Causes of out-toeing gait in children with cerebral palsy

Background: Out-toeing is common in children with cerebral palsy (CP), contributing to lever arm dysfunction and functional limitations. It is important to determine the cause(s) of out-toeing prior to treatment, whether surgical or non-surgical.Research Questions: What are the contributors to out-toeing in children with CP and do they differ between children with bilateral and unilateral involvement?Methods: The causes of out-toeing gait were determined retrospectively, with the use of computerized gait analysis, in 261 children with cerebral palsy (344 sides). The prevalence of various causes was calculated separately for children with bilateral and unilateral involvement, and compared statistically between groups using Fisher’s Exact analysis.Results: The most common cause of out-toeing was pes valgus in bilaterally involved subjects (71%) and pelvic external rotation (64%) in unilaterally involved subjects. Over half of the cases of out-toeing were due to multiple causes: 62% of the unilateral group and 53% of the bilateral group. In limbs with multiple causes of out-toeing in the bilateral group, pes valgus was one of the causes in 91% of limbs (146/161), and was most commonly combined with hip external rotation (27%), pelvic external rotation (22%), or external tibial torsion (20%). For the unilateral group with multiple causes of out-toeing, pelvic external rotation was one of the causes in 83% of limbs (20/24) and hip external rotation in 63% (15/24). Both were present (with or without additional causes) in 46% (11/24) of such limbs.Significance: The causes of out-toeing are multifactorial in over half of affected limbs of children with cerebral palsy. They also differ for children with bilateral and unilateral involvement. These findings should be carefully considered prior to non-surgical or surgical treatment of out-toeing gait in these patients, to allow all sites of pathology to be addressed, and to optimize outcomes.     

A cohort study of tibialis anterior tendon shortening in combination with calf muscle lengthening in spastic equinus in cerebral palsy

The aim of this study was to evaluate the outcome of combined tibialis anterior tendon shortening (TATS) and calf muscle-tendon lengthening (CMTL) in spastic equinus.Prospectively collected data was analysed in 26 patients with hemiplegic (n = 13) and diplegic (n = 13) cerebral palsy (CP) (GMFCS level I or II, 14 males, 12 females, age range 10–35 years; mean 16.8 years). All patients had pre-operative 3D gait analysis and a further analysis at a mean of 17.1 months (±5.6 months) after surgery. None was lost to follow-up. Twenty-eight combined TATS and CMTL were undertaken and 19 patients had additional synchronous multilevel surgery. At follow-up 79% of patients had improved foot positioning at initial contact, whilst 68% reported improved fitting or reduced requirement of orthotic support. Statistically significant improvements were seen in the Movement Analysis Profile for ankle dorsi-/plantarflexion (4.15°, p = 0.032), maximum ankle dorsiflexion during swing phase (11.68°, p < 0.001), and Edinburgh Visual Gait Score (EVGS) (4.85, p = 0.014). Diplegic patients had a greater improvement in the EVGS than hemiplegics (6.27 -vs- 2.21, p = 0.024).The originators of combined TATS and CMTL showed that it improved foot positioning during gait. The present study has independently confirmed favourable outcomes in a similar patient population and added additional outcome measures, the EVGS, foot positioning at initial contact, and maximum ankle dorsiflexion during swing phase. Study limitations include short term follow-up in a heterogeneous population and that 19 patients had additional surgery. TATS combined with CMTL is a recommended option for spastic equinus in ambulatory patients with CP.     

Classification of equinus in ambulatory children with cerebral palsy-discrimination between dynamic tightness and fixed contracture

In this study a generalised dynamic neural network (GDNN) was designed to process gait analysis parameters to evaluate equinus deformity in ambulatory children with cerebral palsy. The aim was to differentiate dynamic calf muscle tightness from fixed muscle contracture. Patients underwent clinical examination and had instrumented gait analysis before evaluating their equinus under anaesthesia and muscle relaxation at the time of surgery to improve gait. The performance of the clinical examination, the subjective interpretation of gait analysis results, and the application of the neural network to assess ankle function were compared to the examination under anaesthesia. Evaluation of equinus by a Neural Network showed high sensitivity and specificity values with a likelihood ratio of +14.63. The results indicate that dynamic calf muscle tightness can be differentiated from fixed calf muscle contracture with considerable precision that might facilitate clinical decision-making.     

