three-year period. They were able to negotiate a critical stance into their teacher education courses in several ways: using an…
Escamilla, R F; Fleisig, G S; Lowry, T M; Barrentine, S W; Andrews, J R
The purpose of this study was to quantify biomechanical parameters employing two-dimensional (2-D) and three-dimensional (3-D) analyses while performing the squat with varying stance widths. Two 60-Hz cameras recorded 39 lifters during a national powerlifting championship. Stance width was normalized by shoulder width (SW), and three stance groups were defined: 1) narrow stance squat (NS), 107 +/- 10% SW; 2) medium stance squat (MS), 142 +/- 12% SW; and 3) wide stance squat (WS), 169 +/- 12% SW. Most biomechanical differences among the three stance groups and between 2-D and 3-D analyses occurred between the NS and WS. Compared with the NS at 45 degrees and 90 degrees knee flexion angle (KF), the hips flexed 6-11 degrees more and the thighs were 7-12 degrees more horizontal during the MS and WS. Compared with the NS at 90 degrees and maximum KF, the shanks were 5-9 degrees more vertical and the feet were turned out 6 degrees more during the WS. No significant differences occurred in trunk positions. Hip and thigh angles were 3-13 degrees less in 2-D compared with 3-D analyses. Ankle plantar flexor (10-51 N.m), knee extensor (359-573 N.m), and hip extensor (275-577 N.m) net muscle moments were generated for the NS, whereas ankle dorsiflexor (34-284 N.m), knee extensor (447-756 N.m), and hip extensor (382-628 N.m) net muscle moments were generated for the MS and WS. Significant differences in ankle and knee moment arms between 2-D and 3-D analyses were 7-9 cm during the NS, 12-14 cm during the MS, and 16-18 cm during the WS. Ankle plantar flexor net muscle moments were generated during the NS, ankle dorsiflexor net muscle moments were produced during the MS and WS, and knee and hip moments were greater during the WS compared with the NS. A 3-D biomechanical analysis of the squat is more accurate than a 2-D biomechanical analysis, especially during the WS.
Veltink, Petrus H.; Franken, Henry M.; Franken, H.M.
Detection of knee unlock is a crucial part of finite state artificial reflex control of paraplegic standing supported by functional neuromuscular stimulation (FNS). This paper investigates knee unlock detection schemes using small uniaxial accelerometers mounted on the thigh and shank. Four single
Geller, Josie; Srikameswaran, Suja; Iyar, Megumi; Zelichowska, Joanna; Thibodeau, Michel; Brown, Krista E; Dunn, Erin C
The support provided by family and friends is integral to patient motivation and clinical outcomes across health care populations. However, little is known about factors that promote or interfere with the type of support offered. This research examined factors associated with collaborative versus directive support among carers of adults with eating disorders. Participants were mothers, fathers, partners, friends, and siblings (N = 141) of eating disorder patients in hospital or residential treatment. Two methodologies were used to assess directive and collaborative support stance: a questionnaire of support behaviors and coded responses to clinical vignettes. Measures of interpersonal functioning, psychiatric distress, caregiving experience, and closeness with their loved one were also completed. Although carers rated a collaborative stance as more helpful than a directive stance, 60% of responses to the clinical vignettes were directive. Across both methodologies, collaborative support behaviors were associated with beliefs about helpful support and with a less vindictive and cold interpersonal style. Whereas use of a directive support stance was exclusively associated with negative caregiving experiences, collaborative responses were associated with both positive and negative experiences. Although the benefits of collaborative support have been well established, this is the first study to examine factors associated with the use of support stance. Findings suggest a number of ways to help carers create and maintain collaborative relationships, including addressing beliefs and interpersonal style and capitalizing on both positive and negative experiences with their loved one. © 2016 Wiley Periodicals, Inc.(Int J Eat Disord 2017; 50:498-505). © 2016 Wiley Periodicals, Inc.
Full Text Available BACKGROUND: To achieve good performance, taekwondo athletes should optimize the stance position of the foot on the ground. OBJECTIVE: The aim of this study is to compare generated net joint power (hip, knee and ankle during stance phase, magnitude of peak foot velocity of the attacking lower extremity and execution stance time produced from three stance positions (forward "0°", diagonal "45°", orthogonal "90°" in the taekwondo roundhouse kick. METHODS: Ten taekwondo athletes participated in the study; their experience of practicing taekwondo ranged between 13.8 ± 5.8 years. The kinetics and kinematics of the athletes’ movement during the roundhouse kick were recorded. The execution stance time and the magnitude of peak foot velocity were determined. The net joint power of the kicking lower extremity during the stance phase was calculated using the inverse dynamics method. Then the peak net joint power was determined. RESULTS: The analysis of variance for repeated measures showed that there is a significant main effect of the stance position on the peak net hip joint power in the three planes. In addition, the stance position does not affect the magnitude of the peak foot velocity of the kicking lower extremity and execution stance time. CONCLUSIONS: The necessity to produce a higher net hip joint power in the stance phase of the roundhouse kick from the position when the feet are placed orthogonal to the target of the kick, compared with the execution of the kick from the forward or diagonal position, must be taken into account for purposes of rationalizing strength training of taekwondo athletes or for selecting the technique of the roundhouse kick.
Penney, Tracy; Ploughman, Michelle; Austin, Mark W; Behm, David G; Byrne, Jeannette M
To determine the activation of the gluteus medius in persons with chronic, nonspecific low back pain compared with that in control subjects, and to determine the association of the clinical rating of the single leg stance (SLS) with chronic low back pain (CLBP) and gluteus medius weakness. Cohort-control comparison. Academic research laboratory. Convenience sample of people (n=21) with CLBP (>12wk) recruited by local physiotherapists, and age- and sex-matched controls (n=22). Subjects who received specific pain diagnoses were excluded. Not applicable. Back pain using the visual analog scale (mm); back-related disability using the Oswestry Back Disability Index (%); strength of gluteus medius measured using a hand dynamometer (N/kg); SLS test; gluteus medius onset and activation using electromyography during unipedal stance on a forceplate. Individuals in the CLBP group exhibited significant weakness in the gluteus medius compared with controls (right, P=.04; left, P=.002). They also had more pain (CLBP: mean, 20.50mm; 95% confidence interval [CI], 13.11-27.9mm; control subjects: mean, 1.77mm; 95% CI, -.21 to 3.75mm) and back-related disability (CLBP: mean, 18.52%; 95% CI, 14.46%-22.59%; control subjects: mean, .68%; 95% CI, -.41% to 1.77%), and reported being less physically active. Weakness was accompanied by increased gluteus medius activation during unipedal stance (R=.50, P=.001) but by no difference in muscle onset times. Although greater gluteus medius weakness was associated with greater pain and disability, there was no difference in muscle strength between those scoring positive and negative on the SLS test (right: F=.002, P=.96; left: F=.1.75, P=.19). Individuals with CLBP had weaker gluteus medius muscles than control subjects without back pain. Even though there was no significant difference in onset time of the gluteus medius when moving to unipedal stance between the groups, the CLBP group had greater gluteus medius activation. A key finding was that
Byl, Nancy N
An emerging area of neurorehabilitation is the use of robotic devices to enhance the efficiency and effectiveness of lower extremity physical therapy post-stroke. Many of the robotic devices currently available rely on computer-driven locomotive algorithms combined with partial bodyweight-supported treadmill training that drive reflex stepping with minimal patient intention during therapy. In this case series, we examined the effect of task-oriented mobility training in patients in a post-stroke chronic state using a novel, wearable, mobile, intention-based robotic leg orthosis. Three individuals, all of whom had reached a plateau with conventional bodyweight-supported treadmill training, participated in task-oriented mobility therapy (1.5 hours, two to four times per week for four weeks) with a robotic leg orthosis under supervision by a physical therapist. Participant 1 was a 59-year-old Caucasian man, who had an ischemic left stroke six years previously with resultant right hemiparesis. Participant 2 was a 42-year-old Caucasian woman with left hemiparesis after a right stroke 15 months previously. Participant 3 was a 62-year-old Caucasian woman with a history of a right middle cerebral artery aneurysm with third degree sub-arachnoid hemorrhage 10 years ago.Immediately after training, all participants demonstrated improved gait speed (10 meter walk), stride length and walking endurance (6 minute walk) compared with baseline measurements. Improvements were maintained one month after training. Timed up and go and five times sit-to-stand were maintained for all three participants, with only one individual remaining outside the safety performance norm. Lower extremity training integrating an intention-based robotic leg orthosis may improve gait speed, endurance and community levels of participation in select patients in a post-stroke chronic state after plateauing within a bodyweight-supported treadmill training program. The wearable, mobile assistive robotic device
Full Text Available Introduction. Many studies have compared different backpack designs and their influence on the carrier; however, no data referring to school students aged 7-8 years are currently available. Therefore, the aim of the research was to assess the influence of backpack design on centre of pressure (COP displacement and plantar force distribution in children during an upright stance. Material and methods. Nineteen school students (9 males and 10 females volunteered for the study. Two Polish backpacks intended for school use were evaluated: backpack A, which had two main compartments, and backpack B, which had one main compartment. The backpack load was composed of books, binders, and regular school equipment. During the measurements, the subjects were asked to look ahead with the head straight and arms at the sides in a comfortable position and to stand barefoot on the F-Scan® sensors (Tekscan, F-Scan® attached to the force platform (Kistler, carrying a load corresponding to 10% of their body mass. Results. The study found insignificant differences between the two backpack designs. Moreover, COP parameters increased significantly during an upright stance while carrying backpack B in comparison to the empty backpack condition. Additionally, we observed significantly higher values of plantar force distribution in the heel region for the condition without load and insignificantly higher ones for carrying backpack A. Conclusions. The results of the current study suggest that the differences between the two backpack designs are too marginal to be detected through COP displacement. Disturbances in plantar force distribution suggest a lack of posture control and a lower stability of the standing position with a backpack, but these disturbances were significant only when the backpack with one main compartment was used.
Mariani, Benoit; Rouhani, Hossein; Crevoisier, Xavier; Aminian, Kamiar
Time periods composing stance phase of gait can be clinically meaningful parameters to reveal differences between normal and pathological gait. This study aimed, first, to describe a novel method for detecting stance and inner-stance temporal events based on foot-worn inertial sensors; second, to extract and validate relevant metrics from those events; and third, to investigate their suitability as clinical outcome for gait evaluations. 42 subjects including healthy subjects and patients before and after surgical treatments for ankle osteoarthritis performed 50-m walking trials while wearing foot-worn inertial sensors and pressure insoles as a reference system. Several hypotheses were evaluated to detect heel-strike, toe-strike, heel-off, and toe-off based on kinematic features. Detected events were compared with the reference system on 3193 gait cycles and showed good accuracy and precision. Absolute and relative stance periods, namely loading response, foot-flat, and push-off were then estimated, validated, and compared statistically between populations. Besides significant differences observed in stance duration, the analysis revealed differing tendencies with notably a shorter foot-flat in healthy subjects. The result indicated which features in inertial sensors' signals should be preferred for detecting precisely and accurately temporal events against a reference standard. The system is suitable for clinical evaluations and provides temporal analysis of gait beyond the common swing/stance decomposition, through a quantitative estimation of inner-stance phases such as foot-flat. Copyright © 2012 Elsevier B.V. All rights reserved.
Qualitative methods are not intrinsically progressive. Methods are simply tools to conduct research. Epistemology, the justification of knowledge, shapes methodology and methods, and thus is a vital starting point for a critical health equity research stance, regardless of whether the methods are qualitative, quantitative, or mixed. In line with this premise, I address four themes in this commentary. First, I criticize the ubiquitous and uncritical use of the term health disparities in U.S. public health. Next, I advocate for the increased use of qualitative methodologies-namely, photovoice and critical ethnography-that, pursuant to critical approaches, prioritize dismantling social-structural inequities as a prerequisite to health equity. Thereafter, I discuss epistemological stance and its influence on all aspects of the research process. Finally, I highlight my critical discourse analysis HIV prevention research based on individual interviews and focus groups with Black men, as an example of a critical health equity research approach.
Roč. 72, č. 6 (2017), s. 451-462 ISSN 0046-385X R&D Projects: GA ČR(CZ) GA16-23046S Institutional support: RVO:67985955 Keywords : performative turn * performance * sacrifice * ludic stance * play * postmodern condition * Brecht * Benjamin * Grotowski Subject RIV: AA - Philosophy ; Religion OBOR OECD: Philosophy , History and Philosophy of science and technology http://www.klemens.sav.sk/fiusav/doc/filozofia/2017/6/451-462.pdf
Chapouthier , Georges
International audience; Biocosmology implies that the laws of the microcosm (i.e. the laws governing living beings and their minds) mimic the laws of the macrocosm. These laws are based on a mosaic structure and triune organisation, with some roots that may be in the classical dialectical movement. A number of modern stances can be seen in relation to the Biocosmological perspective. The relationship to the mosaic structure may be direct, as with the experimental work of Michod, or indirect, ...
Sochan, Anne M
How should nursing knowledge advance? This exploration contextualizes its evolution past and present. In addressing how it evolved in the past, a probable historical evolution of its development draws on the perspectives of Frank & Gills's World System Theory, Kuhn's treatise on Scientific Revolutions, and Foucault's notions of Discontinuities in scientific knowledge development. By describing plausible scenarios of how nursing knowledge evolved, I create a case for why nursing knowledge developers should adopt a post-structural stance in prioritizing their research agenda(s). Further, by adopting a post-structural stance, I create a case on how nurses can advance their disciplinary knowledge using an engaging post-colonial strategy. Given an interrupted history caused by influence(s) constraining nursing's knowledge development by power structures external, and internal, to nursing, knowledge development can evolve in the future by drawing on post-structural interpretation, and post-colonial strategy. The post-structural writings of Deleuze & Guattari's understanding of 'Nomadology' as a subtle means to resist being constrained by existing knowledge development structures, might be a useful stance to understanding the urgency of why nursing knowledge should advance addressing the structural influences on its development. Furthermore, Bhabha's post-colonial elucidation of 'Hybridity' as an equally discreet means to change the culture of those constraining structures is an appropriate strategy to enact how nursing knowledge developers can engage with existing power structures, and simultaneously influence that engagement. Taken together, 'post-structural stance' and 'post-colonial strategy' can refocus nursing scholarship to learn from its past, in order to develop relevant disciplinary knowledge in its future. © 2011 Blackwell Publishing Ltd.
This paper offers steps towards overcoming current fragmentation within sociocultural approaches by expansively reconstructing a broad dialectical view on human development and learning (drawing on Vygotsky's project) underwritten by ideology of social justice. The common foundation for sociocultural approaches is developed by dialectically supplanting relational ontology with the notion that collaborative purposeful transformation of the world is the core of human nature and the principled grounding for learning and development. An activist transformative stance suggests that people come to know themselves and their world as well as ultimately come to be human in and through (not in addition to) the processes of collaboratively transforming the world in view of their goals. This means that all human activities (including psychological processes and the self) are instantiations of contributions to collaborative transformative practices that are contingent on both the past and the vision for the future and therefore are profoundly imbued with ideology, ethics, and values. And because acting, being, and knowing are seen from a transformative activist stance as all rooted in, derivative of, and instrumental within a collaborative historical becoming, this stance cuts across and bridges the gaps (a) between individual and social and (b) among ontological, epistemological, and moral-ethical (ideological) dimensions of activity.
Simonsen, Erik B; Cappelen, Katrine L; Skorini, Ragnhild
A hip joint flexor moment in the last half of the stance phase during walking has repeatedly been reported. However, the purpose of this moment remains uncertain and it is unknown how it is generated. Nine male subjects were instructed to walk at 4.5 km/h with their upper body in three different ...... activity but only in the swing phase. It is concluded that the hip flexor moment in question is largely generated by passive structures in the form of ligaments resisting hip joint extension.......A hip joint flexor moment in the last half of the stance phase during walking has repeatedly been reported. However, the purpose of this moment remains uncertain and it is unknown how it is generated. Nine male subjects were instructed to walk at 4.5 km/h with their upper body in three different...... positions: normal, inclined and reclined. Net joint moments were calculated about the hip, knee and ankle joint. The peak hip joint flexor moment during late stance was significantly lower during inclined walking than in the two other conditions. During normal walking the iliacus muscle showed no or very...
Swigchem, R. van; Roerdink, M.; Weerdesteyn, V.G.M.; Geurts, A.C.H.; Daffertshofer, A.
BACKGROUND: A reduced capacity to modify gait to the environment may contribute to the risk of falls in people with poststroke foot drop using an ankle-foot orthosis. OBJECTIVE: This study aimed to quantify their capacity to restore steady gait after a step modification. DESIGN: This was a
van Swigchem, R.; Roerdink, M.; Weerdesteyn, V.; Geurts, A.C.; Daffertshofer, A.
Background. A reduced capacity to modify gait to the environment may contribute to the risk of falls in people with poststroke foot drop using an ankle-foot orthosis. Objective. This study aimed to quantify their capacity to restore steady gait after a step modification. Design. This was a
Gupta, Anupam; Taly, Arun B; Srivastava, Abhishek; Murali, Thyloth
To analyse long-term functional recovery, deficits and requirement of lower limb orthosis (LLO) for locomotion in patients with Guillain-Barre Syndrome (GBS). Prospective longitudinal follow-up study. Neurological Rehabilitation unit of university hospital. Sixty-nine patients of GBS admitted for inpatient rehabilitation. Thirty-five patients (M:F, 19:16) reporting after 1 year follow-up (50.72%) were included in study (between September 2005 and July 2009). Their residual deficits and requirement of LLO were recorded and analysed. Age ranged from 4 to 65 year (29.74 ± 15.75). Twenty-seven patients had typical GBS and eight patients had acute motor axonal neuropathy variant. Twenty-eight patients (80%) had neuropathic pain needing medication with 11 required more than one drug. Twenty-one patients (60%) had foot drop and advised ankle-foot orthosis-AFO (20 bilateral AFO). Thirty patients (85.71%) needed assistive devices also for locomotion at discharge. After 1 year, foot drop was still present in 12 patients (34.28%) using orthosis. Modified Barthel Index scores, Modified Rankin Scale and Hughes Disability Scale were used to assess functional disabilities. Significant recovery was observed at the time of discharge and after 1 year (p < 0.001 each). Patients with GBS continue to show significant functional recovery for long period. They have residual deficits even after 1 year with requirement of orthosis in large number of patients.
Full Text Available Background. Osteoarthritis (OA is a disease which influences the performance of the knee joint. Moreover, the force and moments applied on the joint increase in contrast to normal subjects. Various types of knee orthoses have been designed to solve the mentioned problems. However, there are other problems in terms of distal migration during walking and the alignment of the orthosis which cannot be changed following the use of brace. Therefore, the main aim of the research was to design an orthosis to solve the aforementioned problems. Method. A new type of knee orthosis was designed with a modular structure. Two patients with knee OA participated in this research project. The force applied on the foot, moment transmitted through the knee joint, and spatiotemporal gait parameters were measured by use of a motion analysis system. Results. The results of the research showed that the adduction moment applied on the knee joint decreased while subjects walked with the new knee orthosis (P-value < 0.05. Conclusion. The new design of the knee brace can be used as an effective treatment to decrease the loads applied on the knee joint and to improve the alignment whilst walking.
Kiers, Henri; van Dieën, Jaap; Dekkers, Henk; Wittink, Harriët; Vanhees, Luc
In many sports, maintaining balance is necessary to compete at a high level. Also, in many health problems, balance is impaired. Postural sway (PS) is often used as an indicator of upright balance control, and physical activity (PA) might enhance balance control. However, the relationship between PS and PA has never been systematically reviewed. Our objective was to summarize the evidence regarding the relationship between PS in upright bipedal and unipedal standing and PA. We conducted a literature search in MEDLINE, EmBase, CINAHL, the Cochrane Database, and PEDro, up to March 2012, with no limit on the starting date. Characteristics and methodological aspects of each article were extracted by two reviewers. We used centre of pressure (CoP) velocity, and variables related to the CoP area, to compare studies. A total of 39 articles were reviewed from an initial yield of 2,058. Of these 39 studies, 37 used a comparative design, one was a cohort study, and one was a randomized controlled trial. The main conclusion was that in general, sport practitioners sway less than controls, and high-level athletes sway less than low-level athletes. Additionally, we identified specific effects dependent on the use of vision, sport-specific postures, and frequency and duration of the (sports) activity. PS in unperturbed bipedal stance appears to have limited sensitivity to detect subtle differences between groups of healthy people.
Full Text Available Background: There are various studies using Mulligan’s MWM with or without combining with electrotherapy modalities and proved the efficacy of the technique in immediately decreasing pain and improving grip strength in patients with lateral epicondylitis. Orthotic as a treatment is also proved to be beneficial in decreasing pain and improving grip strength. There is evidence that housewives are prone to develop lateral epicondylitis due to their routine household work. But there is lack of evidence which compare initial effects of MWM and orthosis in housewives bringing up better outcome measures. The purpose of this study is to compare the initial effectiveness of Mulligan’s MWM and elbow orthosis on pain and grip strength in housewives with lateral epicondylitis. The aim of the study is to evaluate the effectiveness of Mulligan’s MWM technique versus counterforce elbow orthosis in immediately reducing pain and improving grip strength in lateral epicondylitis in housewives. Methodos: All subjects underwent a pre-treatment examination to assess pain and pain free hand grip strength with the help of outcome measures. Subjects were randomly assigned into two groups, A and B respectively; having 25 subjects in each group. Group A was treated with one session of Mulligan’s MWM technique. Group B was treated with Counterforce elbow strap orthosis. Data was assessed pre-treatment and immediately after treatment. Visual Analogue Scale (VAS and hand grip on Hand Grip Dynamometer (HGD were used as outcome measures. Results: Independent t-test was performed to see the effectiveness between Mulligan’s MWM and elbow orthosis. For VAS, t = - 2.243 which is significant at 5% level of significance. It has been inferred that VAS decreases more when Mulligan’s MWM was applied. For HGD, t = 0.878 which is not significant implying that increase in HGD do not differ remarkably for the two treatments. Conclusion: It has been recorded from the study that
Full Text Available Junji Katsuhira,1 Ko Matsudaira,2 Tadashi Yasui,3 Shinno Iijima,4 Akihiro Ito4 1Department of Nursing and Rehabilitation Science at Odawara, International University of Health and Welfare, Odawara, Kanagawa, 2Department of Medical Research and Management for Musculoskeletal Pain, 22nd Century Medical and Research Center, The University of Tokyo, Tokyo, 3Kawamura-Gishi Company, Ltd., Daito-shi, Osaka, 4Graduate School of International University of Health and Welfare, Otawara, Tochigi, Japan Purpose: Postural alignment of elderly people becomes poor due to aging, possibly leading to low-back pain and spinal deformity. Although there are several interventions for treating these conditions, no previous study has reported the effectiveness of a spinal orthosis or lumbosacral orthosis (LSO in healthy elderly people without specific spinal deformity. We therefore developed a trunk orthosis to decrease low-back muscle activity while training good postural alignment through resistive force provided by joints with springs (here, called the ORF, which stands for orthosis with joints providing resistive force as a preventive method against abnormal posture and low-back pain in healthy elderly persons. Patients and methods: Fifteen community-dwelling elderly men participated in this study. Participants stood freely for 10 seconds in a laboratory setting under three conditions: without an orthosis, with the ORF, and with an LSO. The Damen corset LSO was selected as it is frequently prescribed for patients with low-back pain. Postural alignment during static standing was recorded using a three-dimensional motion capture system employing infrared cameras. Two force plates were used to record center of pressure. Electromyograms were obtained for bilateral erector spinae (ES, left internal abdominal oblique, and right gluteus medius muscles. Results: Pelvis forward tilt angle tended to increase while wearing the ORF and decrease while wearing the LSO, but these
de Niet, Mark; Latour, Hilde; Hendricks, Henk; Geurts, Alexander C; Weerdesteyn, Vivian
To identify whether a relationship exists between stretch and activity of the calf muscles during the stance phase of gait in patients with upper motor neuron syndrome (UMNS), while taking into account the physiologic phase shift between these entities. Survey. Ambulatory care and general community. Patients with UMNS (n=15; 9 patients with stroke, 6 patients with hereditary spastic paraparesis) with premature calf muscle activity during the stance phase of gait and healthy controls (n=13). Not applicable. Timing of optimal association (phase shift) between the lengthening velocity of the gastrocnemius muscle and its electromyographic activity as revealed by cross-correlation analyses. Although premature calf muscle activity was evident in the patient groups, the phase shift between calf muscle stretch and its activity did not correspond with the monosynaptic stretch reflex latency (40- to 80-ms time window). However, there was a main effect of group on the phase shifts (F(3,33)=3.23, P=.035). Post hoc analysis revealed that in the paretic leg of stroke patients, the electromyographic activity preceded the lengthening velocity by 9 ± 54ms, whereas in the control group, the electromyographic activity followed the pattern of the muscle-lengthening velocity with a delay of 61 ± 54ms (P=.029). Short-latency stretch reflexes do not significantly contribute to premature calf muscle activity in the stance phase of (spastic) gait. This notion questions the validity of the clinical assessment of hyperreflexia and clonus of the calf as a predictor of calf muscle spasticity during gait. Copyright © 2011 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.
Pittaccio, S.; Viscuso, S.
The capacity of flexing one's ankle is an indispensible segment of gait re-learning, as imbalance, wrong compensatory use of other joints and risk of falling may depend on the so-called drop-foot. The rehabilitation of ankle dorsiflexion may be achieved through active exercising of the relevant musculature (especially tibialis anterior, TA). This can be troublesome for patients affected by weakness and flaccid paresis. Thus, as needs evolve during patient's improvements, a therapeutic device should be able to guide and sustain gradual recovery by providing commensurate aid. This includes exploiting even initial attempts at voluntary motion and turns those into effective workout. An active orthosis powered by two rotary actuators containing NiTi wire was designed to obtain ankle dorsiflexion. A computer routine that analyzes the electromyographic (sEMG) signal from TA muscle is used to control the orthosis and trigger its activation. The software also provides instructions and feed-back for the patient. Tests on the orthosis proved that it can produce strokes up to 36° against resisting torques exceeding 180 Ncm. Three healthy subjects were able to control the orthosis by modulating their TA sEMG activity. The movement produced in the preliminary tests is interesting for lower limb rehabilitation, and will be further improved by optimizing body-orthosis interface. It is hoped that this device will enhance early rehabilitation and recovery of ankle mobility in stroke patients.
Dingenen, B; Peeraer, L; Deschamps, K; Fieuws, S; Janssens, L; Staes, F
The aim of this study was to evaluate the influence of shoes and foot orthoses on lower extremity muscle activation patterns in healthy subjects during the transition from double-leg stance to single-leg stance. Eight male and seven female young asymptomatic adults who wear foot orthoses were recruited. Muscle activation onset times of 9 lower extremity muscles were recorded using surface electromyography during the transition from double-leg stance to single-leg stance, performed with eyes open and with eyes closed. This was tested in 4 experimental conditions: 1) barefoot (BF); 2) shoes only (SO); 3) shoes with standardized FO (SSFO); and 4) shoes with customized FO (SCFO). Based on a four-way (condition-region-leg-vision) linear model for repeated measures, we found a significant condition effect (P=0.025). Differences between conditions did not depend on the leg and/or the vision condition, but on the region (ankle-knee-hip). Based on a two-way (condition-muscle) linear model within each region, only significant differences between conditions for peroneus longus (P=0.003) were found. The onset times of peroneus longus were significantly earlier in SO (P=0.029) and SCFO (P=0.001) compared to BF. These results indicate that SO and SCFO can accelerate peroneus longus muscle activation onset times during the transition from double-leg stance to single-leg stance. Further research is required to determine how these adaptations may develop over time.
dos Santos, Marcio José; Gorges, Ana Luiza; Rios, Jaqueline Lourdes
Individuals with chronic ankle instability (CAI) usually experience deficits in balance control, which increase displacement in the body's center of pressure (COP) when they balance on a single leg. Little is known, however, about whether or not these individuals use the strategies of postural adjustment properly, especially during functional tasks that may predispose them to ankle sprain. The aim of this study was to investigate anticipatory (APA) and compensatory (CPA) postural adjustments in individuals with and without CAI as they kick a ball while standing in a single-leg stance with their ankle in neutral and supinated positions. COP displacements were calculated and their magnitudes (range) analyzed during APA and CPA intervals and over the duration of the whole task, represented by the COP area of sway and mean velocity. The CAI group exhibited a significant decrease in CPA and area of sway over the whole task, relative to controls. These results suggest that the decreased balance sway could be caused by the need for further stabilization of the ankle in more unstable postures to prevent recurrent sprain. Our findings could help clinicians to better understand the strategies of postural adjustments in individuals with CAI, and may assist and motivate new investigations into balance control interventions in such individuals, as well as proactively address recurrent ankle sprain conditions. Published by Elsevier B.V.
d'Elia, Nicolò; Vanetti, Federica; Cempini, Marco; Pasquini, Guido; Parri, Andrea; Rabuffetti, Marco; Ferrarin, Maurizio; Molino Lova, Raffaele; Vitiello, Nicola
In human-centered robotics, exoskeletons are becoming relevant for addressing needs in the healthcare and industrial domains. Owing to their close interaction with the user, the safety and ergonomics of these systems are critical design features that require systematic evaluation methodologies. Proper transfer of mechanical power requires optimal tuning of the kinematic coupling between the robotic and anatomical joint rotation axes. We present the methods and results of an experimental evaluation of the physical interaction with an active pelvis orthosis (APO). This device was designed to effectively assist in hip flexion-extension during locomotion with a minimum impact on the physiological human kinematics, owing to a set of passive degrees of freedom for self-alignment of the human and robotic hip flexion-extension axes. Five healthy volunteers walked on a treadmill at different speeds without and with the APO under different levels of assistance. The user-APO physical interaction was evaluated in terms of: (i) the deviation of human lower-limb joint kinematics when wearing the APO with respect to the physiological behavior (i.e., without the APO); (ii) relative displacements between the APO orthotic shells and the corresponding body segments; and (iii) the discrepancy between the kinematics of the APO and the wearer's hip joints. The results show: (i) negligible interference of the APO in human kinematics under all the experimented conditions; (ii) small (i.e., body segments (called stability); and (iii) significant increment in the human-robot kinematics discrepancy at the hip flexion-extension joint associated with speed and assistance level increase. APO mechanics and actuation have negligible interference in human locomotion. Human kinematics was not affected by the APO under all tested conditions. In addition, under all tested conditions, there was no relevant relative displacement between the orthotic cuffs and the corresponding anatomical segments
Melissa C Kilby
Full Text Available Falls among the older population can severely restrict their functional mobility and even cause death. Therefore, it is crucial to understand the mechanisms and conditions that cause falls, for which it is important to develop a predictive model of falls. One critical quantity for postural instability detection and prediction is the instantaneous stability of quiet upright stance based on motion data. However, well-established measures in the field of motor control that quantify overall postural stability using center-of-pressure (COP or center-of-mass (COM fluctuations are inadequate predictors of instantaneous stability. For this reason, 2D COP/COM virtual-time-to-contact (VTC is investigated to detect the postural stability deficits of healthy older people compared to young adults. VTC predicts the temporal safety margin to the functional stability boundary ( = limits of the region of feasible COP or COM displacement and, therefore, provides an index of the risk of losing postural stability. The spatial directions with increased instability were also determined using quantities of VTC that have not previously been considered. Further, Lempel-Ziv-Complexity (LZC, a measure suitable for on-line monitoring of stability/instability, was applied to explore the temporal structure or complexity of VTC and the predictability of future postural instability based on previous behavior. These features were examined as a function of age, vision and different load weighting on the legs. The primary findings showed that for old adults the stability boundary was contracted and VTC reduced. Furthermore, the complexity decreased with aging and the direction with highest postural instability also changed in aging compared to the young adults. The findings reveal the sensitivity of the time dependent properties of 2D VTC to the detection of postural instability in aging, availability of visual information and postural stance and potential applicability as a
Byl Nancy N
Full Text Available Abstract Introduction An emerging area of neurorehabilitation is the use of robotic devices to enhance the efficiency and effectiveness of lower extremity physical therapy post-stroke. Many of the robotic devices currently available rely on computer-driven locomotive algorithms combined with partial bodyweight-supported treadmill training that drive reflex stepping with minimal patient intention during therapy. In this case series, we examined the effect of task-oriented mobility training in patients in a post-stroke chronic state using a novel, wearable, mobile, intention-based robotic leg orthosis. Case presentation Three individuals, all of whom had reached a plateau with conventional bodyweight-supported treadmill training, participated in task-oriented mobility therapy (1.5 hours, two to four times per week for four weeks with a robotic leg orthosis under supervision by a physical therapist. Participant 1 was a 59-year-old Caucasian man, who had an ischemic left stroke six years previously with resultant right hemiparesis. Participant 2 was a 42-year-old Caucasian woman with left hemiparesis after a right stroke 15 months previously. Participant 3 was a 62-year-old Caucasian woman with a history of a right middle cerebral artery aneurysm with third degree sub-arachnoid hemorrhage 10 years ago. Immediately after training, all participants demonstrated improved gait speed (10 meter walk, stride length and walking endurance (6 minute walk compared with baseline measurements. Improvements were maintained one month after training. Timed up and go and five times sit-to-stand were maintained for all three participants, with only one individual remaining outside the safety performance norm. Conclusions Lower extremity training integrating an intention-based robotic leg orthosis may improve gait speed, endurance and community levels of participation in select patients in a post-stroke chronic state after plateauing within a bodyweight
Dindo, Haris; Donnarumma, Francesco; Chersi, Fabian; Pezzulo, Giovanni
Recent theories of mindreading explain the recognition of action, intention, and belief of other agents in terms of generative architectures that model the causal relations between observables (e.g., observed movements) and their hidden causes (e.g., action goals and beliefs). Two kinds of probabilistic generative schemes have been proposed in cognitive science and robotics that link to a "theory theory" and "simulation theory" of mindreading, respectively. The former compares perceived actions to optimal plans derived from rationality principles and conceptual theories of others' minds. The latter reuses one's own internal (inverse and forward) models for action execution to perform a look-ahead mental simulation of perceived actions. Both theories, however, leave one question unanswered: how are the generative models - including task structure and parameters - learned in the first place? We start from Dennett's "intentional stance" proposal and characterize it within generative theories of action and intention recognition. We propose that humans use an intentional stance as a learning bias that sidesteps the (hard) structure learning problem and bootstraps the acquisition of generative models for others' actions. The intentional stance corresponds to a candidate structure in the generative scheme, which encodes a simplified belief-desire folk psychology and a hierarchical intention-to-action organization of behavior. This simple structure can be used as a proxy for the "true" generative structure of others' actions and intentions and is continuously grown and refined - via state and parameter learning - during interactions. In turn - as our computational simulations show - this can help solve mindreading problems and bootstrap the acquisition of useful causal models of both one's own and others' goal-directed actions.
