Susan J. Hillman

Edinburgh visual gait score for use in cerebral palsy

Complex gait analysis systems are not generally available worldwide, and no simple system of assessing gait by observation has been validated specifically for use in patients with cerebral palsy. The authors have developed a visual gait analysis score for use in cerebral palsy. Videotaped sequences of patients were recorded before and after surgery as part of a three-dimensional gait study using a Vicon (Oxford, U.K.) gait analysis system. The score demonstrated good intraobserver and interobserver reliability. The numeric values of the score elements correlated well with the measurements obtained from instrumented gait analysis for the same patients, and the score was able to detect postoperative change.

Kinematic and kinetic gait characteristics of normal children walking at a range of clinically relevant speeds.

Kinematic and kinetic data were obtained from 36 normal children who walked at five different clinically relevant speeds, which were mostly slower than normal speed. Speed groups were normalized for body height. Speed significantly affected most of the stride parameters, joint angles, joint moments, and the ground reaction force in all three planes of motion. The effects of speed were not always the same over the whole range of speeds studied. The clinical relevance of these findings is that when comparing pathologic gait characteristics with those of normal children, these should be derived from the same walking speed. This may help to differentiate between effects caused by speed and underlying pathology.

Gait analysis alters decision-making in cerebral palsy.

This study was designed to assess the impact of gait analysis on the treatment of patients with cerebral palsy. One hundred two ambulant patients with cerebral palsy were assessed clinically and with gait analysis. Separate treatment proposals for each patient were recorded after clinical examination and after gait analysis. The results of the two methods of assessment were compared. After clinical assessment, 71 of the 102 patients evaluated were recommended for a surgical procedure and 31 for nonoperative treatment. After gait analysis, the indications for treatment were confirmed in 91 cases (89%). Clinical assessment by the same orthopedic surgeon was in close agreement with gait analysis in identifying an indication for surgery. There was less agreement in the type or level of operation recommended. Gait analysis altered the decision in 106 of 267 operations (40%). There was good agreement for bone surgery, suggesting that clinical evaluation of torsional problems was fairly reliable. The poorer agreement seen for soft tissue operations probably reflects the difficulties in assessing tone-related problems in these patients clinically. This study confirms the value of gait analysis for decision-making in cerebral palsy.

Sagittal joint kinematics, moments, and powers are predominantly characterized by speed of progression, not age, in normal children.

Twenty-six healthy 7-year-old children were enrolled in a 5-year longitudinal study to examine the importance of age and speed in the characterization of sagittal joint angles, moments, and powers. In 740 gait trials, children walking at self-selected speeds were examined on the basis of age and normalized speed [speed/(height ×g)1/2]. The kinematics and kinetics in these children were characterized predominantly by normalized speed of progression and not age. The clinical relevance of these findings is that normalized speed of walking, rather than age, should be considered when comparing normal with pathologic gait.

Normalized speed, not age, characterizes ground reaction force patterns in 5-to 12-year-old children walking at self-selected speeds.

Twenty-six healthy 5-year-old children were enrolled in a 7-year longitudinal study to examine the importance of age and speed in the characterization of ground reaction forces. One thousand forty gait trials of children walking at self-selected speeds were examined on the basis of age and normalized speed [speed/(height ×g)½]. Results, presented as discrete peak and trough values and as continuous trace plots over the stance phase, indicated that there was little change in ground reaction forces with age, but there were significant changes in vertical force and anterior-posterior force values with normalized speed. The ground reaction force patterns in these children were characterized predominantly by normalized speed of progression and not age. The clinical relevance of these findings is that normalized speed of walking, rather than age, should be considered when comparing normal with pathological gait.

Development of temporal and distance parameters of gait in normal children

Temporal and distance parameters of 33 normal children were obtained from instrumented gait analysis prospectively over five consecutive years. The parameters were normalised to minimise the confounding effects of increasing height and leg length. Rank correlations were performed on normalised speed, normalised stride length, normalised cadence and normalised walk ratio across consecutive pairs of years to examine the ranking of these parameters for an individual child over time. Consistent trends of increasing rank correlation were observed in normalised stride length and normalised walk ratio suggesting that individual children were continuing to adjust these gait parameters towards their own characteristic position within the normal range. Consistent trends were not observed in the rank correlations for normalised speed and normalised cadence. These findings support the concept that individual children predominantly adjusted their cadence to effect changes in speed, while the development of stride length was dictated by other factors specific to the individual child. Rank correlation coefficients for walk ratio between consecutive years increased from the ages of 7-11 years of age and hence walk ratio appears be a feature of gait that matures beyond the age of 7 years. This accords with the proposal that it is an invariant parameter for an individual.

