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20.10 Analysis of locomotor parameter programming in a neuromuscular disease
Chapter 20. Rehabilitation and training Results: The increase of area of sway and amplitude of deviation in the sagittal and frontal planes has been revealed in the whole MS patients group and also in relapse and secondary progressive MS as compared with control. The hyperstability type of spectral changes has been shown in remission of disease. Patients with dominant paresis were more unstable than healthy subjects in the sagittal plane. The changes of all parameters (area of sway, amplitude of deviation in both planes, spectral characteristics) have been found at the Romberg test (with closed eyes). Vestibulo-cerebellar disorders were accompanied by increase of area of sway and amplitude of deviation in the sagittal and frontal planes and the changes of spectral analysis. Discussion and conclusion: Results reflect the presence of different patterns of postural ataxias in MS. The presence of compensative reorganization of the postural control system in remission and the presence of tremor in patients with vestibulo-cerebellar disorders have been revealed by spectral analysis. Thus, MS may be used as the model for posturograthic study of the role of vision, vestibular and pyramidal systems in the maintenance of standing balance.
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Correlation between the speed of exercise and joint loading during a close-chain exercise of the upper extremity
RH. Chou 1, Y.L. Chou 2, C.K. Chen 1, C.M. Kuo 2. 1Department of Orthopedic Surgery, Kaohsiung Medical University, Kaohsiung, Taiwan," 2 Institute of Biomedical Engineering, National Cheng-Kung University, Tainan, Taiwan Introduction: Push-up is a commonly used close-chain exercise to strengthen the upper extremity. Nonetheless, there is very little research regarding the kinematics of the close-chain exercise of the upper extremity. The purpose of this study is to investigate the correlation between the speed of exercise and joint loading during a close-chain exercise of the upper extremity. Methods: Fourteen male subjects volunteered in this study. The subjects were asked to perform push-up exercises in various speed (fast, regular, and slow). The Expert Vision motion system was used to measure relative joint positions and ground reaction forces. The kinematics and kinetics of the upper extremity were calculated by inverse dynamics and Newton-Eulerian's equation. Additionally, muscle activities of the shoulder were measured with surface EMG during the push-up exercise. Results: Results showed that the loading biomechanics of the upper extremity differed with various exercise speed (Table 1). Performing push-up exercise in a faster speed resulted in the greatest joint loading upon the upper extremity. Furthermore, performing the exercise in slower speed resulted in more muscle activities in pectorals, triceps, biceps, and deltoid (p < 0.05). Discussion and Conclusion: Greatest medial and lateral shear stress was produced during faster speed of push-up exercise. Performing push-up exercise in a slower speed resulted in smaller joint loading and more muscle activation upon the upper extremity. Therefore, performing close-chain exercise under slower speed may be a better strategy for strengthening of the upper extremity.
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Analysis of locomotor parameter programming in a neuromuscular disease
A. Couillandre 1'2, Y. Breni~re 3, J.Y. Hogrel 1, B. Eymard 4, R Portero 1. llnstitut de Myologie, GH Piti~ SalpOtri~re, Paris',
2Laboratoire Sport et Culture, EA 2931, UniversitO Paris' X, France; SlSERM U-483, Laboratoire de Physiologie du Mouvement, Orsay, France; 4 Unit~ clinique de pathologic neuromusculaire, Institut de Myologie, GH Piti~ SalpOtri~re, Paris', France Introduction: The nervous system has to combine step length (L) and frequency (f) in order to adjust the velocity of the centre of foot pressure (CP), expressed as v Lf, to the one of the centre of gravity (CG) at the end of gait initiation, expressed as V, resulting from the integration of propulsives forces acting on the body. Locomotor parameter programming is considered through: a) its objective, i.e., the
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adjustment of both velocities which is a necessary condition for normal walking and b) the strategy used in order to achieve this objective, i.e., the contributions of L and f to CP velocity [1]. Here, we wanted to know if a neuromuscular disease could change this programming. Methods: Gait initiation was performed by a control group and by a patient group presenting Becket Myopathy on a force plate, which allowed the computing of CG accelerations and CP positions from the ground reaction forces. We analysed the adjustment of both velocities through the slopes (s) of the linear regressions established between V and v L f a n d used the differential method [1] to analyse the strategy. Results: For both groups, V and v were adjusted at the end of the first step (sc 1.09 and sp 1.016). Step length and frequency had different contributions to CP velocity from one group to another, step frequency being the parameter contributing the most to CP velocity in the patient group. Discussion and Conclusion: These results suggest that the nervous system, by taking into account the motor deficit induced by the pathology, introduces specific changes on step length and frequency, in order to preserve the adjustment of CP to CG velocity. The differential method could be very useful in the follow up of a disease, where one could see modifications of the strategy.