Reliability and validity of an activity monitor (IDEEA) in the determination of temporal-spatial gait parameters in individuals with cerebral palsy

This study evaluated within- and between-session reliability and validity of temporal–spatial gait parameters derived from the intelligent device for energy expenditure and activity (IDEEA) activity monitor (Minisun, Fresno, CA) in subjects with cerebral palsy, using three-dimensional gait analysis (3-DGA) as the criterion standard. Twenty-five subjects with cerebral palsy (mean age 14.1 years, range 8–23) and 30 control subjects (mean age 14.2 years, range 7–24) completed two 3-DGA, 1 week apart with simultaneous IDEEA data collection. The IDEEA had lower within-session reliability than the 3-DGA for both groups, indicated by greater measurement errors and wider repeatability values for all temporal–spatial parameters. Between-session reliability of 3-DGA was high for both groups with intra-class correlation coefficients (ICC) >0.80. The IDEEA monitor showed high between-session reliability for control subjects (ICC 0.71–0.89), but lower reliability in subjects with cerebral palsy, particularly for walking velocity and stride length (ICC 0.53 and 0.62, respectively). Validity comparison between IDEEA and 3-DGA measures using Bland Altman 95% limits of agreement showed a measurement bias, with the IDEEA over-estimating step and stride length and underestimating cadence in both subject groups compared to 3-DGA. The 95% limits of agreement were smaller in controls (step ±0.20 m; stride ±0.27 m; walking velocity ±0.28 m/s) than in subjects with cerebral palsy (step ±0.36 m; stride ±0.37 m; velocity ±0.58 m/s). Modifications may be necessary to improve the reliability and validity of the IDEEA in children, particularly for use in neurological conditions.     

The effect of a low-load plyometric running intervention on leg stiffness in youth with cerebral palsy: A randomised controlled trial

AimTo determine whether a running intervention utilising plyometric activities improved leg stiffness in youth with cerebral palsy (CP), GMFCS levels I and II.MethodThis stratified randomised controlled trial examined the lower limb kinetics and kinematics of a sample of youths with CP during sub-maximal hopping and running, prior to and immediately following a 12-week running intervention that incorporated low load plyometric training. Included participants were 13 in the control group (mean age 13 years 2 months [SD 2 years 7 months]; six males; nine GMFCS level I; six unilateral) and 18 in the intervention group (mean age 12 years 9 months [SD 2 years 10 months]; 13 males; 11 GMFCS level I; nine unilateral). Derived variables included three-dimensional leg stiffness as well as resultant ground reaction force and change in leg length. Generalised linear mixed models were developed for statistical analysis.ResultsAt follow-up the intervention group had greater leg stiffness than the control group during submaximal hopping (Intervention median = 3278Nm⁻¹; Control median = 1556Nm⁻¹; p < 0.01). At follow-up, participants in the intervention group in GMFCS Level I had greater leg stiffness than the control group during jogging (Intervention mean=38.84 (SD=25.55); Control mean=29.38 (SD=11.11); t = 2.61 p = 0.01).InterpretationA running training intervention which includes plyometric activities can improve leg stiffness in young people with CP, especially those in GMFCS level I.     

Common abnormal kinetic patterns of the knee in gait in spastic diplegia of cerebral palsy

We studied the kinetic characteristics of the knee in patients with spastic diplegia. Twenty three children with spastic diplegia were recruited and had their 46 limbs categorised into the following four groups: jump (n=7), crouch (n=8), recurvatum (n=14) and mild (n=17). In the crouch pattern, the patients usually had a larger and longer lasting internal knee extensor moments in stance suggesting that rectus femoris had a relatively high activation. In the recurvatum pattern, the internal knee flexor moment was large and long lasting in stance. The biceps femoris showed less activity on EMG although the knee flexor moment was large and we concluded that the soft tissue behind the knee joint provided this flexor moment. In the jump knee pattern there was abnormal power generation at the knee and ankle joints in initial stance, which did not contribute to normal progression but aided upward body motion. In the mild group the kinetic data was similar to that seen in normal children. Knowledge of kinetic patterns in these patients may help in their subsequent management.     

