THE USE OF WARTENBERG TEST IN ADOLESCENTS AND ADULTS WITH DOWN SYNDROME: AN ANALYSIS OF KNEE EXTENSOR MUSCLE ACTIVATION PATTERNS Casabona 1,3, MS.Valle 3, M. Pisasale 1, Camerano C1, M.R. Pantò3,4, M.Cioni 1,2 1Gait Analysis Laboratory, Physical Medicine and Rehabilitation Residency Program, University of Catania 2Department of Clinical and Molecular Bio-Medicine, University of Catania. 3 Department of Bio-Medical Sciences, section of Physiology, University of Catania. 4 Italian Association Down People, section of Catania. Introduction In a previous work [1] we used the Wartenberg test [2] to assess knee joint mobility in adults with Down syndrome (DS). This test allows to evaluate the kinematics of knee joint during passive pendular motion of the leg under the influence of gravity. The EMG of muscle rectus femoris (RF), during the first swing of the leg, exhibited large phasic activity in DS group, whereas the EMG of persons without DS was characterized by low tonic activity. We hypothesized that these phasic muscular activations could be pre-programmed strategies to increase joint stability and optimize the leg dropping. Here, in order to identify the nature of these muscle reactions we further elaborated the set of data obtained by adults sample and compared with a new set collected from a group of younger people with DS. This comparison should provide insights on whether these strategies have been acquired during development or, rather, they are part of congenital characteristics of the DS person. Methods This study involved 20 persons with DS, 10 adults aged between 20-32 years, and 10 adolescents aged between 10-17 years. Each subject was seated in a semi-reclined position and received extensive explanation and demonstration of the procedure. The test was repeated 10 times and for each trial the leg fell down from the horizontal position and swung liberally between flexions and extensions until it stopped to the gravitational resting position. The angular displacements, recorded at the knee joint, were captured with an electrogoniometer and the surface EMG of RF was obtained from a bioelectric amplifier connected to 2 of surface electrodes. Measurements from each kinematic trajectory were elaborated to obtain parameters regarding the first swing: maximum flexion angle; mean value and peak of angular velocity; mean value, first and second peak of angular acceleration. In order to identify the latencies from the movement onset and to compute the EMG area during the first flexion, we filtered EMG traces by 2nd order Butterworth low-pass filter with a cutoff of 10 Hz. In addition, to describe the patterns of muscle activation for each group, the entire datasets of EMG traces were reduced to few representative waveforms by using the Principal Component Analysis (PCA). Results Except for the second peak of acceleration, there was no difference among the kinematic parameters considered in the two groups of participants. Instead, we found differences between the two groups in the basic waveforms representing EMG activity and in the distribution of latencies of the responses. The dataset of the adult subjects can be represented by 6 principal components (PCs) explaining the 87% of the variance whereas the EMG activity of the adolescents group can be summarized by 5 PCs explaining the 82% of the variance. The most important difference between the two set of PCs was the temporal distribution of the waveforms over the interval of the first swing: the basic EMG responses of young DS people fell on the first third of the leg dropping whereas in the adults the responses occurred in almost all the time interval of the first swing. Consistently, the 72% of the original EMG activity in the adolescents group occurred below 50 ms from the movement onset while the 60% of EMG responses of adult people took place between 50 and 150 ms. Thus, with respect to the adults, the younger persons with DS showed a temporal shift of muscle reactions toward the beginning of the leg movement. Conclusions The earlier reactions showed by adolescent people with DS are compatible with the time course of spinal stretch reflex while the delayed components, more represented in adults, should involve transcortical loops. The muscle activity observed in the first swing should evolve during the development from a simple reflex reactions to more complex and flexible pre-programmed patterns. This adaptation should optimize the process of stabilizing joint when rapid changes in the environment occur. Bibliography [1] Valle MS., Casabona A., Pisasale M., Pantò MR., Cioni M. Gait & Posture 2012; 35: S1-S47 [2] Wartenberg R. Neurology 1951; 1:18-24

THE USE OF WARTENBERG TEST IN ADOLESCENTS AND ADULTS WITH DOWN SYNDROME: AN ANLYSIS OF KNEE EXTENSOR MUSCLE ACTIVATION PATTERN

