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Special Issue "Orthopaedic and Rehabilitation Engineering"

Joseph Mizrahi, Oron Levin
2020 Applied Sciences  
This paper serves as an editorial preface to a Special Issue on Orthopaedic and Rehabilitation Engineering. The fields of Orthopaedic and Rehabilitation Engineering encompass a variety of topics. Perspectives on a variety of topics in these fields are presented, followed by a brief description of the contributions comprised in this Special Issue.
doi:10.3390/app10103556 fatcat:juxj5w6i2be6pizxm53cz2f6ze

Factors underlying age-related changes in discrete aiming

Florian Van Halewyck, Ann Lavrysen, Oron Levin, Matthieu P. Boisgontier, Digby Elliott, Werner F. Helsen
2015 Experimental Brain Research  
Age has a clear impact on one's ability to make accurate goal-directed aiming movements. Older adults seem to plan slower and shorter-ranged initial pulses towards the target, and rely more on sensory feedback to ensure endpoint accuracy. Despite the fact that these agerelated changes in manual aiming have been observed consistently, the underlying mechanism remains speculative. In an attempt to isolate four commonly suggested underlying factors, young and older adults were instructed to make
more » ... screte aiming movements under varying speed and accuracy constraints. Results showed that older adults were physically able to produce fast primary submovements and that they demonstrated similar movement-programming capacities as young adults. On the other hand, considerable evidence was found supporting a decreased visual feedback-processing efficiency and the implementation of a play-it-safe strategy in older age. In conclusion, a combination of the latter two factors seems to underlie the agerelated changes in manual aiming behaviour.
doi:10.1007/s00221-015-4247-3 pmid:25788008 fatcat:wvr7v7wk4zbpnafsspyazgv5pu

Changes in corticomotor excitability following prolonged muscle tendon vibration

Arturo Forner-Cordero, Maarten Steyvers, Oron Levin, Kaat Alaerts, Stephan P. Swinnen
2008 Behavioural Brain Research  
The present experiment addressed whether increases in corticospinal excitability following sensory stimulation with muscle tendon vibration are accompanied by reorganization of the forearm musculature representation within the primary motor cortex. Using transcranial magnetic stimulation, we mapped the corticomotor projection to the dominant flexor carpi radialis (FCR) and extensor carpi radialis brevis (ECR) muscle before and after interventional sensory stimulation obtained via muscle tendon
more » ... ibration (80 Hz, 60 min) to the dominant distal wrist flexor tendons. Following vibration, MEP amplitude at the optimal stimulation position, motor output area, as well as map volume, increased significantly for the ECR. None of these effects reached significance for the FCR. These results suggest that the antagonistic vibratory response (AVR), which is considered to be of cortical origin, induces a delayed facilitation of musculature that is antagonistic to the site of the directly activated Ia afferent pathways. This example demonstrates that peripheral sensory stimulation can induce lasting increases in corticospinal excitability in the absence of actual movements.
doi:10.1016/j.bbr.2008.02.019 pmid:18378327 fatcat:t6rmb32stjenjoj3vusqji42vm

Behavioral and Neurophysiological Aspects of Inhibition—The Effects of Acute Cardiovascular Exercise

Oron Levin, Yael Netz, Gal Ziv
2021 Journal of Clinical Medicine  
This review summarizes behavioral and neurophysiological aspects of inhibitory control affected by a single bout of cardiovascular exercise. The review also examines the effect of a single bout of cardiovascular exercise on these processes in young adults with a focus on the functioning of prefrontal pathways (including the left dorsolateral prefrontal cortex (DLPFC) and elements of the prefrontal-basal ganglia pathways). Finally, the review offers an overview on the potential effects of
more » ... ascular exercise on GABA-ergic and glutamatergic neurotransmission in the adult brain and propose mechanisms or processes that may mediate these effects. The main findings show that a single bout of cardiovascular exercise can enhance inhibitory control. In addition, acute exercise appears to facilitate activation of prefrontal brain regions that regulate excitatory and inhibitory pathways (specifically but not exclusively the prefrontal-basal-ganglia pathways) which appear to be impaired in older age. Based on the reviewed studies, we suggest that future work examine the beneficial effects of exercise on the inhibitory networks in the aging brain.
doi:10.3390/jcm10020282 pmid:33466667 fatcat:6qv4ihrbqjcwvbavox4gn7i6ni

Manual aiming in healthy aging: does proprioceptive acuity make the difference?