Mobility and gait in adults with cerebral palsy: Evaluating change from adolescence

BackgroundPrevious studies have looked at the short-term effectiveness of conservative and surgical treatment of children with cerebral palsy (CP), but few have explored the long-term outcomes into adulthood using gait analysis and patient-reported outcome measures.Research questionHow do gait, mobility, and patient-reported outcomes in adults with CP who received specialized pediatric orthopedic care change from adolescence?MethodsWe identified 645 adults with 1) CP, 2) age 25–45 years, and 3) an adolescent instrumented gait analysis (IGA) at our center. Measurement outcomes included physical examination, IGA, and select domains of the Patient-Reported Outcomes Measurement Information System (PROMIS).ResultsParticipants included 136 adults with CP; Gross Motor Function Classification System levels I (21 %), II (51 %), III (22 %), and IV (7%); 57 % males; and average age 16 ± 3/29 ± 3 years (adolescent/adult visits). There was no significant difference in gait deviation index, stride length, or gross motor function between adolescent and adult visits. There were statistically significant but not clinically meaningful declines in gait velocity. At adulthood, PROMIS results revealed limitations in physical function compared with a normative sample but no differences in depression, participation, or pain interference.SignificanceIn this relatively homogeneous group of adults with CP who received orthopedic care from one center, gait and gross motor function showed no clinically meaningful change from adolescence, which differs from recent reports of declining mobility in adulthood. Expert orthopedic care, guided by IGA, may prevent losses in functional mobility for adults with CP.     

Reliability and validity of Edinburgh visual gait score as an evaluation tool for children with cerebral palsy

Assessment of gait abnormalities in cerebral palsy (CP) is challenging, and access to instrumented gait analysis is not always feasible. Therefore, many observational gait analysis scales have been devised. This study aimed to evaluate the interobserver reliability, intraobserver reliability, and validity of Edinburgh visual gait score (EVGS). Video of 30 children with spastic CP were reviewed by 7 raters (10 children each in GMFCS levels I, II, and III, age 6–12 years). Three observers had high level of experience in gait analysis (10+ years), two had medium level (2–5 years) and two had no previous experience (orthopedic fellows). Interobserver reliability was evaluated using percentage of complete agreement and kappa values. Criterion validity was evaluated by comparing EVGS scores with 3DGA data taken from the same video visit. Interobserver agreement was 60–90% and Kappa values were 0.18–0.85 for the 17 items in EVGS. Reliability was higher for distal segments (foot/ankle/knee 63–90%; trunk/pelvis/hip 60–76%), with greater experience (high 66–91%, medium 62–90%, no-experience 41–87%), with more EVGS practice (1st 10 videos 52–88%, last 10 videos 64–97%) and when used with higher functioning children (GMFCS I 65–96%, II 58-90%, III 35–65%). Intraobserver agreement was 64–92%. Agreement between EVGS and 3DGA was 52–73%. We believe that having EVGS as part of the standardized gait evaluation is helpful in optimizing the visual scoring. EVGS can be a supportive tool that adds quantitative data instead of only qualitative assessment to a video only gait evaluation.     

Selective motor control correlates with gait abnormality in children with cerebral palsy

Children with bilateral cerebral palsy (CP) commonly have limited selective motor control (SMC). This affects their ability to complete functional tasks. The impact of impaired SMC on walking has yet to be fully understood. Measures of SMC have been shown to correlate with specific characteristics of gait, however the impact of SMC on overall gait pattern has not been reported. This study explored SMC data collected as part of routine gait analysis in children with bilateral CP.As part of their clinical assessment, SMC was measured with the Selective Control Assessment of the Lower Extremities (SCALE) in 194 patients with bilateral cerebral palsy attending for clinical gait analysis at a single centre. Their summed SCALE score was compared with overall gait impairment, as measured by Gait Profile Score (GPS).Score on SCALE showed a significant negative correlation with GPS (r_s = −0.603, p < 0.001). Cerebral injuries in CP result in damage to the motor tracts responsible for SMC. Our results indicate that this damage is also associated with changes in the development of walking pattern in children with CP.     

