- Email: [email protected]
PS-24-7 Postural adjustments associated with arm movements during balancing on unstable support surface
S144
Poster session 24. Movement disorders (1)
P$-24-7 t Postural adjustments associated with arm movements during balancing on unstable support surface
I PS-24-91 Coupling between voluntary tapping, stepping and cardiac rhythms in healthy human subjects
Diana Dimitrova, Gantcho N. Gantchev. Institute of Physiology, Bulgarian Academy of Sciences, Sofia, Bulgaria
Jun-ichi Shimizu, Kazuto Furukawa, lshio Ninomiya. Institute of Health Sciences, School of Medicine, Hiroshima University
The purpose of this study was to compare postural activity associated with arm movements during balancing on stable and unstable support surface. The experiments were arranged in two series: 1 ) the subjects stood on a force platform, and 2) on unstable platform (see-saw). They performed self-paced arm elevations as fast as possible for each support condition. E M G activity of deltoideus anterior, soleus, tibialis anterior, biceps femoris and erector spinae muscles were recorded. The acceleration of the arm, the center of foot pressure (CFP) and ankle joint angle were recorded also. The integral I E M G s of SOL and TA 500 and 100 ms prior to the onset of DA E M G were measured. For both series an anticipatory postural adjustment of BF was found, proceeding the ES activation. During balancing on see-saw the following differences from the stable condition were found: co-contraction of SOL and TA muscles; significantly earlier recruitment of BF; later related activity of ES; decrease of SOL I E M G and increase o f T A I E M G activities for both measured time intervals prior to the onset of DA E M G activity; no consistency of CFP position was found during maintaining of upright posture on stable force platform, and during balancing on unstable support surface a tendency for domination of forward displacement of CFP position prior to D A E M G onset was observed. These data showed that posture control during balancing on unstable support surface consists mainly in adapting the motor program according to the postural requirements rather than in changes in postural strategy.
The aim of this study is to investigate how free tapping and stepping rhythms relate with cardiac rhythm in 12 healthy h u m a n subjects. In a comfortable sitting posture, free tapping, stepping or tappingstepping were repeated six times with three minutes resting intervals. Heart rates were obtained by R spikes of E C G signal per one minute. Tapping, stepping or tapping-stepping rates were measured simultaneously with heart rates. To evaluate the degree of coupling, relative rates of tapping, stepping and tapping-stepping rhythms to heart rates were calculated. The relative rates of right and left side tapping were 1.25 and 1.32 respectively (p > 0.05). The relative tapping rates of right and left side stepping ryhthms were 1.26 and 1.38 respectively. The stepping rate of left side was significantly larger than that of the right side (p < 0.05). The voluntary tapping and stepping rates rhythms were almost the same. W h e n the right side of tapping and stepping was made simultaneously, the tapping-stepping was 1.44. This value was significantly greater than the individual tapping (1.25) and stepping rate (1.26). W h e n bilateral tapping-stepping was increased up to 1.54, the increase in tapping and stepping rates was significant (p < 0.05). Our data indicate that the tapping-stepping rate was greater than the tapping or stepping rate, and that increase in tapping and stepping rates was greater than the increase in heart rate when the tapping and stepping was made simultaneuosly.
PS-24-81 On adjustment of muscle visco-elasticity in constant speed tracking motion T. Irikura 1, j. Hayakawa 1, A. Kato 1, R. Hayashi 2. l Department
of Electronics, Aichi Institute of Technology; z Department of Neurology, Shinsyu University An equivalent visco-elastic coefficient change of the in-vivo muscle in the constant tracking motion is investigated. The tracking experiments in a constant velocity has been made on human wrist joint with elastic load. A vibration frequency change of the tracking error is analyzed by the FFT method. And simulation by control model of a neuromuscular system of human was made, then it made sure that the vibration frequency increase proportionally not only an elastic coefficient but also a viscous coefficient. By the experimental results, as high linear correlation with the frequency increase was seen on seven normal subjects of nineteen persons, so the increase of the equivalent visco-elastic coefficient was made sure. The same tendency was seen only one SCD subject of nineteens, and only two PD subjects of thirteens. A following conclusion was got that an adjustment of the equivalent viscoelastic coefficient is depended on cellebler-cotex movement.
I PS-24-10 ] Is the ability to reach a high level in the motor program selectivity related to the mode of the daily manipulatory activities? Claude Tomberg, Caroline Andries, Karin Pedersen. Brain
Research Unit, University of Brussels, Belgium The cortico-motoneuronal systems of the two muscles producing index finger extension (extensor indicis proprius and extensor digitorum communis) disclose a remarkable physiological differentiation of their central motor commands (Neurosci. lett., 1995, 185:41-43). Brain magnetic stimulation delivered just before a voluntary finger extension revealed early cortico-motoneuronal facilitation for one extensor muscle and concomitant inhibition for the other, depending on the movement performed by the subject. Any subject may not be able to disclose such pattern of selectivity in motor programming and the question was to determine whether this might be related to any usual manipulatory finger activities. We have compared the left and right finger extensors of a practicing musician whose hands were involved in a different type of movement. For the violonist, the left hand is involved in fractionated finger movements while the right hand manipulating the bow performs rather global movements. When the violonist was instructed to perform an isolated index finger extension, the selectivity in motor programming was found in 82% of the trials for the left hand, but only in 43% of the trials with the right hand. There were no differences between right and left hand for global fingers extension (respectively 71% and 69% of selectivity pattern in the experimental trials). As the violonist was right-handed, his ability to provide more selective motor programming for fractionated movements of the left hand can be related to the daily use of his instrument.