Werner F. Helsen, Florian Van Halewyck, Oron Levin, Matthieu P. Boisgontier, Ann Lavrysen, Digby Elliott
2016 Age  
The present study examines whether nonactive older adults are more dependent on visual information when executing aiming movements and whether age-related declines in proprioception play a mediating role herein. Young (N = 40) and older adults (N = 38) were divided into physically active and non-active subgroups based on self-reported sports participation levels. In experiment 1, participants executed wrist-aiming movements with and without visual feedback. In experiment 2, passive
more » ... e acuity was assessed using wrist motion detection and position matching tests. Results showed similar aiming accuracy across age groups both with and without visual feedback, but older adults exhibited longer movement times, prolonged homing-in phase, and made more corrective submovements. Passive proprioceptive acuity was significantly affected by physical activity level and age, with participants in the active group scoring better than their non-active peers. However, these declines did not predict performance changes on the aiming task. Taken together, our observations suggest that decline in proprioceptive acuity did not predict performance changes on the aiming task and older adults were able to compensate for their decreased motion and position sense when allowed sufficient time. In line with these observations, we proposed that older adults are able to compensate for their decline in proprioception by increasing their reliance on predictive models.
doi:10.1007/s11357-016-9908-z pmid:27044301 pmcid:PMC5005912 fatcat:6nbvtgauoze4rfcc3hsdljxmoa

Muscle Strength and Geometrical Changes in A Paralysed Muscle Following FES

Oron Levin, Joseph Mizrahi, Menahem Gornish, Eli Isakov
2000 Hong Kong Physiotherapy Journal  
This study proposes the application of a strengthening index to quantify the effect of training, by functional electrical stimulation (FES), on the force capacity of the quadriceps in spinal cord injury (SCI) subjects. The index is based on evaluating the average muscle force per unit area. This measure is shown to express the overall increase in the muscle force capacity, while accounting for the changes taking place in muscle geometry. The proposed index is demonstrated on one subject with
more » ... , on whom a longitudinal follow-up was conducted. The measurements included the knee extension torque, from which the force in the quadriceps muscle was evaluated. Additionally, in vivo magnetic resonance imaging of the thigh was used to obtain the muscle anthropometry. In the training period followed-up in this study, the average force per unit area was found to increase from 27 N/cm 2 in the pretrained muscle to 40 N/cm 2 after eight weeks of training by FES. The major increase in the physiological cross-sectional area of the muscle took place during the first four-week period; 12% of the total 13.5%. Conversely, only a minor change in the average force per unit area of the muscle was observed during the first four weeks of training (28 N/cm 2 at the end of the fourth week). Thus, the major increase (43%) in the ratio of peak force to muscle physiological cross-sectional area was observed during the second four-week period of training. This latter response is attributed to neural adaptation of the axons and neuromuscular junction rather than to an increase in the muscle fibre specific tension.
doi:10.1016/s1013-7025(09)70011-9 fatcat:pibg33y4brdfxanstfbsvdaguq

Age-related differences in corticospinal excitability during a choice reaction time task

Koen Cuypers, Herbert Thijs, Julie Duque, Stephan P. Swinnen, Oron Levin, Raf L. J. Meesen
2012 Age  
. , 2012b Levin et al. 2011) . However, there are virtually no studies examining agerelated changes of CS excitability during preparation and motor generation in CRT tasks.  ...  study, we showed that older adults can compensate for a deficient motor activation by increasing excitability of the CS pathways to the moving effector prior to the onset of the IS in a simple RT task (Levin  ... 
doi:10.1007/s11357-012-9471-1 pmid:23007962 pmcid:PMC3776102 fatcat:4jzg5ixuzbdsvalvuw7tgrlmae

Directional invariance during loading-related modulations of muscle activity: evidence for motor equivalence

