N. Susan Stott

Reliability and validity of the Observational Gait Scale in children with spastic diplegia

The aim of this study was to establish the reliability and validity of visual gait assessment in children with spastic diplegia, who were community or household ambulators, using a modified version of the Physicians Rating Scale, known as the Observational Gait Scale (OGS). Two clinicians viewed edited split-screen video recordings of 20 children/adolescents (11 males, 9 females; mean age 12 years, range 6 to 21 years) made at the time of three-dimensional gait analysis (3-DGA). Walking ability in each child was scored at initial assessment and reassessed from the same videos three months later using the first seven sections of the OGS. Validity of the OGS score was determined by comparison with 3-DGA. The OGS was found to have acceptable interrater and intrarater reliability for knee and foot position in mid-stance, initial foot contact, and heel rise with weighted kappas (wk) ranging from 0.53 to 0.91 (intrarater) and 0.43 to 0.86 (interrater). Comparison with 3-DGA suggests that these sections might also have high validity(wk range 0.38-0.94). Base of support and hind foot position had lower interrater and intrarater reliabilities (wk 0.29 to 0.71 and wk 0.30 to 0.78 respectively) and were not easily validated by 3-DGA.

Circuit-Based Rehabilitation Improves Gait Endurance but Not Usual Walking Activity in Chronic Stroke: A Randomized Controlled Trial

UNLABELLED Mudge S, Barber PA, Stott NS. Circuit-based rehabilitation improves gait endurance but not usual walking activity in chronic stroke: a randomized controlled trial. OBJECTIVE To determine whether circuit-based rehabilitation would increase the amount and rate that individuals with stroke walk in their usual environments. DESIGN Single-blind randomized controlled trial. SETTING Rehabilitation clinic. PARTICIPANTS Sixty participants with a residual gait deficit at least 6 months after stroke originally enrolled in the study. Two withdrew in the initial phase, leaving 58 participants (median age, 71.5y; range, 39.0-89.0y) who were randomized to the 2 intervention groups. INTERVENTIONS The exercise group had 12 sessions of clinic-based rehabilitation delivered in a circuit class designed to improve walking. The control group received a comparable duration of group social and educational classes. MAIN OUTCOME MEASURES Usual walking performance was assessed using the StepWatch Activity Monitor. Clinical tests were gait speed (timed 10-meter walk) and endurance (six-minute walk test [6MWT]), confidence (Activities-Based Confidence Scale), self-reported mobility (Rivermead Mobility Index [RMI]), and self-reported physical activity (Physical Activity and Disability Scale). RESULTS Intention-to-treat analysis revealed that the exercise group showed a significantly greater distance for the 6MWT than the control group immediately after the intervention (P=.030) but that this effect was not retained 3 months later. There were no changes in the StepWatch measures of usual walking performance for either group. The exercise and control groups had significantly different gait speed (P=.038) and scores on the RMI (P=.025) at the 3-month follow-up. These differences represented a greater decline in the control group compared with the exercise group for both outcome measures. CONCLUSIONS Circuit-based rehabilitation leads to improvements in gait endurance but does not change the amount or rate of walking performance in usual environments. Clinical gains made by the exercise group were lost 3 months later. Future studies should consider whether rehabilitation needs to occur in usual environments to improve walking performance.

Intraobserver reliability of the modified Tardieu scale in the upper limb of children with hemiplegia

This study investigated the reliability of the modified Tardieu scale in the assessment of biceps spasticity in the upper limbs of children with hemiplegic cerebral palsy (CP). Ten children, with hemiplegic CP participated in the study: six males (mean age 9 years, SD 4 years) and four females (mean age 12 years, SD 3 years). Blinded, duplicate measures of dynamic elbow extension were performed on the hemiplegic arm at time 0 and 7 days later, using the three angular velocities described in the Tardieu scale (V1, slow; V2, speed of gravity; V3, as fast as possible). The resulting elbow joint angles were defined as R1, the angle of catch following a fast velocity stretch at either V2 or V3; and R2, the passive range of movement achieved following a slow velocity stretch at V1. Both elbow joint angle and movement angular velocity were measured by three‐dimensional kinematics. Median error in measured elbow joint angle within one session ranged from 3 to 5°. Between sessions median absolute differences in measured elbow joint angle ranged from 4 to 13°, with measurement errors of up to 25 to 30° in some participants at the fastest velocity (V3). The therapist was able to apply three significantly different angular velocities as required for the Tardieu scale (p < 0.001). However, the ranges of the three angular velocities overlapped, with fast velocities for some participants being equivalent to slow velocities for other participants. Three out of 10 participants had an intersessional difference in their R2‐R1 score of more than 20°. From this study, we concluded that the R2‐R1 value determined from the modified Tardieu scale may be of limited value in assessing biceps spasticity the upper limbs in children with hemiplegic CP.