Reschke, Millard F.; Bloomberg, J. J.; Wood, S. J.; Harm, D. L.
Introduction: Both balance and locomotor ataxia is severe in astronauts returning from spaceflight with serious implications for unassisted landings. As a part of an ongoing effort to demonstrate the functional significance of the postflight ataxia problem our laboratory has evaluated jumping, walking heel-to-toe and quite stance balance immediately following spaceflight. Methods: Six astronauts from 12-16 day flights and three from 6-month flights were asked to perform three self-initiated two-footed jumps from a 30-cm-high platform, walking for 10 steps (three trials) placing the feet heel to toe in tandem, arms folded across the chest and the eyes closed, and lastly, recover from a simulated fall by standing from a prone position on the floor and with eyes open maintain a quiet stance for 3 min with arms relaxed along the side of the body and feet comfortably positioned on a force plate. Crewmembers were tested twice before flight, on landing day (short-duration), and days 1, 6, and 30 following all flight durations. Results/Conclusions: Many of astronauts tested fell on their first postflight jump but recovered by the third jump showing a rapid learning progression. Changes in take-off strategy were clearly evident in duration of time in the air between the platform and the ground (significant reduction in time to land), and also in increased asymmetry in foot latencies on take-off postflight. During the tandem heel-to-toe walking task there was a significant decrease in percentage of correct steps on landing day (short-duration crew) and on first day following landing (long-duration) with only partial recovery the following day. Astronauts for both short and long duration flight times appeared to be unaware of foot position relative to their bodies or the floor. During quite stance most of crewmembers tested exhibited increased stochastic activity (larger short-term COP diffusion coefficients postflight in all planes and increases in mean sway speed).
Susannah C R Maidment
Full Text Available BACKGROUND: The most primitive ornithischian dinosaurs were small bipeds, but quadrupedality evolved three times independently in the clade. The transition to quadrupedality from bipedal ancestors is rare in the history of terrestrial vertebrate evolution, and extant analogues do not exist. Constraints imposed on quadrupedal ornithischians by their ancestral bipedal bauplan remain unexplored, and consequently, debate continues about their stance and gait. For example, it has been proposed that some ornithischians could run, while others consider that none were cursorial. METHODOLOGY/PRINCIPAL FINDINGS: Drawing on biomechanical concepts of limb bone scaling and locomotor theory developed for extant taxa, we use the largest dataset of ornithischian postcranial measurements so far compiled to examine stance and gait in quadrupedal ornithischians. Differences in femoral midshaft eccentricity in hadrosaurs and ceratopsids may indicate that hadrosaurs placed their feet on the midline during locomotion, while ceratopsids placed their feet more laterally, under the hips. More robust humeri in the largest ceratopsids relative to smaller taxa may be due to positive allometry in skull size with body mass in ceratopsids, while slender humeri in the largest stegosaurs may be the result of differences in dermal armor distribution within the clade. Hadrosaurs are found to display the most cursorial morphologies of the quadrupedal ornithischian cades, indicating higher locomotor performance than in ceratopsids and thyreophorans. CONCLUSIONS/SIGNIFICANCE: Limb bone scaling indicates that a previously unrealised diversity of stances and gaits were employed by quadrupedal ornithischians despite apparent convergence in limb morphology. Grouping quadrupedal ornithischians together as a single functional group hides this disparity. Differences in limb proportions and scaling are likely due to the possession of display structures such as horns, frills and dermal armor
Maidment, Susannah C R; Linton, Deborah H; Upchurch, Paul; Barrett, Paul M
The most primitive ornithischian dinosaurs were small bipeds, but quadrupedality evolved three times independently in the clade. The transition to quadrupedality from bipedal ancestors is rare in the history of terrestrial vertebrate evolution, and extant analogues do not exist. Constraints imposed on quadrupedal ornithischians by their ancestral bipedal bauplan remain unexplored, and consequently, debate continues about their stance and gait. For example, it has been proposed that some ornithischians could run, while others consider that none were cursorial. Drawing on biomechanical concepts of limb bone scaling and locomotor theory developed for extant taxa, we use the largest dataset of ornithischian postcranial measurements so far compiled to examine stance and gait in quadrupedal ornithischians. Differences in femoral midshaft eccentricity in hadrosaurs and ceratopsids may indicate that hadrosaurs placed their feet on the midline during locomotion, while ceratopsids placed their feet more laterally, under the hips. More robust humeri in the largest ceratopsids relative to smaller taxa may be due to positive allometry in skull size with body mass in ceratopsids, while slender humeri in the largest stegosaurs may be the result of differences in dermal armor distribution within the clade. Hadrosaurs are found to display the most cursorial morphologies of the quadrupedal ornithischian cades, indicating higher locomotor performance than in ceratopsids and thyreophorans. Limb bone scaling indicates that a previously unrealised diversity of stances and gaits were employed by quadrupedal ornithischians despite apparent convergence in limb morphology. Grouping quadrupedal ornithischians together as a single functional group hides this disparity. Differences in limb proportions and scaling are likely due to the possession of display structures such as horns, frills and dermal armor that may have affected the center of mass of the animal, and differences in locomotor
Hoof-ground interaction impacts on the health and performance characteristics of horses. Due to complex interactions between hoof and ground during the stance phase, previous experimentally dominated studies concentrated on subproblems of the phenomena observed. A multidisciplinary methodology with mathematical modelling, material testing and in vivo experimental measurements seems promising. With the help of a mathematical approach, this contribution aims to explain from a biomechanical point of view the phenomena observed during experimental investigations (hoof acceleration, interacting forces) and aims to contribute to an overall experimental-mathematical multidisciplinary approach. In silico modelling of hoof-ground interaction (limb, hoof and horizontally unbounded ground). Hoof-ground interaction is represented by a time-domain finite element model including the limb, the hoof and the unbounded representation of the ground via the scaled boundary finite element method to capture radiation damping during the stance phase. Motoric forces (driving forces) of the horse during locomotion are included. Numerical model results for acceleration-time relations (hoof) at different trotting velocities are compared with previously published acceleration-time relations and show qualitative agreement. From the model approach, power loss due to different ground properties and ground damping is computed in combination with the maximum limb force during the stance phase. Intentionally, a simplified model approach for the material and structural representation of the limb, the hoof and the ground in terms of material features and spatial resolution has been used for this study, which might be the basis for a model refinement in terms of contact properties as well as the integration of bone and joint structures. The comparison to experimentally obtained results demonstrates the applicability of the model, which, in turn, enables an insight into the processes taking place
SUN, YULIANG; WEI, SHUTAO; ZHONG, YUNJIAN; FU, WEIJIE; LI, LI; LIU, YU
ABSTRACT Purpose The potential mechanisms of hamstring strain injuries in athletes are not well understood. The study, therefore, was aimed at understanding hamstring mechanics by studying loading conditions during maximum-effort overground sprinting. Methods Three-dimensional kinematics and ground reaction force data were collected from eight elite male sprinters sprinting at their maximum effort. Maximal isometric torques of the hip and knee were also collected. Data from the sprinting gait cycle were analyzed via an intersegmental dynamics approach, and the different joint torque components were calculated. Results During the initial stance phase, the ground reaction force passed anteriorly to the knee and hip, producing an extension torque at the knee and a flexion torque at the hip joint. Thus, the active muscle torque functioned to produce flexion torque at the knee and extension torque at the hip. The maximal muscle torque at the knee joint was 1.4 times the maximal isometric knee flexion torque. During the late swing phase, the muscle torque counterbalanced the motion-dependent torque and acted to flex the knee joint and extend the hip joint. The loading conditions on the hamstring muscles were similar to those of the initial stance phase. Conclusions During both the initial stance and late swing phases, the large passive torques at both the knee and hip joints acted to lengthen the hamstring muscles. The active muscle torques generated mainly by the hamstrings functioned to counteract those passive effects. As a result, during sprinting or high-speed locomotion, the hamstring muscles may be more susceptible to high risk of strain injury during these two phases. PMID:24911288
Santos, E. S. D.; Picoli, S.; Deprá, P. P.; Mendes, R. S.
In the present study, we investigate patterns in the postural sway that characterize the static balance in human beings. To measure the postural sway, sixteen healthy young subjects performed quiet stance tasks providing the center-of-pressure (COP) trajectories. From these trajectories, we obtained the COP velocities. We verified that the velocity distributions exhibit non-normal behavior and can be approximated by generalized Gaussians with fat tails. We also discuss possible implications of modeling COP velocity by using generalized Fokker-Planck equations related to Tsallis statistics and Richardson anomalous diffusion.
Don Kim, Kyoung; Lee, Hyun Jin; Lee, Myoung Hyo; Hwangbo, Gak
[Purpose] This study examined how an ankle-foot orthosis (AFO) influences the weight-bearing of chronic stroke patients during the performance of five functional standing tasks. [Subjects and Methods] Sixteen patients with stroke participated in this experiment. The subjects performed functional standing tasks with or without the AFO and weight bearing was measured during the tasks. [Results] Patients showed increased weight-bearing ability on the affected side during wearing the AFO in all tasks, and there were significant differences among Tasks 1, 2, and 3. Patients showed a small amount of increased weight bearing on the unaffected side while wearing the AFO in all tasks except for Task 2. [Conclusion] ADL-related functional standing tasks with AFO increased the weight bearing.
Tanner, Lynn R; Hooke, Mary C; Hinshon, Scott; Hansen, Cheryl R
Children with cancer are at risk for physical performance limitations. In this pilot study we investigated the feasibility and initial efficacy of an ankle foot orthosis (AFO) in children with non-central nervous system cancer with peripheral weakness. Participants included children aged 5 to 11 years diagnosed with cancer. Children wore AFOs for 1 cycle of chemotherapy. Pre- and postintervention adverse events, adherence, gait, strength, range of motion, activity, and fatigue were measured. Six of 7 children completed the study; none of the 7 reported adverse events. Positive trends were observed in step length (46.23-49.25 cm), dorsiflexion strength (19.25-24.50 lb), ankle dorsiflexion range of motion (0.5-8°), and activity (7850-9857 epochs). Negative trends observed included cadence and fatigue ratings. No change was observed in the 6-minute walk or parent-reported fatigue. An AFO intervention is feasible in children with cancer. Initial efficacy results warrant further study.
Haraguchi, Naoki; Armiger, Robert S; Myerson, Mark S; Campbell, John T; Chao, Edmund Y S
Our goal was to quantify and visualize the three-dimensional loading relationship between the ligaments and articular surfaces of the ankle to identify and determine the stabilizing roles of these anatomical structures during the stance phase of gait. We applied discrete element analysis to computationally model the three-dimensional contact characteristics and ligament loading of the ankle joint. Physiologic loads approximating those at five positions in the stance phase of a normal walk cycle were applied. We analyzed joint contact pressures and periankle ligament tension concurrently. Most ankle joint loading during the stance phase occurred across the articular surfaces of the joint, and the amount of ligament tension was small. The tibiotalar articulation showed full congruency throughout most of the stance phase, with peak pressure developing anteriorly toward the toe-off frame. Of the periankle ligaments, the deep deltoid ligament transferred the most force during the stance phase (57.2%); the superficial deltoid ligament transferred the second-most force (26.1%). The anterior talofibular ligament transferred force between the talus and fibula continuously, whereas the calcaneofibular ligament did not carry force during gait. The distal tibiofibular ligaments and the interosseous membrane were loaded throughout the stance phase. Force transmission through the ankle joint during the stance phase is predominantly through the articular surfaces, and the periankle ligaments do not play a major stabilizing role in constraining ankle motion. The medial ligaments have a more important role than do the lateral ligaments in stabilizing the ankle joint. In addition to ligament insufficiency, other factors, such as varus tilt of the tibial plafond, may be important in the development of recurrent instability. Continuous loading of syndesmosis ligaments provides a theoretical basis for evidence of syndesmosis screw breakage or loosening. The analysis method has
Gupta, Anupam; Nalini, Atchayaram; Arya, Shanti Prakash; Vengalil, Seena; Khanna, Meeka; Krishnan, Rashmi; Taly, Arun B
To assess Ankle-Foot-Orthosis (AFO) requirement and ambulation in Duchenne Muscular Dystrophy (DMD) patients seen over a period of 4 y at a multi-disciplinary Neuromuscular disorders clinic (NMD). A study was conducted in university quaternary research hospital with DMD patients confirmed by MLPA (multiplex ligation - dependent probe amplification) method and were evaluated between January 2012 and December 2015. Their ambulatory status, detailed neurological and functional status were recorded. Requirement of AFOs was determined and provided. In total 126 DMD children reported to the NMD clinic. Mean age at presentation was 7.6 y (range 2 to12 y, SD 2.1). Mean duration of illness at first evaluation was 3.4 y (range 0.5 to 10 y, SD 2.0). AFO's were advised at a mean age of 8.5 y (range 7 to 12 y, SD 1.8). Fifty-nine patients were advised AFO as resting or walking splint. At last follow-up 113 patients were still ambulatory whereas 13 had become wheel chair bound. Out of 59 patients, 48 were still wearing AFOs and the remaining discontinued AFOs for various reasons. Children with DMD require wearing of AFOs as resting or walking splint, mostly in first or early second decade of life. As there is some gap between onset of clinical signs and requirement of orthosis, follow-up preferably at a multidisciplinary clinic at regular intervals is desirable for timely intervention in the form of AFOs or other splints to prolong ambulatory status in these patients.
Best, Raymond; Böhle, Caroline; Schiffer, Thorsten; Petersen, Wolf; Ellermann, Andree; Brueggemann, Gert Peter; Liebau, Christian
Purpose of the study was the evaluation of the early functional outcome of patients with an acute ankle sprain treated either with a semirigid, variable, phase-adapted modular ankle orthosis or an invariable orthotic reference device. Forty-seven patients with acute ankle sprain grade II or more were included. In addition, 77 healthy controls as a reference were investigated. The injured subjects were treated with one of the two devices by random for 6 weeks. Ankle scores (FAOS, AOFAS) were taken at baseline after injury, 1 and 3 months after injury. Functional performance tests (balance platform, zig zag run, shuttle run, vertical drop jump) were performed at 1 and 3 months after injury. No significant score differences could be found between the two intervention groups except for achieving a preinjury activity level after 3 months only in the modular orthosis group. Postural functional performances (balance test) also showed no significant differences whereas the results of the agility tests revealed small but significant better results in the modular orthosis group in comparison to the invariable orthosis group. Cohen's effect sizes were high. Differences between the two intervention groups were marginal and very small but significant and--regarding Cohen's effect sizes--effective. Especially relating to functional performance, this might be a careful indication that a more effective strategy for promoting a protected, rapid recovery to physical activity after ankle sprains might be achieved by applying a phase-adapted ankle orthosis. Especially in athletic patients, phase-adapted orthosis should be further investigated and considered to ensure fully protected ligament healing as well as to regain early functional recovery.
Roth, Robin; Wank, Veit; Müller, Otto; Hochwald, Harald; Günther, Michael
This article describes a new measuring device to investigate balancing strategies of human stance: the totter-slab, i.e., a standing plate suspended with steel cables to hooks on a steel frame. First, we analysed the physical properties of the device by recording free oscillations under different conditions [varying amplitude, mass and centre of mass (COM) height]. This allowed us to determine the eigenfrequency f and the damping coefficient Dslab. We found that the totter-slab is a useful, well-defined, reliable and developable measuring device for different non-rigid-ground stance conditions. In a second part of the investigation, we compared the frequency spectra of six subjects balancing on the totter-slab with their spectra while standing quietly on a force plate fixed to the ground. The totter-slab spectra showed two distinct, dominant peak regions at approximately 0.3 and 1.1 Hz. This finding enforces the double inverted pendulum to be an adequate model particularly for balancing on the totter-slab. Compared with the firm ground condition, these two peak regions were more pronounced when balancing on the totter-slab. However, there is a variety of frequencies in the region 0.2...1.5 Hz specific for an individual subject in both balancing conditions.
Wolburg, Thomas; Rapp, Walter; Rieger, Jochen; Horstmann, Thomas
To test the hypotheses that less stable therapy devices require greater muscle activity and that lower leg muscles will have greater increases in muscle activity with less stable therapy devices than upper leg muscles. Cross-sectional laboratory study. Laboratory setting. Twenty-five healthy subjects. Electromyographic activity of four lower (gastrocnemius medialis, soleus, tibialis anterior, peroneus longus) and four upper leg muscles (vastus medialis and lateralis, biceps femoris, semitendinosus) during unipedal quiet barefoot stance on the dominant leg on a flat rigid surface and on five therapy devices with varying stability properties. Muscle activity during unipedal stance differed significantly between therapy devices (P leg) and therapy device (P = 0.985). Magnitudes of additional relative muscle activity for the respective therapy devices differed substantially among lower extremity muscles. The therapy devices offer a progressive increase in training intensity, and thus may be useful for incremental training programs in physiotherapeutic practice and sports training programs. Copyright © 2015 Elsevier Ltd. All rights reserved.
Full Text Available Biomechanical data characterizing the quasi-stiffness of lower-limb joints during human locomotion is limited. Understanding joint stiffness is critical for evaluating gait function and designing devices such as prostheses and orthoses intended to emulate biological properties of human legs. The knee joint moment-angle relationship is approximately linear in the flexion and extension stages of stance, exhibiting nearly constant stiffnesses, known as the quasi-stiffnesses of each stage. Using a generalized inverse dynamics analysis approach, we identify the key independent variables needed to predict knee quasi-stiffness during walking, including gait speed, knee excursion, and subject height and weight. Then, based on the identified key variables, we used experimental walking data for 136 conditions (speeds of 0.75-2.63 m/s across 14 subjects to obtain best fit linear regressions for a set of general models, which were further simplified for the optimal gait speed. We found R(2 > 86% for the most general models of knee quasi-stiffnesses for the flexion and extension stages of stance. With only subject height and weight, we could predict knee quasi-stiffness for preferred walking speed with average error of 9% with only one outlier. These results provide a useful framework and foundation for selecting subject-specific stiffness for prosthetic and exoskeletal devices designed to emulate biological knee function during walking.
Ree, Jennifer; Hayashi, Kei; Woelz, Jacqueline; Kim, Sun Young
A 3.5 yr old spayed female Staffordshire terrier weighing 25.5 kg was presented with a 7 wk history of bilateral plantigrade stance in the pelvic limbs directly following an ovariohysterectomy procedure. Upon presentation, the dog had bilateral atrophy of the distal pelvic limb muscles, enlarged popliteal lymph nodes, and ulcerative wounds on the dorsa of her rear paws. Orthopedic examination revealed intact calcaneal tendons bilaterally and neurologic examination localized the lesion to the distal sciatic nerve. A diagnosis of compressive and stretch neuropathy was made affecting the distal sciatic nerve branches. Physical therapy modalities included neuromuscular electrical stimulation, ultrasound, and low-level laser therapy. Other therapeutic modalities included the use of orthotics and progressive wound care. The dog had increased muscle mass, return of segmental reflexes, return of nociception, and the ability to walk on pelvic limbs with higher carriage of the hock 15 mo following presentation. The use of custom orthotics greatly increased the quality of life and other physical therapy modalities may have improved the prognosis in this dog with severe bilateral plantigrade stance due to neuropathy.
Full Text Available In his work as a writer, Józef Wittlin searched for literature able to grant the reader moral support, while at the same time being artistically successful. In his novel Salt of the Earth, the way to com-bine these two, to a certain extent contradictionary aims, is found in the use of irony. An analysis of the classical types of irony appearing in the novel (naive irony, irony of the sender, verbal irony leads to the conclusion that each of those was remarkably modified by the author. As a result, the “ironical anthropology” created by Wittlin in his novel lacks any elements of simple moralizing or giving ready-made moral solutions, but brings a striking image of a human commu-nity, unified not by a common status, but by a common fate. In the novel, irony turns out to be not only a textual figure, but first and foremost a moral stance, approximate to that of Socrates as described by Kierkegaard. Thanks to this stance, Wittlin enthuses his readers with the longing for the ideal, shaping their moral sensibility, at the same time granting them the sovereignty to which the reader of a literary work should be entitled.
Екатерина Юрьевна Хрисонопуло
Full Text Available This paper presents an account of the phenomenon of mental construal manifested in English expressions of stance through the distinction of clauses that are headed by subjects associated with two conceptual archetypes: participant (P invoked by the first-person pronoun ( I am certain that and abstract setting (S conveyed by anticipatory it ( It is certain that . With recourse to the main theoretical points on the anchoring of linguistic meaning in the acts of speech activity (Leontiev A.A., mental construal (Langacker R., processes of discourse-driven conceptualization and categorization (Kubryakova E.S. and with reference to discourse oriented studies of stance (Biber D., Finegan E., Kärkkäinen E., the conducted analysis focuses on a corpus of about 350 examples that represent narrative and dialogic discourse in English-language fiction. As evidenced by linguistic data, the choice of stance expressions with P- and S-subjects is motivated, respectively, by the distinctions that arise in discourse between actual and mentally represented types of reality, the contrast between reference-making and viewing as types of cognitive events and the distinction between event-schemas and mental experiences. These discursively relevant distinctions are further shown to be related to narrative and dialogic strategies that are used in literary texts for the expression of stance with the alternative stance-clauses.
Leonardo George Victorio Victor
Full Text Available Physical inactivity and aging are functional disability factors for older individuals, causing loss of balance and increasing the risk of falls. The purpose of this study was to compare the balance of physically independent older individuals, both participants and non-participants in a regular exercise program. Fifty six physically independent older participants were divided into G1ACTIVE = 28 individuals who participate in a regular exercise program and G2SEDENTARY = 28 individuals who did not participate in any physical exercise program. All participants underwent an eyes-open during one-leg balance test on a force platform. The postural oscillation parameters included center of pressure (COP; sway mean velocity and frequency of COP oscillations. G2 SEDENTARY showed higher postural instability than G1ACTIVE. Significant differences were observed for the main balance parameters. The results of this study support the concept that participation in regular physical activity is beneficial for postural balance of older individuals.
Danna-Dos-Santos, A.; Boonstra, T.W.; Degani, A.M.; Cardoso, V.S.; Magalhaes, A.T.; Mochizuki, L.
Posture and postural reactions to mechanical perturbations require the harmonic modulation of the activity of multiple muscles. This precision can become suboptimal in the presence of neuromuscular disorders and result in higher fall risk and associated levels of comorbidity. This study was designed
Fabian M Stuby
Full Text Available This study was conducted according to GCP criteria as a prospective randomized cross-over study. The primary goal of the study was to determine clinical findings and patient satisfaction with postoperative treatment. 29 patients with a distal radius fracture that was surgically stabilized from volar and who met the inclusion criteria were enrolled over a 12-month period. Each patient randomly received either a dorsal plaster splint or a vacuum-fit flexible but blocked orthosis applied postoperatively in the operating theatre to achieve postoperative immobilization. After one week all patients were crossed over to the complementary device maintaining the immobilization until end of week 2. After week 2 both groups were allowed to exercise wrist mobility with a physiotherapist, in the orthosis group the device was deblocked, thus allowing limited wrist mobility. After week 4 the devices were removed in both groups. Follow-up exams were performed after postoperative weeks 1, 2, 4 and 12.Results were determined after week 1 and 2 using SF 36 and a personally compiled questionnaire; after weeks 4 and 12 with a clinical check-up, calculation of ROM and the DASH Score. Comparison of the two groups showed a significant difference in ROM for volar flexion after 4 weeks, but no significant differences in DASH Score, duration of disability or x-ray findings. With regard to satisfaction with comfort and hygiene, patients were significantly more satisfied with the dynamic orthosis, and 23 of the 29 patients would prefer the flexible vacuum orthosis in future.German Clinical Trials Register (DRKS DRKS00006097.
Kim, Sung-Min; Kim, Sung-Jae; Bae, Ha-Suk
In this study, ground reaction force (GRF), absolute symmetry index (ASI) and coefficient of variation (CV) of fixed, single-axis and multi-axis prosthetic ankle assemblies were investigated by biomechanical evaluation of above knee amputees. In the experiments, 37 normal male volunteers, two male and two female Above Knee (AK) amputees GRF data were tested with fixed, single-axis and multi-axis prosthetic ankle assembly. A gait analysis was carried out to derive the ratio of GRF to weight as the percentage of total stance phase for ten points. The results showed that fixed-axis ankle assembly was superior to other two ankle assemblies for forwarding and braking forces. Multi-axis ankle was relatively superior to other two ankle assemblies for gait balancing and movement of the mass center. Single-axis ankle was relatively superior to the other two ankle assemblies for CV and ASI of GRF.
Full Text Available Abstract Background Modulation of nociceptive withdrawal reflex (NWR excitability was evaluated during gait initiation in 10 healthy subjects to investigate how load- and movement-related joint inputs activate lower spinal centres in the transition from quiet stance to walking. A motion analysis system integrated with a surface EMG device was used to acquire kinematic, kinetic and EMG variables. Starting from a quiet stance, subjects were asked to walk forward, at their natural speed. The sural nerve was stimulated and EMG responses were recorded from major hip, knee and ankle muscles. Gait initiation was divided into four subphases based on centre of pressure and centre of mass behaviours, while joint displacements were used to categorise joint motion as flexion or extension. The reflex parameters were measured and compared between subphases and in relation to the joint kinematics. Results The NWR was found to be subphase-dependent. NWR excitability was increased in the hip and knee flexor muscles of the starting leg, just prior to the occurrence of any movement, and in the knee flexor muscles of the same leg as soon as it was unloaded. The NWR was hip joint kinematics-dependent in a crossed manner. The excitability of the reflex was enhanced in the extensor muscles of the standing leg during the hip flexion of the starting leg, and in the hip flexors of the standing leg during the hip extension of the starting leg. No notable reflex modulation was observed in the ankle muscles. Conclusions Our findings show that the NWR is modulated during the gait initiation phase. Leg unloading and hip joint motion are the main sources of the observed modulation and work in concert to prepare and assist the starting leg in the first step while supporting the contralateral leg, thereby possibly predisposing the lower limbs to the cyclical pattern of walking.
Ravitch, Sharon M.
Within the ever-developing, intersecting, and overlapping contexts of globalization, top-down policy, mandates, and standardization of public and higher education, many conceptualize and position practitioner research as a powerful stance and a tool of social, communal, and educational transformation, a set of methodological processes that…
Park, Seol; Ko, Yu-Min; Park, Ji-Won
[Purpose] This study examined the relationship between the center of pressure (COP) displacement time during the stance subphases and dynamic balance ability when elderly cross obstacles 0, 10, and 40 cm in height. [Subjects] Fifteen older adults were enrolled in this study (≥65 years of age). [Methods] An F-Scan System was used to measure the COP displacement time when subjects crossed obstacles 0, 10, and 40 cm in height, and the Dynamic Gait Index, Berg Balance Scale, and Four Square Step Test were used to measure dynamic balance ability. [Results] The Dynamic Gait Index, Berg Balance Scale, and Four Square Step Test were correlated with each other. Dynamic balance tests were correlated with the COP displacement time during the stance phase. At obstacle heights of 10 and 40 cm during loading response and at all heights during pre-swing, there were correlations with dynamic balance ability. However, dynamic balance ability did not affect the COP displacement time during mid-stance and terminal stance. [Conclusion] People with a lower dynamic balance ability show a larger COP displacement time during loading response and pre-swing. Therefore, dynamic balance ability can be predicted by measuring the COP displacement time.
Hassenfeld, Ziva R.