VALLE, Maria Stella Carmela;CIONI, Matteo
2012

Abstract

THE USE OF WARTENBERG TEST IN ADOLESCENTS AND ADULTS WITH DOWN SYNDROME: AN ANALYSIS OF KNEE EXTENSOR MUSCLE ACTIVATION PATTERNS Casabona 1,3, MS.Valle 3, M. Pisasale 1, Camerano C1, M.R. Pantò3,4, M.Cioni 1,2 1Gait Analysis Laboratory, Physical Medicine and Rehabilitation Residency Program, University of Catania 2Department of Clinical and Molecular Bio-Medicine, University of Catania. 3 Department of Bio-Medical Sciences, section of Physiology, University of Catania. 4 Italian Association Down People, section of Catania. Introduction In a previous work [1] we used the Wartenberg test [2] to assess knee joint mobility in adults with Down syndrome (DS). This test allows to evaluate the kinematics of knee joint during passive pendular motion of the leg under the influence of gravity. The EMG of muscle rectus femoris (RF), during the first swing of the leg, exhibited large phasic activity in DS group, whereas the EMG of persons without DS was characterized by low tonic activity. We hypothesized that these phasic muscular activations could be pre-programmed strategies to increase joint stability and optimize the leg dropping. Here, in order to identify the nature of these muscle reactions we further elaborated the set of data obtained by adults sample and compared with a new set collected from a group of younger people with DS. This comparison should provide insights on whether these strategies have been acquired during development or, rather, they are part of congenital characteristics of the DS person. Methods This study involved 20 persons with DS, 10 adults aged between 20-32 years, and 10 adolescents aged between 10-17 years. Each subject was seated in a semi-reclined position and received extensive explanation and demonstration of the procedure. The test was repeated 10 times and for each trial the leg fell down from the horizontal position and swung liberally between flexions and extensions until it stopped to the gravitational resting position. The angular displacements, recorded at the knee joint, were captured with an electrogoniometer and the surface EMG of RF was obtained from a bioelectric amplifier connected to 2 of surface electrodes. Measurements from each kinematic trajectory were elaborated to obtain parameters regarding the first swing: maximum flexion angle; mean value and peak of angular velocity; mean value, first and second peak of angular acceleration. In order to identify the latencies from the movement onset and to compute the EMG area during the first flexion, we filtered EMG traces by 2nd order Butterworth low-pass filter with a cutoff of 10 Hz. In addition, to describe the patterns of muscle activation for each group, the entire datasets of EMG traces were reduced to few representative waveforms by using the Principal Component Analysis (PCA). Results Except for the second peak of acceleration, there was no difference among the kinematic parameters considered in the two groups of participants. Instead, we found differences between the two groups in the basic waveforms representing EMG activity and in the distribution of latencies of the responses. The dataset of the adult subjects can be represented by 6 principal components (PCs) explaining the 87% of the variance whereas the EMG activity of the adolescents group can be summarized by 5 PCs explaining the 82% of the variance. The most important difference between the two set of PCs was the temporal distribution of the waveforms over the interval of the first swing: the basic EMG responses of young DS people fell on the first third of the leg dropping whereas in the adults the responses occurred in almost all the time interval of the first swing. Consistently, the 72% of the original EMG activity in the adolescents group occurred below 50 ms from the movement onset while the 60% of EMG responses of adult people took place between 50 and 150 ms. Thus, with respect to the adults, the younger persons with DS showed a temporal shift of muscle reactions toward the beginning of the leg movement. Conclusions The earlier reactions showed by adolescent people with DS are compatible with the time course of spinal stretch reflex while the delayed components, more represented in adults, should involve transcortical loops. The muscle activity observed in the first swing should evolve during the development from a simple reflex reactions to more complex and flexible pre-programmed patterns. This adaptation should optimize the process of stabilizing joint when rapid changes in the environment occur. Bibliography [1] Valle MS., Casabona A., Pisasale M., Pantò MR., Cioni M. Gait & Posture 2012; 35: S1-S47 [2] Wartenberg R. Neurology 1951; 1:18-24
Pendulum test; Hypotonia; Muscle
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.11769/100065
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact