Sandy A. Ross

Ankle spasticity and strength in children with spastic diplegic cerebral palsy

Ankle spasticity and strength in 27 children with spastic diplegic cerebral palsy (CP) (mean age 9 years, range 3 to 18 years) and a group of 12 children without CP (comparison group) (mean age 9 years, range 5 to 18 years) were observed. To measure spasticity, a KinCom dynamometer dorsiflexed the passive ankle at five different speeds and recorded the resistive plantarflexion torques. Work values for the torque‐angle data were calculated at each speed. Using this data, linear regression was used to measure spasticity. To measure strength, the dynamometer rotated the ankle from maximum dorsiflexion to maximum plantarflexion at a speed of 10°/s while the child performed a maximum plantarflexion concentric contraction. The movement was reversed to record maximum dorsiflexion. Maximum torques and work by the plantarflexors and dorsiflexors were calculated. The group with CP had significantly more spasticity in the plantarflexors and significantly less strength in the plantarflexors and dorsiflexors than the group without CP. Results provide objective information quantifying ankle spasticity and strength in children with CP.

Relation between spasticity and strength in individuals with spastic diplegic cerebral palsy

The relation between spasticity and strength in individuals with cerebral palsy (CP) has not been extensively researched. Knee and ankle spasticity and strength were quantified in a retrospective analysis of 60 individuals with spastic diplegic CP (mean age 12 years, range 3 to 38) and a group of 50 individuals without disabilities (WD group; mean age 12 years, range 4 to 36). Spasticity was measured using a KinCom dynamometer that stretched the passive knee flexors or ankle plantarflexors at different speeds and recorded the amount of resistive torques. For the strength tests, the participant performed a maximum contraction of the knee flexors/extensors and ankle plantarflexors/dorsiflexors throughout their range of motion at a speed of 10/s on the dynamometer. Pearsons correlation coefficient was used to determine if a relation existed between spasticity and strength within the same muscle group and in opposing muscle groups at the knee and ankle joints. A t‐test was performed to determine if greater spasticity and less strength existed at the ankles compared with the knees in those with CP. Results show that there was no relation between spasticity and strength either within the same muscle group or at opposing muscle groups at the knee and ankle joints in persons with CP. Individuals with spastic diplegic CP were more involved (greater spasticity, less strength) distally at the ankles compared with the knees. The findings conflict with the literature, which contains several assumptions, one of which is that a spastic muscle is a strong muscle and that spasticity causes weakness in the opposing muscle group. We found no relation between spasticity and strength in individuals with CP. Our findings support the literature, which states that individuals with spastic diplegic CP are more involved distally compared with proximally in the lower extremities.

Prospective Comparison of Gait and Trunk Range of Motion in Adolescents With Idiopathic Thoracic Scoliosis Undergoing Anterior or Posterior Spinal Fusion

Study Design. Prospective evaluation of gait and spinal range of motion (ROM) in adolescent idiopathic scoliosis (AIS) patients undergoing either an anterior or a posterior spinal fusion. Objective. Compare changes in gait and spine ROM between AIS patients undergoing either an anterior or posterior spinal fusion. Summary and Background Data. Problems with AIS posterior spinal fusion and attempts to minimize the number of spinal segments fused have led to the promotion of anterior spinal fusion. Comparison of functional outcomes of the two surgeries has not been reported. Materials and Methods. Thirty-one patients with single or double thoracic AIS undergoing an anterior (n = 16) or posterior (n = 15) instrumented spinal fusion underwent gait and triplanar ROM tests before surgery and 24 months postoperative. Videography with reflective surface markers on the scapula, spine, and pelvis were used to quantify changes in gait and trunk ROM. Results. Surgical results indicated that an average of four fewer levels was fused and the lowest instrumented vertebrae were one level higher in the spine for the anterior group compared to the posterior group. Gait results showed no change in gait speed and no change in coronal and sagittal plane kinematics, regardless of group. Transverse plane motion during gait was reduced in both groups. Spinal ROM results indicated motion loss in all three planes, regardless of group, with the posterior group having less postoperative ROM than the anterior group. Unlinking surgical approach from number of fused levels and lowest instrumented vertebrae with a subset of subjects also indicated less postoperative ROM for the posterior group. Conclusions. The surgical and ROM results seem to favor the anterior approach over the posterior approach for the classification of patients in this investigation. However, it should be noted that both groups had decreased postoperative ROM.