This study investigated the voices of students interpreting Hebrew Bible texts in one fourth-grade classroom. Through think-alouds on the Biblical text with each student, exit interviews, teacher interviews, and classroom observations, this study found that those students whose interpretive stances were more aligned with the teacher's were given…
This paper develops the idea that classroom investigation can be an integral part of teaching and learning, an ongoing "stance" that enables us to gather valuable information about teaching and learning that may otherwise go unnoticed. This information can in turn inform how teachers understand and develop intercultural language teaching and…
Full Text Available The One-Leg Stance (OLS test is a widely adopted tool for the clinical assessment of balance in the elderly and in subjects with neurological disorders. It was previously showed that the ability to control anticipatory postural adjustments (APAs prior to lifting one leg is significantly impaired by idiopathic Parkinson’s disease (iPD. However, it is not known how APAs are affected by other types of parkinsonism, such as frontal gait disorders (FGD. In this study, an instrumented OLS test based on wearable inertial sensors is proposed to investigate both the initial anticipatory phase and the subsequent unipedal balance. The sensitivity and the validity of the test have been evaluated. Twenty-five subjects with iPD presenting freezing of gait (FOG, 33 with iPD without FOG, 13 with FGD, and 32 healthy elderly controls were recruited. All subjects wore three inertial sensors positioned on the posterior trunk (L4–L5, and on the left and right frontal face of the tibias. Participants were asked to lift a foot and stand on a single leg as long as possible with eyes open, as proposed by the mini-BESTest. Temporal parameters and trunk acceleration were extracted from sensors and compared among groups. The results showed that, regarding the anticipatory phase, the peak of mediolateral trunk acceleration was significantly reduced compared to healthy controls (p < 0.05 in subjects with iPD with and without FOG, but not in FGD group (p = 0.151. Regarding the balance phase duration, a significant shortening was found in the three parkinsonian groups compared to controls (p < 0.001. Moreover, balance was significantly longer (p < 0.001 in iPD subjects without FOG compared to subjects with FGD and iPD subjects presenting FOG. Strong correlations between balance duration extracted by sensors and clinical mini-BESTest scores were found (ρ > 0.74, demonstrating the method’s validity. Our findings support the validity of the proposed
Duplessis, D H; Greenway, E H; Keene, K L; Lee, I E; Clayton, R L; Metzler, T; Underwood, F B
The use of back belts in industry has increased despite the lack of scientific evidence supporting their efficacy. The purpose of this study was to investigate the effect of a semi-rigid lumbosacral orthosis (SRLSO) on oxygen consumption during 6-min submaximal repetitive lifting bouts of 10 kg at a lifting frequency of 20 repetitions min-1. Fifteen healthy subjects (13 men, two women) participated in this study. Each subject performed squat and stoop lifting with and without an SRLSO for a total of four lifting bouts. Lifting bouts were performed in random order. Oxygen consumption during the final minute of each lifting bout was used for analysis. A two-way analysis of variance with repeated measures was used to analyse the effects of lift and belt conditions. The stoop and squat methods were significantly different, with the squat lift requiring 23% more oxygen on average than the stoop lift for equal bouts of work. No significant difference was found between the belt and no belt condition within the same lifting technique and no interaction was present. These data suggest that an SRLSO does not passively assist the paravertebral muscles (PVM) in stabilizing the spine during submaximal lifting bouts.
Chakraborty, Partha Pratim; Ray, Sayantan; Biswas, Dibakar; Baidya, Arjun; Bhattacharjee, Rana; Mukhopadhyay, Pradip; Ghosh, Sujoy; Mukhopadhyay, Satinath; Chowdhury, Subhankar
Off-loading of the ulcer area is extremely important for the healing of plantar ulcers. Off-loading with total contact cast (TCC) may be superior to other off-loading strategies studied so far, but practical limitations can dissuade clinicians from using this modality. This study was conducted to evaluate the efficacy of TCC compared with that of a pressure-relieving ankle foot orthosis (PRAFO) in healing of diabetic neuropathic foot ulcers and their effect on gait parameters. Thirty adult diabetic patients attending the foot clinic with neuropathic plantar ulcers irrespective of sex, age, duration and type of diabetes were randomly assigned to 1 of 2 off-loading modalities (TCC and PRAFO). Main outcome measures were ulcer healing after 4 weeks of randomization and effect of each of the modalities on various gait parameters. The percentage reduction of the ulcer surface area at 4 weeks from baseline was 75.75 ± 9.25 with TCC and 34.72 ± 13.07 with PRAFO, which was significantly different (P diabetic neuropathic foot ulcer. Further studies are needed involving larger subjects and using 3D gait analysis to collect more accurate data on gait parameters and wound healing with different off-loading devices. © 2014 Diabetes Technology Society.
Full Text Available Abstract – This study explores the web-mediated genre of TED (Technology, Entertainment, Design talks, speech events whereby experts in their field disseminate knowledge from different domains (e.g. science, technology, design, global issues addressing an audience of both co-present participants and web-users all over the world. The aim of this study is to investigate the way academics convey epistemic stance (Conrad, Biber 2000 and build up their image as experts on the TED stage. To this purpose, a contrastive analysis was carried out comparing two corpora of spoken discourse, i.e. a corpus of TED talks and a corpus of MICASE university lectures from different disciplines. Although in both genres the speaker is an academic, both the communicative purpose and audience expectations differ substantially in the two contexts under scrutiny. This comparison highlights some distinguishing traits of TED talks and provides a better insight into this genre. Adopting a corpus-based approach, attention is first paid to the most recurrent epistemic lexical verbs (ELVs and to the use of first and second person pronouns in the two corpora. The qualitative analysis then focuses on similarities and differences in the discourse functions of the four most frequent ELVs (see, show, know, think and of their clusters when they combine with first and second person pronouns in the two corpora. Previous studies in the field of English for Academic Purposes (Rounds 1987; Fortanet 2004; Walsh 2004; Artiga León 2006; Bamford 2009 are referred to as a starting point to investigate a novel, unexplored pragmatic space (i.e. that of TED wherein academics accomplish purposes other than merely disseminating knowledge and training students, such as promoting their research and building up their image as experts. Keywords: Languages for Special Purposes, popularization, web-mediated genres, evidentiality, epistemic stance Abstract – I generi mediati dalla rete svolgono un
Knudsen, Nikolas Sten; Andersen, Thomas Bull
The purpose of this study was to evaluate 3 different starting techniques from the staggered stance with regards to sprint time, reaction time, linear impulse and power. 11 male amateur American football players volunteered to participate in a testing session consisting of twelve 5 m sprints, 4...... in each technique (normal (NORM), backwards false step (BFS) and forwards false step (FFS)) in random order. Sprint starts were performed on force plates to investigate ground reaction forces, reaction time and total sprint time. Analysis showed significant differences in sprint times, with NORM (1.......77±0.10 s) being faster than FFS (1.81±0.12 s) and BFS (2.01±0.13 s), and FFS being faster than BFS, although no differences were found in reaction time. In terms of mean force and power, NORM (331.1±39.2N, 542.2±72.3W) and FFS (320.8±43.2N, 550.9±81.4W) were significantly larger than BFS (256.9±36.2N, 443...
Callejo Goena, Daniel
En este proyecto se presenta el diseño mecánico de un banco de pruebas para el sistema de actuación de una ortesis activa de rodilla-tobillo-pie (knee-ankle-foot orthosis en inglés) para lesionados medulares incompletos. El objetivo de dicho banco es caracterizar con precisión el comportamiento dinámico del sistema de actuación de la rodilla: estudiar su funcionamiento directo e inverso y la posibilidad de emplear materiales elásticos en alguna de las piezas que transmite el movimiento a l...
Steinmetz, Michael P; Verrees, Meg; Anderson, James S; Lechner, Roseanna M
Two children who were 13 months and 3 years old and who had suffered traumatic atlantooccipital dislocation were each treated by being placed in a halo orthosis for 10 weeks. Because of a continued loss of reduction due to the poor fit of the halo vest, a dual-strap augmentation was developed. This strap augmentation allowed consistent reduction to be maintained. Both children were therefore successfully treated nonsurgically with a halo vest. One child remained neurologically intact and the other had improvement in motor strength. There were no complications from the use of strap augmentation for halo vest fixation.
Full Text Available Hinge-based Ankle Foot Orthosis (HAFO is one of the most common non-surgical solutions for the foot drop. In conventional HAFOs, the ankle joint is almost locked, and plantar flexion is restricted due to the high stiffness of the hinge mechanism. This often leads to a rigid walking gate cycle, poor muscle activity, and muscle atrophy. Since the ankle torque-angle loop has a non-linear profile, the use of a superelastic NiTi spring within the hinge, due to its nonlinear behavior, could recreate a close-to-normal stiffness of the normal ankle joint, which, in turn, could create a more natural walk. The focus of this study is to evaluate the performance of a superelastic NiTi spring versus a conventional Stainless Steel spring in a hinge mechanism of a custom-fit HAFO. To this aim, a custom-fit HAFO was fabricated via the fast casting technique. Then, motion analysis was performed for two healthy subjects (Case I and Case II: (i subjects with bare foot; (ii subjects wearing a conventional HAFO with no spring; (iii subjects wearing a conventional Stainless Steel-based HAFO; and (iv subjects wearing a NiTi spring-based HAFO. The data related to the ankle angle and the amount of moment applied to the ankle during walking were recorded using Cortex software and used for the evaluations. Finally, Finite Element Analysis (FEA was performed to evaluate the safety of the designed HAFO. The NiTi spring offers a higher range of motion (7.9 versus 4.14 degree and an increased level of moment (0.55 versus 0.36 N·m/kg. Furthermore, a NiTi spring offers an ankle torque-angle loop closer to that of the healthy subjects.
Amerinatanzi, Amirhesam; Zamanian, Hashem; Shayesteh Moghaddam, Narges; Jahadakbar, Ahmadreza; Elahinia, Mohammad
Hinge-based Ankle Foot Orthosis (HAFO) is one of the most common non-surgical solutions for the foot drop. In conventional HAFOs, the ankle joint is almost locked, and plantar flexion is restricted due to the high stiffness of the hinge mechanism. This often leads to a rigid walking gate cycle, poor muscle activity, and muscle atrophy. Since the ankle torque-angle loop has a non-linear profile, the use of a superelastic NiTi spring within the hinge, due to its nonlinear behavior, could recreate a close-to-normal stiffness of the normal ankle joint, which, in turn, could create a more natural walk. The focus of this study is to evaluate the performance of a superelastic NiTi spring versus a conventional Stainless Steel spring in a hinge mechanism of a custom-fit HAFO. To this aim, a custom-fit HAFO was fabricated via the fast casting technique. Then, motion analysis was performed for two healthy subjects (Case I and Case II): (i) subjects with bare foot; (ii) subjects wearing a conventional HAFO with no spring; (iii) subjects wearing a conventional Stainless Steel-based HAFO; and (iv) subjects wearing a NiTi spring-based HAFO. The data related to the ankle angle and the amount of moment applied to the ankle during walking were recorded using Cortex software and used for the evaluations. Finally, Finite Element Analysis (FEA) was performed to evaluate the safety of the designed HAFO. The NiTi spring offers a higher range of motion (7.9 versus 4.14 degree) and an increased level of moment (0.55 versus 0.36 N·m/kg). Furthermore, a NiTi spring offers an ankle torque-angle loop closer to that of the healthy subjects.
Mergner, Thomas; Schweigart, Georg; Fennell, Luminous
Many of our motor activities require stabilization against external disturbances. This especially applies to biped stance since it is inherently unstable. Disturbance compensation is mainly reactive, depending on sensory inputs and real-time sensor fusion. In humans, the vestibular system plays a major role. When there is no visual space reference, vestibular-loss clearly impairs stance stability. Most humanoid robots do not use a vestibular system, but stabilize upright body posture by means of center of pressure (COP) control. We here suggest using in addition a vestibular sensor and present a biologically inspired vestibular sensor along with a human-inspired stance control mechanism. We proceed in two steps. First, in an introductory review part, we report on relevant human sensors and their role in stance control, focusing on own models of transmitter fusion in the vestibular sensor and sensor fusion in stance control. In a second, experimental part, the models are used to construct an artificial vestibular system and to embed it into the stance control of a humanoid. The robot's performance is investigated using tilts of the support surface. The results are compared to those of humans. Functional significance of the vestibular sensor is highlighted by comparing vestibular-able with vestibular-loss states in robot and humans. We show that a kinematic body-space sensory feedback (vestibular) is advantageous over a kinetic one (force cues) for dynamic body-space balancing. Our embodiment of human sensorimotor control principles into a robot is more than just bionics. It inspired our biological work (neurorobotics: 'learning by building', proof of principle, and more). We envisage a future clinical use in the form of hardware-in-the-loop simulations of neurological symptoms for improving diagnosis and therapy and designing medical assistive devices.
Norma R. A. Romm D Litt et Phil
Full Text Available In this article, I delve into what it might mean to employ questionnaires without regarding them simply as a way of attempting to discern relationships of correlation or causality between defined variables (as in positivist and post-positivist conceptions of questionnaires. I shall consider the implications of researchers using questionnaires on the basis of alternative paradigmatic orientations. I shall discuss, in particular, interpretivist stances and more constructively-oriented stances (as qualitatively-oriented paradigmatic positions with reference to different understandings of questionnaire use. I shall also reflect on how qualitative positions that embrace a constructivist epistemological stance can lead to a redirection of questionnaires in relation to more “usual” (post-positivist-directed usages. In the course of the discussion I make a case, drawing on a version of constructivism, for researchers taking responsibility for their involvement—no matter what methods are used—in the unfolding of the social worlds of which research is a part. Taking into account the constructivist epistemological understanding that questionnaires—as well as other research methods—contribute to the construction of responses rather than merely “finding” responses from research participants, I suggest that some responsibility needs to be taken by those employing questionnaires for the potential social impact of these on research participants as well as wider audiences.
Küng, U M; Horlings, C G C; Honegger, F; Allum, J H J
Stabilising shifts of the centre of mass (COM) are observed during balance recovery when subjects simultaneously execute voluntary unilateral knee flexion or unilateral arm raising. Here, we examined whether voluntary lateral trunk bending provided more beneficial stabilising effects, and how motor programs of balance corrections are combined with those of the focal voluntary action. The upright balance of 24 healthy young subjects (19-33 years of age) was perturbed using multi-directional rotations of the support-surface. The perturbations consisted of combined pitch and roll rotations (7.5 degrees and 60 degrees/s) presented randomly in six different directions. Three conditions were tested: perturbation of stance only (PO); combined balance perturbation and cued uphill bending of the trunk (CONT); and combined perturbation and cued downhill bending of the trunk (IPS). For comparison, subjects were required to perform trunk bending alone (TO). Outcome measures were biomechanical responses and surface EMG activity of several muscles. Calculated predicted outcomes (PO + TO) were compared with combined measures (CONT or IPS). CONT trunk bending uphill showed two phases of benefit in balance recovery for laterally but, in contrast to voluntary knee bending, not for posterior directed components of the perturbations. IPS trunk bending had negative effects on balance. Early balance correcting muscle responses were marginally greater than PO responses. Prominent secondary balance correcting responses, having a similar timing as voluntary responses observed under TO conditions, were seen under CONT only in trunk muscles. These, and later stabilising, responses had amplitudes as expected from PO + TO conditions being significantly greater than PO responses. The ability with which different muscle synergies for balance corrections and voluntary trunk bending were integrated into one indicates a flexible adjustment of the CNS programs to the demands of both tasks.
Veneva, Ivanka; Vanderborght, Bram; Lefeber, Dirk; Cherelle, Pierre
The aim of this paper is to present the design of device for control of new propulsion system with pneumatic artificial muscles. The propulsion system can be used for ankle joint articulation, for assisting and rehabilitation in cases of injured ankle-foot complex, stroke patients or elderly with functional weakness. Proposed device for control is composed by microcontroller, generator for muscles contractions and sensor system. The microcontroller receives the control signals from sensors and modulates ankle joint flex- ion and extension during human motion. The local joint control with a PID (Proportional-Integral Derivative) position feedback directly calculates desired pressure levels and dictates the necessary contractions. The main goal is to achieve an adaptation of the system and provide the necessary joint torque using position control with feedback.
Shoham, Yehudit; Meyer, Shirley; Katz-Leurer, Michal; Tamar Weiss, Patrice L
To determine the effect of a thoraco-lumbar-sacral orthosis (TLSO) on the distribution of body-seat interface pressure in children with concomitant scoliosis and pelvic obliquity and to determine the effects of two methods commonly used in customized seating--elevation (push up) of the lower side of the pelvis or a wedge insertion beneath the raised pelvis--on the distribution of body-seat interface pressure. The study population comprised 15 children with an underlying neuromuscular disorder. All had scoliosis and pelvic obliquity when seated, and used a TLSO during sitting. Body-seat interface pressure was measured using the QA Pad. Maximum pressure, mean pressure and contact area were recorded at baseline and at 10 degrees 'push up' and 10 degrees wedge insertion, with and without the TLSO. X-rays were performed with and without the orthosis at baseline position. The TLSO reduced the scoliosis deformity by a mean of 5.3 degrees and significantly (p pelvic obliquity was contralateral to the side of the curve. Seat adjustment did not have any significant effect on pressure readings. Application of a TLSO in a child with scoliosis and contralateral pelvic obliquity significantly reduced the spinal curvature and interface sitting pressure. Manipulation of sitting by use of wedges under the pelvis had no significant effect on pressure distribution.
Saharan, Lokesh; Sharma, Ashvath; Jung de Andrade, Monica; Baughman, Ray H.; Tadesse, Yonas
Partial or total upper extremity impairment affects the quality of life of a vast number of people due to stroke, neuromuscular disease, or trauma. Many researchers have presented hand orthosis to address the needs of rehabilitation or assistance on upper extremity function. Most of the devices available commercially and in literature are powered by conventional actuators such as DC motors, servomotors or pneumatic actuators. Some prototypes are developed based on shape memory alloy (SMA) and dielectric elastomers (DE). This study presents a customizable, 3D printed, a lightweight exoskeleton (iGrab) based on recently reported Twisted and Coiled Polymer (TCP) muscles, which are lightweight, provide high power to weight ratio and large stroke. We used silver coated nylon 6, 6 threads to make the TCP muscles, which can be easily actuated electrothermally. We reviewed briefly hand orthosis created with various actuation technologies and present our design of tendon-driven exoskeleton with the muscles confined in the forearm area. A single muscle is used to facilitate the motion of all three joints namely DIP (Distal interphalangeal), PIP (Proximal Interphalangeal) and MCP (Metacarpophalangeal) using passive tendons though circular rings. The grasping capabilities, along with TCP muscle properties utilized in the design such as life cycle, actuation under load and power inputs are discussed.
Schiemanck, Sven; Berenpas, Frank; van Swigchem, Roos; van den Munckhof, Pepijn; de Vries, Joost; Beelen, Anita; Nollet, Frans; Geurts, Alexander C.
To investigate whether an implantable functional electrical stimulation (FES) system of the common peroneal nerve (ActiGait®) improves relevant aspects of gait in chronic stroke patients with a drop foot typically using an ankle-foot orthosis (AFO). Ten community-dwelling patients participated, of
Is transcutaneous peroneal stimulation beneficial to patients with chronic stroke using an ankle-foot orthosis? A within-subjects study of patients' satisfaction, walking speed and physical activity level.
Swigchem, R. van; Vloothuis, J.; Boer, J. de; Weerdesteijn, V.G.M.; Geurts, A.C.H.
OBJECTIVE: The aim of this study was to evaluate whether community-dwelling chronic stroke patients wearing an ankle-foot orthosis would benefit from changing to functional electrical stimulation of the peroneal nerve. METHODS: In 26 community-dwelling chronic (> 6 months post-onset) patients after
Veale, Allan Joshua; Anderson, Iain Alexander; Xie, Shane Q.; Lynch, Jerome P.
Robotic orthoses have the potential to provide effective rehabilitation while overcoming the availability and cost constraints of therapists. These orthoses must be characterized by the naturally safe, reliable, and controlled motion of a human therapist's muscles. Such characteristics are only
Sienko Thomas, Susan; Buckon, Cathleen E; Jakobson-Huston, Sabrina; Sussman, Michael D; Aiona, Michael D
The purpose of this study was to investigate the impact of three different ankle foot orthoses (AFO) configurations on the function and kinematics of stair locomotion in children with spastic hemiplegia. Nineteen children were evaluated barefoot and with a hinged, posterior leaf spring (PLS) and solid AFO during stair ascent and descent. Stair specific items from the Pediatric Evaluation of Disability Inventory (PEDI) were used to evaluate function, while a motion measurement system was used to evaluate kinematics. The PEDI revealed no significant differences between AFOs and barefoot, although a greater percentage of children were able to keep up with their peers while wearing a hinged AFO. At the ankle, the hinged AFO provided the greatest amount of dorsiflexion during stance. All AFOs reduced plantarflexion in comparison to barefoot. The results of this study indicate that for children with spastic hemiplegia the use of an AFO did not impair stair ambulation.
Menotti, Federica; Laudani, Luca; Damiani, Antonello; Mignogna, Teresa; Macaluso, Andrea
Ankle-foot orthoses are commonly prescribed in Charcot-Marie-Tooth type 1A disease to improve quality of walking and reduce the risk of falling due to the foot drop. This study aimed at assessing the effect of an anterior ankle-foot orthosis on walking economy in a group of Charcot-Marie-Tooth type 1A patients. Within-group comparisons. 7 Charcot-Marie-Tooth type 1A patients (four women and three men; 37 ± 11 years; age range = 22-53 years) were asked to walk on a circuit at their self-selected speeds ('slow', 'comfortable' and 'fast') in two walking conditions: (1) with shoes only and (2) with Taloelast(®) anterior elastic ankle-foot orthoses. Speed of walking and metabolic cost of walking energy cost per unit of distance were assessed at the three self-selected speeds of walking for both walking conditions. Speed of walking at the three self-selected speeds did not differ between shoes only and anterior elastic ankle-foot orthoses, whereas walking energy cost per unit of distance at comfortable speed was lower in patients using anterior elastic ankle-foot orthoses with respect to shoes only (2.39 ± 0.22 vs 2.70 ± 0.19 J kg(-1) m(-1); P Charcot-Marie-Tooth type 1A patients, the use of anterior elastic ankle-foot orthoses improved walking economy by reducing the energy cost of walking per unit of distance, thus reflecting a lower level of metabolic effort and improved mechanical efficiency in comparison with shoes only. From a practical perspective, Charcot-Marie-Tooth type 1A patients with anterior elastic ankle-foot orthoses can walk for a longer duration with a lower level of physical effort. Improvements in walking economy due to ankle-foot orthoses are likely a consequence of the reduction in steppage gait. © The International Society for Prosthetics and Orthotics 2013.
Discussion: RAFO led to a significant improvement in functional mobility in hemiplegic patients post stroke. This may be due to the positive effect of rocker modification on improving push off and transferring weight during the stance phase of gait.
Kerkum, Y.L.; Buizer, A.I.; van den Noort, J.C.; Becher, J.G.; Harlaar, J.; Brehm, M.A.
Introduction: Rigid Ankle-Foot Orthoses (AFOs) are commonly prescribed to counteract excessive knee flexion during the stance phase of gait in children with cerebral palsy (CP). While rigid AFOs may normalize knee kinematics and kinetics effectively, it has the disadvantage of impeding push-off
Kerkum, Yvette L.; Buizer, Annemieke I.; van den Noort, Josien C.; Becher, Jules G.; Harlaar, Jaap; Brehm, Merel-Anne
Rigid Ankle-Foot Orthoses (AFOs) are commonly prescribed to counteract excessive knee flexion during the stance phase of gait in children with cerebral palsy (CP). While rigid AFOs may normalize knee kinematics and kinetics effectively, it has the disadvantage of impeding push-off power. A
Grooms, Jonathon A.
This quasi-experimental study assesses the extent to which the Argument-Driven Inquiry (ADI) instructional model enhances undergraduate students' abilities to generate quality arguments supporting their stance in the context of a Socioscientific Issue (SSI) as compared to students experiencing a traditional style of instruction. Enhancing the quality of undergraduate students' arguments in the context of SSI can serve as an indirect measure of their scientific literacy and their ability to make sound decisions on issues that are inherently scientific but also involve social implications. Data collected in this study suggest that the undergraduate students experiencing the ADI instruction more readily provide rationales in their arguments supporting their decisions regarding two SSI-tasks as compared to a group of undergraduate students experiencing traditional instruction. This improvement in argument quality and gain in scientific literacy was achieved despite the overall lower SSI related content knowledge of the ADI students. Furthermore, the gap between the argument quality of those students with high versus low SSI related content knowledge was closed within the ADI group, while the same gap persisted post-intervention within the traditional instruction students. The role of students' epistemological sophistication was also investigated, which showed that neither instructional strategy was effective at shifting students' epistemological sophistication toward an evaluativist stance. However, the multiplists within the ADI group were able to significantly increase the sophistication of their arguments whereas the traditional students were not. There were no differences between the quality of arguments generated by the evaluativist students with either the treatment or comparison groups. Finally, the nature of the justifications used by the students revealed that the students (both comparison and treatment groups) did not invoke science-based justifications when
Background Robotic and non-robotic training devices are increasingly being used in the rehabilitation of upper limb function in subjects with neurological disorders. As well as being used for training such devices can also provide ongoing assessments during the training sessions. Therefore, it is mandatory to understand the reliability and validity of such measurements when used in a clinical setting. The aim of this study was to evaluate the reliability of movement measures as assessed in the Armeo Spring system for the eventual application to the rehabilitation of patients suffering from cervical spinal cord injury (SCI). Methods Reliability (intra- and inter-rater reliability) of the movement workspace (representing multiple ranges of movement) and the influence of varying seating conditions (5 different chair conditions) was assessed in twenty control subjects. In eight patients with cervical SCI the test-retest reliability (tested twice on the same day by the same rater) was assessed as well as a correlation of the movement workspace to retrieve self-care items as scored by the spinal cord independence measure (SCIM 3). Results Analysis of workspace measures in control subjects revealed intra-class correlation coefficients (ICC) ranging from 0.747 to 0.837 for the intra-rater reliability and from 0.661 to 0.855 for the inter-rater reliability. Test-retest analysis in SCI patients showed a similar high reliability with ICC = 0.858. Also the reliability of the movement workspace between different seating conditions was good with ICCs ranging from 0.844 to 0.915. The movement workspace correlated significantly with the SCIM3 self-care items (p measures assessed in the Armeo Spring device revealed fair to good clinical reliability. These findings suggest that measures retrieved from such a training device can be used to monitor changes in upper limb function over time. The correlation between the workspace measures and SCIM3 self-care items indicates that
Sharifi, M; Shirazi-Adl, A; Marouane, H
As one of the most complex and vulnerable structures of body, the human knee joint should maintain dynamic equilibrium and stability in occupational and recreational activities. The evaluation of its stability and factors affecting it is vital in performance evaluation/enhancement, injury prevention and treatment managements. Knee stability often manifests itself by pain, hypermobility and giving-way sensations and is usually assessed by the passive joint laxity tests. Mechanical stability of both the human knee joint and the lower extremity at early stance periods of gait (0% and 5%) were quantified here for the first time using a hybrid musculoskeletal model of the lower extremity. The roles of muscle coactivity, simulated by setting minimum muscle activation at 0-10% levels and ACL deficiency, simulated by reducing ACL resistance by up to 85%, on the stability margin as well as joint biomechanics (contact/muscle/ligament forces) were investigated. Dynamic stability was analyzed using both linear buckling and perturbation approaches at the final deformed configurations in gait. The knee joint was much more stable at 0% stance than at 5% due to smaller ground reaction and contact forces. Muscle coactivity, when at lower intensities (knee joint at the heel strike. It also markedly diminishes forces in lateral hamstrings (by up to 39%) and contact forces on the lateral plateau (by up to 17%). Current work emphasizes the need for quantification of the lower extremity stability margin in gait. Copyright © 2017 Elsevier Ltd. All rights reserved.
Hegarty, Amy K; Petrella, Anthony J; Kurz, Max J; Silverman, Anne K
Musculoskeletal modeling and simulation techniques have been used to gain insights into movement disabilities for many populations, such as ambulatory children with cerebral palsy (CP). The individuals who can benefit from these techniques are often limited to those who can walk without assistive devices, due to challenges in accurately modeling these devices. Specifically, many children with CP require the use of ankle-foot orthoses (AFOs) to improve their walking ability, and modeling these devices is important to understand their role in walking mechanics. The purpose of this study was to quantify the effects of AFO mechanical property assumptions, including rotational stiffness, damping, and equilibrium angle of the ankle and subtalar joints, on the estimation of lower-limb muscle forces during stance for children with CP. We analyzed two walking gait cycles for two children with CP while they were wearing their own prescribed AFOs. We generated 1000-trial Monte Carlo simulations for each of the walking gait cycles, resulting in a total of 4000 walking simulations. We found that AFO mechanical property assumptions influenced the force estimates for all the muscles in the model, with the ankle muscles having the largest resulting variability. Muscle forces were most sensitive to assumptions of AFO ankle and subtalar stiffness, which should therefore be measured when possible. Muscle force estimates were less sensitive to estimates of damping and equilibrium angle. When stiffness measurements are not available, limitations on the accuracy of muscle force estimates for all the muscles in the model, especially the ankle muscles, should be acknowledged.
AN ANALYSIS OF THE MANUFACTURING POSSIBILITY OF SPECIAL ANKLE FOOT ORTHOSIS COMPONENTS BY OMPARISON BETWEEN THE REQUIRED PRECISION AND THE VAILABLE PRECISION ON A VERTICAL MACHINING CENTER PROGRAMED WITH TOPSOLID
Full Text Available Validation of different solutions adopted to achieve new ankle foot orthosis involves among others their prototyping. In these paper we developed a representative part for two axis machining that requires the use of the main features of TopSolid Cad and Cam modules, and that assumes the use of the main manufacturing processes that usually may be met on a vertical machining center. Also, in order to determine the dimensional and geometrical deviations of the part this was done on the YMC 1050 machining center. After comparing the measured deviations with the requirements of various components of orthesis, we concluded that the available precision meets the requirements and that the machining center with TopSolid software that we have will enable us to realize special ankle foot orthosis of quality, for experimental research .
Uso de órtese para abdução do polegar no desempenho funcional de criança portadora de paralisia cerebral: estudo de caso único Use of abduction thumb orthosis in functional performance of a child with cerebral palsy: a single-subject study
Adriana M. Valladão N. Rodrigues
Full Text Available OBJETIVOS: documentar o impacto do uso da órtese de abdução do polegar no desempenho funcional de uma criança hemiparética com leve espasticidade. MÉTODOS: foi utilizado um desenho experimental de caso-único do tipo AB. A fase A consistiu na coleta de dados durante um período sem intervenção (condição controle. A fase B incluiu o uso de órtese de abdução do polegar como procedimento terapêutico associado ao atendimento de terapia ocupacional tradicional. A fase A teve a duração de seis semanas e a fase subseqüente de oito semanas. A criança foi avaliada semanalmente quanto à amplitude ativa de movimento de extensão e flexão de punho, abdução e oponência do polegar e quanto à função manual. A análise dos dados foi realizada através dos métodos estatísticos Celeration Line e Banda de Dois Desvios-Padrão, assim como da Análise Visual. RESULTADOS: a criança apresentou melhora significativa na amplitude de movimento do punho e polegar (ADM ativa. Com relação à função manual observou-se redução do tempo para realização das tarefas, porém não significativa, exceto para a tarefa de empilhar blocos. CONCLUSÕES: os resultados sugerem que o uso da órtese de abdução do polegar pode ser útil no tratamento de crianças com paralisia cerebral espástica para a melhoria da ADM ativa da mão, podendo ser utilizada como adjuvante a outras terapêuticas.OBJECTIVE: to investigate the impact of a thumb abduction orthosis on functional skills of a child with hemiparetic cerebral palsy and mild spasticity. METHODS: an AB single-subject design was used in this study. Baseline A consisted of data collected during a period without intervention (control conditions. The intervention phase B included the use of a thumb abduction orthosis in association with traditional occupational therapy. The baseline lasted six weeks and the intervention period eight weeks. Assessments were performed once a week throughout the study and
Doherty, Cailbhe; Bleakley, Chris; Hertel, Jay; Caulfield, Brian; Ryan, John; Delahunt, Eamonn
Instrumented postural control analysis plays an important role in evaluating the effects of injury on dynamic stability during balance tasks, and is often conveyed with measures based on the displacement of the center-of-pressure (COP) assessed with a force platform. However, the desired outcome of the task is frequently characterized by a loss of dynamic stability, secondary to injury. Typically, these failed trials are discarded during research investigations, with the potential loss of informative data pertaining to task success. The novelty of the present study is that COP characteristics of failed trials in injured participants are compared to successful trial data in another injured group, and a control group of participants, using the fractal dimension (FD) method. Three groups of participants attempted a task of eyes closed single limb stance (SLS): twenty-nine participants with acute ankle sprain successfully completed the task on their non-injured limb (successful injury group); twenty eight participants with acute ankle sprain failed their attempt on their injured limb (failed injury group); sixteen participants with no current injury successfully completed the task on their non-dominant limb (successful non-injured group). Between trial analyses of these groups revealed significant differences in COP trajectory FD (successful injury group: 1.58±0.06; failed injury group: 1.54±0.07; successful non-injured group: 1.64±0.06) with a large effect size (0.27). These findings demonstrate that successful eyes-closed SLS is characterized by a larger FD of the COP path when compared to failed trials, and that injury causes a decrease in COP path FD. Copyright © 2014 Elsevier B.V. All rights reserved.