Reliability and validity of the gait classification system in children with cerebral palsy (GCS-CP)

BackgroundGait classification systems (GCS) may enable clinicians to differentiate gait patterns into clinically significant categories that assist in clinical decision-making and assessment of outcomes. Davids and Bagley in 2014 [1] described a GCS for children with cerebral palsy (GCS-CP). The purpose of our study was to use the GCS-CP for the first time on a sample of patients with CP and to evaluate the reliability and utility of the classification system.MethodsThe gait of 131 children with CP was retrospectively reviewed and classified according to Davids and Bagley’s classification using two-dimensional (2D) video and three-dimensional (3D) lower limb kinematics and kinetics. Gross Motor Function Classification System (GMFCS) levels were determined, and the Gait Profile Scores (GPS) calculated to characterize the sample concerning gait classification. The comparison between the groups was performed using the Kruskal-Wallis test with respect to the non-normal distribution of the data. The intrarater and interrater reliability was determined using the Kappa index (k) statistics with 95% CI.ResultsAll GCS-CP groups were represented within the evaluated sample. Of the 131 cases evaluated, 127 (96.95%) were able to be classified with respect to sagittal plane stance phase gait deviations. All patients in the sample were able to be classified with respect to sagittal plane swing phase and transverse plane gait deviations. The interrater reliability was 0.596 and 0.485 for the first and second levels of the classification, respectively, according to the Fleiss’s Kappa statistics. Intrarater reliability was 0.776 and 0.714 for the raters one and two, respectively, according to the Cohen’s Kappa statistics.SignificanceThe GCS-CP exhibited clinical utility, successfully classifying almost all subjects with CP in two planes, based upon kinematic and kinetic data. The classification is valid and has moderate interrater and moderate to substantial intrarater reliability.     

The impact of walking devices on kinematics in patients with spastic bilateral cerebral palsy

Increased anterior pelvic and trunk tilt is a common finding in patients with bilateral cerebral palsy especially during walking with assistive devices. As previous studies demonstrate various gait alterations when using assistive devices, the assessment of surgical interventions may be biased when the patients become independent of (or dependent on) assistive devices after therapy. Furthermore, some of these patients in fact are able to walk without devices even though in daily life they prefer to use them. Consequently, for such patients the classification into GMFCS level II or III may be ambiguous. The specific aim of this study was therefore to assess the influence of the use of forearm crutches and posterior walker during walking and to set this influence in relation to outcome effects of surgical intervention studies.26 ambulatory patients with spastic bilateral CP (GMFCS II–III) were included who underwent 3D gait analysis. All patients used forearm crutches or posterior walkers in everyday life even though they were able to walk without assistive devices for short distances.Independent of the type of assistive devices, the patients walk on average with more anterior trunk tilt and pelvic tilt (7° ± 6° and 3° ± 2°) and with a maximum ankle dorsiflexion decreased by 2° (±3°) when walking with assistive devices, enhancing the mal-positioning present without device. Oppositely, the knees on average are more extended by 6° (±4°) when using the assistive devices.These effects have to be taken into account when assessing gait patterns or when monitoring the outcome after intervention as assistive devices may partially hide or exaggerate therapeutic effects.     

Factors related to better outcomes after single-event multilevel surgery (SEMLS) in patients with cerebral palsy

BackgroundGood outcomes have been described after single-event multilevel surgery (SEMLS) in cerebral palsy (CP); however, there is limited evidence regarding factors influencing them.Research questionWhat were the factors related to kinematic outcomes after SEMLS in the present study?MethodsTwo hundred and fifty-eight patients with spastic diplegic CP, GMFCS I-III, who underwent SEMLS and had done pre and post-operative gait analyses were included in the SEMLS Group (SEMLS-G). A second search was performed in the same database looking for patients to compose the Control Group (CG), and 88 subjects, with at least two gait analyses and with no surgical intervention between tests, were identified. Demographic data, GDI and GPS (Gait Profile Score) were analyzed in both groups, and the results compared. A second evaluation was performed in the SEMLS-G in order to identify the influence of age, gender, follow-up time, pre-operative GDI, GMFCS and gait velocity on results.ResultsThe GDI (51.3–58.4) and GPS (2.5°) improvement occurred only in SEMLS-G (p < 0.001). On sagittal plane, there was an improvement at the knee and ankle levels in SEMLS-G, whereas the pelvic alignment improved in the CG. In SEMLS-G, patients with improvement on GDI > 10 points had lower pre-operative GDI (46.15) than other groups (p < 0.001). In addition, patients with reduction on GDI after intervention had lower pre-operative gait velocity than subjects with improvement >10 points (p = 0. 01). The increase on GDI after SEMLS was greater in patients GMFCS I and II than GMFCS III (p = 0.003). There was a negative effect of GMFCS III on GDI improvement after intervention (p = 0.014).SignificanceLower pre-operative GDI, higher baseline gait velocity and GMFCS levels I and II were related to better outcomes after SEMLS in the present study. On the other hand, patients GMFCS III were more susceptible to deteriorate after SEMLS.     