Poster session 24. Movement disorders (1)
P$-24-7 t Postural adjustments associated with arm movements during balancing on unstable support surface
I PS-24-91 Coupling between voluntary tapping, stepping and cardiac rhythms in healthy human subjects
Diana Dimitrova, Gantcho N. Gantchev. Institute of Physiology, Bulgarian Academy of Sciences, Sofia, Bulgaria
Jun-ichi Shimizu, Kazuto Furukawa, lshio Ninomiya. Institute of Health Sciences, School of Medicine, Hiroshima University
The purpose of this study was to compare postural activity associated with arm movements during balancing on stable and unstable support surface. The experiments were arranged in two series: 1 ) the subjects stood on a force platform, and 2) on unstable platform (see-saw). They performed self-paced arm elevations as fast as possible for each support condition. E M G activity of deltoideus anterior, soleus, tibialis anterior, biceps femoris and erector spinae muscles were recorded. The acceleration of the arm, the center of foot pressure (CFP) and ankle joint angle were recorded also. The integral I E M G s of SOL and TA 500 and 100 ms prior to the onset of DA E M G were measured. For both series an anticipatory postural adjustment of BF was found, proceeding the ES activation. During balancing on see-saw the following differences from the stable condition were found: co-contraction of SOL and TA muscles; significantly earlier recruitment of BF; later related activity of ES; decrease of SOL I E M G and increase o f T A I E M G activities for both measured time intervals prior to the onset of DA E M G activity; no consistency of CFP position was found during maintaining of upright posture on stable force platform, and during balancing on unstable support surface a tendency for domination of forward displacement of CFP position prior to D A E M G onset was observed. These data showed that posture control during balancing on unstable support surface consists mainly in adapting the motor program according to the postural requirements rather than in changes in postural strategy.
The aim of this study is to investigate how free tapping and stepping rhythms relate with cardiac rhythm in 12 healthy h u m a n subjects. In a comfortable sitting posture, free tapping, stepping or tappingstepping were repeated six times with three minutes resting intervals. Heart rates were obtained by R spikes of E C G signal per one minute. Tapping, stepping or tapping-stepping rates were measured simultaneously with heart rates. To evaluate the degree of coupling, relative rates of tapping, stepping and tapping-stepping rhythms to heart rates were calculated. The relative rates of right and left side tapping were 1.25 and 1.32 respectively (p > 0.05). The relative tapping rates of right and left side stepping ryhthms were 1.26 and 1.38 respectively. The stepping rate of left side was significantly larger than that of the right side (p < 0.05). The voluntary tapping and stepping rates rhythms were almost the same. W h e n the right side of tapping and stepping was made simultaneously, the tapping-stepping was 1.44. This value was significantly greater than the individual tapping (1.25) and stepping rate (1.26). W h e n bilateral tapping-stepping was increased up to 1.54, the increase in tapping and stepping rates was significant (p < 0.05). Our data indicate that the tapping-stepping rate was greater than the tapping or stepping rate, and that increase in tapping and stepping rates was greater than the increase in heart rate when the tapping and stepping was made simultaneuosly.
PS-24-81 On adjustment of muscle visco-elasticity in constant speed tracking motion T. Irikura 1, j. Hayakawa 1, A. Kato 1, R. Hayashi 2. l Department
of Electronics, Aichi Institute of Technology; z Department of Neurology, Shinsyu University An equivalent visco-elastic coefficient change of the in-vivo muscle in the constant tracking motion is investigated. The tracking experiments in a constant velocity has been made on human wrist joint with elastic load. A vibration frequency change of the tracking error is analyzed by the FFT method. And simulation by control model of a neuromuscular system of human was made, then it made sure that the vibration frequency increase proportionally not only an elastic coefficient but also a viscous coefficient. By the experimental results, as high linear correlation with the frequency increase was seen on seven normal subjects of nineteen persons, so the increase of the equivalent visco-elastic coefficient was made sure. The same tendency was seen only one SCD subject of nineteens, and only two PD subjects of thirteens. A following conclusion was got that an adjustment of the equivalent viscoelastic coefficient is depended on cellebler-cotex movement.
I PS-24-10 ] Is the ability to reach a high level in the motor program selectivity related to the mode of the daily manipulatory activities? Claude Tomberg, Caroline Andries, Karin Pedersen. Brain
Research Unit, University of Brussels, Belgium The cortico-motoneuronal systems of the two muscles producing index finger extension (extensor indicis proprius and extensor digitorum communis) disclose a remarkable physiological differentiation of their central motor commands (Neurosci. lett., 1995, 185:41-43). Brain magnetic stimulation delivered just before a voluntary finger extension revealed early cortico-motoneuronal facilitation for one extensor muscle and concomitant inhibition for the other, depending on the movement performed by the subject. Any subject may not be able to disclose such pattern of selectivity in motor programming and the question was to determine whether this might be related to any usual manipulatory finger activities. We have compared the left and right finger extensors of a practicing musician whose hands were involved in a different type of movement. For the violonist, the left hand is involved in fractionated finger movements while the right hand manipulating the bow performs rather global movements. When the violonist was instructed to perform an isolated index finger extension, the selectivity in motor programming was found in 82% of the trials for the left hand, but only in 43% of the trials with the right hand. There were no differences between right and left hand for global fingers extension (respectively 71% and 69% of selectivity pattern in the experimental trials). As the violonist was right-handed, his ability to provide more selective motor programming for fractionated movements of the left hand can be related to the daily use of his instrument.