References [1] Couillandre A, Breni~re Y. J Mot Behav. 2003 Sep; 35 (3): 221 7.
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Change in standing posture of lower limb amputees after muscle vibration: a potential tool for rehabilitation
C. Duclos 1'2, R. Roll 2, A. Kavounoudias 2, J.R Roll 2, R. Forget 1.
1Centre de recherche interdisciplinaire en rdadaptation du MontrEal mdtropolitain (CRIR), Institut de Rdadaptation de Montrdal, 6300 avenue Darlington, Montreal (QC), H3S 2J4, Canada; 2 UMR 6149, Laboratoire de Neurobiologie Humaine, Universitd de Provence/CNRS, 3 place Victor Hugo, case B, 13331 Marseille cedex 03, France The application of a 30s proprioceptive stimulation, such as an isometric voluntary contraction or mechanical vibration to the neck muscles leads to long-lasting body leanings [1,2]. Both types of stimulation produce postural post-effects of similar duration with a direction of response that is specific to the stimulated muscle. In this study, muscle vibration was used in lower-leg amputees to increase weight bearing on their prosthetic leg. A 30 s vibration (80 Hz) was applied to the trapezius and medial gluteus muscles ipsilaterally to the amputation (14 patients) or to the left body side (18 healthy subjects). The centre of pressure (COP) displacements were recorded for 15 minutes after the vibration to evaluate postural changes while standing with closed eyes. Asymmetrical weight bearing was observed before vibration in the amputees. Vibration of either one of the muscles produced changes of CoP position in the frontal plane that were of similar amplitudes in both groups of individuals. Although larger in the first minute after vibration, the changes remained significant for the duration of the recording. The direction of the changes was variable in both groups, but less in the amputees where overall reduced asymmetrical weight bearing was observed, particularly following a medial gluteus muscle vibration. Amputees are therefore likely to experience vibration-induced posteffects that help to correct their standing posture. However, vibration application procedures need further exploration to induce stronger oriented post-effects.
References [1] Duclos C, Roll R, Kavounoudias A, Roll J-P. Long-lasting body leanings following neck muscle isometric contractions. Exp Brain Res 2004; 158:58 66. [2] Wierzbicka MM, Gilhodes J-C, Roll J-R Vibration-induced postural posteffects. J Neurophysiol 1998; 79:143 150.
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Correlation between the speed of exercise and joint loading during a close-chain exercise of the upper extremity
RH. Chou 1, Y.L. Chou 2, C.K. Chen 1, C.M. Kuo 2. 1Department of Orthopedic Surgery, Kaohsiung Medical University, Kaohsiung, Taiwan," 2 Institute of Biomedical Engineering, National Cheng-Kung University, Tainan, Taiwan Introduction: Push-up is a commonly used close-chain exercise to strengthen the upper extremity. Nonetheless, there is very little research regarding the kinematics of the close-chain exercise of the upper extremity. The purpose of this study is to investigate the correlation between the speed of exercise and joint loading during a close-chain exercise of the upper extremity. Methods: Fourteen male subjects volunteered in this study. The subjects were asked to perform push-up exercises in various speed (fast, regular, and slow). The Expert Vision motion system was used to measure relative joint positions and ground reaction forces. The kinematics and kinetics of the upper extremity were calculated by inverse dynamics and Newton-Eulerian's equation. Additionally, muscle activities of the shoulder were measured with surface EMG during the push-up exercise. Results: Results showed that the loading biomechanics of the upper extremity differed with various exercise speed (Table 1). Performing push-up exercise in a faster speed resulted in the greatest joint loading upon the upper extremity. Furthermore, performing the exercise in slower speed resulted in more muscle activities in pectorals, triceps, biceps, and deltoid (p < 0.05). Discussion and Conclusion: Greatest medial and lateral shear stress was produced during faster speed of push-up exercise. Performing push-up exercise in a slower speed resulted in smaller joint loading and more muscle activation upon the upper extremity. Therefore, performing close-chain exercise under slower speed may be a better strategy for strengthening of the upper extremity.