Intrarater reliability of lower limb sagittal range-of-motion measures in children with spastic diplegia

In this study, 10 sagittal lower limb range-of-motion measures were conducted in a blinded fashion in 25 children with spastic diplegic cerebral palsy and in 25 age- and sex-matched controls. The participants comprised 22 males, mean age 10 years 8 months and 28 females, with mean age 9 years 8 months; age range 6 to 17 years. One paediatric physical therapist performed duplicate goniometric measures at zero time and 7 days later using the same sequence of measures, location, and time of day. Mean absolute differences for measures within one session ranged from 0.7 to 2.9 degrees in controls and from 1 to 4.2 degrees in children with spastic diplegia. Most intraclass correlation coefficients (ICCs) for intra-sessional measures were more than 0.90 in both groups. Measures between sessions were less reliable. Mean absolute differences between sessions were up to 7.1 degrees for children with spastic diplegia and 8.6 degrees for controls, with most ICCs being less than 0.80. Inter-sessional variation in measures was similar in both groups, suggesting that measurement variability is not influenced by the presence of spasticity. Averaging of two measures did not improve inter-sessional reliability compared with the use of a single measure. Dynamic measures (R1) were as reliable as passive measures (R2), but there were inter-sessional differences in calculations using R1 and R2 measures of up to 30 degrees.

Bone morphogenetic protein‐2 modulation of chondrogenic differentiation in vitro involves gap junction‐mediated intercellular communication

Undifferentiated mesenchymal cells in the limb bud integrate a complex array of local and systemic signals during the process of cell condensation and chondrogenic differentiation. To address the relationship between bone morphogenetic protein (BMP) signaling and gap junction‐mediated intercellular communication, we examined the effects of BMP‐2 and a gap junction blocker 18 alpha glycyrrhetinic acid (18α‐GCA) on mesenchymal cell condensation and chondrogenic differentiation in an in vitro chondrogenic model. We find that connexin43 protein expression significantly correlates with early mesenchymal cellular condensation and chondrogenesis in high‐density limb bud cell culture. The level of connexin43 mRNA is maximally upregulated 48 h after treatment with recombinant human BMP‐2 with corresponding changes in protein expression. Inhibition of gap junction‐mediated intercellular communication with 2.5 μM 18α‐GCA decreases chondrogenic differentiation by 50% at 96 h without effects on housekeeping genes. Exposure to 18α‐GCA for only the first 24–48 h after plating does not affect condensation or later chondrogenic differentiation suggesting that gap junction‐mediated intercellular communication is not critical for the initial phase of condensation but is important for the onset of differentiation. 18α‐GCA can also block the chondrogenic effects of BMP‐2 without effects on cell number or connexin43 expression. These observations demonstrate 18α‐GCA‐sensitive regulation of intercellular communication in limb mesenchymal cells undergoing chondrogenic differentiation and suggest that BMP‐2 induced chondrogenic differentiation may be mediated in part through the modulation of connexin43 expression and gap junction‐mediated intercellular communication. J. Cell. Physiol. 193: 233–243, 2002.

Test—retest reliability of the StepWatch Activity Monitor outputs in individuals with chronic stroke

Objective: To examine the test—retest reliability of the StepWatch Activity Monitor outputs over two periods, a week apart, in participants with stroke. Design: Test—retest reliability study over monitoring periods of one, two and three days. Setting: Participants usual environment. Participants: Forty participants more than six months post stroke. Main measures: StepWatch outputs: total step count, number of steps at high medium and low stepping rates, sustained activity indices, peak activity index. Results: The intraclass correlation coefficients were high for all StepWatch outputs and all monitoring periods but were highest for the three-day monitoring period (0.930—0.989) and lowest for the one-day monitoring period (0.830—0.950). The coefficient of variation ranged from 6.7% to 48.7% over the monitoring periods, with higher variation shown for shorter monitoring periods. The most reliable four outputs had 95% limits of agreement between three-day periods that were less than 40%. These were total step count (±37.8%), highest step rate in 1 minute (±23.0%), highest step rate in 5 minutes (±38.6%) and peak activity index (±29.8%). The highest step rate in 1 minute was the only StepWatch output that had 95% limits of agreement less than 40% for the two-day (±31.2%) and one-day (±36.7%) monitoring periods. Conclusions: Total step count, highest step rate in 1 minute, highest step rate in 5 minutes and peak activity index have good test—retest reliability over a three-day monitoring period, with lower reliability shown by the other StepWatch outputs. In general, monitoring over one or two days is less reliable.

