Cocontraction and phasic activity during GAIT in children with cerebral palsy

V.B. Unnithan, J.J. Dowling, G. Frost, B. Volpe Ayub, O. Bar-Or

Research output: Contribution to journalArticle

Abstract

Simultaneous activity of agonist and antagonistic muscles during a task is known as cocontraction. The primary aim of the present study was to use a cocontraction index (CI) to quantify differences in EMG activity between a group of CP and control children at two different walking speeds. The secondary aim was to compare the amount of time the muscles were activated ("on" thresholds) between the groups. Seventeen subjects volunteered for the study. One group consisted of 9 (7M, 2F) children with CP (age 12.7 +/- 2.8 years, mean +/- SD). The second group consisted of 8 able-bodied controls (7M, 1F). The discontinuous submaximal treadmill walking protocol had two 4min stages at 0% gradient. Speeds selected were 3 km.h-1 and 90% of the pre-determined fastest walking speed (FWS). Two sites of CI were measured from the EMGs of tibialis anterior and soleus (leg) and vastus lateralis and hamstrings (thigh). Significantly (p < 0.05) higher CI values were noted for the CP subjects compared to the controls, irrespective of speed or cocontraction site and there was a significant (p < 0.05) increase in CI values with increased walking speed for both CP and control subjects. Phasic analyses for 5% max EMG and 10% max EMG "on" thresholds demonstrated significant (p < 0.05) main effects for group (CP subjects had a longer time period of muscle activation than controls) and speed (muscles were active longer at 90% FWS than 3 km.h-1). The precise mechanisms by which cocontraction contributes toward abnormal gait and wasted mechanical energy require further research incorporating both electromyographic and kinematic analysis.
Original languageEnglish
Pages (from-to)487-494
Number of pages8
JournalElectromyography and Clinical Neurophysiology
Volume36
Issue number8
Publication statusPublished - Dec 1996
Externally publishedYes

Fingerprint

Cerebral Palsy
Muscles
Quadriceps Muscle
Thigh
Gait
Biomechanical Phenomena
Walking
Leg
Control Groups
Walking Speed
Research

Cite this

Unnithan, V.B. ; Dowling, J.J. ; Frost, G. ; Volpe Ayub, B. ; Bar-Or, O. / Cocontraction and phasic activity during GAIT in children with cerebral palsy. In: Electromyography and Clinical Neurophysiology. 1996 ; Vol. 36, No. 8. pp. 487-494.
@article{4ee143b323d545f48fa55eaeda34665b,
title = "Cocontraction and phasic activity during GAIT in children with cerebral palsy",
abstract = "Simultaneous activity of agonist and antagonistic muscles during a task is known as cocontraction. The primary aim of the present study was to use a cocontraction index (CI) to quantify differences in EMG activity between a group of CP and control children at two different walking speeds. The secondary aim was to compare the amount of time the muscles were activated ({"}on{"} thresholds) between the groups. Seventeen subjects volunteered for the study. One group consisted of 9 (7M, 2F) children with CP (age 12.7 +/- 2.8 years, mean +/- SD). The second group consisted of 8 able-bodied controls (7M, 1F). The discontinuous submaximal treadmill walking protocol had two 4min stages at 0{\%} gradient. Speeds selected were 3 km.h-1 and 90{\%} of the pre-determined fastest walking speed (FWS). Two sites of CI were measured from the EMGs of tibialis anterior and soleus (leg) and vastus lateralis and hamstrings (thigh). Significantly (p < 0.05) higher CI values were noted for the CP subjects compared to the controls, irrespective of speed or cocontraction site and there was a significant (p < 0.05) increase in CI values with increased walking speed for both CP and control subjects. Phasic analyses for 5{\%} max EMG and 10{\%} max EMG {"}on{"} thresholds demonstrated significant (p < 0.05) main effects for group (CP subjects had a longer time period of muscle activation than controls) and speed (muscles were active longer at 90{\%} FWS than 3 km.h-1). The precise mechanisms by which cocontraction contributes toward abnormal gait and wasted mechanical energy require further research incorporating both electromyographic and kinematic analysis.",
author = "V.B. Unnithan and J.J. Dowling and G. Frost and {Volpe Ayub}, B. and O. Bar-Or",
year = "1996",
month = "12",
language = "English",
volume = "36",
pages = "487--494",
journal = "Electromyography and Clinical Neurophysiology",
issn = "0301-150X",
publisher = "Editions Nauwelaerts SA",
number = "8",

}

Unnithan, VB, Dowling, JJ, Frost, G, Volpe Ayub, B & Bar-Or, O 1996, 'Cocontraction and phasic activity during GAIT in children with cerebral palsy' Electromyography and Clinical Neurophysiology, vol. 36, no. 8, pp. 487-494.

