TY - JOUR
T1 - Quantitative analysis of the velocity related pathophysiology of spasticity and rigidity in the elbow flexors
AU - Lee, H. M.
AU - Huang, Y. Z.
AU - Chen, Jia Jin J.
AU - Hwang, I. S.
PY - 2002
Y1 - 2002
N2 - Objective: To quantify velocity dependent and position related properties of increased muscle tone measured during a constant velocity stretch. Methods: Elbow flexors were vertically stretched under four different velocities (40, 80, 120, and 160°/s) through a 75° range of motion in 12 patients with hemiparesis, 16 with parkinsonism, and 12 normal controls. From reactive torque measurement, a linear second order model was adopted to dissociate velocity dependent viscous and velocity independent elastic components. The averaged speed dependent reflex torque (ASRT) - defined as the deviation of measured torque from baseline torque - was used to quantify the viscous component of hypertonia. Velocity sensitivity of ASRT (VASRT) and segmented ASRT (SASRT), derived from the slope of the regression line among ASRT velocity plots and from segmentations of reactive torque, respectively, were used to differentiate the increased muscle tone of spasticity and rigidity. Results: ASRT and VASRT were significantly higher in both spasticity and rigidity than in normal controls. SASRT analysis showed three different position related patterns among spasticity, rigidity, and normal groups: spasticity showed progressively increasing muscle tension relative to position; rigidity showed increased (relative to the norm) but constant muscle tone over the entire stretch range; the normal control group showed a consistently low reactive torque over the entire range. Conclusions: Velocity dependence analysis indicates that rigidity and spasticity have approximately equal velocity dependent properties. For differentiating these two types of hypertonia, position dependent properties my be employed.
AB - Objective: To quantify velocity dependent and position related properties of increased muscle tone measured during a constant velocity stretch. Methods: Elbow flexors were vertically stretched under four different velocities (40, 80, 120, and 160°/s) through a 75° range of motion in 12 patients with hemiparesis, 16 with parkinsonism, and 12 normal controls. From reactive torque measurement, a linear second order model was adopted to dissociate velocity dependent viscous and velocity independent elastic components. The averaged speed dependent reflex torque (ASRT) - defined as the deviation of measured torque from baseline torque - was used to quantify the viscous component of hypertonia. Velocity sensitivity of ASRT (VASRT) and segmented ASRT (SASRT), derived from the slope of the regression line among ASRT velocity plots and from segmentations of reactive torque, respectively, were used to differentiate the increased muscle tone of spasticity and rigidity. Results: ASRT and VASRT were significantly higher in both spasticity and rigidity than in normal controls. SASRT analysis showed three different position related patterns among spasticity, rigidity, and normal groups: spasticity showed progressively increasing muscle tension relative to position; rigidity showed increased (relative to the norm) but constant muscle tone over the entire stretch range; the normal control group showed a consistently low reactive torque over the entire range. Conclusions: Velocity dependence analysis indicates that rigidity and spasticity have approximately equal velocity dependent properties. For differentiating these two types of hypertonia, position dependent properties my be employed.
UR - http://www.scopus.com/inward/record.url?scp=0036240892&partnerID=8YFLogxK
U2 - 10.1136/jnnp.72.5.621
DO - 10.1136/jnnp.72.5.621
M3 - 文章
C2 - 11971049
AN - SCOPUS:0036240892
SN - 0022-3050
VL - 72
SP - 621
EP - 629
JO - Journal of Neurology, Neurosurgery and Psychiatry
JF - Journal of Neurology, Neurosurgery and Psychiatry
IS - 5
ER -