Head position signal is crucial for preparing reaching movements because it contributes to specifying the position of body and target in space and relative to each other. However, it is unclear whether sensory information pertaining head position is used to control the movement after movement onset. In this study, nineteen participants performed discrete reaches towards a virtual target while neck vibration was randomly applied before and/or during the movement or not at all. The main dependent variable was the directional bias of the reaching finger. Neck vibration induced early leftward or late rightward trajectory biases. It appears that participants interpreted the sensed head shift as a target or an eye-in-head motion, which can be explained by individual differences in the use of reference frames. Nevertheless, body-centered and head-centered frames of reference appear to be important for the early and late stages of a goal-directed movement, respectively.

Comme l'indiquent les divergences observées dans la littérature, la question de l'existence d'une modification du contrôle proprioceptif du mouvement au cours du vieillissement physiologique de l'adulte fait encore débat. Pour mieux comprendre ces divergences, 3 études ont été menées afin de tester les effets de contraintes d'origines musculaire, attentionnelle et temporelle sur le contrôle proprioceptif du mouvement. La tâche commune à ces 3 études était une tâche d'estimation active directe controlatérale de la cheville. Les effets de contraintes musculaire, cognitive et temporelle sur les performances de contrôle proprioceptif ont été respectivement testés dans les conditions de fatigue et non fatigue, de simple et double tâche, et de vitesses libre et rapide. Pour évaluer la performance de contrôle proprioceptif, les erreurs totales, variables et constantes ainsi que des variables temporelles et cinématiques ont été analysées. Chez les participants jeunes, les résultats de la première étude montrent que la fatigue musculaire altère la performance d'estimation de position lorsque la cheville de référence est maintenue activement en position mais pas lorsqu'elle est maintenue passivement. Afin d'éviter de confondre un effet de la fatigue musculaire éventuellement induite par la répétition de la tâche d'estimation de position, les deuxième et troisième études ont été réalisées avec la référence maintenue passivement en position. Les résultats de ces deux études montrent qu'en l'absence de contrainte cognitive et temporelle la position finale dans la tâche proprioceptive est comparable entre les adultes jeunes et âgés. Cependant, la stratégie utilisée pour atteindre cette position est différente selon l'âge. L'adjonction d'une contrainte cognitive ou temporelle produit une dégradation de la performance de contrôle proprioceptif des adultes âgés par rapport aux adultes jeunes. Dans l'ensemble, ces résultats montrent que les adultes âgés ont une capacité de résistance aux contraintes inférieure à celle des adultes jeunes. Cette thèse met donc en évidence la modification de contrôle proprioceptif du mouvement qui s'opère au cours du vieillissement physiologique.

The purpose of this study was to display increase in eccentric hamstring strength after 10-weeks training program. Secondly, if such an increase occurred, would this strength change result in altered landing kinetics and improved jumping performance? 27 recreational female athletes assigned into experimental (n = 14) and control (n = 13) groups. Baseline measures of landing kinetics were collected using a force plate, strength data and proprioceptive measurements were evaluated using an isokinetic dynamometer and vertical jump performance were determined by a jumping mat. Results indicated that NHST group increased their eccentric hamstring strength after eccentric strength training program (week-1 = 233.6&plusmn / 27.5, week-10 = 253.8&plusmn / 28.4 Nm/kgbw / p&lt / .05). The results demonstrated that there were significant differences in landing mechanics for NHST group. PVGRF (week-1 = 6.2&plusmn / 0.9, week-5 = 5.3&plusmn / 0.9 / p&lt / .05), PAPGRF (week-1 = 1.1&plusmn / 0.2 &amp / week-10 = 0.8&plusmn / 0.3 / p&lt / .05) and APImp results demonstrated significant differences in trained group (week-1 = 78.1&plusmn / 13.6 &amp / week-10 = 67.8&plusmn / 9.2 / p&lt / .05). NHST group exhibited significant increase in vertical jumping ability (week-1 = 0.25&plusmn / 0.0 &amp / week-10 = 0.27&plusmn / 0.0 cm / p&lt / .01). This study supported the following points: 1) increases in the eccentric hamstring strength were evident after NHST program, 2) the increases in isokinetic strength were sufficient to cause alterations in landing kinetics to decrease the applied joint forces, so the NHST program would be an influential factor in decreasing the lower extremity injuries, and 3) the increase in the efficiency of force transfer at the final take off phase of jumping contributed to a higher performance in vertical jump.

The purpose of this study was to investigate the effects of Swiss ball training on (1) knee joint reposition sense (knee proprioception), (2) core muscle strength and (3) dynamic balance in sedentary collegiate students. In this thesis, two different participant groups and two different training methods were used. In order to evaluate the effect of Swiss ball training on knee proprioception and core strength, 3 days per week training was conducted throughout 10 weeks (Study 1). In order to evaluate the effect of Swiss ball training on dynamic balance, 2 days per week training was conducted throughout 10 weeks (Study 2). 60 sedentary university students participated in Study 1. 47 sedentary university students participated in Study 2. The results of the study indicated that Swiss ball training has significant effect on knee proprioception and core muscle strength. For dynamic balance, at the end of the 10-week Swiss ball training, in both groups (Swiss ball and control), dynamic balance scores were improved significantly. Therefore, effect of the Swiss ball training on dynamic balance could not be determined. As a conclusion, an instability training program using Swiss balls with body weight as resistance can provide prolonged improvements in joint proprioception and core strength which would contribute to general health and performance.