Treatment for Idiopathic Toe-walking: Results at Skeletal Maturity

Thirteen skeletally mature subjects who had been treated as children for idiopathic toe-walking underwent gait analysis and calf muscle strength testing at an average of 10.8 years from the last intervention. Six had had serial casting only; seven had had either a percutaneous tendo Achilles lengthening or a Bakers gastroc-soleus lengthening. Sagittal plane kinematics at the ankle was altered in 12 of the 13 subjects, but the changes were detectable visually in only 3 subjects. One subject had increased ankle plantarflexion at initial contact, but the other 12 subjects had a normal first rocker. Peak ankle dorsiflexion in stance averaged only 9°, and 11 of the subjects had a peak ankle dorsiflexion in stance greater than 2 standard deviations below normative values. Ankle dorsiflexion was also restricted on passive measures, but there was no correlation between ankle dorsiflexion non-weight-bearing and in gait. Inversion of second rocker was seen in two subjects with peak ankle dorsiflexion in stance occurring before 25% of the gait cycle. Power generation by the calf during a single heel-rise test was variable between subjects but within normative values compared with controls. The authors conclude that most subjects showed persistent changes in ankle kinematics and kinetics despite treatment but that this was not detectable visually in most subjects.

Enabling Self-Directed Computer Use for Individuals with Cerebral Palsy: A Systematic Review of Assistive Devices and Technologies

Aim  The purpose of this study was to systematically review published evidence on the development, use, and effectiveness of devices and technologies that enable or enhance self‐directed computer access by individuals with cerebral palsy (CP).

The Sensitivity and Specificity of an Activity Monitor in Detecting Functional Activities in Young People With Cerebral Palsy

OBJECTIVE To evaluate the sensitivity and specificity of the Intelligent Device for Energy Expenditure and Activity (IDEEA) monitor in detecting functional activities in young people with cerebral palsy (CP). DESIGN Validation study. SETTING Two identical data collections completed 1 week apart at a gait laboratory. PARTICIPANTS Twenty-five young people with CP and 30 able-bodied (AB) peers (age 8-25 y; mean age CP 14.1 y, Gross Motor Function Classification System Level I-III; mean age AB, 14.2 y). INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Each participant completed 5 functional activities (sitting, lying, standing, walking, and stairs), with the monitor attached. The sensitivity and specificity of the monitor in detecting each activity was calculated by comparison to a written timed report. RESULTS Sitting, lying, and standing were detected with median 100% sensitivity in both participant groups and across both testing sessions. Accuracy of walking detection was reduced compared with static activities (P<.05) across the 2 sessions and groups. The CP group had a significantly higher number of participants where the activity was not detected with 100% sensitivity (lie: 18% CP, 5% AB, P<.04; stand: 12% CP, 0% AB, P<.02; walk: 96% CP, 81% AB, P<.03). Stair climbing was detected in only half of the 12 participants with CP who could achieve the task. The IDEEA demonstrated high specificity (range, 97%-100%) for both participant groups. CONCLUSIONS The IDEEA activity monitor had high levels of sensitivity and specificity in determining everyday static activities in participants with CP, with greater difficulties in detecting dynamic activities of walking and stair climbing.

Effect of botulinum toxin A-induced paralysis and exercise training on mechanosensing and signalling gene expression in juvenile rat gastrocnemius muscle

Intramuscular injections of the paralytic botulinum neurotoxin A (Btx) and physical exercise are used in the treatment of chronic spasticity in children with cerebral palsy. We tested whether Btx‐induced paralysis and/or exercise training would have differential effects on the expression of mechanosensing and signalling genes implicated in the adaptive remodelling of skeletal muscle. Juvenile (29‐day‐old) male rats were injected with Btx or saline (NoBtx) into the right gastrocnemius and housed in standard cages (NoEx) or with running wheels (Ex), for 3 weeks (n= 6 per group). The mRNA expression of nine sarcomere‐associated genes in the medial gastrocnemius was then determined by quantitative reverse transcriptase‐polymerase chain reaction. The Btx‐injected muscles weighed 50% less than NoBtx muscles, but Ex had no effect on the wet mass of Btx or NoBtx muscles. Atrogenic MuRF1, sarcomeric Titin and myogenic MyoD were upregulated (2‐fold) with the elimination of contractile activity in Btx muscle. Expression of CARP, Ankrd2 and MLP was increased with mechanical stimuli associated with Btx (5‐ to 10‐fold) or Ex (2‐ to 4‐fold). Expression of CARP and Ankrd2 increased synergistically in Btx–Ex muscle (≥20‐fold), indicating that these genes may be sensitive to passive stretch of the sarcomeric I‐band region of titin to which their proteins bind. Tcap, Myopalladin and Atrogin1 were not, or were no longer responsive to the altered mechanical stimuli after 3 weeks of Btx or Ex. The expression of Ankrd2, CARP and MLP may thus be enhanced by passive stretch within the Btx‐paralysed and/or exercising gastrocnemius and contribute to adaptations, other than muscle mass, in juvenile rats.