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Analysis of locomotor parameter programming in a neuromuscular disease
A. Couillandre 1'2, Y. Breni~re 3, J.Y. Hogrel 1, B. Eymard 4, R Portero 1. llnstitut de Myologie, GH Piti~ SalpOtri~re, Paris',
2Laboratoire Sport et Culture, EA 2931, UniversitO Paris' X, France; SlSERM U-483, Laboratoire de Physiologie du Mouvement, Orsay, France; 4 Unit~ clinique de pathologic neuromusculaire, Institut de Myologie, GH Piti~ SalpOtri~re, Paris', France Introduction: The nervous system has to combine step length (L) and frequency (f) in order to adjust the velocity of the centre of foot pressure (CP), expressed as v Lf, to the one of the centre of gravity (CG) at the end of gait initiation, expressed as V, resulting from the integration of propulsives forces acting on the body. Locomotor parameter programming is considered through: a) its objective, i.e., the
$129
adjustment of both velocities which is a necessary condition for normal walking and b) the strategy used in order to achieve this objective, i.e., the contributions of L and f to CP velocity [1]. Here, we wanted to know if a neuromuscular disease could change this programming. Methods: Gait initiation was performed by a control group and by a patient group presenting Becket Myopathy on a force plate, which allowed the computing of CG accelerations and CP positions from the ground reaction forces. We analysed the adjustment of both velocities through the slopes (s) of the linear regressions established between V and v L f a n d used the differential method [1] to analyse the strategy. Results: For both groups, V and v were adjusted at the end of the first step (sc 1.09 and sp 1.016). Step length and frequency had different contributions to CP velocity from one group to another, step frequency being the parameter contributing the most to CP velocity in the patient group. Discussion and Conclusion: These results suggest that the nervous system, by taking into account the motor deficit induced by the pathology, introduces specific changes on step length and frequency, in order to preserve the adjustment of CP to CG velocity. The differential method could be very useful in the follow up of a disease, where one could see modifications of the strategy.
References [1] Couillandre A, Breni~re Y. J Mot Behav. 2003 Sep; 35 (3): 221 7.
I•
Change in standing posture of lower limb amputees after muscle vibration: a potential tool for rehabilitation
C. Duclos 1'2, R. Roll 2, A. Kavounoudias 2, J.R Roll 2, R. Forget 1.
1Centre de recherche interdisciplinaire en rdadaptation du MontrEal mdtropolitain (CRIR), Institut de Rdadaptation de Montrdal, 6300 avenue Darlington, Montreal (QC), H3S 2J4, Canada; 2 UMR 6149, Laboratoire de Neurobiologie Humaine, Universitd de Provence/CNRS, 3 place Victor Hugo, case B, 13331 Marseille cedex 03, France The application of a 30s proprioceptive stimulation, such as an isometric voluntary contraction or mechanical vibration to the neck muscles leads to long-lasting body leanings [1,2]. Both types of stimulation produce postural post-effects of similar duration with a direction of response that is specific to the stimulated muscle. In this study, muscle vibration was used in lower-leg amputees to increase weight bearing on their prosthetic leg. A 30 s vibration (80 Hz) was applied to the trapezius and medial gluteus muscles ipsilaterally to the amputation (14 patients) or to the left body side (18 healthy subjects). The centre of pressure (COP) displacements were recorded for 15 minutes after the vibration to evaluate postural changes while standing with closed eyes. Asymmetrical weight bearing was observed before vibration in the amputees. Vibration of either one of the muscles produced changes of CoP position in the frontal plane that were of similar amplitudes in both groups of individuals. Although larger in the first minute after vibration, the changes remained significant for the duration of the recording. The direction of the changes was variable in both groups, but less in the amputees where overall reduced asymmetrical weight bearing was observed, particularly following a medial gluteus muscle vibration. Amputees are therefore likely to experience vibration-induced posteffects that help to correct their standing posture. However, vibration application procedures need further exploration to induce stronger oriented post-effects.
References [1] Duclos C, Roll R, Kavounoudias A, Roll J-P. Long-lasting body leanings following neck muscle isometric contractions. Exp Brain Res 2004; 158:58 66. [2] Wierzbicka MM, Gilhodes J-C, Roll J-R Vibration-induced postural posteffects. J Neurophysiol 1998; 79:143 150.