The contribution of deficits in limb position sense to the motor impairments of children with cerebral palsy, as well as other neurodevelopmental disorders, is increasingly being recognized. A more complete understanding of the development of multi-joint upper limb position sense is needed and has been limited, to date, by the absence of a reliable measurement technique to produce clinically meaningful information. The KINARM Exoskeleton’s bilateral position matching task, which involves passive movement of one of the subject’s arms to one of eight positions requiring different combinations of elbow and shoulder positions and active matching by the participant’s other arm, was evaluated for interrater and retest reliability. Intraclass correlation coefficients, absolute difference, minimum detectable difference that would be considered a significant change in performance, standard error of the measure, coefficient of variation, index of reliability, limit of agreement and confidence intervals were used to determine reliability on three measures of multi-joint position sense: (1) inter-trial variability in end-point position, (2) the ratio between actual and matched position, or spatial contraction/expansion, which provides a measure of the absolute accuracy of position matching, and (3) systematic errors in matching. Interrater index of reliability was very good to excellent with values of 72% for systematic errors in matching to 93% for contraction/expansion. Interrater intraclass correlation values were fair to excellent at 0.46 for systematic errors in matching to 0.81 for contraction/expansion. Standard errors in measurement were low and ranged from 0.002 to 0.06, for inter-trial variability and contraction/expansion respectively. Similarly, minimal detectable difference values for retest reliability ranged from 0.005 for inter-trial variability to 0.161 for contraction/expansion. Retest intraclass correlation values were fair to excellent at 0.38 for systematic errors in matching to 0.82 for contraction/expansion. Moderate to strong interrater and retest reliability and high measurement precision support the use of robot-based assessment of multi-joint position sense for developmental studies and promises to be a reliable clinical and research tool in the advancement of knowledge on sensory-motor coordination difficulties in children with neurodevelopmental disorders. / Thesis (Master, Rehabilitation Science) -- Queen's University, 2011-09-29 05:43:47.255

Thèse diffusée initialement dans le cadre d'un projet pilote des Presses de l'Université de Montréal/Centre d'édition numérique UdeM (1997-2008) avec l'autorisation de l'auteur.

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Tyrimo objektas: skirtingų kinezioteipo metodikų poveikis blauzdą tiesiančių raumenų jėgos momento variabilumui ir tikslaus judesio atkartojimui tiesiant blauzdą. Tikslas - išsiaiškinti kaip skirtingos kinezioteipavimo metodikos veikia kelio sąnario propriocepciją. Uždaviniai: 1. Ištirti ir palyginti skirtingų kinezioteipavimo metodikų poveikį blauzdą tiesiančių raumenų jėgos momento variabilumui, su ir be vaizdinės grįžtamosios informacijos, kai kelio sąnarys sulenktas 60º kampu. 2. Ištirti ir palyginti skirtingų kinezioteipavimo metodikų poveikį blauzdą tiesiančių raumenų jėgos momento variabilumui, su ir be vaizdinės grįžtamosios informacijos, kai kelio sąnarys sulenktas 90º kampu. 3. Ištirti ir palyginti skirtingų kinezioteipavimo metodikų poveikį tikslaus judesio atkartojimui, tiesiant blauzdą be vaizdinės grįžtamosios informacijos. Hipotezė. Žinant, kad raumeninės kinezioteipavimo metodikos (KT1) naudojimas labiau veikia raumeninius judesio valdymo aspektus, manome, kad judesio variabilumas sumažės ypač prie vidutinio raumens ilgio, o raištinė kinezioteipavimo metodika (KT2) veikianti sąnarinius judesio valdymo aspektus pagerins tikslaus judesio atkartojimą tiesiant blauzdą. Tyrimo metodai ir organizavimas: Tyrimas atliktas Lietuvos kūno kultūros akademijos Judesių klinikinių ir fundamentaliųjų tyrimų centre. Tyrimo pradžioje buvo išmatuoti maksimalūs blauzdą tiesiančių raumenų valingos jėgos momentai, kai koja sulenkta per kelio sąnarį 90° ir 60° kampu. Vėliau buvo... [toliau žr. visą tekstą] / Object of the study: the effect of different kinesio taping techniques for knee isometric torque variability and joint position sense Aim of the study: to investigate the effect of different kinesio taping techniques for knee proprioception Goals of the study: 1. To investigate and compare the effect of different kinesio taping techniques for knee extensors torque variability with and without visual feedback when knee is in 60º flexion. 2. To investigate and compare the effect of different kinesio taping techniques for knee extensors torque variability with and without visual feedback when knee is in 90º flexion. 3. To investigate and compare the effect of different kinesio taping techniques for joint position sense with and without visual feedback. Hypothesis of the study: Knowing that kinesio taping technique for muscle (KT1) affects motor control of muscles, it might be supposed that movement variability will decrease when muscle will be in the medium length and it’s known that kinesio taping technique for ligament (KT2) affects motor control of joints so we believe that it will improve the joint position of the knee. Methods and organization of the study: The study was performed in the Lithuanian Academy of Physical Education in the Center of Movements Clinical and Basic Research. At the beginning maximal isometric knee extension torque at knee joint angles of 60º, 90º was measured. Furthermore, isometric knee extension torque variability at 20% of maximal voluntary... [to full text]