Hill, M W; Duncan, M J; Oxford, S W; Kay, A D; Price, M J
The purpose of this study was to investigate the effects of holding external loads on postural sway during upright stance across age decades. Sixty-five healthy adults (females, n = 35), aged 18-80 years were assessed in four conditions; (1) standing without holding a load, holding a load corresponding to 5% body mass in the (2) left hand, (3) right hand and (4) both hands. The centre of pressure (COP) path length and anteroposterior and mediolateral COP displacement were used to indirectly assess postural sway. External loading elicited reductions in COP measures of postural sway in older age groups only (P 0.05). Holding external loads during standing is relevant to many activities of daily living (i.e. holding groceries). The reduction in postural sway may suggest this type of loading has a stabilising effect during quiet standing among older adults. Copyright © 2017 Elsevier Ltd. All rights reserved.
Full Text Available The imposing mass of the trunk in relation to the whole body has an important impact on human motion. The objective of this study is to determine the influence of trunk's natural inclination--forward (FW or backward (BW with respect to the vertical--on body kinematics and stance limb kinetics during gait initiation.Twenty-five healthy males were divided based on their natural trunk inclination (FW or BW during gait initiation. Instantaneous speed was calculated at the center of mass at the first heel strike. The antero-posterior impulse was calculated by integrating the antero-posterior ground reaction force in time. Ankle, knee, hip and thoraco-lumbar (L5 moments were calculated using inverse dynamics and only peaks of the joint moments were analyzed. Among all the investigated parameters, only joint moments present significant differences between the two groups. The knee extensor moment is 1.4 times higher (P<0.001 for the BW group, before the heel contact. At the hip, although the BW group displays a flexor moment 2.4 times higher (P<0.001 before the swing limb's heel-off, the FW group displays an extensor moment 3.1 times higher (P<0.01 during the swing phase. The three L5 extensor peaks after the toe-off are respectively 1.7 (P<0.001, 1.4 (P<0.001 and 1.7 (P<0.01 times higher for the FW group. The main results support the idea that the patterns described during steady-state gait are already observable during gait initiation. This study also provides reference data to further investigate stance limb kinetics in specific or pathologic populations during gait initiation. It will be of particular interest for elderly people, knowing that this population displays atypical trunk postures and present a high risk of falling during this forward stepping.
Arnold, John B; Mackintosh, Shylie; Jones, Sara; Thewlis, Dominic
Confidence in 3D multi-segment foot models has been limited by a lack of repeatability data, particularly in older populations that may display unique functional foot characteristics. This study aimed to determine the intra and inter-observer repeatability of stance phase kinematic data from a multi-segment foot model described by Leardini et al.  in people aged 50 years or older. Twenty healthy adults participated (mean age 65.4 years SD 8.4). A repeated measures study design was used with data collected from four testing sessions on two days from two observers. Intra (within-day and between-day) and inter-observer coefficient of multiple correlations revealed moderate to excellent similarity of stance phase joint range of motion (0.621-0.975). Relative to the joint range of motion (ROM), mean differences (MD) between sessions were highest for the within-day comparison for all planar ROM at the metatarsus-midfoot articulation (sagittal plane ROM 5.2° vs. 3.9°, MD 3.1°; coronal plane ROM 3.9 vs. 3.1°, MD 2.3°; transverse plane ROM 6.8° vs. 5.16°, MD 3.5°). Consequently, data from the metatarsus-midfoot articulation in the Istituto Ortopedico Rizzoli (IOR) foot model in adults aged over 50 years needs to be considered with respect to the findings of this study. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.
Leteneur, Sébastien; Simoneau, Emilie; Gillet, Christophe; Dessery, Yoann; Barbier, Franck
The imposing mass of the trunk in relation to the whole body has an important impact on human motion. The objective of this study is to determine the influence of trunk's natural inclination--forward (FW) or backward (BW) with respect to the vertical--on body kinematics and stance limb kinetics during gait initiation.Twenty-five healthy males were divided based on their natural trunk inclination (FW or BW) during gait initiation. Instantaneous speed was calculated at the center of mass at the first heel strike. The antero-posterior impulse was calculated by integrating the antero-posterior ground reaction force in time. Ankle, knee, hip and thoraco-lumbar (L5) moments were calculated using inverse dynamics and only peaks of the joint moments were analyzed. Among all the investigated parameters, only joint moments present significant differences between the two groups. The knee extensor moment is 1.4 times higher (P<0.001) for the BW group, before the heel contact. At the hip, although the BW group displays a flexor moment 2.4 times higher (P<0.001) before the swing limb's heel-off, the FW group displays an extensor moment 3.1 times higher (P<0.01) during the swing phase. The three L5 extensor peaks after the toe-off are respectively 1.7 (P<0.001), 1.4 (P<0.001) and 1.7 (P<0.01) times higher for the FW group. The main results support the idea that the patterns described during steady-state gait are already observable during gait initiation. This study also provides reference data to further investigate stance limb kinetics in specific or pathologic populations during gait initiation. It will be of particular interest for elderly people, knowing that this population displays atypical trunk postures and present a high risk of falling during this forward stepping.
Diffo Kaze, Arnaud; Maas, Stefan; Arnoux, Pierre-Jean; Wolf, Claude; Pape, Dietrich
Results of finite element (FE) analyses can give insight into musculoskeletal diseases if physiological boundary conditions, which include the muscle forces during specific activities of daily life, are considered in the FE modelling. So far, many simplifications of the boundary conditions are currently made. This study presents an approach for FE modelling of the lower limb for which muscle forces were included. The stance phase of normal gait was simulated. Muscle forces were calculated using a musculoskeletal rigid body (RB) model of the human body, and were subsequently applied to a FE model of the lower limb. It was shown that the inertial forces are negligible during the stance phase of normal gait. The contact surfaces between the parts within the knee were modelled as bonded. Weak springs were attached to the distal tibia for numerical reasons. Hip joint reaction forces from the RB model and those from the FE model were similar in magnitude with relative differences less than 16%. The forces of the weak spring were negligible compared to the applied muscle forces. The maximal strain was 0.23% in the proximal region of the femoral diaphysis and 1.7% in the contact zone between the tibia and the fibula. The presented approach based on FE modelling by including muscle forces from inverse dynamic analysis of musculoskeletal RB model can be used to perform analyses of the lower limb with very realistic boundary conditions. In the present form, this model can be used to better understand the loading, stresses and strains of bones in the knee area and hence to analyse osteotomy fixation devices.
Renata Hessmann Dalaqua
Full Text Available The long-lasting struggle against nuclear tests can be examined through different perspectives. In this paper, the focus will be on the part played by the USSR and Russia in the international efforts aimed at establishing legal instruments to outlaw nuclear explosions in space, underground, under water and in the atmosphere. A luta contra os testes nucleares pode ser examinada sob diferentes perspectivas. Aqui, o foco recairá sobre o papel desempenhado pela União Soviética e Rússia na criação de instrumentos legais para proibir explosões nucleares no espaço, no subsolo, debaixo da água e na atmosfera.
Fransz, Duncan P.; Huurnink, Arnold; Kingma, Idsart; van Dieën, Jaap H.
We aimed to verify whether the static phase after a single leg drop jump (DJ) landing on a force plate may serve as a proxy for a single leg stance (SLS) balance task, as this would increase the application possibilities of landing tasks in the evaluation of sensorimotor function in relation to
Niet, M. de; Latour, H.; Hendricks, H.T.; Geurts, A.C.H.; Weerdesteijn, V.G.M.
de Niet M, Latour H, Hendricks H, Geurts AC, Weerdesteyn V. Short-latency stretch reflexes do not contribute to premature calf muscle activity during the stance phase of gait in spastic patients. OBJECTIVE: To identify whether a relationship exists between stretch and activity of the calf muscles
Skjøth, F; Thorup, Vivi Mørkøre; do Nascimento, Omar Feix
Lameness is a frequent disorder in dairy cows and in large dairy herds manual lameness detection is a time-consuming task. This study describes a method for automatic identification of stance phases in walking cows, and their classification as made by a front or a hind foot based on ground reacti...
Hirata, Rogério Pessoto; Ervilha, Ulysses Fernandes; Arendt-Nielsen, Lars; Graven-Nielsen, Thomas
Musculoskeletal pain impairs postural control and stability. Nine subjects stood as quietly as possible on a moveable force platform before, during, and after experimental pain in the right leg muscles. A moveable force platform was used to measure the center of pressure and provided unexpected perturbations. Lower limb muscle activity, joint angles, and foot pressure distributions were measured. Hypertonic saline was used to induce pain in the vastus lateralis, vastus medialis, or biceps femoris muscle of the right leg. Compared to baseline and control sessions, pain in the knee extensor muscles during quiet standing evoked: 1) larger sway area, greater medial-lateral center of pressure displacement and higher speed (P Pain provoked longer time to return to an equilibrium posture after forward EMG activity for, and pain in vastus medialis muscle decreased the time for the maximum hip flexion during this perturbation (P pain impairs postural stability during quiet standing and after unexpected perturbation, which suggest that people suffering from leg muscle pain are more vulnerable to falls. This article presents the acute responses to leg muscle pain on the postural control. This measure could potentially help clinicians who seek to assess how pain responses may contribute to patient's postural control and stability during quiet standing and after recovering from unexpected perturbations. Copyright © 2011 American Pain Society. Published by Elsevier Inc. All rights reserved.
Hansen, Clint; Einarson, Einar; Thomson, Athol; Whiteley, Rodney
The hamstrings are seen to work during late swing phase (presumably to decelerate the extending shank) then during stance phase (presumably stabilizing the knee and contributing to horizontal force production during propulsion) of running. A better understanding of this hamstring activation during running may contribute to injury prevention and performance enhancement (targeting the specific role via specific contraction mode). Twenty active adult males underwent surface EMG recordings of their medial and lateral hamstrings while running on a reduced gravity treadmill. Participants underwent 36 different conditions for combinations of 50%-100% altering bodyweight (10% increments) & 6-16km/h (2km/h increments, i.e.: 36 conditions) for a minimum of 6 strides of each leg (maximum 32). EMG was normalized to the peak value seen for each individual during any stride in any trial to describe relative activation levels during gait. Increasing running speed effected greater increases in EMG for all muscles than did altering bodyweight. Peak EMG for the lateral hamstrings during running trials was similar for both swing and stance phase whereas the medial hamstrings showed an approximate 20% reduction during stance compared to swing phase. It is suggested that the lateral hamstrings work equally hard during swing and stance phase however the medial hamstrings are loaded slightly less every stance phase. Likely this helps explain the higher incidence of lateral hamstring injury. Hamstring injury prevention and rehabilitation programs incorporating running should consider running speed as more potent stimulus for increasing hamstring muscle activation than impact loading. Copyright © 2017 Elsevier B.V. All rights reserved.
Udoekwere, Ubong Ime; Oza, Chintan S; Giszter, Simon F
Rodents are important model systems used to explore spinal cord injury (SCI) and rehabilitation, and brain machine interfaces (BMI). We present a new method to provide mechanical interaction for BMI and rehabilitation in rat models of SCI. We present the design and implantation procedures for a pelvic orthosis that allows direct force application to the skeleton in brain machine interface and robot rehabilitation applications in rodents. We detail the materials, construction, machining, surgery and validation of the device. We describe the statistical validation of the implant procedures by comparing stepping parameters of 8 rats prior to and after implantation and surgical recovery. An ANOVA showed no effects of the implantation on stepping. Paired tests in the individual rats also showed no effect in 7/8 rats and minor effects in the last rat, within the group's variance. Our method allows interaction with rats at the pelvis without any perturbation of normal stepping in the intact rat. The method bypasses slings, and cuffs, avoiding cuff or slings squeezing the abdomen, or other altered sensory feedback. Our implant osseointegrates, and thus allows an efficient high bandwidth mechanical coupling to a robot. The implants support quadrupedal training and are readily integrated into either treadmill or overground contexts. Our novel device and procedures support a range of novel experimental designs and motor tests for rehabilitative and augmentation devices in intact and SCI model rats, with the advantage of allowing direct force application at the pelvic bones. Copyright © 2013 Elsevier B.V. All rights reserved.
Hamdan, Puteri N F; Hamzaid, Nur Azah; Usman, Juliana; Islam, Md Anamul; Kean, Victor S P; Wahab, Ahmad K Abdul; Hasnan, Nazirah; Davis, Glen M
Previous research investigated recumbent cycle power output (PO) from the perspective of knee and hip joint biomechanics. However, ankle-foot biomechanics and, in particular, the effect of ankle-foot orthosis (AFO)-constrained movements on cycle PO has not been widely explored. Therefore, the purpose of this study was to determine whether AFOs of a fixed position (FP) and in dorsi-plantarflexion (DPF)-, dorsiflexion (DF)- and plantarflexion (PF)-constrained movements might influence PO during voluntary recumbent cycling exercises. Twenty-five healthy individuals participated in this study. All underwent 1-min cycling at a fixed cadence for each of the AFOs. The peak and average PO of each condition were analyzed. The peak and average PO were 27.2±12.0 W (range 6-60) and 17.2±9.0 W (range 2-36), respectively, during voluntary cycling. There were no significant differences in the peak PO generated by the AFOs (p=0.083). There were also no significant differences in the average PO generated using different AFOs (p=0.063). There were no significant differences in the changes of the hip and knee joint angles with different AFOs (p=0.974 and p=1.00, respectively). However, there was a significant difference in the changes of the ankle joint angle (pcycling in healthy individuals. This finding might serve as a reference for future rehabilitative cycling protocols.
Danino, Barry; Erel, Snir; Kfir, Meital; Khamis, Sam; Batt, Reuven; Hemo, Yoram; Wientroub, Shlomo; Hayek, Shlomo
Neuromuscular impairments may compromise gait function in patients with cerebral palsy (CP). As such, ambulatory children with CP often use ankle foot orthosis (AFO) to facilitate and optimize their ability to walk.The aim of this study was to evaluate whether the different gait indices, the Gillette Gait Index (GGI), the Gait Deviation Index (GDI), and the Gait Profile Score (GPS), reflect the improved gait that was previously shown using AFO. A retrospective analysis of 53 studies on children with spastic diplegic CP. All had undergone a comprehensive gait study and were analyzed while walking, both barefoot and with their braces, in the same session.Kinematic and temporal spatial data were determined and summarized by 3 methods: GPS, GDI, and GGI. Significant differences were found between the barefoot condition and the AFO conditions for temporal and kinematic parameters: changes in GGI, GDI, and GPS were not statistically significant, with an improvement of 9.33% in GGI (P=0.448) and no change in GDI and GPS. The use of AFO in diplegic CP children caused a statistically significant improvement in temporal and kinematic parameters. Interestingly, it was found that this improvement was not reflected by GGI, GDI, or GPS.These findings might suggest that gait indices, as outcome measures, may sometimes not reflect all the effects of specific interventions. Level III-retrospective study.
Samadian, M; Arazpour, M; Ahmadi Bani, M; Pouyan, A; Bahramizadeh, M; Hutchins, S W
The aim of this study was to evaluate the influence of walking with an isocentric reciprocating gait orthosis (IRGO) by spinal cord injury (SCI) patients on walking speed, distance walked and energy consumption whilst participating in a 12-week gait re-training program. Six people with motor complete SCI (mean age 29 years, weight 63 kg and height 160 cm with injury levels ranging from T8 to T12) participated in this study. Gait evaluation was performed at baseline and after 4, 8 and 12 weeks. Walking speed and heart rate were measured to calculate the resulting physiological cost index (PCI). Reductions in energy consumption were observed after 4, 8 and 12 weeks compared with baseline but were not significant. However, walking distance increased significantly (P=0.010, P=0.003 and P=0.005, respectively) and also did so during the 8-12-week period (P=0.013). Walking speed also improved, but not significantly. Intensive gait training with the IRGO improved walking speed and the distance walked by paraplegics, as well as reducing the PCI of walking, as compared with baseline during the whole 12-week period. This indicates that further improvements in these parameters may be expected when utilizing gait training longer than 8 weeks.
Kerkum, Yvette L; Buizer, Annemieke I; van den Noort, Josien C; Becher, Jules G; Harlaar, Jaap; Brehm, Merel-Anne
Rigid Ankle-Foot Orthoses (AFOs) are commonly prescribed to counteract excessive knee flexion during the stance phase of gait in children with cerebral palsy (CP). While rigid AFOs may normalize knee kinematics and kinetics effectively, it has the disadvantage of impeding push-off power. A spring-like AFO may enhance push-off power, which may come at the cost of reducing the knee flexion less effectively. Optimizing this trade-off between enhancing push-off power and normalizing knee flexion in stance is expected to maximize gait efficiency. This study investigated the effects of varying AFO stiffness on gait biomechanics and efficiency in children with CP who walk with excessive knee flexion in stance. Fifteen children with spastic CP (11 boys, 10±2 years) were prescribed with a ventral shell spring-hinged AFO (vAFO). The hinge was set into a rigid, or spring-like setting, using both a stiff and flexible performance. At baseline (i.e. shoes-only) and for each vAFO, a 3D-gait analysis and 6-minute walk test with breath-gas analysis were performed at comfortable speed. Lower limb joint kinematics and kinetics were calculated. From the 6-minute walk test, walking speed and the net energy cost were determined. A generalized estimation equation (pchildren with spastic CP, the vAFO stiffness that maximizes gait efficiency is primarily determined by its effect on knee kinematics and kinetics rather than by its effect on push-off power. Dutch Trial Register NTR3418.
The good, the bad and the ugly: The shifting ethical stance of Malaysian consumers The good, the bad and the ugly: The shifting ethical stance of Malaysian consumers The good, the bad and the ugly: The shifting ethical stance of Malaysian consumers
Full Text Available Due to the recent business ethical problems in Malaysia such as tax fraud, deceptive advertising, production of unsafe products and copyright piracy, the current research aim to examine ethical issues in the marketplace from the perspective of consumers. There are three objectives of this research. The first objective is to investigate the effect of moral ideologies and Machiavellianism on consumer ethical beliefs. The second objective is to determine which of these ideologies exert the greatest influence on consumer ethical beliefs and the third objective is to discover whether Malaysian consumers have evolved in their ethical stance over the last ten years. The dependent variable in this research is the recently modified consumer ethics scale developed by Vitell and Muncy (2005. An online survey was adopted as data collection method as it was inexpensive, fast and could ensure high response rates. However it has several limitations such as the possible non-representativeness of Internet respondents to the Malaysian population and higher non-response error. The results indicated that idealism exerted the greatest influence on all the four dimensions of consumer ethics. It was also revealed that Malaysian consumers had evolved over the past ten years in their moral ideology: from relativism to idealism.Due to the recent business ethical problems in Malaysia such as tax fraud, deceptive advertising, production of unsafe products and copyright piracy, the current research aim to examine ethical issues in the marketplace from the perspective of consumers. There are three objectives of this research. The first objective is to investigate the effect of moral ideologies and Machiavellianism on consumer ethical beliefs. The second objective is to determine which of these ideologies exert the greatest influence on consumer ethical beliefs and the third objective is to discover whether Malaysian consumers have evolved in their ethical stance over the
Duerksen, Kari N; Lawson, Karen L
In recent years, anti-choice dialog has shifted from a focus on the fetus to a focus on the woman. This new movement constructs itself as positive and pro-woman, while perpetuating harmful stereotypes about women and the effects of abortion. Research has shown a relationship between benevolent sexism (beliefs that women are morally pure creatures in need of protection and nurturing) and restrictive attitudes towards abortion, although no research has qualitatively explored this relationship. The present study seeks to explore this by interpreting the content of one-on-one interviews with Canadian individuals holding an anti-choice stance through the theoretical framework of benevolent sexism. Thematic analysis of the interviews revealed three main themes: (1) protective paternalism, (2) complementary gender differentiation, and (3) the categorization of women. These themes connect strongly with benevolent sexism, providing evidence that abortion is still a stigmatized procedure. This stigma has shifted from viewing women who have abortions in an overtly negative way to viewing them as pitiable and poor decision makers.
An essential issue in future climate negotiations is how to bring developing countries on board. This paper proposes and applies the two-level interest-based model to analyze the factors that affect the likely stances of the 'Plus Five' countries (Brazil, China, India, Mexico, and South Africa) on international climate negotiations. This study finds mitigation capability to be a crucial factor which consists of at least such sub-factors as per capita income, energy endowment, and economic structure, while ecological vulnerability does not seem to play an important role which includes reductions in agricultural outputs, sea-level rise, climate-related natural disasters, and others. The paper proposes six options in an ascending order of stringency that the Plus Five are likely to adopt. The paper suggests that the 'Basic Four' (the Plus Five excluding Mexico), particularly China and India, are less likely to adopt a voluntary commitment to an emissions cap on the national economy in the near future than Mexico, which has the highest mitigation capability among all five. The Basic Four are likely to adopt more stringent climate polices with increasing mitigation capabilities, suggesting the importance of effective international financial and technology transfer mechanisms and further tighten emission reduction targets from developed countries.
Gibson, T; Jeffery, R S; Bakheit, A M O
Different criteria are used to define the terms mid-stance (MST) and mid-swing (MSW) when describing the gait cycle. None of these definitions is universally accepted. This causes difficulties with the interpretation of gait analysis data and hinders the comparison between the different studies. The aim of the present study was to compare three definitions of MST and MSW by examining the gait of a group of healthy children. A prospective comparison of three commonly used definitions of the MST and MSW events of the gait cycle. The timing of the temporal, kinematic and kinetic MST and MSW of the gait cycle. Thirty healthy 8 - 10-year-old children were studied. There was no consistent correlation between the timing of the chosen definitions of MST and MSW. However, there was a tendency for the timing of the temporal and kinetic MST and MSW to occur, respectively, at approximately 30 and 80% of the gait cycle. The temporal definition of MST and MSW as the midpoints in time of the respective phases of the gait cycle appears to be more appropriate than other definitions. The use of this definition may prevent misunderstanding and permit comparison of the results of the different gait analysis studies.
Yang, Jong Hyun; Lee, Young Suk
The purpose of this study was to find the defensive stance and calculate an optimal defense position for goalkeepers while blocking forward jump shots made from a distance of 9 m. Nine men's handball matches were recorded and 78 video clips were selected for analysis. These are the top class goalkeepers, which included players from the national team and reserve team of Korea. The goalkeeper's actual defensive position was significantly different from instructional suggestions; the width of both feet of the goalkeeper was approximately 2.5 times the width of the shoulders, and the hands were at waist height. The goalkeeper's actual defense position was about 1.10 (± 0.3) m from the goal line and also significantly different than instructional material (0.75 m). The optimal defense position, which was calculated from the goalkeeper's actual movement, was 1.44 m from the goal line, because the ratio of goalkeeper's defensive area in relation to the total area to be defended is highest at this point. In summary, we recommended that handball goalkeepers move forward, about a half step (0.34 m), when defending a forward jump shot made from 9 m, and instructional material should be modified according to the findings from this study.
Brendan K. O'Rourke
Full Text Available Among the various approaches that have developed from FOUCAULT's work is an Anglophone discourse analysis that has attempted to combine FOUCAULTian insights with the techniques of Conversation Analysis. An important current methodological issue in this discourse analytical approach is its theoretical preference for "naturally occurring" rather than research interview data. A FOUCAULTian perspective on the interview as a research instrument, questions the idea of "naturally-occurring discourse". The "technology of the confessional" operates, not only within research interviews, but permeates other interactions as well. Drawing on FOUCAULT does not dismiss the problems of the interview as research instrument rather it shows they cannot be escaped by simply switching to more "natural" interactions. Combining these insights with recent developments within discourse analysis can provide analytical resources for, rather than barriers to, the discourse analysis of research interviews. To aid such an approach, we develop a four-way categorisation of analytical stances towards the research interview in discourse analysis. A demonstration of how a research interview might be subjected to a discourse analysis using elements of this approach is then provided. URN: urn:nbn:de:0114-fqs070238
Pantall, Annette; Ewins, David
A recent development in prosthetics is the osseointegrated fixation (OF), with improvements in comfort, fatigue, hip movement, and ease of prosthetic attachment reported. However, little information is available regarding muscle function. This study reports on selected gait parameters of the residual limb during the stance phase of level overground walking, focusing on muscle activity. Five males with transfemoral amputation (TFA) with OFs were recruited. Ground reaction force (GRF), lower-limb kinematics, and surface electromyography (sEMG) from residual-limb muscles were recorded. sEMG data were also collected from a group of 10 nondisabled male subjects. Interstance variability of gait parameters was assessed by coefficient of multiple correlations. Repeatability of GRF and hip kinematics was high, whereas repeatability of the sEMG was low for four of the five individuals with TFA. Interstance variability of the sEMG for gluteus medius (GMED) was significantly greater in the group with TFA. The main difference in sEMG between the groups was the phase, with GMED and adductor magnus displaying greater differences than their counterparts in the nondisabled group. Results demonstrate that muscles in the residual limb retain aspects of their previous functional pattern.
Rong Fang, E-mail: firstname.lastname@example.org [Laboratory on International Law and Regulation, School of International Relations and Pacific Studies, University of California, San Diego, 92093 (United States); Center for Industrial Development and Environmental Governance, School of Public Policy and Management, Tsinghua University, Beijing 100084 (China)
An essential issue in future climate negotiations is how to bring developing countries on board. This paper proposes and applies the two-level interest-based model to analyze the factors that affect the likely stances of the 'Plus Five' countries (Brazil, China, India, Mexico, and South Africa) on international climate negotiations. This study finds mitigation capability to be a crucial factor which consists of at least such sub-factors as per capita income, energy endowment, and economic structure, while ecological vulnerability does not seem to play an important role which includes reductions in agricultural outputs, sea-level rise, climate-related natural disasters, and others. The paper proposes six options in an ascending order of stringency that the Plus Five are likely to adopt. The paper suggests that the 'Basic Four' (the Plus Five excluding Mexico), particularly China and India, are less likely to adopt a voluntary commitment to an emissions cap on the national economy in the near future than Mexico, which has the highest mitigation capability among all five. The Basic Four are likely to adopt more stringent climate polices with increasing mitigation capabilities, suggesting the importance of effective international financial and technology transfer mechanisms and further tighten emission reduction targets from developed countries.
Rong, Fang [Laboratory on International Law and Regulation, School of International Relations and Pacific Studies, University of California, San Diego, 92093 (United States); Center for Industrial Development and Environmental Governance, School of Public Policy and Management, Tsinghua University, Beijing 100084 (China)
An essential issue in future climate negotiations is how to bring developing countries on board. This paper proposes and applies the two-level interest-based model to analyze the factors that affect the likely stances of the Plus Five countries (Brazil, China, India, Mexico, and South Africa) on international climate negotiations. This study finds mitigation capability to be a crucial factor which consists of at least such sub-factors as per capita income, energy endowment, and economic structure, while ecological vulnerability does not seem to play an important role which includes reductions in agricultural outputs, sea-level rise, climate-related natural disasters, and others. The paper proposes six options in an ascending order of stringency that the Plus Five are likely to adopt. The paper suggests that the Basic Four (the Plus Five excluding Mexico), particularly China and India, are less likely to adopt a voluntary commitment to an emissions cap on the national economy in the near future than Mexico, which has the highest mitigation capability among all five. The Basic Four are likely to adopt more stringent climate polices with increasing mitigation capabilities, suggesting the importance of effective international financial and technology transfer mechanisms and further tighten emission reduction targets from developed countries. (author)
Lee, Jae-Woong; Kim, Yeong-Ju; Koo, Hyun-Mo
[Purpose] This study researched the influences of different loads on muscle activity of the posterior fibers of the gluteus medius in a one-leg standing position. [Subjects] Twenty-four healthy adult men participated in this study. [Methods] All participants performed the one-leg standing position under four conditions: the standard no-load condition, in which the non-weight-bearing leg was lifted and kept parallel to the back and then pelvic or lumbar rotation was performed without thorax rotation, and the 0 kg, 1 kg, and 3 kg load conditions, in which horizontal shoulder abduction was performed with a load of 0 kg, 1 kg, or 3 kg added to the hand. The electromyographic activity of the posterior fibers of the gluteus medius was measured using a wireless surface electromyography under all conditions. The electromyographic activity of each muscle under the four conditions during the one-leg stance was analyzed using one-way analysis of variance. [Results] The electromyographic activity of the posterior fiber of the gluteus medius was significantly increased under the 3 kg load condition compared with the no-load, 0 kg load, and 1 kg load conditions. [Conclusion] These findings indicated that muscle activation is affected by increases in load in the one-leg standing position. The load on the upper extremity influences the muscle activity of the contralateral lower extremity.
Eichenberg, Christiane; Grabmayer, Gloria; Green, Nikos
Serious games are computer or video games that contain elements that are specifically designed for the purpose of education or training. Serious games are increasingly being used within healthcare, but their introduction into and application in psychotherapeutic settings as an e-mental health treatment modality raises questions for both patients and therapists. Current research demonstrates the potential role and effectiveness of serious games within a psychotherapeutic context. However, a limited understanding of patients' and therapists' existing knowledge and experience of serious games, as well as of their readiness to utilize and apply them for the treatment of psychological conditions, requires further investigation. Acceptance, experience, and requirements for the utilization of serious games in therapeutic contexts were assessed through online surveys with German-speaking patients (n = 260) and psychotherapists (n = 234). Respondents' answers were analyzed by a combination of descriptive and inferential statistics by using SPSS. Current knowledge regarding serious games was very limited, with only 10.4% of patients and 11.5% of therapists reporting existing knowledge. However, a general openness toward the concept was observed: 88% of patients and 90% of therapists could envisage a therapeutic use. Patients (rs = 0.169, p = 0.006) who self-rated their level of computer and video game expertise as high were more likely to consider use within psychotherapy, compared with patients who self-rated their expertise as low. Therapists who currently play computer and video games perceive fewer disadvantages of serious game application in a psychotherapeutic context (p = 0.097). Consideration of serious game use was differentiated by the therapeutic approach (p = 0.003), specific mental disorders (highest rated relevant cases: anxiety disorders, affective disorders, disorders regarding impulse control, and adjustment disorders), and patient
Huxtable, Rose E; Ackland, Timothy R; Janes, Gregory C; Ebert, Jay R
Hip abductor tendon tears are a common cause of Greater Trochanteric Pain Syndrome. Conservative treatments are often ineffective and surgical reconstruction may be recommended. This study investigated the improvement in clinical outcomes and frontal plane two-dimensional biomechanics during a 30-second single leg stance test, in patients undergoing reconstruction. We hypothesized that clinical scores and pertinent biomechanical variables would significantly improve post-surgery, and these outcomes would be significantly correlated. Twenty-one patients with symptomatic tendon tears underwent reconstruction. Patients were evaluated pre-surgery, and at 6 and 12months post-surgery, using patient-reported outcome measures, assessment of hip abductor strength and six-minute walk capacity. Frontal plane, two-dimensional, biomechanical variables including pelvis-on-femur angle, pelvic drop, trunk lean and lateral pelvic shift, were evaluated throughout a 30-second single leg stance test. ANOVA evaluated outcomes over time, while Pearson's correlations investigated associations between clinical scores, pain, functional and biomechanical outcome variables. While clinical and functional measures significantly improved (P0.05) were observed in biomechanical variables from pre- to post-surgery. While five patients displayed a positive Trendelenburg sign pre-surgery, only one was positive post-surgery. Clinical outcomes and biomechanical variables during the single leg stance test were not correlated. Despite improvements in clinical and functional measures over time, biomechanical changes during a weight bearing single leg stance test were not significantly different following tendon repair. Follow up beyond 12months may be required, whereby symptomatic relief may precede functional and biomechanical improvement. Copyright © 2017 Elsevier Ltd. All rights reserved.