Reliability and validity of the Edinburgh Visual Gait Score for cerebral palsy when used by inexperienced observers

The Edinburgh Visual Gait Score (EVGS) for cerebral palsy has been validated for observer reliability and validity for observers experienced in gait analysis. This study investigated the reliability and validity of the EVGS for observers inexperienced in gait analysis. Six medical students used the score to analyse videotapes from the original study by Read et al. [Read HS, Hazlewood ME, Hillman SJ, Prescott RJ, Robb JE. Edinburgh visual gait score for use in cerebral palsy. J Pediatr Orthop 2003;23:296-301]. These were viewed on two separate occasions to provide inter- and intra-observer reliability, and the results of the numerical items were compared to those from three-dimensional (3D) gait analyses for validity. Observer agreement was tested using Coefficient of Repeatability (CoR), percentage of complete agreement and the kappa statistic. The CoR for inter-observer agreement for inexperienced observers was 5.99/5.07 (Session 1/Session 2) compared to 4.60/3.95 (Session 1/Session 2) for experienced observers. The CoR for intra-observer agreement for inexperienced observers was 5.15 compared to 4.21 for experienced observers. There was complete agreement for 52% of the 10 numerical items with 3D-gait analysis data for inexperienced observers compared to 64% for experienced observers. Ranking of reliability of individual items was similar between the two groups and was generally best for events occurring at the foot and ankle. Observations of gait events by the inexperienced observers using the EVGS were reasonably reliable but not very accurate when compared to experienced observers and 3D-gait analysis.

Correlation of the Edinburgh Gait Score with the Gillette Gait Index, the Gillette Functional Assessment Questionnaire, and dimensionless speed

This study examines the correlation of the Edinburgh Gait Score (EGS) with the Gillette Gait Index (GGI; formerly the Normalcy Index), the Gillette Functional Assessment Questionnaire, and speed, all of which are used as measures of gait quality or function. Scores were computed for 58 subjects, all with a diagnosis of cerebral palsy. The correlation of the EGS with all of the other scores was found to be significant, with r2 ranging from 0.26 to 0.79. The strongest correlation was found with the GGI, which may reflect common features in the derivation of both of these scores, although the EGS was derived from observational gait analysis and the GGI from principal component analysis of variables from computerized 3-dimensional gait data. We conclude that the EGS shows good concurrent validity with alternative gait assessment scores.

Functional Electrical Stimulation to the Dorsiflexors and Quadriceps in Children with Cerebral Palsy

Purpose: To assess the effects of functional electrical stimulation (FES) of the ankle dorsiflexors and quadriceps in children with cerebral palsy. Methods: Fourteen children (mean age 8 years) were randomly allocated to a treatment or control group. The treatment group received 2 weeks of neuromuscular electrical stimulation followed by 8 weeks of FES used at home and school. The control group continued with its usual physiotherapy program. Assessment took place at baseline and before and after the treatment period. Both control and treatment groups were fitted with FES for gait analysis at the second and final assessments. Results: In both groups, FES of the ankle dorsiflexors resulted in a significant (p < 0.01) effect on gait kinematics. However, no long-term treatment effect of using FES for 8 weeks was found. Conclusions: FES for selected children with cerebral palsy, receiving adequate support, can be a practical treatment option to improve gait kinematics.

Effects of surgical lengthening of the hamstrings without a concomitant distal rectus femoris transfer in ambulant patients with cerebral palsy

Eighteen ambulant patients (32 legs) who had undergone fractional lengthening of the medial and lateral hamstrings without rectus femoris transfer underwent pre- and postoperative gait analysis. A significant increase in the amount of knee extension and a decrease in the amount of peak knee flexion in swing were observed. This decrease in knee flexion signified a change towards more normal speed-related values. Dorsiflexion at initial contact decreased significantly for patients who did not undergo a gastrocnemius lengthening (n = 24). Absolute cadence was significantly lower after surgery, but the change in dimensionless cadence was not significantly different. This difference in the outcome between dimensionless and absolute stride parameters can be attributed to the increase in body height after surgery. The clinical significance of these findings is that it is important to recognize that postoperative effects of surgery on gait in children may, in part, be explained by changes in height and not surgery alone.