Chronic lateral instability of the ankle (CLI), defined as frequent sprains and recurrent giving way, difficulty in walking and running on uneven surface, is often connected with pain and swollen ankles. It occurs in 10 to 20 percent after acute ankle injuries. Mechanical instability of the talocrural and subtalar joint, peroneal weakness and impaired proprioception has been suggested as etiological factors. Aim. To investigate the natural course in conservatively treated patients with CLI. To assess the mechanical stability in patients with CLI by measuring the three dimensional motions in the talus, the fibula and the calcaneus in relation to the tibia during different testing procedures pre- and postoperatively. To determine if CLI is associated with proprioceptive deficiency. Patients and Methods. This Thesis includes 127 ankles in 78 patients (30 women, 48 men) with CLI. Thirty-seven patients were followed up 20 years after their first contact with the orthopaedic department because of CLI. Forty-six ankles were evaluated radiographically and the result was compared with a gender- and age - matched control-material. The neuromuscular response to a sudden angular displacement of the ankles was studied in 15 ankles in 13 patients using EMG. Thirty-six patients entered a prospective study using roentgen stereophotogrammetric analysis (RSA) in which the ankles were tested at manual adduction, adduction with predetermined torque, with and without external support and at drawer tests (40 N and 160N). Twenty-seven patients were followed five years postoperatively. Result. After 20 years 22 patients, conservatively treated still suffered from instability of the ankle and ten had recurrent giving way symptoms even on plane surface. Six ankles in the patient group and four in the control group displayed osteoarthritic changes Prolonged ipsilateral reaction time (m. per. long, and m. tib. ant.) was found in patients with CLI indicating proprioceptive insufficiency. Increased talar adduction and a tendency toward increased total translation of the talar center was found in ankles with CLI. Concomitant fibular rotations and translations were found but with no conclusive deviation in the ankles with symptoms. The talo-calcaneal adduction reached the same level in the patient and control groups regardless of symptoms. External support (ankle brace) increased the talar stability. The use of predetermined torque and constrained testing procedure did not add information compared with the manual test Twenty-five patients graded the result as excellent or good five years after lateral ligament reconstruction. Talar stability (decreased adduction and translation) was increased two years postoperatively and was improved or remained the same at five years without comprising the range of motion. Conclusion. In more than half the cases symptoms of CLI did not resolve spontaneously. Minor degenerative changes was found after twenty years, but not to a greater extent than in a control group. CLI was associated with proprioceptive insufficiency and talocrural but not subtalar instability. Increased ankle stability can be obtained by the use of an ankle brace and by an anatomical ligament reconstruction. / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 1994</p> / digitalisering@umu

Movement is central for life, and all animals depend on accurate regulation of movement for purposeful behavior. There is great diversity of movements, ranging between simple and vital breathing movements to minute and subtle movements of the face used to communicate emotions. Consequently, motor neurons, which are the only route of central nervous system output, are essential for all motor behaviors. To control the many motor behaviors expressed by an animal, motor neurons are exposed to a large number and variety of modulating synaptic inputs and have evolved into subtypes with specific functions. In this thesis, motor neuron subtypes and the synaptic input to motor neurons from Renshaw cells and Ia afferents have been studied. Novel molecular markers that identify subtypes of motor neurons are described. Three markers, Chodl, Calca and ERRβ, have been used to study the degeneration of subtypes of motor neurons in a mouse model of the neurodegenerative disease amyotrophic lateral sclerosis (ALS). Another marker, 5-ht1d, has been used to record the electrophysiological character of gamma motor neurons. In mice that lack 5-ht1d, motor neurons develop with reduced proprioceptive input. Remarkably, these mice had fewer foot faults than control animals when challenged to cross a narrow beam suggesting that the amplitude of monosynaptic proprioceptive input to motor neurons is not essential for motor coordination. In a final set of experiments, genetic removal of vesicular transport of neurotransmitter from Renshaw cells suggest that Renshaw cells are not integral for motor circuit function or motor behaviors. However, they are involved in the development of motor circuits in the spinal cord. Together, this thesis provides novel molecular tools for studies of motor neuron subtypes and novel data regarding the development and function of spinal motor circuits.