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.     

Botulinum toxin A in hamstring spasticity

Hamstring injection of Botulinum toxin A (BtA) may have a role in the conservative management of flexed knee gait in cerebral palsy or in simulating the effect of surgery. Ten children who were likely to require future hamstring lengthening were injected. Short term outcome was assessed by clinical examination and 3-D gait analysis. Mean popliteal angle decreased by 16° and maximum knee extension in stance increased by 8°, the latter relapsing by 12 weeks. Mean pelvic tilt tended to increase suggesting that isolated hamstring weakening be approached with caution. Energy cost of walking was not significantly changed in six of the ten patients. A small increase in knee extension in stance was often associated with patient satisfaction. There are theoretical grounds for expecting an associated increased longitudinal muscle growth after BtA injection.     

Reliability and validity of the Visual Gait Assessment Scale for children with hemiplegic cerebral palsy when used by experienced and inexperienced observers

This study investigated the reliability and validity of the Visual Gait Assessment Scale when used by experienced and inexperienced observers. Four experienced and six inexperienced observers viewed videotaped footage of four children with hemiplegic cerebral palsy on two separate occasions. Validity of the Scale was obtained by comparison with three-dimensional gait analysis (3DGA). The experienced observers generally had higher inter-observer and intra-observer reliability than the inexperienced observers. Both groups showed higher agreement for assessments made at the ankle and foot than at the knee and hip. The experienced observers had slightly higher agreement with 3DGA than the inexperienced observers. The inexperienced observers showed a learning effect and had higher inter-observer agreement and higher agreement with 3DGA in the second assessment of the videotapes. This scale can be used by inexperienced observers but is limited to observations in the sagittal plane and by poor reliability at the knee and hip for experienced and inexperienced observers.     

Gait adaptations of individuals with cerebral palsy on irregular surfaces: A scoping review

BackgroundIndividuals with cerebral palsy (CP) have a reduced ability to perform motor tasks such as walking. During daily walking, they are confronted with environmental constraints such as irregular surfaces (e.g., relief and uneven surfaces) which may require adaptations to maintain stability and avoid falls. Laboratory gait assessments are conventionally conducted under ideal conditions (e.g., regular and even surfaces) and may overlook subtle problems which may only present in challenging walking environments. Increased knowledge of adaptations to successfully navigate irregular surfaces may contribute to a better understanding of everyday walking barriers.Research questionThis scoping review aims to describe gait adaptations to irregular surfaces in individuals with CP and contrast adaptations with those of healthy individuals.MethodsThis review followed the 6-stage Joanna Briggs Institute methodology and respected the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews statement. The MEDLINE, EMBASE, CINAHL, SPORTDiscus, and Web of Science databases were searched on March 2021.ResultsThe research strategy identified 1616 studies published between 2014 and 2020, of which 10 were included after abstract and full-text screening. This review reported on 152 individuals with CP (diplegia: n = 117, hemiplegia: n = 35) and 159 healthy individuals. The included studies focused on spatial-temporal, kinematic, kinetic, and muscle activity parameters over relief, inclined, and staircase surfaces. 7/10 studies were conducted in laboratories, often using surfaces that are not representative of the real-world. The results suggest that for individuals with CP, adaptations on irregular surfaces differ from flat surface walking and across CP subtype. Moreover, individuals with CP present with typical and pathology-specific adaptations to irregular surfaces compared to healthy individuals.SignificanceThis review highlights the clinical and research interest of focusing future studies on more ecologically valid data collection approaches and provides important recommendations to overcome research gaps in the existing literature.