Quantifying muscle tone in spinal cord injury patients using isokinetic dynamometric techniques

Abstract

The torque generated during a passive movement of the knee joint was used to quantify muscle tone in normal able-bodied subjects and spastic and flaccid spinal cord injury (SCI) subjects using a computerized isokinetic dynamometer. Maximum peak (Tmax) and the sum of four consecutive peaks (Tsum) were calculated for each velocity (30, 60, 120° Is) and for each phase (flexing or extending) separately and compared statistically using a one-way ANOV A. Statistical significance between groups was found in T max FLEXION (FLX) at 60 and 1200/s. Scheffe's tests revealed that the spastic group was significantly less than both the flaccid and normal groups, although the flaccid and normal groups were not significantly different from each other. The slopes of the linear regression curve of the torque-velocity data were found and compared statistically using a t-test for parallelism. In all parameters, the data increased in a linear fashion with increasing velocity of knee motion. The slope of the regression curve for the spastic group was significantly lower than that of the normal group for T max and was significantly lower than that of the flaccid group for Tsum while the slopes for the flaccid and normal groups were not significantly different. The ability of the entire set of variables to classify subjects into three groups (normal, spastic, and flaccid) was tested using discriminant analysis. By taking into account 7 of the 12 original variables, this multivariate technique correctly classified 100% of the spastic, 90% of the normal, but only 67% of the flaccid subjects. Separation of observations was between spastic and normal subjects was good, except for only one case. This feature could be useful when dealing with assessment of individual responses to therapeutic interventions aimed at modification of spasticity.

Spasticity-assessment: a review

“…There was a significantly lower average torque in the SCL group with AS scores 1-2 compared to the normal group for extension of the knee at 601 and 1201/s, and correspondingly a higher average peak torque in the SCL group with the AS score 3 compared to the normal group at extension and flexion at 601 and at 1201/s (Table 5). They state that the lower or equal peak torque in the SCL group with AS score 1-2 were comparable to data from a normal group reported by Perell et al 45 This comparison seems a bit dared, since the two studies used different AS scores for subdivision of SCL individuals (Table 5). Consequently, it is difficult to draw conclusions in this respect from the two studies.…”

Assessment of spasticity using isokinetic dynamometry in patients with spinal cord injury

“…Perell et al used the same method to assess muscle tone in ten normal individuals, and 11 spastic and six¯accid SCI patients. 12 They pointed out that this technique correctly classi®ed 100% of the spastic subjects and could be useful in assessing individual response to therapeutic interventions aimed at modifying spasticity. In their recent report, Engsberg et al suggested that a combination of the key elements of stretch, resistance, and velocity under the mechanical term work' be used as a measure of spasticity instead of torque.…”

The effect of passive cycling movements on spasticity after spinal cord injury: preliminary results

“…[11][12][13] With this technique, it is possible to test the resistance to passive movement in the joints with preset speeds at different lengths of the same muscle. As one of the definitions of spasticity is a velocity-dependent increase in muscle tone to passive stretching, 14 isokinetic dynamometry seems to be a suitable technique suited for this purpose.…”