TY - JOUR
T1 - Motor impairments related to brain injury timing in early hemiparesis. part ii
T2 - Abnormal upper extremity joint torque synergies
AU - Sukal-Moulton, Theresa
AU - Krosschell, Kristin J.
AU - Gaebler-Spira, Deborah J.
AU - Dewald, Julius P.A.
PY - 2014/1/1
Y1 - 2014/1/1
N2 - Background. Extensive neuromotor development occurs early in human life, and the timing of brain injury may affect the resulting motor impairment. In Part I of this series, it was demonstrated that the distribution of weakness in the upper extremity depended on the timing of brain injury in individuals with childhood-onset hemiparesis. Objective. The goal of this study was to characterize how timing of brain injury affects joint torque synergies, or losses of independent joint control. Method. Twenty-four individuals with hemiparesis were divided into 3 groups based on the timing of their injury: before birth (PRE-natal, n = 8), around the time of birth (PERI-natal, n = 8), and after 6 months of age (POST-natal, n = 8). Individuals with hemiparesis and 8 typically developing peers participated in maximal isometric shoulder, elbow, wrist, and finger torque generation tasks while their efforts were recorded by a multiple degree-of-freedom load cell. Motor output in 4 joints of the upper extremity was concurrently measured during 8 primary torque generation tasks to quantify joint torque synergies. Results. There were a number of significant coupling patterns identified in individuals with hemiparesis that differed from the typically developing group. POST-natal differences were most noted in the coupling of shoulder abductors with elbow, wrist, and finger flexors, while the PRE-natal group demonstrated significant distal joint coupling with elbow flexion. Conclusion. The torque synergies measured provide indirect evidence for the use of bulbospinal pathways in the POST-natal group, while those with earlier injury may use relatively preserved ipsilateral corticospinal motor pathways.
AB - Background. Extensive neuromotor development occurs early in human life, and the timing of brain injury may affect the resulting motor impairment. In Part I of this series, it was demonstrated that the distribution of weakness in the upper extremity depended on the timing of brain injury in individuals with childhood-onset hemiparesis. Objective. The goal of this study was to characterize how timing of brain injury affects joint torque synergies, or losses of independent joint control. Method. Twenty-four individuals with hemiparesis were divided into 3 groups based on the timing of their injury: before birth (PRE-natal, n = 8), around the time of birth (PERI-natal, n = 8), and after 6 months of age (POST-natal, n = 8). Individuals with hemiparesis and 8 typically developing peers participated in maximal isometric shoulder, elbow, wrist, and finger torque generation tasks while their efforts were recorded by a multiple degree-of-freedom load cell. Motor output in 4 joints of the upper extremity was concurrently measured during 8 primary torque generation tasks to quantify joint torque synergies. Results. There were a number of significant coupling patterns identified in individuals with hemiparesis that differed from the typically developing group. POST-natal differences were most noted in the coupling of shoulder abductors with elbow, wrist, and finger flexors, while the PRE-natal group demonstrated significant distal joint coupling with elbow flexion. Conclusion. The torque synergies measured provide indirect evidence for the use of bulbospinal pathways in the POST-natal group, while those with earlier injury may use relatively preserved ipsilateral corticospinal motor pathways.
KW - cerebral palsy
KW - childhood hemiparesis
KW - childhood hemiplegia
KW - independent joint control
KW - selective motor control
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U2 - 10.1177/1545968313497829
DO - 10.1177/1545968313497829
M3 - Article
C2 - 23911972
AN - SCOPUS:84890961177
VL - 28
SP - 24
EP - 35
JO - Journal of Neurologic Rehabilitation
JF - Journal of Neurologic Rehabilitation
SN - 1545-9683
IS - 1
ER -