Cocontraction and phasic activity during GAIT in children with cerebral palsy. / Unnithan, V.B.; Dowling, J.J.; Frost, G.; Volpe Ayub, B.; Bar-Or, O.

In: Electromyography and Clinical Neurophysiology, Vol. 36, No. 8, 12.1996, p. 487-494.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Cocontraction and phasic activity during GAIT in children with cerebral palsy

AU - Unnithan, V.B.

AU - Dowling, J.J.

AU - Frost, G.

AU - Volpe Ayub, B.

AU - Bar-Or, O.

PY - 1996/12

Y1 - 1996/12

N2 - Simultaneous activity of agonist and antagonistic muscles during a task is known as cocontraction. The primary aim of the present study was to use a cocontraction index (CI) to quantify differences in EMG activity between a group of CP and control children at two different walking speeds. The secondary aim was to compare the amount of time the muscles were activated ("on" thresholds) between the groups. Seventeen subjects volunteered for the study. One group consisted of 9 (7M, 2F) children with CP (age 12.7 +/- 2.8 years, mean +/- SD). The second group consisted of 8 able-bodied controls (7M, 1F). The discontinuous submaximal treadmill walking protocol had two 4min stages at 0% gradient. Speeds selected were 3 km.h-1 and 90% of the pre-determined fastest walking speed (FWS). Two sites of CI were measured from the EMGs of tibialis anterior and soleus (leg) and vastus lateralis and hamstrings (thigh). Significantly (p < 0.05) higher CI values were noted for the CP subjects compared to the controls, irrespective of speed or cocontraction site and there was a significant (p < 0.05) increase in CI values with increased walking speed for both CP and control subjects. Phasic analyses for 5% max EMG and 10% max EMG "on" thresholds demonstrated significant (p < 0.05) main effects for group (CP subjects had a longer time period of muscle activation than controls) and speed (muscles were active longer at 90% FWS than 3 km.h-1). The precise mechanisms by which cocontraction contributes toward abnormal gait and wasted mechanical energy require further research incorporating both electromyographic and kinematic analysis.

AB - Simultaneous activity of agonist and antagonistic muscles during a task is known as cocontraction. The primary aim of the present study was to use a cocontraction index (CI) to quantify differences in EMG activity between a group of CP and control children at two different walking speeds. The secondary aim was to compare the amount of time the muscles were activated ("on" thresholds) between the groups. Seventeen subjects volunteered for the study. One group consisted of 9 (7M, 2F) children with CP (age 12.7 +/- 2.8 years, mean +/- SD). The second group consisted of 8 able-bodied controls (7M, 1F). The discontinuous submaximal treadmill walking protocol had two 4min stages at 0% gradient. Speeds selected were 3 km.h-1 and 90% of the pre-determined fastest walking speed (FWS). Two sites of CI were measured from the EMGs of tibialis anterior and soleus (leg) and vastus lateralis and hamstrings (thigh). Significantly (p < 0.05) higher CI values were noted for the CP subjects compared to the controls, irrespective of speed or cocontraction site and there was a significant (p < 0.05) increase in CI values with increased walking speed for both CP and control subjects. Phasic analyses for 5% max EMG and 10% max EMG "on" thresholds demonstrated significant (p < 0.05) main effects for group (CP subjects had a longer time period of muscle activation than controls) and speed (muscles were active longer at 90% FWS than 3 km.h-1). The precise mechanisms by which cocontraction contributes toward abnormal gait and wasted mechanical energy require further research incorporating both electromyographic and kinematic analysis.

M3 - Article

VL - 36

SP - 487

EP - 494

JO - Electromyography and Clinical Neurophysiology

JF - Electromyography and Clinical Neurophysiology

SN - 0301-150X

IS - 8

ER -