Changes in hip spasticity and strength following selective dorsal rhizotomy and physical therapy for spastic cerebral palsy

Hip adductor spasticity and strength in participants with cerebral palsy (CP) were quantified before and after selective dorsal rhizotomy (SDR) and intensive physical therapy. Twenty-four participants with cerebral palsy (CP group) and 35 non-disabled participants (ND controls) were tested with a dynamometer (OP group: mean age 8 years 5 months, 13 males, 11 females; ND group: mean age 8 years 6 months, 19 males, 16 females). According to the Gross Motor Function Classification System (GMFCS), of the 24 participants with CP, eight were at level I, six were at level II, and 10 participants were at level III. For the spasticity measure, the dynamometer quantified the resistive torque of the hip adductors during passive abduction at 4 speeds. The adductor strength test recorded a maximum concentric contraction. CP group spasticity was significantly reduced following SDR and adductor strength was significantly increased after surgery. Both pre- and postoperative values remained significantly less than the ND controls. Spasticity results agreed with previous studies indicating a reduction. Strength results conflicted with previous literature subjectively reporting a decrease following SDR. However, results agreed with previous objective investigations examining knee and ankle strength, suggesting strength did not decrease following SDR.

Changes in synergistic movement patterns after selective dorsal rhizotomy.

The purpose of this investigation was to quantitatively compare synergistic movement patterns between seven children (four male, three female; aged 3 to 17 years; mean 6.7, SD 5.3) without cerebral palsy (CP) (controls) and 27 children (15 male, 12 female; aged 2 to 16 years; mean 5.7, SD 3.7) with spastic diplegic CP before and after selective dorsal rhizotomy (SDR). The study design was also descriptive, comparing results of before and after SDR to control children. A two dimensional video system and retroreflective markers were used to obtain sagittal plane angles for the hip, knee, and ankle during maximum active knee flexion and extension. Correlations were calculated between the knee and hip and between the knee and ankle joint pairs. Control children demonstrated non‐synergistic movement patterns (‐0.75 and ‐0.61). These results were significantly different from children with CP (0.40 and 0.43, p<0.05). Eight months after SDR, synergistic patterns did not significantly change from preoperative results (0.23 and 0.36, p>0.05) and remained significantly different from control children (p<0.05). We conclude that it may not be possible to significantly alter synergistic patterns after SDR.

Quadriceps and hamstring strength changes as a function of selective dorsal rhizotomy surgery and rehabilitation.

Purpose: Objective measures of strength in children with cerebral palsy (CP) are needed to determine the effect that selective dorsal rhizotomy surgery (SDR) and subsequent rehabilitation have on muscle strength. This investigation quantified quadriceps and hamstring strength in children with CP pre‐SDR and eight months post‐SDR. Method: Nineteen children with CP and 20 children without disabilities (WD group) were tested with an isokinetic dynamometer. The children performed a maximum concentric contraction of the quadriceps muscles as the dynamometer moved the knee from a flexed position to an extended position at 10 degrees per second. A maximum concentric contraction of the hamstring muscles was then performed as the knee was moved from extension to flexion. Four variables were recorded from the torque‐angle data; peak extension and flexion torque and extension and flexion work. Results: Children with CP, both pre‐ and post‐SDR were significantly weaker in all strength measures compared with the WD group. Children with CP post‐SDR and rehabilitation had significantly greater peak torque and work values compared with their pre‐SDR values. The results agreed with previous studies indicating that children with CP are weaker than their peers without disabilities. Previous studies on strength changes after SDR remain controversial. Conclusions: The results of this study showed a significant increase in strength at the knee after rhizotomy and rehabilitation.