Oron Levin, Nicole Wenderoth, Maarten Steyvers, Stephan Swinnen
2003 Experimental Brain Research  
In the present study, we investigated the influence of external force manipulations on movements in different directions, while keeping the amplitude invariant. Subjects (n=10) performed a series of cyclical anteroposterior, mediolateral, and oblique line-drawing movements (star drawing task) with their dominant limb in the horizontal plane. To dissociate kinematics from the underlying patterns of muscle activation, spring loading was applied to the forearm of the moving limb. Whereas spring
more » ... ding of the arm resulted in considerable changes in the overall amount of muscle activation in the elbow and shoulder muscles, invariance was largely maintained at the kinematic level. Subjects produced the required movement directions and amplitudes of the star drawing largely successfully, irrespective of the force bias induced by the spring. These observations demonstrate motor equivalence and strengthen the notion that the spatial representation of drawing movements is encoded in the higher brain regions in a rather abstract form that is dissociated from the concrete muscle activation patterns underlying a particular movement direction. To achieve this goal, the central nervous system shifted between two or more muscle grouping strategies to overcome modulations in the interaction among posture-dependent (joint stiffness), dynamic (inertial), and elastic (spring) torque components in the joints. Spring loading induced general changes in the overall amount of EMG activity, which was largely muscle but not direction specific, presumably to represent the posture-dependent biasing force of the spring. Loading was mainly shown to increase muscle coactivation in the elbow joint. This indicates that the subjects tended to increase stiffness in the elbow to compensate for changes in the spring bias forces in order to minimize trajectory errors. Changes in muscle group-ing of the shoulder antagonists were mainly a consequence of movement direction but were also affected partly by loading, presumably reflecting the influence of dynamic force components. Taken together, the results confirmed the hypothesis that changes of movement direction and direction of force in the end-effector generated specific sets of muscle grouping to overcome the dynamic requirements in the joints while keeping the kinematics largely unchanged. This suggests that directional tuning in muscle activity and changes in muscle grouping reflects the formation of appropriate internal models in the CNS that give rise to motor equivalence.
doi:10.1007/s00221-002-1277-4 pmid:12478397 fatcat:k3kq4fywn5duxk7wmeopas6xlq

Complexity of Central Processing in Simple and Choice Multilimb Reaction-Time Tasks

Matthieu P. Boisgontier, George F. Wittenberg, Hakuei Fujiyama, Oron Levin, Stephan P. Swinnen, Thomas Boraud
2014 PLoS ONE  
The default mode of the motor system is a coupling between limbs. However, in some movements, a decoupling is required and thus calls for selection and facilitation/inhibition processes. Here, we investigate the relative contribution of recruitment versus selection processes to the overall processing complexity. To this aim we proposed a new multilimb reaction-time task (MUL-RT). Simple, choice and normalized (choice minus simple) RT were analysed together with error rates in thirty-six young
more » ... ults for 15 coordination modes including all possible configuration of limb recruitment. Simple and normalized RTs were respectively assumed to be indicative of the recruitment and selection processes. Results supported a model of coupling/decoupling interactions respectively reporting weak, intermediate and strong interaction for selecting diagonal, ipsilateral and homologous limbs. Movement laterality (left vs. right) had no effect on selection complexity, whereas selecting upper limbs was less challenging than selecting lower limbs. Results in the different coordination modes suggested that recruitment complexity decreased as follows: 3 limbs = 4 limbs.2 limbs (homologous, ipsilateral and diagonal).1 limb, and selection complexity as follows: 2 diagonal limbs.3 limbs.2 ipsilateral limbs.1 limb = 2 homologous limbs.4 limbs. Based on these ordinal scales of recruitment and selection complexity, we extrapolated the overall processing complexity of the simple and choice MUL-RT. This method was efficient in reproducing the absolute results we obtained on a ratio scale (ms) and demonstrated that processing complexity in simple RT was mainly governed by the 'recruitment principle' (the more limbs recruited the lower the performance), whereas contributions of recruitment and 'selection principle' (nature of the coordination determines performance) to overall processing complexity were similar in choice RT.
doi:10.1371/journal.pone.0090457 pmid:24587371 pmcid:PMC3938735 fatcat:iuyjjx5ygfcm7h7j5nqp2xgfiy

Aerobic training as a means to enhance inhibition: what's yet to be studied?