Koo, Seungbum; Lee, Kyoung Min; Cha, Young Joo
Gross motion of the ankle joint complex (AJC) is a summation of the ankle and subtalar joints. Although AJC kinematics have been widely used to evaluate the function of the AJC, the coordinated movements of the ankle and subtalar joints are not well understood. The purpose of this study was to accurately quantify the individual kinematics of the ankle and subtalar joints in the intact foot during ground walking by using a bi-planar fluoroscopic system. Bi-planar fluoroscopic images of the foot and ankle during walking and standing were acquired from 10 healthy subjects. The three-dimensional movements of the tibia, talus, and calcaneus were calculated with a three-dimensional/two-dimensional registration method. The skeletal kinematics were quantified from 9% to 86% of the full stance phase because of the limited camera speed of the X-ray system. At the beginning of terminal stance, plantar-flexion of the AJC was initiated in the subtalar joint on average at 75% ranging from 62% to 76% of the stance phase, and plantar-flexion of the ankle joint did not start until 86% of the stance phase. The earlier change to plantar-flexion in the AJC than the ankle joint due to the early plantar-flexion in the subtalar joint was observed in 8 of the 10 subjects. This phenomenon could be explained by the absence of direct muscle insertion on the talus. Preceding subtalar plantar-flexion could contribute to efficient and stable ankle plantar-flexion by locking the midtarsal joint, but this explanation needs further investigation. Copyright © 2015 Elsevier B.V. All rights reserved.
Jagadamma, Kavi C; Coutts, Fiona J; Mercer, Thomas H; Herman, Janet; Yirrel, Jacqueline; Forbes, Lyndsay; Van Der Linden, Marietta L
This pilot study investigated the feasibility of reducing stance phase knee hyperextension in children with cerebral palsy by tuning the ankle foot orthoses-footwear combination (AFO-FC) using different sizes of wedges. Five children with cerebral palsy underwent three dimensional gait analysis and tuning of their AFO-FC using wedges. Data analysis was carried out by comparing relevant gait parameters between the non-tuned and tuned prescription. Knee hyperextension during stance significantly decreased, and the shank to vertical angle was closer to normal after tuning. Although none of the other parameters showed statistically significant changes, the wide confidence intervals and lack of power indicated the likelihood of a type II error. Further, it was noted that the influence of tuning on temporal-spatial parameters was different between children with diplegia and those with hemiplegia. It was estimated that a sample size of 15 is required to detect significant changes at p = 0.05 and power of 0.8. The findings of this study clearly indicate the potential clinical utility of tuning using wedges to correct knee hyperextension during the stance phase in children with cerebral palsy. However, observations support the need for an adequately powered study to assess the long-term effects of tuning on gait parameters, activity level and quality of life.
Reconstruction of limb posture is a challenging task in assessing functional morphology and biomechanics of extinct tetrapods, mainly because of the wide range of motions possible at each limb joint and because of our poor knowledge of the relationship between posture and musculoskeletal structure, even in the extant taxa. This is especially true for extinct mammals such as the desmostylian taxa Desmostylus and Paleoparadoxia. This study presents a procedure that how the elbow joint angles of extinct quadruped mammals can be inferred from osteological characteristics. A survey of 67 dried skeletons and 113 step cycles of 32 extant genera, representing 25 families and 13 orders, showed that the olecranon of the ulna and the shaft of the humerus were oriented approximately perpendicular to each other during the stance phase. At this angle, the major extensor muscles maximize their torque at the elbow joint. Based on this survey, I suggest that olecranon orientation can be used for inferring the elbow joint angles of quadruped mammals with prominent olecranons, regardless of taxon, body size, and locomotor guild. By estimating the elbow joint angle, it is inferred that Desmostylus would have had more upright forelimbs than Paleoparadoxia, because their elbow joint angles during the stance phase were approximately 165 degrees and 130 degrees , respectively. Difference in elbow joint angles between these two genera suggests possible differences in stance and gait of these two mammals. Copyright 2009 Wiley-Liss, Inc.
Kochanska, Grazyna; Kim, Sanghag; Boldt, Lea J.
In contrast to once dominant views of children as passive in the parent-led process of socialization, they are now seen as active agents who can considerably influence that process. But those newer perspectives typically focus on the child's antagonistic influence, due either to a difficult temperament or aversive, resistant, negative behaviors that elicit adversarial responses from the parent and lead to future coercive cascades in the relationship. Children's capacity to act as receptive, willing, even enthusiastic, active socialization agents is largely overlooked. Informed by attachment theory and other relational perspectives, we depict children as able to adopt an active willing stance and to exert robust positive influence in the mutually cooperative socialization enterprise. A longitudinal study of 100 community families (mothers, fathers, and children) demonstrates that willing stance (a) is a latent construct, observable in diverse parent-child contexts parallel at 38, 52, and 67 months, and longitudinally stable, (b) originates within an early secure parent-child relationship at 25 months, and (c) promotes a positive future cascade toward adaptive outcomes at age 10. The outcomes include the parent's observed and child-reported positive, responsive behavior, as well as child-reported internal obligation to obey the parent and parent-reported low level of child behavior problems. The construct of willing stance has implications for basic research in typical socialization and in developmental psychopathology, and for prevention and intervention. PMID:26439058
Goffin, Kathryn C; Boldt, Lea J; Kochanska, Grazyna
Early secure attachment plays a key role in socialization by inaugurating a long-term mutual positive, collaborative interpersonal orientation within the parent-child dyad. We report findings from Family Study (community mothers, fathers, and children, from age 2 to 12, N = 102, 51 girls) and Play Study (exclusively low-income mothers and children, from age 3.5 to 7, N = 186, 90 girls). We examined links among observed secure attachment at toddler age, child and parent receptive, willing stance to each other, observed in parent-child contexts at early school age, and developmental outcomes. The developmental outcomes included parent-rated child antisocial behavior problems and observed positive mutuality with regard to conflict issues at age 12 in Family Study, and mother-rated child antisocial behavior problems and observed child regard for rules and moral self at age 7 in Play Study. In mother-child relationships, the child's willing stance mediated indirect effects of child security on positive mutuality in Family Study and on all outcomes in Play Study. In father-child relationships, both the child's and the parent's willing stance mediated indirect effects of child security on both outcomes. Early security initiates an adaptive developmental cascade by enlisting the child and the parent as active, willingly receptive and cooperative agents in the socialization process. Implications for children's parenting interventions are noted.
Kochanska, Grazyna; Kim, Sanghag; Boldt, Lea J
In a change from the once-dominant view of children as passive in the parent-led process of socialization, children are now seen as active agents who can considerably influence that process. However, these newer perspectives typically focus on the child's antagonistic influence, due either to a difficult temperament or aversive, resistant, negative behaviors that elicit adversarial responses from the parent and lead to future coercive cascades in the relationship. Children's capacity to act as receptive, willing, even enthusiastic, active socialization agents is largely overlooked. Informed by attachment theory and other relational perspectives, we depict children as able to adopt an active willing stance and to exert robust positive influence in the mutually cooperative socialization enterprise. A longitudinal study of 100 community families (mothers, fathers, and children) demonstrates that willing stance (a) is a latent construct, observable in diverse parent-child contexts, parallel at 38, 52, and 67 months and longitudinally stable; (b) originates within an early secure parent-child relationship at 25 months; and (c) promotes a positive future cascade toward adaptive outcomes at age 10. The outcomes include the parent's observed and child-reported positive, responsive behavior, as well as child-reported internal obligation to obey the parent and parent-reported low level of child behavior problems. The construct of willing stance has implications for basic research in typical socialization and in developmental psychopathology as well as for prevention and intervention.
Mei, Zhanyong; Zhao, Guoru; Ivanov, Kamen; Guo, Yanwei; Zhu, Qingsong; Zhou, Yongjin; Wang, Lei
Motion characteristics of CoP (Centre of Pressure, the point of application of the resultant ground reaction force acting on the plate) are useful for foot type characteristics detection. To date, only few studies have investigated the nonlinear characteristics of CoP velocity and acceleration during the stance phase. The aim of this study is to investigate whether CoP regularity is different among four foot types (normal foot, pes valgus, hallux valgus and pes cavus); this might be useful for classification and diagnosis of foot injuries and diseases. To meet this goal, sample entropy, a measure of time-series regularity, was used to quantify the CoP regularity of four foot types. One hundred and sixty five subjects that had the same foot type bilaterally (48 subjects with healthy feet, 22 with pes valgus, 47 with hallux valgus, and 48 with pes cavus) were recruited for this study. A Footscan® system was used to collect CoP data when each subject walked at normal and steady speed. The velocity and acceleration in medial-lateral (ML) and anterior-posterior (AP) directions, and resultant velocity and acceleration were derived from CoP. The sample entropy is the negative natural logarithm of the conditional probability that a subseries of length m that matches pointwise within a tolerance r also matches at the next point. This was used to quantify variables of CoP velocity and acceleration of four foot types. The parameters r (the tolerance) and m (the matching length) for sample entropy calculation have been determined by an optimal method. It has been found that in order to analyze all CoP parameters of velocity and acceleration during the stance phase of walking gait, for each variable there is a different optimal r value. On the contrary, the value m=4 is optimal for all variables.Sample entropies of both velocity and acceleration in AP direction were highly correlated with their corresponding resultant variables for r>0.91. The sample entropy of the velocity in
Long, Zhi; Wang, Renwei; Han, Jia; Waddington, Gordon; Adams, Roger; Anson, Judith
To explore the effects of kinesiology taping (KT) and athletic taping (AT) on ankle proprioception when tested in functional, full weight-bearing stance. Cross-sectional study. Twenty-four healthy university students participated. Proprioception was measured using the Active Movement Extent Discrimination Apparatus (AMEDA). The three testing conditions: no-taping, KT, AT, and foot tested were randomly assigned. Perceived comfort, support and proprioceptive performance under two taping conditions were recorded. Proprioceptive discrimination scores with 95% CIs for no-taping, KT and AT were 0.81 (0.79-0.84), 0.81 (0.79-0.83), and 0.79 (0.77-0.81). Repeated measures ANOVA showed neither any significant difference associated with taping compared with no-taping (p=0.30), nor any difference between KT and AT (p=0.19). The group was then divided, according to their no-taping scores, into two sub-groups: with scores below the no-taping mean (n=13), and above the mean (n=11). ANOVA revealed a significant interaction (p=0.008) indicating that above-average no-taping performers proprioception scores were worse when taped, whereas below-average performers improved. For both KT and AT, only ratings of perceived comfort when taped were significantly associated with actual proprioceptive performance (both r>0.44, p≤0.03). Other perception ratings (support and performance) were significantly inter-correlated (both r>0.42, p0.31). Taping of the foot and ankle may amplify sensory input in a way that enhances proprioception of poor performers but produces an input overload that impairs proprioception in those who originally performed well when no-taping. Screening of ankle proprioception may identify those who would benefit most from taping. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.
Mancilla S, Eladio; Valenzuela H, José; Escobar C, Máximo
The Preventive Health Examination of older people in Chile incorporates the timed up and go (TUG) and right and left unipodal stance test (RUPS and LUPS) as functional assessment methods. To assess if TUG and LUPS discriminate older people with different degrees of disability. TUG, RUPS and LUPS were assessed in 860 participants aged 71.3 ± 6.9 years (591 females) attending a primary health care clinic. The results of the three tests were expressed in seconds. Participants were classified as non-disabled without any risk, non-disabled with risk and in risk of dependence, using the Functional Assessment of Older People of EFAM (the Spanish acronym), previously validated for Chilean older people. In all participants TUG, LUPS and RUPS values were 8.9 ± 3.6, 10 ± 10.6 and 9.7 ± 10.3 seconds (sec) respectively. Among non-disabled participants without risk, the values for TUG, RUPS and LUPS were: 7.9 ± 2.3, 12.7 ± 11.1 and 12.2 ± 10.9 sec respectively. The figures for non-disabled participants with risk were 8.4 ± 2.6, 8.8 ± 9.8 and 8.9 ± 9.8 sec respectively. The figures for participants in risk of dependence were 11.7 ± 5.3, 5.1 ± 7.8 and 4.5 ± 7.1 sec, respectively. In this group of older participants there is an association between the degree of disability and the results of TUG, RUPS and LUPS.
Yvette L Kerkum
Full Text Available Rigid Ankle-Foot Orthoses (AFOs are commonly prescribed to counteract excessive knee flexion during the stance phase of gait in children with cerebral palsy (CP. While rigid AFOs may normalize knee kinematics and kinetics effectively, it has the disadvantage of impeding push-off power. A spring-like AFO may enhance push-off power, which may come at the cost of reducing the knee flexion less effectively. Optimizing this trade-off between enhancing push-off power and normalizing knee flexion in stance is expected to maximize gait efficiency. This study investigated the effects of varying AFO stiffness on gait biomechanics and efficiency in children with CP who walk with excessive knee flexion in stance. Fifteen children with spastic CP (11 boys, 10±2 years were prescribed with a ventral shell spring-hinged AFO (vAFO. The hinge was set into a rigid, or spring-like setting, using both a stiff and flexible performance. At baseline (i.e. shoes-only and for each vAFO, a 3D-gait analysis and 6-minute walk test with breath-gas analysis were performed at comfortable speed. Lower limb joint kinematics and kinetics were calculated. From the 6-minute walk test, walking speed and the net energy cost were determined. A generalized estimation equation (p<0.05 was used to analyze the effects of different conditions. Compared to shoes-only, all vAFOs improved the knee angle and net moment similarly. Ankle power generation and work were preserved only by the spring-like vAFOs. All vAFOs decreased the net energy cost compared to shoes-only, but no differences were found between vAFOs, showing that the effects of spring-like vAFOs to promote push-off power did not lead to greater reductions in walking energy cost. These findings suggest that, in this specific group of children with spastic CP, the vAFO stiffness that maximizes gait efficiency is primarily determined by its effect on knee kinematics and kinetics rather than by its effect on push-off power
Kuban, D.P.; Perkins, G.S.
The Advanced Servomanipulator (ASM) slave was designed with an anthropomorphic stance, gear/torque tube power drives, and modular construction. These features resulted in increased inertia, friction, and backlash relative to tape-driven manipulators. Studies were performed which addressed the human factors design and performance trade-offs associated with the corresponding master controller best suited for the ASM. The results of these studies, as well as the conceptual design of the dual arm master controller, are presented. 6 references, 3 figures
Negahban, Hossein; Aryan, Najmolhoda; Mazaheri, Masood; Norasteh, Ali Asghar; Sanjari, Mohammad Ali
It was hypothesized that training in 'static balance' or 'dynamic balance' sports has differential effects on postural control and its attention demands during quiet standing. In order to test this hypothesis, two groups of female athletes practicing shooting, as a 'static balance' sport, and Taekwondo, as a 'dynamic balance' sport, and a control group of non-physically active females voluntarily participated in this study. Postural control was assessed during bipedal and unipedal stance with and without performing a Go/No-go reaction time task. Visual and/or support surface conditions were manipulated in bipedal and unipedal stances in order to modify postural difficulty. Mixed model analysis of variance was used to determine the effects of dual tasking on postural and cognitive performance. Similar pattern of results were found in bipedal and unipedal stances, with Taekwondo practitioners displaying larger sway, shooters displaying lower sway and non-athletes displaying sway characteristics intermediate to Taekwondo and shooting athletes. Larger effect was found in bipedal stance. Single to dual-task comparison of postural control showed no significant effect of mental task on sway velocity in shooters, indicating less cognitive effort invested in balance control during bipedal stance. We suggest that expertise in shooting has a more pronounced effect on decreased sway in static balance conditions. Furthermore, shooters invest less attention in postures that are more specific to their training, i.e. bipedal stance. Copyright © 2012 Elsevier B.V. All rights reserved.
Full Text Available A safe interaction is crucial in wearable robotics in general, while in assistive and rehabilitation applications, robots may also be required to minimally perturb physiological movements, ideally acting as perfectly transparent machines. The actuation system plays a central role because the expected performance, in terms of torque, speed and control bandwidth, must not be achieved at the expense of lightness and compactness. Actuators embedding compliant elements, such as series elastic actuators, can be designed to meet the above-mentioned requirements in terms of high energy storing capacity and stability of torque control. A number of series elastic actuators have been proposed over the past 20 years in order to accommodate the needs arising from specific applications. This paper presents a novel series elastic actuator intended for the actuation system of a lower limb wearable robot, recently developed in our lab. The actuator is able to deliver 300 W and has a novel architecture making its centre of mass not co-located with its axis of rotation, for an easier integration into the robotic structure. A custom-made torsion spring with a stiffness of 272.25 N·m·rad–1 is directly connected to the load. The delivered torque is calculated from the measurement of the spring deflection, through two absolute encoders. Testing on torque measurement accuracy and torque/stiffness control are reported.
Mugge, W.; Abbink, D.A.; Schouten, Alfred Christiaan; van der Helm, F.C.T.; Arendzen, J.H.; Meskers, C.G.M.
Motor control tasks like stance or object handling require sensory feedback from proprioception, vision and touch. The distinction between tactile and proprioceptive sensors is not frequently made in dynamic motor control tasks, and if so, mostly based on signal latency. We previously found that
van Wegen, E. E.; van Emmerik, R. E.; Wagenaar, R. C.; Ellis, T.
Postural instability is a major problem in patients with Parkinson's disease (PD). We examined balance control in PD by using center of pressure (CP) variability and time-to-contact to investigate boundary relevant postural control behavior under quiet stance leaning conditions. Postural orientation
Pereira, Camila; Silva, Rubens A da; de Oliveira, Marcio R; Souza, Rejane D N; Borges, Renata J; Vieira, Edgar R
The purpose of this study was to evaluate the impact of body mass index (BMI) and fat mass on balance force platform measurements in older adults. The sample consisted of 257 participants who were stratified into four groups by BMI: low weight, normal weight, pre-obesity and obesity. For fat mass variables, older individuals were classified into low and high-fat mass. All groups investigated performed three trials of one-legged stance balance on a force platform. Center of pressure (COP) domain parameters were computed from the mean across trials. Analysis of variance results revealed no significant interactions for groups and sexes for all COP parameters. Comparable balance results were found for BMI and fat groups for all COP parameters. A statistical effect (P COP parameters, regardless of BMI and fat mass variables. Overall, women presented better balance than men. In conclusion, BMI and fat mass do not seem to influence the balance of older adults during a one-leg stance task.
Kirkwood, Renata Noce; Franco, Rosa de Lourdes Lima Dias; Furtado, Sheyla Cavalcanti; Barela, Ana Maria Forti; Deluzio, Kevin John; Mancini, Marisa Cotta
Objective. To determine if gait waveform could discriminate children with diplegic cerebral palsy of the GMFCS levels I and II. Patients. Twenty-two children with diplegia, 11 classified as level I and 11 as level II of the GMFCS, aged 7 to 12 years. Methods. Gait kinematics included angular displacement of the pelvis and lower limb joints during the stance phase. Principal components (PCs) analyses followed by discriminant analysis were conducted. Results. PC1s of the pelvis and hip in the frontal plane differ significantly between groups and captured 80.5% and 86.1% of the variance, respectively. PC1s captured the magnitude of the pelvic obliquity and hip adduction angle during the stance phase. Children GMFCS level II walked with reduced pelvic obliquity and hip adduction angles, and these variables could discriminate the groups with a cross-validation of 95.5%. Conclusion. Reduced pelvic obliquity and hip adduction were observed between children GMFCS level II compared to level I. These results could help the classification process of mild-to-moderate children with diplegia. In addition, it highlights the importance of rehabilitation programs designed to improve pelvic and hip mobility in the frontal plane of diplegic cerebral palsy children level II of the GMFCS.
Ignacio Vázquez Orta
Full Text Available In the present paper an intercultural quantitative and qualitative analysis of the use of modal verbs as epistemic stance markers in SERAC (Spanish-English Research Article Corpus, a corpus of research articles (RAs in different disciplines, is carried out. The corpus selected for this research consists of 48 Business Management research articles. Special emphasis is laid on the introduction and discussion sections of RAs, where stance devices are most frequently located to pursue convergence with the readership. This kind of intercultural analysis has been achieved through both a bottom-up research approach and a top-down research approach. The results obtained in this study point in the direction that there are obvious differences between the use of modal verbs by native writers and the use of modal verbs by non-native Spanish writers. The most remarkable aspect is that Spanish writers show a deviant handling of hedges and boosters. Therefore, they have difficulties in establishing a proper tenor when they write in English.
Full Text Available The theme of crisis, and consequently of crisis response, has been extensively studied within the disciplines of crisis communication (see Rachfał (2013a for an overview of crisis communication as an independent academic discipline and its place among other allied sub-disciplines of public relations and public relations with the aim of protecting organisations or reducing the damage caused by a crisis episode (Fediuk, Pace and Botero, 2010. Nowadays, with the growing recognition of crisis response as persuasive communication there is a need for an interdisciplinary approach which would help researchers understand the effects that crisis messages have on the perceptions and behaviours of stakeholders. Therefore, this paper seeks to bridge the aforementioned disciplines and examines crisis from the perspective of linguistics. Thus, it analyses grammatical stance-marking devices (Biber, et al., 1999, which might provide insights into how speakers manipulate linguistic resources for persuasive purposes. The paper focuses on explicit stance attribution and explores how the first-person plural pronoun we is used in crisis response to alter the stakeholders’ perceptions concerning people and events. The analysis draws on statements issued in 2011 by people in top public positions in the wake of the phone-hacking scandal at the News of the World.
Moltedo, Marta; Bacek, Tomislav; Langlois, Kevin; Junius, Karen; Vanderborght, Bram; Lefeber, Dirk
The human ankle joint plays a crucial role during walking. At the push-off phase the ankle plantarflexors generate the highest torque among the lower limb joints during this activity. The potential of the ankle plantarflexors is affected by numerous pathologies and injuries, which cause a decrease in the ability of the subject to achieve a natural gait pattern. Active orthoses have shown to have potential in assisting these subjects. The design of such robots is very challenging due to the contrasting design requirements of wearability (light weight and compact) and high torques capacity. This paper presents the development of a high-torque ankle actuator to assist the ankle joint in both dorsiflexion and plantarflexion. The compliant actuator is a spindle-driven MACCEPA (Mechanically Adjustable Compliance and Controllable Equilibrium Position Actuator). The design of the actuator was made to keep its weight as low as possible, while being able to provide high torques. As a result of this novel design, the actuator weighs 1.18kg. Some static characterization tests were perfomed on the actuator and their results are shown in the paper.
Míriam Raquel Meira Mainenti
Full Text Available OBJECTIVE: The purpose of this study was to investigate the correlation between body adiposity and postural control in elderly women. INTRODUCTION: Aging and obesity account for a significant portion of healthcare spending. Life expectancy is increasing worldwide, and Rio de Janeiro has the largest proportion of elderly residents of all Brazilian states. METHODS: A total of 45 women underwent bioelectrical impedance analysis, waist circumference measurements, weight and height measurements, and stabilometric tests in eight different stance conditions (opened and closed bases with both eyes opened and closed and right and left tandem and unilateral stances with eyes opened. During unilateral stances, the number of hand or foot contacts was counted. RESULTS: Weight, body mass index, waist circumference, fat percentage, and fat mass showed statistically significant (p,0.05 and positive correlations with the number of contacts made during unilateral stances. The subjects with greater fat mass showed significantly higher anterior-posterior standard deviation and range when their eyes were closed. The sway area was also greater for this group in opened base when their eyes were closed. DISCUSSION: The results relating body adiposity and postural control can be explained by the difficulty of maintaining a greater quantity of body fat mass within the limits of the individual support base, especially while assuming a unilateral stance. CONCLUSION: The subjects with a greater fat mass exhibited poor balance control, indicating that body adiposity level was associated with postural control in the elderly women examined in the present study.
Mainenti, Míriam Raquel Meira; de Carvalho Rodrigues, Érika; de Oliveira, Juliana Flávia; de Sá Ferreira, Arthur; Dias, Cristina Márcia; dos Santos Silva, André Luís
OBJECTIVE: The purpose of this study was to investigate the correlation between body adiposity and postural control in elderly women. INTRODUCTION: Aging and obesity account for a significant portion of healthcare spending. Life expectancy is increasing worldwide, and Rio de Janeiro has the largest proportion of elderly residents of all Brazilian states. METHODS: A total of 45 women underwent bioelectrical impedance analysis, waist circumference measurements, weight and height measurements, and stabilometric tests in eight different stance conditions (opened and closed bases with both eyes opened and closed and right and left tandem and unilateral stances with eyes opened). During unilateral stances, the number of hand or foot contacts was counted. RESULTS: Weight, body mass index, waist circumference, fat percentage, and fat mass showed statistically significant (p<0.05) and positive correlations with the number of contacts made during unilateral stances. The subjects with greater fat mass showed significantly higher anterior-posterior standard deviation and range when their eyes were closed. The sway area was also greater for this group in opened base when their eyes were closed. DISCUSSION: The results relating body adiposity and postural control can be explained by the difficulty of maintaining a greater quantity of body fat mass within the limits of the individual support base, especially while assuming a unilateral stance. CONCLUSION: The subjects with a greater fat mass exhibited poor balance control, indicating that body adiposity level was associated with postural control in the elderly women examined in the present study. PMID:22179151
Friedman, Lissy C
This paper analyses Philip Morris's evolving website and the legal strategies employed in its creation and dissemination. Internal tobacco documents were searched and examined and their substance verified and triangulated using media accounts, legal and public health research papers, and visits to Philip Morris's website. Various drafts of website language, as well as informal discussion of the website's creation, were located in internal Philip Morris documents. I compared website statements pertaining to Philip Morris's stance on cigarette smoking and disease with statements made in tobacco trials. Philip Morris created and disseminated its website's message that it agreed that smoking causes disease and is addictive in an effort to sway public opinion, while maintaining in a litigation setting its former position that it cannot be proved that smoking causes disease or is addictive. Philip Morris has not changed its position on smoking and health or addiction in the one arena where it has the most to lose-in the courtroom, under oath.
Kiers, H.; van Dieen, J.H.; Dekkers, H.; Wittink, H.; Vanhees, L.
Background: In many sports, maintaining balance is necessary to compete at a high level. Also, in many health problems, balance is impaired. Postural sway (PS) is often used as an indicator of upright balance control, and physical activity (PA) might enhance balance control. However, the
Holmes, Charles Damian; Wronkiewicz, Mark; Somers, Thane; Liu, Jenny; Russell, Elizabeth; Kim, DoHyun; Rhoades, Colleen; Dunkley, Jason; Bundy, David; Galboa, Elad; Leuthardt, Eric
Stroke and other nervous system injuries can damage or destroy hand motor control and greatly upset daily activities. Brain computer interfaces (BCIs) represent an emerging technology that can bypass damaged nerves to restore basic motor function and provide more effective rehabilitation. A wireless BCI system was implemented to realize these goals using electroencephalographic brain signals, machine learning techniques, and a custom designed orthosis. The IpsiHand Bravo BCI system is designed to reach a large demographic by using non-traditional brain signals and improving on past BCI system pitfalls.
Verstegen, B.; De Loo, I.G.M.; Mol, P.; Slagter, K.; Geerkens, H.
There is conflicting evidence about the current stance of the controller profession. Some researchers say that controllers have evolved into strategic partners of their managers, while others assert that they are still mainly concerned with internal and external reporting. In order to assess the
Adriana Maria Valladão Novais Van Petten
(James® dynamometer under three conditions: free hand, wearing a composite orthosis, and wearing a thermoplastic orthosis. The tests were carried out using the dominant hand only. During the tests, surface electrodes were placed on the flexor and extensor muscles of the forearm to record the electrical muscle activity. The results obtained in the three conditions were compared, and the results analyzed using the statistical Wilcoxon Test. RESULTS: Significant differences were found in muscle activation when comparing the free hand with the use of any of the orthoses. In the comparison of data for the two different orthoses, no significant differences were found. A decrease in activity of the extensor muscles of the forearm was observed during all the tasks, as well as an increase in activation of the flexor muscles with the use of the orthoses. CONCLUSION: These results are important for the prescription of an orthosis during the rehabilitation process of a wide range of pathologies, such as tendinitis of the flexors and extensors of the first and fingers, as well as for forecasting the time of use of these devices.
Erika H. Tanaka
Full Text Available Background: Risk of falls increases as age advances. Complaints of impaired balance are very common in the elderly age group. Objectives: The objective of this study was to investigate whether the subjective perception of impaired balance was associated with deficits in postural control (objective analysis in elderly community-dwelling women. Method: Static posturography was used in two groups: elderly women with (WC group and without (NC group complaints of impaired balance. The area, mean sway amplitude and mean speed of the center of pressure (COP in the anterior-posterior (AP and medial-lateral (ML directions were analyzed in three stances: single-leg stance, double-leg stance and tandem stance, with eyes open or closed on two different surfaces: stable (firm and unstable (foam. A digital chronometer was activated to measure the time limit (Tlimit in the single-leg stance. Kruskal-Wallis tests followed by Mann-Whitney tests, Friedman analyses followed by post hoc Wilcoxon tests and Bonferroni corrections, and Spearman statistical tests were used in the data analysis. Differences of p<0.05 were considered statistically significant. Results: The results of posturography variables revealed no differences between groups. The timed single-leg stance test revealed a shorter Tlimit in the left single-leg stance (p=0.01 in WC group compared to NC group. A negative correlation between posturography variables and Tlimit was detected. Conclusions: Posturography did not show any differences between the groups; however, the timed single-leg stance allowed the authors to observe differences in postural control performance between elderly women with and those without complaints of impaired balance.
de Vries, Astrid J; van den Akker-Scheek, Inge; Diercks, Ron L; Zwerver, Johannes; van der Worp, Henk
Patellar straps or sports tapes are commonly used by athletes with patellar tendinopathy in order to reduce pain and to continue sports participation. Currently, there is no scientific evidence for the effectiveness of a patellar strap or sports tape in the management of this common injury. To investigate the effect of the use of a patellar strap and sports tape on pain and sports participation in subjects with patellar tendinopathy. The study is divided into two parts: a randomised controlled crossover experiment and a randomised controlled trial (parallel group design). 140 patients diagnosed with patellar tendinopathy recruited from sports medical centres and physiotherapist practices. In the first part of the study, participants serve as their own control by performing three functional tests under four different conditions (patellar strap, sports tape, placebo tape, and no orthosis). In the second part, participants keep a log for two weeks (control week and intervention week) about the pain experienced during and after sports and their level of sports participation. In the intervention week participants will use the orthosis assigned to them during training and competition. The amount of pain (both parts of the study) and sports participation (second part only) will be measured. To analyse the effects of the orthoses a Linear Mixed Model will be used. The knowledge gained in this study can be used by practitioners in their advice for athletes with patellar tendinopathy about using patellar strap and sports tape during sports. Copyright © 2013 Australian Physiotherapy Association. Published by Elsevier B.V. All rights reserved.
The topic of my diploma thesis is controlling. The first part is theoretical where I describe the history, meaning and functions of controlling. After that I also specify the methods of strategical, operational and cost controlling. The practical part applied method of controlling to the selected company. The aim of this study is to determine the benefits of controlling for the company. At the operational level it describes the process of controlling in the firm and there are given suggestion...
Full Text Available Unexpected sudden perturbations challenge postural equilibrium and require reactive compensation. This study aimed to assess interaction effects of the direction, displacement and velocity of perturbations on electromyographic (EMG activity, centre of pressure (COP displacement and joint kinematics to detect neuromuscular characteristics (phasic and segmental and kinematic strategies of compensatory reactions in an unilateral balance paradigm. In 20 subjects, COP displacement and velocity, ankle, knee and hip joint excursions and EMG during short (SLR, medium (MLR and long latency response (LLR of four shank and five thigh muscles were analysed during random surface translations varying in direction (anterior-posterior (sagittal plane, medial-lateral (frontal plane, displacement (2 vs. 3 cm and velocity (0.11 vs. 0.18 m/s of perturbation when balancing on one leg on a movable platform. Phases: SLR and MLR were scaled to increased velocity (P<0.05; LLR was scaled to increased displacement (P<0.05. Segments: phasic interrelationships were accompanied by segmental distinctions: distal muscles were used for fast compensation in SLR (P<0.05 and proximal muscles to stabilise in LLR (P<0.05. Kinematics: ankle joints compensated for both increasing displacement and velocity in all directions (P<0.05, whereas knee joint deflections were particularly sensitive to increasing displacement in the sagittal (P<0.05 and hip joint deflections to increasing velocity in the frontal plane (P<0.05. COP measures increased with increasing perturbation velocity and displacement (P<0.05. Interaction effects indicate that compensatory responses are based on complex processes, including different postural strategies characterised by phasic and segmental specifications, precisely adjusted to the type of balance disturbance. To regain balance after surface translation, muscles of the distal segment govern the quick regain of equilibrium; the muscles of the proximal limb serve as delayed stabilisers after a balance disturbance. Further, a kinematic distinction regarding the compensation for balance disturbance indicated different plane- and segment-specific sensitivities with respect to the determinants displacement and velocity.
Huurnink, A.; Fransz, D.P.; Kingma, I.; van Dieen, J.H.
Training and testing of balance have potential applications in sports and medicine. Laboratory grade force plates (FP) are considered the gold standard for the measurement of balance performance. Measurements in these systems are based on the parameterization of center of pressure (CoP)
Huurnink, A.; Fransz, D.P.; Kingma, I.; van Dieen, J.H.
Training and testing of balance have potential applications in sports and medicine. Laboratory grade force plates (FP) are considered the gold standard for the measurement of balance performance. Measurements in these systems are based on the parameterization of center of pressure (CoP) trajectories. Previous research validated the inexpensive, widely available and portable Nintendo Wii Balance Board (WBB). The novelty of the present study is that FP and WBB are compared on CoP data that was ...
Manstead, Antony S R
In this paper, I reflect on past papers published in the British Journal of Social Psychology (BJSP) that have played a role in the development of the theory of reasoned action (TRA) and the theory of planned behaviour (TPB). I focus on seven papers that fall into five categories: (1) those that critique the TRA/TPB for taking insufficient account of social factors; (2) those that critique the models on the grounds that many social behaviours are 'habitual'; (3) those that critically examine the construct of perceived behavioural control; (4) those that argue for the importance of affective factors, which appear to be overlooked in the TRA/TPB; and (5) those that argue for the importance of studying the role of moderating factors and interaction effects in the TRA/TPB. I conclude that BJSP's traditional focus on criticism and theory development is one that benefits the journal and the field. ©2011 The British Psychological Society.
Xuan Vu Trien Nguyen
Full Text Available In the paper, authors generalized the dynamic model of an athlete robot with elastic legs through Lagrange method. Then, a feed-back controller was designed to control the robot through a step-walking. The research just focused on stance phase – the period that robot just touched one leg on the ground. The simulation results showed that system worked well with the designed controller.
Takahashi, Kota Z; Kepple, Thomas M; Stanhope, Steven J
Anatomically-relevant (AR) biomechanical models are traditionally used to quantify joint powers and segmental energies of lower extremity structures during gait. While AR models contain a series of rigid body segments linked together via mechanical joints, prosthetic below-knee structures are often deformable objects without a definable ankle joint. Consequently, the application of AR models for the study of prosthetic limbs has been problematic. The purpose of this study was to develop and validate a unified deformable (UD) segment model for quantifying the total power of below-knee structures. Estimates of total below-knee power derived via the UD segment model were compared to those derived via an AR model during stance in gait of eleven healthy subjects. The UD segment model achieved similar results to the AR model. Differences in peak power, total positive work, and total negative work were 1.91±0.31%, 3.97±0.49%, and 1.39±0.33%, relative to the AR model estimates. The main advantage of the UD segment model is that it does not require the definition of an ankle joint or foot structures. Therefore, this technique may be valuable for facilitating direct comparisons between anatomical and disparate prosthetic below-knee structures in future studies. Copyright © 2012 Elsevier Ltd. All rights reserved.
Wang, Ruoli; Gutierrez-Farewik, Elena M
The purpose of this study was to determine how gait deviation in one plane (i.e. excessive subtalar inversion/eversion) can affect the dynamic function of the tibialis anterior, gastrocnemius, and soleus to accelerate the subtalar, ankle, knee and hip joints, as well as the body center of mass. Induced acceleration analysis was performed based on a subject-specific three-dimensional linkage model configured by stance phase gait data and driven by one unit of muscle force. Eight healthy adult subjects were examined in gait analysis. The subtalar inversion/eversion was modeled by offsetting up to 20° from the normal subtalar angle while other configurations remained unaltered. This study showed that the gastrocnemius, soleus and tibialis anterior generally functioned as their anatomical definition in normal gait, but counterintuitive function was occasionally found in the bi-articular gastrocnemius. The plantarflexors play important roles in the body support and forward progression. Excessive subtalar eversion was found to enlarge the plantarflexors and tibialis anterior's function. Induced acceleration analysis demonstrated its ability to isolate the contributions of individual muscle to a given factor, and as a means of studying effect of pathological gait on the dynamic muscle functions. Copyright © 2011 Elsevier B.V. All rights reserved.
Vieira, Taian M; Baudry, Stéphane; Botter, Alberto
Recent evidence suggests the minimization of muscular effort rather than of the size of bodily sway may be the primary, nervous system goal when regulating the human, standing posture. Different programs have been proposed for balance training; none however has been focused on the activation of postural muscles during standing. In this study we investigated the possibility of minimizing the activation of the calf muscles during standing through biofeedback. By providing subjects with an audio signal that varied in amplitude and frequency with the amplitude of surface electromyograms (EMG) recorded from different regions of the gastrocnemius and soleus muscles, we expected them to be able to minimize the level of muscle activation during standing without increasing the excursion of the center of pressure (CoP). CoP data and surface EMG from gastrocnemii, soleus and tibialis anterior muscles were obtained from 10 healthy participants while standing at ease and while standing with EMG biofeedback. Four sensitivities were used to test subjects' responsiveness to the EMG biofeedback. Compared with standing at ease, the two most sensitive feedback conditions induced a decrease in plantar flexor activity (~15%; P muscle when standing with EMG biofeedback. These results may therefore posit the basis for the development of training protocols aimed at assisting subjects in more efficiently controlling leg muscle activity during standing.
Taian M. Vieira
assisting subjects in more efficiently controlling leg muscle activity during standing.
Major, Matthew J; Scham, Joel; Orendurff, Michael
Prosthetic feet are prescribed based on their mechanical function and user functional level. Subtle changes to the stiffness and hysteresis of heel, midfoot, and forefoot regions can influence the dynamics and economy of gait in prosthesis users. However, the user's choice of shoes may alter the prosthetic foot-shoe system mechanical characteristics, compromising carefully prescribed and rigorously engineered performance of feet. Observe the effects of footwear on the mechanical properties of the prosthetic foot-shoe system including commonly prescribed prosthetic feet. Repeated-measures, Mechanical characterization. The stiffness and energy return was measured using a hydraulic-driven materials test machine across combinations of five prosthetic feet and four common shoes as well as a barefoot condition. Heel energy return decreased by an average 4%-9% across feet in all shoes compared to barefoot, with a cushioned trainer displaying the greatest effect. Foot designs that may improve perceived stability by providing low heel stiffness and rapid foot-flat were compromised by the addition of shoes. Shoes altered prosthesis mechanical characteristics in the sagittal and frontal planes, suggesting that shoe type should be controlled or reported in research comparing prostheses. Understanding of how different shoes could alter certain gait-related characteristics of prostheses may aid decisions on footwear made by clinicians and prosthesis users. Clinical relevance Shoes can alter function of the prosthetic foot-shoe system in unexpected and sometimes undesirable ways, often causing similar behavior across setups despite differences in foot design, and prescribing clinicians should carefully consider these effects on prosthesis performance.
Kuban, D.P.; Perkins, G.S.
The advanced servomanipulator (ASM) slave was designed with an anthropomorphic stance, gear/torque tube power drives, and modular construction. These features resulted in increased inertia, friction, and backlash relative to tape-driven manipulators. Studies were performed which addressed the human factors design and performance trade-offs associated with the corresponding master controller best suited for the ASM. The results of these studies, as well as the conceptual design of the dual arm master controller, are presented. This work was performed as part of the Consolidated Fuel Reprocessing Program at the Oak Ridge National Laboratory. 5 refs., 7 figs., 1 tab
Ji, Sang Gu; Kim, Myoung Kwon
To investigate the effect of mirror therapy on the gait of patients with subacute stroke. Randomized controlled experimental study. Outpatient rehabilitation hospital. Thirty-four patients with stroke were randomly assigned to two groups: a mirror therapy group (experimental) and a control group. The stroke patients in the experimental group underwent comprehensive rehabilitation therapy and mirror therapy for the lower limbs. The stroke patients in the control group underwent sham therapy and comprehensive rehabilitation therapy. Participants in both groups received therapy five days per week for four weeks. Temporospatial gait characteristics, such as single stance, stance phase, step length, stride, swing phase, velocity, and cadence, were assessed before and after the four weeks therapy period. A significant difference was observed in post-training gains for the single stance (10.32 SD 4.14 vs. 6.54 SD 3.23), step length (8.47 SD 4.12 vs. 4.83 SD 2.14), and stride length (17.03 SD 6.57 vs 10.54 SD 4.34) between the experimental group and the control group (p two groups on stance phase, swing phase, velocity, cadence, and step width (P > 0.05). We conclude that mirror therapy may be beneficial in improving the effects of stroke on gait ability. © The Author(s) 2014.
Antonio, TX REFERENCES 1. Lehman E, Amole C. The function of the spleen in the retardation of shock from hemorrhage. Surgery . 1938;4:44 50. 2. Horton...stressful circum stances.4Because it requires laparotomy ,organ manipulation, vascular control and spleen removal, prehemorrhagic splenectomy consti tutes a
Grüneberg, C.; Bloem, B.R.; Honegger, F.; Allum, J.H.J.
Lightweight corsets were used to produce mid-body stiffening, rendering the hip and trunk joints practically inflexible. To examine the effect of this artificially increased stiffness on balance control, we perturbed the upright stance of young subjects (20-34 years of age) while they wore one of
Boonstra, T.A.; Schouten, A.C.; Van der Kooij, H.
Background Human stance involves multiple segments, including the legs and trunk, and requires coordinated actions of both. A novel method was developed that reliably estimates the contribution of the left and right leg (i.e., the ankle and hip joints) to the balance control of individual subjects.
Arumugam, Ashokan; Milosavljevic, Stephan; Woodley, Stephanie; Sole, Gisela
There is some evidence that hamstring function can be influenced by interventions focusing on the pelvis via an anatomic and neurophysiologic link between these two segments. Previous research demonstrated increased electromyographic activity from injured hamstrings during transition from bipedal to unipedal stance (BUS). The aim of this study was to investigate the effects of a pelvic compression belt (PCB) on electromyographic activity of selected muscles during BUS in sportsmen with and without hamstring injury. Electromyographic amplitudes (normalised to maximum voluntary isometric contraction [MVIC]) of the hamstrings, gluteus maximus, gluteus medius and lumbar multifidus were obtained during BUS from 20 hamstring-injured participants (both sides) and 30 healthy participants (one side, randomly selected). There was an increase in biceps femoris (by 1.23 ± 2.87 %MVIC; p = 0.027) and gluteus maximus (by 0.63 ± 1.13 %MVIC; p = 0.023) electromyographic activity for the hamstring-injured side but no significant differences other than a decrease in multifidus activity (by 1.36 ± 2.92 %MVIC; p = 0.023) were evident for healthy participants while wearing the PCB. However, the effect sizes for these findings were small. Wearing the PCB did not significantly change electromyographic activity of other muscles in either participant group (p > 0.050). Moreover, the magnitude of change induced by the PCB was not significantly different between groups (p > 0.050) for the investigated muscles. Thus, application of a PCB to decrease electromyographic activity of injured hamstrings during BUS is likely to have little effect. Similar research is warranted in participants with acute hamstring injury. Copyright © 2014 Elsevier Ltd. All rights reserved.
Evaluation of performance and personal satisfaction of the patient with spastic hand after using a volar dorsal orthosis Avaliação do desempenho e da satisfação pessoal do paciente com mão espástica após o uso da órtese dorsal volar
Danielle dos Santos Cutrim Garros
Full Text Available The performance and the satisfaction of the patient were quantitatively compared with the use of the volar dorsal orthosis in order to position the spastic hand. Thirty patients wearing the orthosis for eight hours daily were evaluated by the Canadian Occupational Performance Measure and the box and blocks test, for a three-month period. Five activities were selected (among daily life activities, productive activities, and leisure activities by the patients, which were impaired by spasticity. There was an improvement related to performance after use of orthosis, with an average of 1.4±0.5 to 6.3±0.8 (pComparou-se quantitativamente o desempenho e a satisfação do paciente com o uso da órtese dorsal volar para posicionamento da mão espástica. Foram analisados 30 pacientes que fizeram uso da órtese por 8 horas diárias, avaliados por meio da Medida Canadense de Desempenho Ocupacional e teste caixa e blocos, no intervalo de 3 meses. Foram selecionadas 5 atividades (entre as atividades de vida diária, produtivas e de lazer pelos pacientes que estavam comprometidas pela espasticidade. Obteve-se melhora em relação ao desempenho após o uso da órtese, com média de 1,4±0,5 para 6,3±0,8 (p<0,01. Quanto à média da satisfação foi de 1,7±0,4 para 6,3±0,6 (p<0,01 com o uso da órtese. Nesta casuística, o uso da órtese de punho e dedos para espasticidade apresentou melhora no desempenho funcional e satisfação do paciente.
Kuban, D.P.; Perkins, G.S.
The Advanced Servomanipulator (ASM) slave was designed with an anthropomorphic stance, gear/torque tube power drives, and modular construction. These features result in increased inertia, friction, and backlash relative to tape-driven manipulators. Studies were performed which addressed the human factors design and performance trade-offs associated with corresponding master controller best suited for the ASM. The results of these studies, as well as the conceptual design of the dual arm master controller, are presented. 6 references, 3 figures
Mortensen, Janus; Mortensen, Sune Sønderberg
The oral examination of defendants and witnesses is a cornerstone in most criminal trials, where the weight and credibility of what is said and the certainty with which testimony is delivered will often be decisive for the ruling of the court. This chapter presents a case study of the linguistic ...
Full Text Available Postural control during free stance has been frequently interpreted in terms of balancing an inverted pendulum. This even holds, if subjects do not balance their own, but an external body weight. We introduce here a virtual balancing apparatus, which produces torque in the ankle joint as a function of ankle angle resembling the gravity and inertial effects of free standing. As a first aim of this study, we systematically modified gravity, damping, and inertia to examine its effect on postural control beyond the physical constraints given in the real world. As a second aim, we compared virtual balancing to free stance to test its suitability for balance training in patients who are not able to balance their full body weight due to certain medical conditions. In a feasibility study, we analyzed postural control during free stance and virtual balancing in 15 healthy subjects. Postural control was characterized by spontaneous sway measures and measures of perturbed stance. During free stance, perturbations were induced by pseudorandom anterior-posterior tilts of the body support surface. In the virtual balancing task, we systematically varied the anterior-posterior position of the foot plate where the balancing forces are zero following a similar pseudorandom stimulus profile. We found that subjects' behavior during virtual balancing resembles free stance on a tilting platform. This specifically holds for the profile of body excursions as a function of stimulus frequencies. Moreover, non-linearity between stimulus and response amplitude is similar in free and virtual balancing. The overall larger stimulus induced body excursions together with an altered phase behavior between stimulus and response could be in part explained by the limited use of vestibular and visual feedback in our experimental setting. Varying gravity or damping significantly affected postural behavior. Inertia as an isolated factor had a mild effect on the response functions. We
Malas, Bryan S
Children with spina bifida often present with functional deficits of the lower limb associated with neurosegmental lesion levels and require orthotic management. The most used orthosis for children with spina bifida is the ankle-foot orthosis (AFO). The AFO improves ambulation and reduces energy cost while walking. Despite the apparent benefits of using an AFO, limited evidence documents the influence of factors predicting the ability of an AFO to improve function and when they are indicated. These variables include AFO design, footwear, AFO-footwear combination, and data acquisition. When these variables are not adequately considered in clinical decision-making, there is a risk the AFO will be abandoned prematurely or the patient's stability, function, and safety compromised. The purposes of this study are to (1) describe the functional deficits based on lesion levels; (2) identify and describe variables that influence the ability of an AFO to control deformities; and (3) describe what variables are indicated for the AFO to control knee flexion during stance, hyperpronation, and valgus stress at the knee. A selective literature review was undertaken searching MEDLINE and Cochrane databases using terms related to "orthosis" and "spina bifida." Based on previous studies and gait analysis data, suggestions can be made regarding material selection/geometric configuration, sagittal alignment, footplate length, and trim lines of an AFO for reducing knee flexion, hyperpronation, and valgus stress at the knee. Further research is required to determine what variables allow an AFO to improve function.
Rajasekaran, Vijaykumar; López-Larraz, Eduardo; Trincado-Alonso, Fernando; Aranda, Joan; Montesano, Luis; Del-Ama, Antonio J; Pons, Jose L
Gait training for individuals with neurological disorders is challenging in providing the suitable assistance and more adaptive behaviour towards user needs. The user specific adaptation can be defined based on the user interaction with the orthosis and by monitoring the user intentions. In this paper, an adaptive control model, commanded by the user intention, is evaluated using a lower limb exoskeleton with incomplete spinal cord injury individuals (SCI). A user intention based adaptive control model has been developed and evaluated with 4 incomplete SCI individuals across 3 sessions of training per individual. The adaptive control model modifies the joint impedance properties of the exoskeleton as a function of the human-orthosis interaction torques and the joint trajectory evolution along the gait sequence, in real time. The volitional input of the user is identified by monitoring the neural signals, pertaining to the user's motor activity. These volitional inputs are used as a trigger to initiate the gait movement, allowing the user to control the initialization of the exoskeleton movement, independently. A Finite-state machine based control model is used in this set-up which helps in combining the volitional orders with the gait adaptation. The exoskeleton demonstrated an adaptive assistance depending on the patients' performance without guiding them to follow an imposed trajectory. The exoskeleton initiated the trajectory based on the user intention command received from the brain machine interface, demonstrating it as a reliable trigger. The exoskeleton maintained the equilibrium by providing suitable assistance throughout the experiments. A progressive change in the maximum flexion of the knee joint was observed at the end of each session which shows improvement in the patient performance. Results of the adaptive impedance were evaluated by comparing with the application of a constant impedance value. Participants reported that the movement of the
da Silva, Rubens A; Vieira, Edgar R; Fernandes, Karen B P; Andraus, Rodrigo A; Oliveira, Marcio R; Sturion, Leandro A; Calderon, Mariane G
To compare the balance of individuals with and without chronic low back pain during five tasks. The participants were 20 volunteers, 10 with and 10 without nonspecific chronic low back pain, mean age 34 years, 50% females. The participants completed the following balance tasks on a force platform in random order: (1) two-legged stance with eyes open, (2) two-legged stance with eyes closed, (3) semi-tandem with eyes open, (4) semi-tandem with eyes closed and (5) one-legged stance with eyes open. The participants completed three 60-s trials of tasks 1-4, and three 30-s trials of task 5 with 30-s rests between trials. The center of pressure area, velocity and frequency in the antero-posterior and medio-lateral directions were computed during each task, and compared between groups and tasks. Participants with chronic low back pain presented significantly larger center of pressure area and higher velocity than the healthy controls (p tasks for all center of pressure variables (p tasks 3 and 4) and one-leg stance (task 5) were more sensitive to identify balance impairments in the chronic low back pain group than two-legged stance tasks 1 and 2 (effect size >1.37 vs. effect size tasks. Individuals with chronic low back pain presented poorer postural control using center of pressure measurements than the healthy controls, mainly during more challenging balance tasks such as semi-tandem and one-legged stance conditions. Implications for Rehabilitation People with chronic low back had poorer balance than those without it. Balance tasks need to be sensitive to capture impairments. Balance assessments during semi-tandem and one-legged stance were the most sensitive tasks to determine postural control deficit in people with chronic low back. Balance assessment should be included during rehabilitation programs for individuals with chronic low back pain for better clinical decision making related to balance re-training as necessary.
Ozdemir, Recep A; Pourmoghaddam, Amir; Paloski, William H
To better understand sensorimotor posture control differences between blind and sighted individuals, we examined the role of ankle joint proprioception and ankle muscle strength on postural control in healthy blind (n=13, 25-58 years) and age- and sex-matched sighted (n=15, 20-65 years) volunteers. We measured ankle joint proprioceptive acuity and isokinetic muscle strength in plantarflexion and dorsiflexion using an isokinetic dynamometer. We also assessed postural control performance during quiet bipedal stance with and without sudden postural perturbations, and during quiet unipedal stance. We found that while our blind subjects exhibited significantly better proprioceptive acuity than our sighted subjects their postural control performance was significantly poorer than that of the sighted group with eyes open, and no different from that of the sighted group with eyes closed suggesting that their superior proprioceptive acuity does not translate to improved balance control. Copyright © 2013 Elsevier B.V. All rights reserved.
Myriam Acero A
Full Text Available La relación entre las desigualdades socioeconómicas y el proceso salud enfermedad ha sido demostrada desde hace ya algún tiempo. Su estudio y posibilidades de intervención, han sido motivo de análisis de actores académicos e institucionales que asumen posturas según la ideología o corriente de pensamiento en la que se inscriben. Con el ánimo de analizar las causas de las inequidades en salud y hacer algunas recomendaciones, la Organización Mundial de la Salud estableció en el año 2005 la Comisión sobre Determinantes Sociales de la Salud. Perspectivas latinoamericanas como la Medicina Social y la Salud Colectiva reconocen la preocupación de la Organización Mundial de la Salud, sin embargo critican la posición asumida por la Comisión y organizan la discusión alrededor de los ejes conceptual, ético y de acción política, proponiendo, a diferencia de la Comisión, buscar las causas de la inequidad y sus vías de solución en lo que significa la determinación social. Cuestionamientos al enfoque de los determinantes sociales de la Comisión llegaron también desde autores como Vicente Navarro, para quien no son las desigualdades las que matan, sino los responsables de esas desigualdades, llamando la atención sobre las relaciones de poder que se ocultan y sobre los responsables y beneficiarios de la inequidad. Finalmente con el objetivo de analizar la determinación social y la ubicación jerárquica de los determinantes sociales, se presenta el problema del hambre, inscrito en un circuito de reproducción y determinación que permite ubicar la particularidad y la generalidad en permanente interrelación The relationship between socioeconomic inequalities and the health-disease process has long been demonstrated. Its study and possibilities for intervention have been submitted to analysis by academic and institutional actors which take more or less critical stances depending on their paradigms. In order to analyze the causes of
Allum, J. H. J.
This review describes the effect of unilateral peripheral vestibular deficit (UPVD) on balance control for stance and gait tests. Because a UPVD is normally defined based on vestibular ocular reflex (VOR) tests, we compared recovery observed in balance control with patterns of recovery in VOR function. Two general types of UPVD are considered; acute vestibular neuritis (AVN) and vestibular neurectomy. The latter was subdivided into vestibular loss after cerebellar pontine angle tumor surgery ...
Arazpour, M; Hojjati, M J; Samadian, M; Bahramizadeh, M; Bani, M Ahmadi; Hutchins, S W
The aim of this study was to evaluate the effect of walking with isocentric reciprocating gait orthoses (IRGOs) utilizing two designs of ankle foot orthoses (AFOs) on specific outcome measures in people with spinal cord injury (SCI). Four volunteer SCI subjects participated in this study, and were fitted with an IRGO equipped with either solid or dorsiflexion-assisted AFOs in a randomized order. Subjects walked at their self-selected speed along a flat walkway to enable a comparison of walking speed, endurance and the resulting physiological cost index (PCI) to be performed. Increased walking speed, increased distance walked and less PCI were demonstrated in walking with the IRGO incorporating dorsiflexion-assisted AFOs as compared to walking with an IRGO plus solid AFO as a control condition. This study demonstrated that people with SCI could walk at relatively higher speeds and with greater endurance and a reduced PCI when utilizing an IRGO with dorsiflexion-assisted AFO components compared to solid ones. It is therefore concluded that the IRGO incorporating dorsiflexion-assisted AFOs may be an effective alternative in helping to reduce the energy consumption experienced by people with SCI.
Thomas, Monika; Kalicinski, Michael
The present study investigated whether slackline training enhances postural control in older adults. Twenty-four participants were randomized into an intervention and a control group. The intervention group received 6 weeks of slackline training, two times per week. Pre-post measurement included the time of different standing positions on a balance platform with and without an external disturbance and the acceleration of the balance platform. Results showed significantly improved standing times during one-leg stance without external disturbance and a significantly reduced acceleration of the balance platform for the intervention group after the training period during tandem stance with and without an external disturbance. We conclude that slackline training in older adults has a positive impact on postural control and thus on the reduction of fall risk.
Mehlhorn, Alexander T; Walther, Markus; Yilmaz, Tayfun
of life. 17 consecutive patients suffering from a Lisfranc fracture dislocation were registered, underwent open reduction and internal fixation and were followed-up for 50.5±25.7months (Mean±SDM). Biomechanical analysis of muscle strength capacities, postural control and plantar pressure distribution......Substantial progress has been made in the operative treatment of Lisfranc fractures, however, the prognosis remains poor. We hypothesized that Lisfranc injuries change the postural control and muscle strength of the lower limb. Both are suggested to correlate with the clinical outcome and quality...... correlated well with clinical outcome. Altered postural control was evident by a significant reduction in unilateral stance time, from which we calculated a strong correlation between stance time and the isokinetic strength measurement. Plantar pressure measurements revealed a significant reduction in peak...
Full Text Available This review describes the effect of unilateral peripheral vestibular deficit (UPVD on balance control as observed in stance and gait tests. Normally, a UPVD is defined based on vestibular ocular reflex (VOR function. Therefore, we compare recovery observed in balance control over time with similar patterns of recovery or lack thereof in VOR function. Three types of UPVD are considered; acute vestibular neuritis, vestibular loss prior to and after cerebellar pontine angle tumor (CPAT surgery during which a vestibular neurectomy was performed, and vestibular loss following neurectomy to eliminate disabling Ménière’s disease.To measure balance control, body-worn gyroscopes, mounted near the body’s centre of mass, were used for stance and gait tests. Measurement variables were the pitch (anterior-posterior and roll (lateral sway angles and angular velocities of the lower trunk-pelvis. All three groups showed balance deficits during stance tasks on foam, especially with eyes closed when stable control is highly dependent on vestibular inputs. Deficits in balance control during gait were present but were more profound for complex gait tasks such as tandem gait. Differences emerged between the groups concerning the severity of the deficit and its recovery. Generally, the effects of acute neuritis were more severe but recovered rapidly, deficits due to vestibular neurectomy were less severe but longer lasting. These results paralleled deficits in VOR function and raise questions about two modes of neural plasticity occurring in the vestibular system following vestibular loss: one mode being the limited central compensation for the loss, and the second mode being some restoration of peripheral vestibular function. Future work will need to correlate deficits in balance control during stance and gait more exactly with VOR deficits and carefully consider the differences between insufficient central compensation compared to inadequate peripheral
Full Text Available Abstract Background There are a number of gaps in the evidence base for the use of ankle-foot orthoses for stroke patients. Three dimensional motion analysis offers an ideal method for objectively obtaining biomechanical gait data from stroke patients, however there are a number of major barriers to its use in routine clinical practice. One significant problem is the way in which the biomechanical data generated by these systems is presented. Through the careful design of bespoke biomechanical visualisation software it may be possible to present such data in novel ways to improve clinical decision making, track progress and increase patient understanding in the context of ankle-foot orthosis tuning. Methods A single-blind randomised controlled trial will be used to compare the use of biomechanical visualisation software in ankle-foot orthosis tuning against standard care (tuning using observation alone. Participants (n = 70 will have experienced a recent hemiplegia (1-12 months and will be identified by their care team as being suitable candidates for a rigid ankle-foot orthosis. The primary outcome measure will be walking velocity. Secondary outcome measures include; lower limb joint kinematics (thigh and shank global orientations & kinetics (knee and hip flexion/extension moments, ground reaction force FZ2 peak magnitude, step length, symmetry ratio based on step length, Modified Ashworth Scale, Modified Rivermead Mobility Index and EuroQol (EQ-5D. Additional qualitative measures will also be taken from participants (patients and clinicians at the beginning and end of their participation in the study. The main aim of the study is to determine whether or not the visualisation of biomechanical data can be used to improve the outcomes of tuning ankle-foot orthoses for stroke patients. Discussion In addition to answering the primary research question the broad range of measures that will be taken during this study are likely to contribute to a
Prangley, Alyssa; Aggerholm, Mathew; Cinelli, Michael
Concussed individuals have been found to experience balance deficits in the anterior-posterior (AP) direction as indicated by greater Center of Pressure (COP) displacement and velocity. One possible reason for this change in balance control could be due to damage to the lateral vestibulospinal tract which sends signals to control posterior muscles, specifically ankle extensors leading to compensatory torques about the ankle. The purpose of the study was to quantify balance assessments in individuals experiencing persistent post-concussion symptoms (PCS) to determine balance control changes following a vestibular training intervention. Participants (N=6,>26days symptomatic), were tested during their first appointment with a registered physiotherapist (PT) and during each follow up appointment. Participants were prescribed balance, visual, and neck strengthening exercises by the PT that were to be completed daily between bi-weekly appointments. Balance assessments were quantified using a Nintendo Wii board to record ground reaction forces. Participants completed 4 balance assessments: 1) Romberg stance eyes open (REO); 2) Romberg stance eyes closed (REC); 3) single leg stance eyes open (SEO); and 4) single leg stance eyes closed (SEC). The balance assessments were conducted on both a firm and compliant surfaces. Significant improvements in balance control were noted in ML/AP displacement and velocity of COP for both SEC and Foam REC conditions, with additional improvements in AP velocity of COP for Foam REC and in ML displacement of COP during Foam SEC. Overall, findings indicate that objectively quantifying balance changes for individuals experiencing persistent PCS allows for a more sensitive measure of balance and detects changes unrecognizable to the naked eye. Copyright © 2017 Elsevier B.V. All rights reserved.