Oron Levin, Yael Netz
2015 European Review of Aging and Physical Activity  
Some of the neurodegenerative processes in healthy aging, including changes in structural and biochemical properties of the brain, are argued to affect cortical inhibitory functions. Age-related deficits in the ability to control cerebral inhibition may explain wide range of motor and cognitive deficits that healthy older adults experience in daily life such as impaired coordination skills and declines in attention, concentration, and learning abilities. Importantly, evidence from many studies
more » ... uggests that impaired inhibitory control in advancing age can be delayed or even alleviated by aerobic exercise training. Findings from a recent study by Duchesne and colleagues (2015) may provide insights into this process. First, observations from Duchesne et al. indicated that aerobic exercise training program improved cognitive inhibitory functioning in both patients with Parkinson's disease (PD) and matched older controls. Second, Duchesne et al. showed that cognitive inhibition and motor skills were highly correlated both pre-and post-exercise in PD but not in controls. Based on the aforementioned findings we highlight possible mechanisms that may play a role in the interactions between cognitive and motor inhibitory functions in healthy elderly that could benefit from aerobic exercise training: specifically, the brain neurotransmission systems and the frontal-basal ganglia network. In conclusion, we raise two fundamental questions which are yet to be addressed: (1) the extent to which different brain neurotransmitter systems are affected by aerobic exercise training; (2) the extent to which neurotransmitter levels prior to the onset of intervention may facilitate (or impede) training-induced neuroplasticity in the aging brain.
doi:10.1186/s11556-015-0160-9 pmid:26865878 pmcid:PMC4748326 fatcat:jcyghevvizcwxbolru2l2psa34

Both age and physical activity level impact on eye-hand coordination

Florian Van Halewyck, Ann Lavrysen, Oron Levin, Matthieu P. Boisgontier, Digby Elliott, Werner F. Helsen
2014 Human Movement Science  
of physically active and sedentary older adults, the typical age-related movement adaptations were observed only in sedentary older adults, but not in physically active ones (Van Halewyck, Lavrysen, Levin  ... 
doi:10.1016/j.humov.2014.05.005 pmid:24964357 fatcat:upxw4cic7bfrdblxowvzfxrbrm

Joint torques during sit-to-stand in healthy subjects and people with Parkinson's disease

Margaret K.Y. Mak, Oron Levin, Joseph Mizrahi, Christina W.Y. Hui-Chan
2003 Clinical Biomechanics  
Levin, and to Miss Y.Y. Wong for her assistance with the experiments. In addition, O. Levin was supported in part by a fellowship from the Research Council of K.U. Leuven (Contract # F99/113).  ...  ., 1996; Kuo, 1998; Levin et al., 1998) .  ...  et al., 1998; Isakov et al., 1992; Levin and Mizrahi, 1996) .  ... 
doi:10.1016/s0268-0033(02)00191-2 pmid:12620782 fatcat:otghtjnl6je3vdotpuyn737rqu

Is a 'quiet eye' all it takes to be successful? Comment on Vickers

Werner F. Helsen, Oron Levin, Gal Ziv, Marco Davare
2016 Current Issues in Sport Science  
., Levin, O., Ziv, G., & Davare, M. (2016) . Is a 'quiet eye' all it takes to be successful?  ... 
doi:10.15203/ciss_2016.109 fatcat:xb6tqq6iencq3bvblcbth7vbuy

Freezing in Parkinson's disease: A spatiotemporal motor disorder beyond gait

Sarah Vercruysse, Joke Spildooren, Elke Heremans, Jochen Vandenbossche, Oron Levin, Nicole Wenderoth, Stephan P. Swinnen, Luc Janssens, Wim Vandenberghe, Alice Nieuwboer
2011 Movement Disorders  
doi:10.1002/mds.24015 pmid:22020744 fatcat:o2dl4ztqljdk5p6bif4tehgi2m

WHOLE-BODY-VIBRATION--INDUCED INCREASE IN LEG MUSCLE ACTIVITY DURING DIFFERENT SQUAT EXERCISES

MACHTELD ROELANTS, SABINE M.P. VERSCHUEREN, CHRISTOPHE DELECLUSE, ORON LEVIN, VALÉRE STIJNEN
2006 Journal of Strength and Conditioning Research  
Levin, and V. Stijnen. Whole-body-vibration-induced increase in leg muscle activity during different squat exercises. J. Strength Cond. Res. 20(1):124-129. 2006.  ... 
doi:10.1519/00124278-200602000-00019 fatcat:n4x76w2nbbgk5hatfckeimtksy
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