Beloozerova, Irina N.; Stout, Erik E.; Sirota, Mikhail G.
Recent data from this laboratory on differential controls for the shoulder, elbow, and wrist exerted by the thalamo-cortical network during locomotion is presented, based on experiments involving chronically instrumented cats walking on a flat surface and along a horizontal ladder. The activity of the following three groups of neurons is characterized: (1) neurons of the motor cortex that project to the pyramidal tract (PTNs), (2) neurons of the ventrolateral thalamus (VL), many identified as projecting to the motor cortex (thalamo-cortical neurons, TCs), and (3) neurons of the reticular nucleus of thalamus (RE), which inhibit TCs. Neurons were grouped according to their receptive field into shoulder-, elbow-, and wrist/paw-related categories. During simple locomotion, shoulder-related PTNs were most active in the late stance and early swing, and on the ladder, often increased activity and stride-related modulation while reducing discharge duration. Elbow-related PTNs were most active during late swing/early stance and typically remained similar on the ladder. Wrist-related PTNs were most active during swing, and on the ladder often decreased activity and increased modulation while reducing discharge duration. In the VL, shoulder-related neurons were more active during the transition from swing-to-stance. Elbow-related cells tended to be more active during the transition from stance-to-swing and on the ladder often decreased their activity and increased modulation. Wrist-related neurons were more active throughout the stance phase. In the RE, shoulder-related cells had low discharge rates and depths of modulation and long periods of activity distributed evenly across the cycle. In sharp contrast, wrist/paw-related cells discharged synchronously during the end of stance and swing with short periods of high activity, high modulation, and frequent sleep-type bursting. We conclude that thalamo-cortical network processes information related to different segments of the
Creylman, Veerle; Knippels, Ingrid; Janssen, Paul; Biesbrouck, Evelyne; Lechler, Knut; Peeraer, Louis
In transfemoral (TF) amputees, the forward propulsion of the prosthetic leg in swing has to be mainly carried out by hip muscles. With hip strength being the strongest predictor to ambulation ability, an active powered knee joint could have a positive influence, lowering hip loading and contributing to ambulation mobility. To assess this, gait of four TF amputees was measured for level walking, first while using a passive microprocessor-controlled prosthetic knee (P-MPK), subsequently while using an active powered microprocessor-controlled prosthetic knee (A-MPK). Furthermore, to assess long-term effects of the use of an A-MPK, a 4-weeks follow-up case study was performed. The kinetics and kinematics of the gait of four TF amputees were assessed while walking with subsequently the P-MPK and the A-MPK. For one amputee, a follow-up study was performed: he used the A-MPK for 4 weeks, his gait was measured weekly. The range of motion of the knee was higher on both the prosthetic and the sound leg in the A-MPK compared to the P-MPK. Maximum hip torque (HT) during early stance increased for the prosthetic leg and decreased for the sound leg with the A-MPK compared to the P-MPK. During late stance, the maximum HT decreased for the prosthetic leg. The difference between prosthetic and sound leg for HT disappeared when using the A-MPK. Also, an increase in stance phase duration was observed. The follow-up study showed an increase in confidence with the A-MPK over time. Results suggested that, partially due to an induced knee flexion during stance, HT can be diminished when walking with the A-MPK compared to the P-MPK. The single case follow-up study showed positive trends indicating that an adaptation time is beneficial for the A-MPK.
Schlenstedt, Christian; Muthuraman, Muthuraman; Witt, Karsten; Weisser, Burkhard; Fasano, Alfonso; Deuschl, Günther
The relationship between freezing of gait (FOG) and postural instability in Parkinson's disease (PD) is unclear. We analyzed the impact of FOG on postural control. 31 PD patients with FOG (PD+FOG), 27 PD patients without FOG (PD-FOG) and 22 healthy control (HC) were assessed in the ON state. Postural control was measured with the Fullerton Advanced Balance (FAB) scale and with center of pressure (COP) analysis during quiet stance and maximal voluntary forward/backward leaning. The groups were balanced concerning age, disease duration and disease severity. PD+FOG performed significantly worse in the FAB scale (21.8 ± 5.8) compared to PD-FOG (25.6 ± 5.0) and HC (34.9 ± 2.4) (mean ± SD, p < 0.01). PD+FOG had impaired ability to voluntary lean forward, difficulties to stand on foam with eyes closed and reduced limits of stability compared to PD-FOG (p < 0.05). During quiet stance the average anterior-posterior COP position was significantly displaced towards posterior in PD+FOG in comparison to PD-FOG and HC (p < 0.05). The COP position correlated with severity of FOG (p < 0.01). PD+FOG and PD-FOG did not differ in average COP sway excursion, sway velocity, sway regularity and postural control asymmetry. PD+FOG have reduced postural control compared to PD-FOG and HC. Our results show a relationship between the anterior-posterior COP position during quiet stance and FOG. The COP shift towards posterior in PD+FOG leads to a restricted precondition to generate forward progression during gait initiation. This may contribute to the occurrence of FOG or might be a compensatory strategy to avoid forward falls. Copyright © 2015 Elsevier Ltd. All rights reserved.
Reginaldo Kisho Fukuchi
stance phase kinematics of running in adults and elderly runners. Seventeen adults (31±5 years old and 17 elderly runners (69±2 years old ran on a treadmill at 11 km/h while they were filmed by four digital cameras at 120 Hz. Rearfoot and knee joint movements were measured during the stance phase of running. The elderly runners showed lower knee flexion and lower tibial internal rotation excursion. Elderly runners apparently presented greater asynchrony between rearfoot and knee joint movement than adults. These findings suggest that during running stance elderly runners adopt different movement patterns when compared to adults. Prescription of physical activities for the elderly and prevention strategies in elderly runners should consider these findings.
Background Only few studies have looked at electromyography (EMG) during prosthetic gait. Differences in EMG between normal and prosthetic gait for stance and swing phase were never separately analyzed. These differences can give valuable information if and how muscle activity changes in prosthetic gait. Methods In this study EMG activity during gait of the upper leg muscles of six transfemoral amputees, measured inside their own socket, was compared to that of five controls. On and off timings for stance and swing phase were determined together with the level of co-activity and inter-subject variability. Results and conclusions Gait phase changes in amputees mainly consisted of an increased double support phase preceding the prosthetic stance phase. For the subsequent (pre) swing phase the main differences were found in muscle activity patterns of the prosthetic limb, more muscles were active during this phase and/or with prolonged duration. The overall inter-subject variability was larger in amputees compared to controls. PMID:23914785
Lin, Chia-Wei; Lin, Cheng-Feng; Hsue, Bih-Jen; Su, Fong-Chin
The purpose of the current study was to evaluate the postural stability of single-leg standing on the retiré position in ballet dancers having three different levels of skill. Nine superior experienced female ballet dancers, 9 experienced, and 12 novice dancers performed single-leg standing in the retiré position. The parameters of center of pressure (COP) in the anterior-posterior and medial-lateral directions and the maximum distance between COP and the center of mass (COM) were measured. The inclination angles of body segments (head, torso, and supporting leg) in the frontal plane were also calculated. The findings showed that the novice dancers had a trend of greater torso inclination angles than the experienced dancers but that the superior experienced dancers had greater maximum COM-COP distance in the anterior-posterior direction. Furthermore, both experienced and novice dancers had better balance when standing on the nondominant leg, whereas the superior experienced dancers had similar postural stability between legs. Based on the findings, ballet training should put equal focus on both legs and frontal plane control (medial-lateral direction) should be integrated to ballet training program.
Graf, John C.; Perry, Jay; Wright, John; Bahr, Jim
Paradoxically, trace contaminant control systems that suffer unexpected upsets and malfunctions can release hazardous gaseous contaminants into a spacecraft cabin atmosphere causing potentially serious toxicological problems. Trace contaminant control systems designed for spaceflight typically employ a combination of adsorption beds and catalytic oxidation reactors to remove organic and inorganic trace contaminants from the cabin atmosphere. Interestingly, the same design features and attributes which make these systems so effective for purifying a spacecraft's atmosphere can also make them susceptible to system upsets. Cabin conditions can be contributing causes of phenomena such as adsorbent "rollover" and catalyst poisoning can alter a systems performance and in some in stances release contamination into the cabin. Evidence of these phenomena has been observed both in flight and during ground-based tests. The following discussion describes specific instances of system upsets found in trace contaminant control systems, groups these specific upsets into general hazard classifications, and recommends ways to minimize these hazards.
Avaliação das propriedades mecânicas de atadura gessada de três diferentes fabricantes, utilizada para confecção de órteses Evaluation of the mechanical properties of plaster bandages used for orthosis manufacture, marketed by three different manufacturers
Gustavo Cardoso Vieira
Full Text Available Foram realizados testes mecânicos com atadura gessada de três diferentes fabricantes, utilizada para confecção de órteses. Para isso, foram confeccionados corpos de provas (CDPs na forma de placas e de cilindros. Os CDPs foram submetidos a dois tipos de ensaios mecânicos: para o grupo das placas foi realizado ensaio de flexão em três pontos e para o grupo dos cilindros, ensaio de compressão. Os ensaios mecânicos foram realizados na Máquina Universal de Ensaios EMIC®. Três propriedades mecânicas foram avaliadas após os ensaios: carga no limite máximo, carga no limite de proporcionalidade e rigidez. Os resultados mostraram que um fabricante foi superior aos demais para as propriedades avaliadas.Mechanical tests have been performed in plaster bandages used in orthosis supplied by three different manufacturers. For this, bodies of evidence (BOEs were made with plates and cylinders shapes. BOEs were submitted to two kinds of mechanical assays: for the plate group, a flexion assay was performed at three points, and, for the cylinder group, a compression assay was performed. Mechanical assays were performed on the Universal Assay Machine EMIC®. Three mechanical properties were assessed after assays: maximum limit load, proportional limit load and stiffness. Results show that a manufacturer was superior over the others for the properties assessed.
Toebes, Marcel J P; Hoozemans, Marco J M; Dekker, Joost; van Dieën, Jaap H
This study assessed effects of unilateral leg muscle fatigue (ULMF) on balance control in gait during the stance and swing phases of the fatigued leg in healthy elderly, to test the assumption that leg muscle strength limits balance control during the stance-phase. Ten subjects (aged 63.4, SD 5.5 years) walked on a treadmill in 4 conditions: unperturbed unfatigued, unperturbed fatigued, perturbed unfatigued, and perturbed fatigued. The perturbations were lateral trunk pulls just before contralateral heel contact. ULMF was evoked by unilateral squat exercise until task failure. Isometric knee extension strength was measured to verify the presence of muscle fatigue. Between-stride standard deviations and Lyapunov exponents of trunk kinematics were used as indicators of balance control. Required perturbation force and the deviation of trunk kinematics from unperturbed gait were used to assess perturbation responses. Knee extension strength decreased considerably (17.3% SD 8.6%) as a result ULMF. ULMF did not affect steady-state gait balance. Less force was required to perturb subjects when the fatigued leg was in the stance-phase compared to the swing-phase. Subjects showed a faster return to the unperturbed gait pattern in the fatigued than in the unfatigued condition, after perturbations in swing and stance of the fatigued leg. The results of this study are not in line with the hypothesized effects of leg muscle fatigue on balance in gait. The healthy elderly subjects were able to cope with substantial ULMF during steady-state gait and demonstrated faster balance recovery after laterally directed mechanical perturbations in the fatigued than in the unfatigued condition. Copyright © 2014 Elsevier B.V. All rights reserved.
Full Text Available Introduction & Objective: It is known that postural control performance in upright standing position could be affected by abnormal posture alignment. Despite the fact that kyphosis is one of the most common spine abnormality, the effect of thoracic curve abnormality at sagittal plane on postural stability has received little attention to date. Therefore, the purpose of our study was to investigate the dynamic and static postural control among individuals with kyphosis in comparison with a control matched group.Materials & Methods: Nineteen males with increased normal thoracic kyphosis (> 40 degrees were randomly selected as kyphotic group. Eighteen controls matched for age, weight and height were selected to participate in the study. We measured the amount of kyphosis using flexible ruler as a noninvasive and reliable method. Dynamic and static postural stability were assessed using the biodex stability system and the balance error scoring system respectively. ANOVA with repeated measures followed by Tukey HSD test and independent t-test were employed for statistical analyses (p<0.05. Results: For dynamic postural assessment, the means of all stability indices were significantly higher in the kyphotic individuals than controls in the eyes-closed condition. With the platform in the most unstable position, kyphotic group were detected to have significantly poorer balance performance than controls in both eyes-open and eyes-closed conditions. For static balance evaluation, no difference was noted between both groups in stability performance during double and tandem stances. During the single-limb stance trials, the kyphotic group had poorer performance than controls while standing on the firm surface and foam surface (firm surface: p=0.044; foam surface: p=0.000.Conclusion: The findings suggest that postural control especially dynamic postural stability may be altered in individuals with increased thoracic kyphosis.
Dean, Jesse C; Kautz, Steven A
Gait instability is a common problem following stroke, as evidenced by increases in fall risk and fear of falling. However, the mechanism underlying gait instability is currently unclear. We recently found that young, healthy humans use a consistent gait stabilization strategy of actively controlling their mediolateral foot placement based on the concurrent mechanical state of the stance limb. In the present work, we tested whether people with stroke (n = 16) and age-matched controls (n = 19) used this neuromechanical strategy. Specifically, we used multiple linear regressions to test whether (1) swing phase gluteus medius (GM) activity was influenced by the simultaneous state of the stance limb and (2) mediolateral foot placement location was influenced by swing phase GM activity and the mechanical state of the swing limb at the start of the step. We found that both age-matched controls and people with stroke classified as having a low fall risk (Dynamic Gait Index [DGI] score >19) essentially used the stabilization strategy previously described in young controls. In contrast, this strategy was disrupted for people with stroke classified as higher fall risk (DGI foot placement may contribute to poststroke instability.
Full Text Available Traces the changes in public attitudes toward and political stances on drug control in the British Caribbean between 1980 and 2000. Author first discusses the origins of drug control, the role of US pressure, and the vulnerability of the Caribbean. He then looks at European involvement and the different plans and policies to control drugs in the region. Finally, he describes the consequences of these policy approaches on the justice system and legal reform, drug demand, and social structures in the region.
Full Text Available Propriocepção refere-se à percepção dos mecanorreceptores para discriminar a posição do corpo e movimentos articulares, bem como tensões sobre os tendões na fase estática ou dinâmica da marcha. Objetivou-se avaliar por eletromiografia a ativação muscular do gastrocnêmio e tibial anterior em diferentes exercícios de propriocepção do tornozelo em apoio unipodal, comparando graus de dificuldade. Foram selecionados 54 voluntários, sedentários, destros, do sexo masculino (20-35 anos. Exercícios foram feitos no balancinho, prancha de equilíbrio, cama elástica e solo, à razão de três repetições de 15 segundos cada, com intervalo de 15 segundos entre as repetições. Ao final dos testes os voluntários indicaram a maior dificuldade. A atividade elétrica de ambos os músculos foi significativamente maior durante o teste no balancinho. No solo, ambos os músculos apresentaram menor atividade, mas apenas no gastrocnêmio essa diferença foi significativa. No exercício na prancha de equilíbrio e na cama elástica não se encontrou diferença quanto à ativação dos músculos. Na análise intermúsculo foi observada maior atividade do tibial anterior, exceto no balancinho. Assim, para o treino do apoio unipodal na aquisição do ganho proprioceptivo, o equipamento adotado deve ser escolhido com cuidado: no balancinho é maior o recrutamento dos músculos tibial anterior e gastrocnêmio, assim como é maior o grau de dificuldade para manutenção do equilíbrio.Proprioception refers to the ability of mechanoreceptors to discriminate body position and joint movements, as well as tensions during static or dynamic phases. The aim of this study was to assess, by means of surface electromyography, activation patterns of the gastrocnemius and tibialis anterior muscles in proprioception exercises, also comparing difficulty levels. Fifty-four sedentary, right-handed, 20-to-35 year-old male volunteers performed single-leg stance
Full Text Available Background: Due to the rotatory nature of the excessive subtalar pronation and the possible impairment of the tibial rotation-knee flexion mechanism, changes of the free moment (FM and changes of the extensor mechanism force are expected in hyper-pronated foot subjects. The purpose of this study was to evaluate the correlation between the FM applied on the lower extremity and the knee extensor mechanism force in subjects with flexible pronated feet. Methods: Fifteen asymptomatic female subjects (21.32±1.66 y, 56.30±6.08 kg, 159±6.3 cm participated in the study. Excessive subtalar pronation was determined by measuring the resting calcaneal stance position (RCSP in the frontal plane during weight bearing. A neutrally aligned foot was defined as having an RCSP between 2° of inversion and 2° of eversion. On the other hand, a flat foot had an RCSP of more than or equal to 4° of eversion. Both kinetic and kinematic data were collected using a six-camera motion analysis system and a single force plate. Three successful barefoot walking trials were recorded at selfselected speeds. The extensor mechanism force and the adductory component of the free moment (ADD FM were calculated. The correlation between the ADD FM and the knee extensor mechanism force was examined using the Pearson correlation test. Results: The Pearson correlation analysis showed a high positive correlation between the ADD FM and the extensor mechanism force (r=0.917, P<0.001. Conclusion: Excessive subtalar pronation, along with a possible impairment of the tibial rotation-knee flexion mechanism, may affect the extensor mechanism force at the knee joint. From a clinical perspective, the possible biomechanical linkage between the knee and the foot complex in the physical examination and treatment of patients should be considered.
Arnould, Eric; Press, Melea
In this paper, we look at how alternative marketing organisations communicate transparency in a climate of generalised risk and scepticism. We contrast the traditional numeric approach to transparency, which involves auditing and third-party certifications; with an alternative approach that we call...... transparency to their stakeholders. These rhetorical tactics include persona, allegory, consumer sovereignty and enlightenment. Community supported agriculture programmes from across the United States are the context for this study. Findings enrich discussions about best practices for transparency...
d'Haenens, L.S.J.; Proulx, S.
This article looks at policy options taken by the Canadian government in an age of globalization and information. A first part explores federal government initiatives pertaining to Canada's preparedness for the information society. A second part assesses some provincial government policy options,
Arnould, Eric; Press, Melea
In this paper, we look at how alternative marketing organisations communicate transparency in a climate of generalised risk and scepticism. We contrast the traditional numeric approach to transparency, which involves auditing and third-party certifications; with an alternative approach that we call...
Allum, J. H. J.
This review describes the effect of unilateral peripheral vestibular deficit (UPVD) on balance control for stance and gait tests. Because a UPVD is normally defined based on vestibular ocular reflex (VOR) tests, we compared recovery observed in balance control with patterns of recovery in VOR function. Two general types of UPVD are considered; acute vestibular neuritis (AVN) and vestibular neurectomy. The latter was subdivided into vestibular loss after cerebellar pontine angle tumor surgery during which a vestibular neurectomy was performed, and vestibular loss following neurectomy to eliminate disabling Ménière’s disease. To measure balance control, body-worn gyroscopes, mounted near the body’s center of mass (CoM), were used. Measurement variables were the pitch (anterior–posterior) and roll (lateral) sway angles and angular velocities of the lower trunk/pelvis. Both patient groups showed balance deficits during stance tasks on foam, especially with eyes closed when stable balance control is normally highly dependent on vestibular inputs. Deficits during gait were also present and were more profound for complex gait tasks such as tandem gait than simple gait tasks. Major differences emerged between the groups concerning the severity of the deficit and its recovery. Generally, the effects of acute neuritis on balance control were more severe but recovered rapidly. Deficits due to vestibular neurectomy were less severe, but longer lasting. These results mostly paralleled recovery of deficits in VOR function. However, questions need to be raised about the effect on balance control of the two modes of neural plasticity occurring in the vestibular system following vestibular loss due to neuritis: one mode being the limited central compensation for the loss, and the second mode being some restoration of peripheral vestibular function. Future work will need to correlate deficits in balance control during stance and gait more exactly with VOR deficits and
Allum, J H J
This review describes the effect of unilateral peripheral vestibular deficit (UPVD) on balance control for stance and gait tests. Because a UPVD is normally defined based on vestibular ocular reflex (VOR) tests, we compared recovery observed in balance control with patterns of recovery in VOR function. Two general types of UPVD are considered; acute vestibular neuritis (AVN) and vestibular neurectomy. The latter was subdivided into vestibular loss after cerebellar pontine angle tumor surgery during which a vestibular neurectomy was performed, and vestibular loss following neurectomy to eliminate disabling Ménière's disease. To measure balance control, body-worn gyroscopes, mounted near the body's center of mass (CoM), were used. Measurement variables were the pitch (anterior-posterior) and roll (lateral) sway angles and angular velocities of the lower trunk/pelvis. Both patient groups showed balance deficits during stance tasks on foam, especially with eyes closed when stable balance control is normally highly dependent on vestibular inputs. Deficits during gait were also present and were more profound for complex gait tasks such as tandem gait than simple gait tasks. Major differences emerged between the groups concerning the severity of the deficit and its recovery. Generally, the effects of acute neuritis on balance control were more severe but recovered rapidly. Deficits due to vestibular neurectomy were less severe, but longer lasting. These results mostly paralleled recovery of deficits in VOR function. However, questions need to be raised about the effect on balance control of the two modes of neural plasticity occurring in the vestibular system following vestibular loss due to neuritis: one mode being the limited central compensation for the loss, and the second mode being some restoration of peripheral vestibular function. Future work will need to correlate deficits in balance control during stance and gait more exactly with VOR deficits and carefully
Alessandro Marco De Nunzio
Full Text Available Objectives. To assess the motor control during quiet stance in patients with established ankylosing spondylitis (AS and to evaluate the effect of visual input on the maintenance of a quiet posture. Methods. 12 male AS patients (mean age 50.1 ± 13.2 years and 12 matched healthy subjects performed 2 sessions of 3 trials in quiet stance, with eyes open (EO and with eyes closed (EC on a baropodometric platform. The oscillation of the centre of feet pressure (CoP was acquired. Indices of stability and balance control were assessed by the sway path (SP of the CoP, the frequency bandwidth (FB1 that includes the 80% of the area under the amplitude spectrum, the mean amplitude of the peaks (MP of the sway density curve (SDC, and the mean distance (MD between 2 peaks of the SDC. Results. In severe AS patients, the MD between two peaks of the SDC and the SP of the center of feet pressure were significantly higher than controls during both EO and EC conditions. The MP was significantly reduced just on EC. Conclusions. Ankylosing spondylitis exerts negative effect on postural stability, not compensable by visual inputs. Our findings may be useful in the rehabilitative management of the increased risk of falling in AS.
Bergmann, J; Krewer, C; Müller, F; Koenig, A; Riener, R
Virtual Reality (VR) provides a promising medium to enrich robot assisted rehabilitation. VR applications present the opportunity to engage patients in therapy and control participation. The aim of this study was to investigate two strategies to control active participation of a stroke patient focusing on the involvement of the paretic leg in task solution. A subacute stroke patient with a severe hemiparesis performed two experiments on the driven gait orthosis Lokomat. Patient activity was quantified by weighted interaction torques measured in both legs (experiment A) and the paretic leg only (experiment B). The patient was able to successfully implement both the bilateral and unilateral control modality. Both control modes increased the motor output of the paretic leg, however the paretic leg control mode resulted in a much more differentiated regulation of the activity in the leg. Both control modes are appropriate approaches to enhance active participation and increase motor output in the paretic leg. Further research should evaluate the therapeutic benefit of patients with hemiparesis using the unilateral control mode depending on the severity of their impairment. © 2011 IEEE
Zhao, Guoping; Sharbafi, Maziar; Vlutters, Mark; van Asseldonk, Edwin; Seyfarth, Andre
We present a novel control approach for assistive lower-extremity exoskeletons. In particular, we implement a virtual pivot point (VPP) template model inspired leg force feedback based controller on a lower-extremity powered exoskeleton (LOPES II) and demonstrate that it can effectively assist humans during walking. It has been shown that the VPP template model is capable of stabilizing the trunk and reproduce a human-like hip torque during the stance phase of walking. With leg force and joint angle feedback inspired by the VPP template model, our controller provides hip and knee torque assistance during the stance phase. A pilot experiment was conducted with four healthy subjects. Joint kinematics, leg muscle electromyography (EMG), and metabolic cost were measured during walking with and without assistance. Results show that, for 0.6 m/s walking, our controller can reduce leg muscle activations, especially for the medial gastrocnemius (about 16.0%), while hip and knee joint kinematics remain similar to the condition without the controller. Besides, the controller also reduces 10% of the net metabolic cost during walking. This paper demonstrates walking assistance benefits of the VPP template model for the first time. The support of human walking is achieved by a force feedback of leg force applied to the control of hip and knee joints. It can help us to provide a framework for investigating walking assistance control in the future.
Ismara Eliane Vidal de Souza Tasso
Full Text Available Current analysis investigates the manner identity constitution and black female’s visual representation in Portinari’s iconography is shown within the theoretical presuppositions of the French Discourse Analysis in alignment with the theoretical bases of Peirce’s Semiotics, the History of the Body and Cultural Studies. The social and the political factors are understood through an interpretative stance, within the paradoxical state of intangible significant materiality. The descriptive, interpretative, archeological andgenealogical movement showed that the half-naked body is presented as erotic, perceived as exotic and treated as profane. The movement also showed that sensuality is signified and resignified by the marginal since it works with discursive memory which conceives the exotic as an order opposed to existence, namely the profane order, and the place in which the subjects of difference encounter one another.O objetivo deste artigo é demonstrar o modo de constituição identitária e de representação visual da mulher negra na iconografiaportinariana, sob os pressupostos teóricos da Análise do Discurso de linha francesa, em diálogo com os fundamentos teóricos da Semiótica peirceana, da História do Corpo e dos Estudos Culturais. Dessa forma, buscamos apreender, no estado paradoxal da materialidade significante intangível, o social e o político, por meio de um gesto de leitura. O movimento descritivo-interpretativo arqueogenealógico empreendido demonstrou que o corpo semidesnudo é apresentado como erótico, visto como exótico e tratado como profano e a sensualidade significada e ressignificada pelo marginal, em razão de operar com a memória discursiva de que o exótico constitui uma ordem contrária de existência, a do profano, lugar em que se encontram os sujeitos da diferença.
Monaco, V.; Tropea, P.; Aprigliano, F.; Martelli, D.; Parri, A.; Cortese, M.; Molino-Lova, R.; Vitiello, N.; Micera, S.
The evolution to bipedalism forced humans to develop suitable strategies for dynamically controlling their balance, ensuring stability, and preventing falling. The natural aging process and traumatic events such as lower-limb loss can alter the human ability to control stability significantly increasing the risk of fall and reducing the overall autonomy. Accordingly, there is an urgent need, from both end-users and society, for novel solutions that can counteract the lack of balance, thus preventing falls among older and fragile citizens. In this study, we show a novel ecological approach relying on a wearable robotic device (the Active Pelvis Orthosis, APO) aimed at facilitating balance recovery after unexpected slippages. Specifically, if the APO detects signs of balance loss, then it supplies counteracting torques at the hips to assist balance recovery. Experimental tests conducted on eight elderly persons and two transfemoral amputees revealed that stability against falls improved due to the “assisting when needed” behavior of the APO. Interestingly, our approach required a very limited personalization for each subject, and this makes it promising for real-life applications. Our findings demonstrate the potential of closed-loop controlled wearable robots to assist elderly and disabled subjects and to improve their quality of life.
Vejdani, H R; Blum, Y; Daley, M A; Hurst, J W
We proposed three swing leg control policies for spring-mass running robots, inspired by experimental data from our recent collaborative work on ground running birds. Previous investigations suggest that animals may prioritize injury avoidance and/or efficiency as their objective function during running rather than maintaining limit-cycle stability. Therefore, in this study we targeted structural capacity (maximum leg force to avoid damage) and efficiency as the main goals for our control policies, since these objective functions are crucial to reduce motor size and structure weight. Each proposed policy controls the leg angle as a function of time during flight phase such that its objective function during the subsequent stance phase is regulated. The three objective functions that are regulated in the control policies are (i) the leg peak force, (ii) the axial impulse, and (iii) the leg actuator work. It should be noted that each control policy regulates one single objective function. Surprisingly, all three swing leg control policies result in nearly identical subsequent stance phase dynamics. This implies that the implementation of any of the proposed control policies would satisfy both goals (damage avoidance and efficiency) at once. Furthermore, all three control policies require a surprisingly simple leg angle adjustment: leg retraction with constant angular acceleration.
Sheykhi-Dolagh, Roghaye; Saeedi, Hassan; Farahmand, Behshid; Kamyab, Mojtaba; Kamali, Mohammad; Gholizadeh, Hossein; Derayatifar, Amir A; Curran, Sarah
Flexible flat foot is described as a reduction in the height of the medial longitudinal arch and may occur from abnormal foot pronation. A foot orthosis is thought to modify and control excessive pronation and improve arch height. To compare the immediate effect of three types of orthoses on foot mobility and the arch height index in subjects with flexible flat feet. A quasi-experimental study. The dorsal arch height, midfoot width, foot mobility and arch height index were assessed in 20 participants with flexible flat feet (mean age = 23.2 ± 3 years) for three different foot orthosis conditions: soft, semi-rigid and rigid University of California Biomechanics Laboratory (UCBL). Maximum midfoot width at 90% with arch mobility in the coronal plane was shown in the semi-rigid orthosis condition. The semi-rigid orthosis resulted in the highest mean foot mobility in 90% of weight bearing, and the rigid orthosis (UCBL) had the lowest mean foot mobility. The soft orthosis resulted in foot mobility between that of the rigid and the semi-rigid orthosis. UCBL orthosis showed the highest arch height index, and the semi-rigid orthosis showed the lowest mean arch height index. Due to its rigid structure and long medial-lateral walls, the UCBL orthosis appears to limit foot mobility. Therefore, it is necessary to make an orthosis that facilitates foot mobility in the normal range of the foot arch. Future studies should address the dynamic mobility of the foot with using various types of foot orthoses. Although there are many studies focussed on flat foot and the use of foot orthoses, the mechanism of action is still unclear. This study explored foot mobility and the influence of foot orthoses and showed that a more rigid foot orthosis should be selected based on foot mobility. © The International Society for Prosthetics and Orthotics 2014.
Alkjaer, Tine; Raffalt, Peter C; Dalsgaard, Helle; Simonsen, Erik B; Petersen, Nicolas C; Bliddal, Henning; Henriksen, Marius
Knee osteoarthritis (OA) is a common disease that impairs walking ability and function. We compared the temporal gait variability and motor control in people with knee OA with healthy controls. The purpose was to test the hypothesis that the temporal gait variability would reflect a more stereotypic pattern in people with knee OA compared with healthy age-matched subjects. To assess the gait variability the temporal structure of the ankle and knee joint kinematics was quantified by the largest Lyapunov exponent and the stride time fluctuations were quantified by sample entropy and detrended fluctuation analysis. The motor control was assessed by the soleus (SO) Hoffmann (H)-reflex modulation and muscle co-activation during walking. The results showed no statistically significant mean group differences in any of the gait variability measures or muscle co-activation levels. The SO H-reflex amplitude was significantly higher in the knee OA group around heel strike when compared with the controls. The mean group difference in the H-reflex in the initial part of the stance phase (control-knee OA) was -6.6% Mmax (95% CI: -10.4 to -2.7, p=0.041). The present OA group reported relatively small impact of their disease. These results suggest that the OA group in general sustained a normal gait pattern with natural variability but with suggestions of facilitated SO H-reflex in the swing to stance phase transition. We speculate that the difference in SO H-reflex modulation reflects that the OA group increased the excitability of the soleus stretch reflex as a preparatory mechanism to avoid sudden collapse of the knee joint which is not uncommon in knee OA. Copyright © 2015 Elsevier B.V. All rights reserved.
Mignardot, Jean-Baptiste; Olivier, Isabelle; Promayon, Emmanuel; Nougier, Vincent
Background This study investigated the effects of obesity on attentional resources allocated to postural control in seating and unipedal standing. Methods Ten non obese adults (BMI = 22.4±1.3, age = 42.4±15.1) and 10 obese adult patients (BMI = 35.2±2.8, age = 46.2±19.6) maintained postural stability on a force platform in two postural tasks (seated and unipedal). The two postural tasks were performed (1) alone and (2) in a dual-task paradigm in combination with an auditory reaction time task (RT). Performing the RT task together with the postural one was supposed to require some attentional resources that allowed estimating the attentional cost of postural control. 4 trials were performed in each condition for a total of 16 trials. Findings (1) Whereas seated non obese and obese patients exhibited similar centre of foot pressure oscillations (CoP), in the unipedal stance only obese patients strongly increased their CoP sway in comparison to controls. (2) Whatever the postural task, the additional RT task did not affect postural stability. (3) Seated, RT did not differ between the two groups. (4) RT strongly increased between the two postural conditions in the obese patients only, suggesting that body schema and the use of internal models was altered with obesity. Interpretation Obese patients needed more attentional resources to control postural stability during unipedal stance than non obese participants. This was not the case in a more simple posture such as seating. To reduce the risk of fall as indicated by the critical values of CoP displacement, obese patients must dedicate a strong large part of their attentional resources to postural control, to the detriment of non-postural events. Obese patients were not able to easily perform multitasking as healthy adults do, reflecting weakened psycho-motor abilities. PMID:21187914
Full Text Available This study investigated the effects of obesity on attentional resources allocated to postural control in seating and unipedal standing.Ten non obese adults (BMI = 22.4±1.3, age = 42.4±15.1 and 10 obese adult patients (BMI = 35.2±2.8, age = 46.2±19.6 maintained postural stability on a force platform in two postural tasks (seated and unipedal. The two postural tasks were performed (1 alone and (2 in a dual-task paradigm in combination with an auditory reaction time task (RT. Performing the RT task together with the postural one was supposed to require some attentional resources that allowed estimating the attentional cost of postural control. 4 trials were performed in each condition for a total of 16 trials.(1 Whereas seated non obese and obese patients exhibited similar centre of foot pressure oscillations (CoP, in the unipedal stance only obese patients strongly increased their CoP sway in comparison to controls. (2 Whatever the postural task, the additional RT task did not affect postural stability. (3 Seated, RT did not differ between the two groups. (4 RT strongly increased between the two postural conditions in the obese patients only, suggesting that body schema and the use of internal models was altered with obesity.Obese patients needed more attentional resources to control postural stability during unipedal stance than non obese participants. This was not the case in a more simple posture such as seating. To reduce the risk of fall as indicated by the critical values of CoP displacement, obese patients must dedicate a strong large part of their attentional resources to postural control, to the detriment of non-postural events. Obese patients were not able to easily perform multitasking as healthy adults do, reflecting weakened psycho-motor abilities.
Full Text Available Background & Objective: Development of gross motor function in children with cerebral palsy has been a primary goal of physical therapists for decades. Suit therapy has been proposed as an adjunct to conventional physiotherapy to treat the impairments associated with cerebral palsy. Providing an orthosis along with the conventional therapy improves the motor performance of the child. Hence, this study aimed to determine the effect of modified suit therapy in gross motor function of spastic diplegic children. Method: A simple random sample of 30 spastic diplegic subjects in age group of 4-12 years fulfilling inclusion criteria from Mobility India, Bangalore was included. The outcome was evaluated using Gross Motor Function Measure-88 scale before and after the intervention. Suit therapy along with the conventional therapy is given for 2hrs daily for duration of 3 weeks. Results & Conclusion: Wilcoxon signed rank test and Mann-Whitney U test were used to find the significance of improvement before and after the intervention. There was statistically significant difference between the experimental and control groups (P=0.030. It is concluded that modified suit therapy along with conventional physiotherapy is effective in improving the gross motor function of children with spastic diplegic cerebral palsy.
Thiele, Julius; Schöllig, Christina; Bellmann, Malte; Kraft, Marc
A crossover design study with a small group of subjects was used to evaluate the performance of three microprocessor-controlled exoprosthetic knee joints (MPKs): C-Leg 4, Plié 3 and Rheo Knee 3. Given that the mechanical designs and control algorithms of the joints determine the user outcome, the influence of these inherent differences on the functional characteristics was investigated in this study. The knee joints were evaluated during level-ground walking at different velocities in a motion analysis laboratory. Additionally, technical analyses using patents, technical documentations and X-ray computed tomography (CT) for each knee joint were performed. The technical analyses showed that only C-Leg 4 and Rheo Knee 3 allow microprocessor-controlled adaptation of the joint resistances for different gait velocities. Furthermore, Plié 3 is not able to provide stance extension damping. The biomechanical results showed that only if a knee joint adapts flexion and extension resistances by the microprocessor all known advantages of MPKs can become apparent. But not all users may benefit from the examined functions: e.g. a good accommodation to fast walking speeds or comfortable stance phase flexion. Hence, a detailed comparison of user demands and performance of the designated knee joint is mandatory to ensure a maximum in user outcome.
Micheau, Philippe; Kron, Aymeric; Bourassa, Paul
An accurate modeling of human stance might be helpful in assessing postural deficit. The objective of this article is to validate a mathematical postural control model for quiet standing posture. The postural dynamics is modeled in the sagittal plane as an inverted pendulum with torque applied at the ankle joint. The torque control system is represented by the physiological lambda model. Two neurophysiological command variables of the central nervous system, designated lambda and micro, establish the dynamic threshold muscle at which motoneuron recruitment begins. Kinematic data and electromyographic signals were collected on four young males in order to measure small voluntary sway and quiet standing posture. Validation of the mathematical model was achieved through comparison of the experimental and simulated results. The mathematical model allows computation of the unmeasurable neurophysiological commands lambda and micro that control the equilibrium position and stability. Furthermore, with the model it is possible to conclude that low-amplitude body sway during quiet stance is commanded by the central nervous system.
Valkering, Kars P; Aufwerber, Susanna; Ranuccio, Francesco; Lunini, Enricomaria; Edman, Gunnar; Ackermann, Paul W
Functional weight-bearing mobilization may improve repair of Achilles tendon rupture (ATR), but the underlying mechanisms and outcome were unknown. We hypothesized that functional weight-bearing mobilization by means of increased metabolism could improve both early and long-term healing. In this prospective randomized controlled trial, patients with acute ATR were randomized to either direct post-operative functional weight-bearing mobilization (n = 27) in an orthosis or to non-weight-bearing (n = 29) plaster cast immobilization. During the first two post-operative weeks, 15°-30° of plantar flexion was allowed and encouraged in the functional weight-bearing mobilization group. At 2 weeks, patients in the non-weight-bearing cast immobilization group received a stiff orthosis, while the functional weight-bearing mobilization group continued with increased range of motion. At 6 weeks, all patients discontinued immobilization. At 2 weeks, healing metabolites and markers of procollagen type I (PINP) and III (PIIINP) were examined using microdialysis. At 6 and 12 months, functional outcome using heel-rise test was assessed. Healing tendons of both groups exhibited increased levels of metabolites glutamate, lactate, pyruvate, and of PIIINP (all p bearing mobilization group demonstrated significantly higher concentrations of glutamate compared to the non-weight-bearing cast immobilization group (p = 0.045).The upregulated glutamate levels were significantly correlated with the concentrations of PINP (r = 0.5, p = 0.002) as well as with improved functional outcome at 6 months (r = 0.4; p = 0.014). Heel-rise tests at 6 and 12 months did not display any differences between the two groups. Functional weight-bearing mobilization enhanced the early healing response of ATR. In addition, early ankle range of motion was improved without the risk of Achilles tendon elongation and without altering long-term functional outcome. The relationship between
Giagazoglou, Paraskevi; Amiridis, Ioannis G; Zafeiridis, Andreas; Thimara, Maria; Kouvelioti, Vassiliki; Kellis, Elefthrerios
The aim of the present study was to examine isokinetic and isometric strength of the knee and ankle muscles and to compare center of pressure (CoP) sway between blind and sighted women. A total of 20 women volunteered to participate in this study. Ten severe blind women (age 33.5 +/- 7.9 years; height 163 +/- 5 cm; mass 64.5 +/- 12.2 kg) and 10 women with normal vision (age 33.5 +/- 8.3 years; height 164 +/- 6 cm; mass 61.9 +/- 14.5 kg) performed 3 different tasks of increasing difficulty: Normal Quiet Stance (1 min), Tandem Stance (20 s), and One-Leg Stance (10 s). Participants stood barefoot on two adjacent force platforms and the CoP variations [peak-to-peak amplitude (CoPmax) and SD of the CoP displacement (CoPsd)] were analyzed. Sighted participants performed the tests in eyes open and eyes closed conditions. Torque/angular velocity and torque/angular position relationships were also established using a Cybex dynamometer for knee extensors and flexors as well as for ankle plantar and dorsiflexors. The main finding of this study was that the ability to control balance in both anterior/posterior and medio/lateral directions was inferior in blind than in sighted women. However, when sighted participants performed the tests blindfolded, their CoP sway increased significantly in both directions. There were no differences in most isometric and concentric strength measurements of the lower limb muscles between the blind and sighted individuals. Our results demonstrate that vision is a more prominent indicator of performance during the postural tasks compared to strength of the lower limbs. Despite similar level of strength, blind individuals performed significantly worse in all balance tests compared to sighted individuals.
Zwick, E B; Saraph, V; Strobl, W; Steinwender, G
To evaluate prospectively the outcome of gait-improvement surgery in children with spastic diplegia. Three-dimensional gait analysis was performed in twenty children with spastic diplegia. Ten children underwent single event multilevel surgery for gait improvement. Indications for individual procedures followed a fixed set of selection criteria. The other ten children continued with their physiotherapy programme and served as a control group. A second gait analysis was performed in all children after 1.5 years. Time-distance parameters and kinematics of the pelvis, hip, knee and ankle joints in the sagittal plane served as main outcome measures The patients walked faster with an increased stride length after surgery in comparison to the conservatively treated controls. The average pelvic tilt increased slightly and the range of motion of the knee joint increased considerably after multilevel surgery. The motion at the ankle remained unchanged over the study period in both the groups. An improved knee extension during the stance phase of gait served to improve stance limb stability and facilitated an unhindered swing phase of the opposite limb. This prospective trial showed favourable changes in gait function after multilevel surgery in spastic diplegic children.
Lee, Hyang Jun; Oh, Jun Ho [KAIST, Daejeon (Korea, Republic of)
A hopping system is highly non-linear due to the nature of its dynamics, which has alternating phases in a cycle, flight and stance phases and related transitions. Every control method that stabilizes the hopping system satisfies the Poincaré stability condition. At the Poincaré section, a hopping system cycle is considered as discrete sectional data set. By controlling the sectional data in a discrete control form, we can generate a stable hopping cycle. We utilize phase-mapping matrices to build a Poincaré return map by approximating the dynamics of the hopping system with SLIP model. We can generate various Poincaré stable gait patterns with the approximated discrete control form which uses upper-body motions as inputs.
Full Text Available The human postural control system represents a biological feedback system responsible for maintenance of upright stance. Vestibular, proprioceptive and visual sensory inputs provide the most important information into the control system, which controls body centre of mass (COM in order to stabilize the human body resembling an inverted pendulum. The COM can be measured indirectly by means of a force plate as the centre of pressure (COP. Clinically used measurement method is referred to as posturography. In this paper, the conventional static posturography is extended by visual stimulation, which provides insight into a role of visual information in balance control. Visual stimuli have been designed to induce body sway in four specific directions – forward, backward, left and right. Stabilograms were measured using proposed single-PC based system and processed to calculate velocity waveforms and posturographic parameters. The parameters extracted from pre-stimulus and on-stimulus periods exhibit statistically significant differences.
Full Text Available Balance deficits are identified as important risk factors for falling in individuals with chronic obstructive pulmonary disease (COPD. However, the specific use of proprioception, which is of primary importance during balance control, has not been studied in individuals with COPD. The objective was to determine the specific proprioceptive control strategy during postural balance in individuals with COPD and healthy controls, and to assess whether this was related to inspiratory muscle weakness.Center of pressure displacement was determined in 20 individuals with COPD and 20 age/gender-matched controls during upright stance on an unstable support surface without vision. Ankle and back muscle vibration were applied to evaluate the relative contribution of different proprioceptive signals used in postural control.Individuals with COPD showed an increased anterior-posterior body sway during upright stance (p = 0.037. Compared to controls, individuals with COPD showed an increased posterior body sway during ankle muscle vibration (p = 0.047, decreased anterior body sway during back muscle vibration (p = 0.025, and increased posterior body sway during simultaneous ankle-muscle vibration (p = 0.002. Individuals with COPD with the weakest inspiratory muscles showed the greatest reliance on ankle muscle input when compared to the stronger individuals with COPD (p = 0.037.Individuals with COPD, especially those with inspiratory muscle weakness, increased their reliance on ankle muscle proprioceptive signals and decreased their reliance on back muscle proprioceptive signals during balance control, resulting in a decreased postural stability compared to healthy controls. These proprioceptive changes may be due to an impaired postural contribution of the inspiratory muscles to trunk stability. Further research is required to determine whether interventions such as proprioceptive training and inspiratory muscle training improve postural balance and reduce the
Enhancement of a prosthetic knee with a microprocessor-controlled gait phase switch reduces falls and improves balance confidence and gait speed in community ambulators with unilateral transfemoral amputation.
Fuenzalida Squella, Sara Agueda; Kannenberg, Andreas; Brandão Benetti, Ângelo
Despite the evidence for improved safety and function of microprocessor stance and swing-controlled prosthetic knees, non-microprocessor-controlled prosthetic knees are still standard of care for persons with transfemoral amputations in most countries. Limited feature microprocessor-control enhancement of such knees could stand to significantly improve patient outcomes. To evaluate gait speed, balance, and fall reduction benefits of the new 3E80 default stance hydraulic knee compared to standard non-microprocessor-controlled prosthetic knees. Comparative within-subject clinical study. A total of 13 young, high-functioning community ambulators with a transfemoral amputation underwent assessment of performance-based (e.g. 2-min walk test, timed ramp/stair tests) and self-reported (e.g. falls, Activities-Specific Balance Confidence scale, Prosthesis Evaluation Questionnaire question #1, Satisfaction with the Prosthesis) outcome measures for their non-microprocessor-controlled prosthetic knees and again after 8 weeks of accommodation to the 3E80 microprocessor-enhanced knee. Self-reported falls significantly declined 77% ( p = .04), Activities-Specific Balance Confidence scores improved 12 points ( p = .005), 2-min walk test walking distance increased 20 m on level ( p = .01) and uneven ( p = .045) terrain, and patient satisfaction significantly improved ( p prosthetic knees. Subjects' satisfaction was significantly higher than with their previous non-microprocessor-controlled prosthetic knees. The 3E80 may be considered a prosthetic option for improving gait performance, balance confidence, and safety in highly active amputees. Clinical relevance This study compared performance-based and self-reported outcome measures when using non-microprocessor and a new microprocessor-enhanced, default stance rotary hydraulic knee. The results inform rehabilitation professionals about the functional benefits of a limited-feature, microprocessor
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Khaled A. Olama
Nov 2, 2012 ... exercise program is highly useful in rehabilitation of spastic diplegic cerebral palsy children as they enabled them ... Rehabilitation of the patient with cerebral ..... Stepping before standing: hip muscle function in stepping and standing balance after stroke. J Neurol Neurosurg Psychiatry 2000;68(4):458–64.
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Full Text Available Background: An acute unilateral peripheral vestibular loss (aUVL initially causes severe gaze and balance control problems. However, vestibulo-ocular reflexes (VOR and balance control are nearly normal 3 months later as a result of peripheral recovery and/or central compensation. As pre-existing vestibular sensory loss is assumed to be greater in the healthy elderly, this study investigated whether improvements in VOR and balance function over time after aUVL are different for the elderly than for the young. Methods: 30 aUVL patients divided into 3 age groups were studied (8 age range 23-35, 10 with range 43-58 and 12 with range 60-74 years. To measure VOR function, eye movements during caloric irrigation, rotating chair (ROT and head impulse tests were performed. Balance control during stance and gait was recorded as lower trunk angular velocity in the pitch and roll planes. Measurements were taken at deficit onset, and 3, 6, and 13 weeks later.Results: There was one difference in VOR improvements over time between the age groups: Low acceleration ROT responses were less at onset in the elderly group. Deficit side VOR responses and asymmetries in each group improved to within ranges of healthy controls at 13 weeks. Trunk sway of the elderly was greater for stance and gait at onset when compared to healthy age-matched controls and the young and greater than that of the young and controls during gait tasks at 13 weeks. The sway of the young was not different from controls at either time point. Balance control for the elderly improved slower than for the young. Conclusions: These results indicate that VOR improvement after an aUVL does not differ with age, except for low accelerations. Recovery rates are different between age groups for balance control tests. Balance control in the elderly is more abnormal at aUVL onset for stance and gait tasks with the gait abnormalities remaining after 13 weeks. Thus we conclude that balance control in the
Scheltinga, Alja; Honegger, Flurin; Timmermans, Dionne P H; Allum, John H J
An acute unilateral peripheral vestibular loss (aUVL) initially causes severe gaze and balance control problems. However, vestibulo-ocular reflexes (VOR) and balance control are nearly normal 3 months later as a result of peripheral recovery and/or central compensation. As pre-existing vestibular sensory loss is assumed to be greater in the healthy elderly, this study investigated whether improvements in VOR and balance function over time after aUVL are different for the elderly than for the young. Thirty aUVL patients divided into three age-groups were studied (8 age range 23-35, 10 with range 43-58, and 12 with range 60-74 years). To measure VOR function eye movements were recorded during caloric irrigation, rotating chair (ROT), and head impulse tests. Balance control during stance and gait was recorded as lower trunk angular velocity in the pitch and roll planes. Measurements were taken at deficit onset, and 3, 6, and 13 weeks later. There was one difference in VOR improvements over time between the age-groups: Low acceleration ROT responses were less at onset in the elderly group. Deficit side VOR responses and asymmetries in each group improved to within ranges of healthy controls at 13 weeks. Trunk sway of the elderly was greater for stance and gait at onset when compared to healthy age-matched controls and the young and greater than that of the young and controls during gait tasks at 13 weeks. The sway of the young was not different from controls at either time point. Balance control for the elderly improved slower than for the young. These results indicate that VOR improvement after an aUVL does not differ with age, except for low accelerations. Recovery rates are different between age-groups for balance control tests. Balance control in the elderly is more abnormal at aUVL onset for stance and gait tasks with the gait abnormalities remaining after 13 weeks. Thus, we conclude that balance control in the elderly is more affected by the UVL than
Full Text Available Patients with bilateral vestibular failure (BVF suffer from postural and gait unsteadiness with an increased risk of falls. The aim of this study was to elucidate the differential role of otolith, semicircular canal (SSC, visual, proprioceptive, and cognitive influences on the postural stability of BVF patients. Center-of-pressure displacements were recorded by posturography under six conditions: target visibility; tonic head positions in the pitch plane; horizontal head shaking; sensory deprivation; dual task; and tandem stance. Between-group analysis revealed larger postural sway in BVF patients on eye closure; but with the eyes open, BVF did not differ from healthy controls (HCs. Head tilts and horizontal head shaking increased sway but did not differ between groups. In the dual task condition, BVF patients maintained posture indistinguishable from controls. On foam and tandem stance, postural sway was larger in BVF, even with the eyes open. The best predictor for the severity of bilateral vestibulopathy was standing on foam with eyes closed. Postural control of our BVF was indistinguishable from HCs once visual and proprioceptive feedback is provided. This distinguishes them from patients with vestibulo-cerebellar disorders or functional dizziness. It confirms previous reports and explains that postural unsteadiness of BVF patients can be missed easily if not examined by conditions of visual and/or proprioceptive deprivation. In fact, the best predictor for vestibular hypofunction (VOR gain was examining patients standing on foam with the eyes closed. Postural sway in that condition increased with the severity of vestibular impairment but not with disease duration. In the absence of visual control, impaired otolith input destabilizes BVF with head retroflexion. Stimulating deficient SSC does not distinguish patients from controls possibly reflecting a shift of intersensory weighing toward proprioceptive-guided postural control. Accordingly
Jeka, J. J.; Easton, R. D.; Bentzen, B. L.; Lackner, J. R.
Haptic cues from fingertip contact with a stable surface attenuate body sway in subjects even when the contact forces are too small to provide physical support of the body. We investigated how haptic cues derived from contact of a cane with a stationary surface at low force levels aids postural control in sighted and congenitally blind individuals. Five sighted (eyes closed) and five congenitally blind subjects maintained a tandem Romberg stance in five conditions: (1) no cane; (2,3) touch contact (postural sway in all subjects, compared to the no-cane condition. A slanted cane was far more effective in reducing postural sway than was a perpendicular cane. Cane use also decreased head displacement of sighted subjects far more than that of blind subjects. These results suggest that head movement control is linked to postural control through gaze stabilization reflexes in sighted subjects; such reflexes are absent in congenitally blind individuals and may account for their higher levels of head displacement.
Wurdeman, Shane R; Koutakis, Panagiotis; Myers, Sara A; Johanning, Jason M; Pipinos, Iraklis I; Stergiou, Nicholas
Previous studies have shown major deficits in gait for individuals with peripheral arterial disease before and after the onset of pain. However, these studies did not have subjects ambulate at similar velocities and potential exists that the differences in joint powers may have been due to differences in walking velocity. The purpose of this study was to examine the joint moments and powers of peripheral arterial disease limbs for subjects walking at similar self-selected walking velocities as healthy controls prior to onset of any symptoms. Results revealed peripheral arterial disease patients have reduced peak hip power absorption in midstance (p=0.017), reduced peak knee power absorption in early and late stance (p=0.037 and p=0.020 respectively), and reduced peak ankle power generation in late stance (p=0.021). This study reveals that the gait of patients with peripheral arterial disease walking prior to the onset of any leg symptoms is characterized by failure of specific and identifiable muscle groups needed to perform normal walking and that these gait deficits are independent of reduced gait velocity. Copyright © 2012 Elsevier B.V. All rights reserved.
Sharbafi, Maziar A; Seyfarth, Andre; Zhao, Guoping
A primary goal of comparative biomechanics is to understand the fundamental physics of locomotion within an evolutionary context. Such an understanding of legged locomotion results in a transition from copying nature to borrowing strategies for interacting with the physical world regarding design and control of bio-inspired legged robots or robotic assistive devices. Inspired from nature, legged locomotion can be composed of three locomotor sub-functions, which are intrinsically interrelated: Stance : redirecting the center of mass by exerting forces on the ground. Swing : cycling the legs between ground contacts. Balance : maintaining body posture. With these three sub-functions, one can understand, design and control legged locomotory systems with formulating them in simpler separated tasks. Coordination between locomotor sub-functions in a harmonized manner appears then as an additional problem when considering legged locomotion. However, biological locomotion shows that appropriate design and control of each sub-function simplifies coordination. It means that only limited exchange of sensory information between the different locomotor sub-function controllers is required enabling the envisioned modular architecture of the locomotion control system. In this paper, we present different studies on implementing different locomotor sub-function controllers on models, robots, and an exoskeleton in addition to demonstrating their abilities in explaining humans' control strategies.
Cruse, H; Bartling, C; Cymbalyuk, G; Dean, J; Dreifert, M
A system that controls the leg movement of an animal or a robot walking over irregular ground has to ensure stable support for the body and at the same time propel it forward. To do so, it has to react adaptively to unpredictable features of the environment. As part of our study of the underlying mechanisms, we present here a model for the control of the leg movement of a 6-legged walking system. The model is based on biological data obtained from the stick insect. It represents a combined treatment of realistic kinematics and biologically motivated, adaptive gait generation. The model extends a previous algorithmic model by substituting simple networks of artificial neurons for the algorithms previously used to control leg state and interleg coordination. Each system controlling an individual leg consists of three subnets. A hierarchically superior net contains two sensory and two 'premotor' units; it rhythmically suppresses the output of one or the other of the two subordinate nets. These are continuously active. They might be called the 'swing module' and the 'stance module' because they are responsible for controlling the swing (return stroke) and the stance (power stroke) movements, respectively. The swing module consists of three motor units and seven sensory units. It can produce appropriate return stroke movements for a broad range of initial and final positions, can cope with mechanical disturbances of the leg movement, and is able to react to an obstacle which hinders the normal performance of the swing movement. The complete model is able to walk at different speeds over irregular surfaces. The control system rapidly reestablishes a stable gait when the movement of the legs is disturbed.
Míriam Raquel Meira Mainenti
The aim of this study was to test whether quiet stance body sway is associated with ankle and knee joint angles in elderly women. Joint angles were measured using a manual goniometer and body sway was assessed using a force platform and four postural tasks with a combination of feet positions and eye condition. The sample (N = 58 showed the following angle values: 102 (100-104 for the tibiotarsal joint, 176 (174-180 for the subtalar joint, 184 (181-187 for knee flexion-extension, and 13 (10-15 for the Q-angle. Q-angle was significantly correlated (p < 0.05 with center of foot pressure (CP displacement area (r = 0.36, anteroposterior (SDy, r = 0.34 and lateral (SDx, r = 0.31 CP standard deviation, and anteroposterior CP range (r = 0.38 during the closed base, eyes opened trial (CBEO. The valgus group showed statistically higher values than the normal and varus groups for SDy (0.56 vs. 0.52 and 0.46 mm; p = 0.02, SDx (0.55 vs. 0.49 and 0.36 mm; p = 0.02 and anteroposterior range (3.32 vs. 2.78 and 2.38 mm; p = 0.01, CBEO. The displacement velocity of the CP was significantly higher for the asymmetric than the symmetric Q-angle group (8.0 vs. 5.3 mm/s – closed base, eyes closed trial. Knee alignment was correlated with measures of body sway in elderly women, but ankle alignment showed no correlation. Knee morphology should be considered an associated factor for quiet stance postural control.
Full Text Available Current active leg prostheses do not integrate the most recent advances in Brain-Computer Interfaces (BCI and bipedal robotics. Moreover, their actuators are seldom driven by the subject’s intention. This paper aims at showing a summary of our current results in the field of human gait rehabilitation. In a first prototype, the main focus was on people suffering from foot drop problems, i.e. people who are unable to lift their feet. However, current work is focusing on a full active ankle orthosis. The approach is threefold: a BCI system, a gait model and an orthosis. Thanks to the BCI system, patients are able to generate high-level commands. Typically, a command could represent a speed modification. Then, a gait model based on a programmable central pattern generator is used to generate the adequate kinematics. Finally, the orthosis is tracking this kinematics when the foot is in the air, whereas, the orthosis is mimicking a spring when the foot is on the ground.
Full Text Available The strategies that humans use to control unsteady locomotion are not well understood. A "spring-mass" template comprised of a point mass bouncing on a sprung leg can approximate both center of mass movements and ground reaction forces during running in humans and other animals. Legged robots that operate as bouncing, "spring-mass" systems can maintain stable motion using relatively simple, distributed feedback rules. We tested whether the changes to sagittal-plane movements during five running tasks involving active changes to running height, speed, and orientation were consistent with the rules used by bouncing robots to maintain stability. Changes to running height were associated with changes to leg force but not stance duration. To change speed, humans primarily used a "pogo stick" strategy, where speed changes were associated with adjustments to fore-aft foot placement, and not a "unicycle" strategy involving systematic changes to stance leg hip moment. However, hip moments were related to changes to body orientation and angular speed. Hip moments could be described with first order proportional-derivative relationship to trunk pitch. Overall, the task-level strategies used for body control in humans were consistent with the strategies employed by bouncing robots. Identification of these behavioral strategies could lead to a better understanding of the sensorimotor mechanisms that allow for effective unsteady locomotion.
Lee, Hong-Jae; Lim, Kil-Byung; Yoo, JeeHyun; Yoon, Sung-Won; Yun, Hyun-Ju; Jeong, Tae-Ho
Objective To evaluate the effect of custom-molded foot orthoses on foot pain and balance in children with symptomatic flexible flat foot 1 month and 3 months after fitting foot orthosis. Method A total of 24 children over 6 years old with flexible flat feet and foot pain for at least 6 months were recruited for this study. Their resting calcaneal stance position and calcaneal pitch angle were measured. Individual custom-molded rigid foot orthoses were prescribed using inverted orthotic techni...
Peterson, Jeffrey J; Keenan, Kevin G
The purpose of this study was to examine the influence of a visuospatial attention task on three measures of postural control in young and older adults. 20 young (19-36 years) and 20 older (67-91 years) adults performed a choice stepping response time (CSRT) task, a submaximal dorsiflexion force steadiness task, and quiet standing in 3 bilateral stances. All tasks were performed with and without a visuospatial (VS) attention task that involved visualizing a star moving within a 2 × 2 grid. CSRT increased with the addition of the VS task in both groups (p .084). The findings suggest that visuospatial attention differentially affects postural control in young and older adults and the effect is task-specific. These findings suggest the need to include stepping and force control tasks to further determine what role visuospatial attention plays in postural control. Copyright © 2017. Published by Elsevier Ltd.
SEYED Hossein Hosseinimehr
Full Text Available The proprioception information is a prerequisite for balance, body’s navigation system, and the movement coordinator. Due to changes between the angles of ankle, knee, and hip joints the aforementioned information are important in the coordination of the limbs and postural balance. The aim of this study was to investigate therole of leg and trunk muscles proprioception on static and dynamic postural control. Thirty males students of physical education and sport sciences (age =21.23 ± 2.95 years, height = 170.4 ± 5.1 cm, and weight = 70.7 ± 5.6 kg participated in this study volunteered. Vibration (100HZ was used to disturb of proprioception. Vibrationoperated on leg muscle (gasterocnemius and trunk muscles (erector spine muscle, at L1 level. Leg stance time and Star Excursion Balance Test were used for evaluation of static and dynamic postural control respectively.Subjects performed pre and post (with operated vibration leg stance time and star excursion balance test. Paired sample test used for investigation the effect of vibration on leg and trunk muscles in static and dynamic postural control. Result of this study showed in static postural control, there is no significant difference between pre and post test (operated vibration in leg and trunk muscles (p≤0.05. In contrast there is significant difference indynamic postural control between pre and post test in leg muscles in 8 directions of star excursion balance test (p≤0.05 while there is only significant difference in trunk muscle in antrolateral and lateral of star excursion balance test (p≤0.05. During physical training such conditions like fatigue and injury can disturbproprioceptions’ information. Thus, due to the importance of this information we recommend that coaches'additionally specific trainings any sport used specific exercises to enhance the proprioception information
Thalassinos, Michalis; Fotiadis, Giorgos; Arabatzi, Fotini; Isableu, Brice; Hatzitaki, Vassilia
The authors asked how sport expertise modulates visual field de