Catherine Huenaerts

Upper limb motor and sensory impairments in children with hemiplegic cerebral palsy. Can they be measured reliably

Purpose. To establish interrater and test–retest reliability of a clinical assessment of motor and sensory upper limb impairments in children with hemiplegic cerebral palsy aged 5–15 years. Method. The assessments included passive range of motion (PROM), Modified Ashworth Scale (MAS), manual muscle testing (MMT), grip strength, the House thumb and Zancolli classification and sensory function. Interrater reliability was investigated in 30 children, test–retest reliability in 23 children. Results. For PROM, interrater reliability varied from moderate to moderately high (correlation coefficients 0.48–0.73) and test–retest reliability was very high (>0.81). For the MAS and MMT, total score and subscores for shoulder, elbow, and wrist showed a moderately high to very high interrater reliability (0.60–0.91) and coefficients of >0.78 for test–retest reliability. The reliability for the individual muscles varied from moderate to high. The Jamar dynamometer was found to be highly reliable. The House thumb classification showed a substantial reliability and the Zancolli classification an almost perfect reliability. All sensory modalities had a good agreement. Conclusions. For all motor and sensory assessments, interrater and test–retest reliability was moderate to very high. Test–retest reliability was clearly higher than interrater reliability. To improve interrater reliability, it was recommended to strictly standardize the test procedure, refine the scoring criteria and provide intensive rater trainings.

Comparison of the Melbourne Assessment of Unilateral Upper Limb Function and the Quality of Upper Extremity Skills Test in hemiplegic CP

This study investigated interrater reliability and measurement error of the Melbourne Assessment of Unilateral Upper Limb Function (Melbourne Assessment) and the Quality of Upper Extremity Skills Test (QUEST), and assessed the relationship between both scales in 21 children (15 females, six males; mean age 6y 4mo [SD 1y 3mo], range 5–8y) with hemiplegic CP. Two raters scored the videotapes of the assessments independently in a randomized order. According to the House Classification, three participants were classified as level 1, one participant as level 3, eight as level 4, three as level 5, one participant as level 6, and five as level 7. The Melbourne Assessment and the QUEST showed high interrater reliability (intraclass correlation 0.97 for Melbourne Assessment; 0.96 for QUEST total score; 0.96 for QUEST hemiplegic side). The standard error of measurement and the smallest detectable difference was 3.2% and 8.9% for the Melbourne Assessment and 5.0% and 13.8% for the QUEST score on the hemiplegic side. Correlation analysis indicated that different dimensions of upper limb function are addressed in both scales.

A Clinical Measurement to Quantify Spasticity in Children with Cerebral Palsy by Integration of Multidimensional Signals

Most clinical tools for measuring spasticity, such as the Modified Ashworth Scale (MAS) and the Modified Tardieu Scale (MTS), are not sufficiently accurate or reliable. This study investigated the clinimetric properties of an instrumented spasticity assessment. Twenty-eight children with spastic cerebral palsy (CP) and 10 typically developing (TD) children were included. Six of the children with CP were retested to evaluate reliability. To quantify spasticity in the gastrocnemius (GAS) and medial hamstrings (MEH), three synchronized signals were collected and integrated: surface electromyography (sEMG); joint-angle characteristics; and torque. Muscles were manually stretched at low velocity (LV) and high velocity (HV). Spasticity parameters were extracted from the change in sEMG and in torque between LV and HV. Reliability was determined with intraclass-correlation coefficients and the standard error of measurement; validity by assessing group differences and correlating spasticity parameters with the MAS and MTS. Reliability was moderately high for both muscles. Spasticity parameters in both muscles were higher in children with CP than in TD children, showed moderate correlation with the MAS for both muscles and good correlation to the MTS for the MEH. Spasticity assessment based on multidimensional signals therefore provides reliable and clinically relevant measures of spasticity. Moreover, the moderate correlations of the MAS and MTS with the objective parameters further stress the added value of the instrumented measurements to detect and investigate spasticity, especially for the GAS.

Effect of dynamic orthoses on gait: a retrospective control study in children with hemiplegia

Several positive influences of orthoses on gait in children with cerebral palsy have been documented, as well as some detrimental effects. Most importantly, push‐off is decreased in orthoses, compromising a physiological third ankle rocker. The aim of this study was to evaluate the effect of three types of orthosis on gait in a homogeneous group of children. All orthoses aimed at improving push‐off and normalizing the pathological plantarflexion–knee extension couple. Thirty‐seven children (22 females, 15 males) with hemiplegia, aged 4 to 10 years (30 Gross Motor Function Classification System [GMFCS] Level I, six GMFCS Level II), walked barefoot and with orthoses being either Orteams® (orthoses with the dorsal part containing 11 sleeves), posterior leafsprings (PLS), or Dual Carbon Fibre Spring ankle foot orthosis (AFOs®; CFO: carbon fibre at the dorsal part of the orthosis). All orthoses were expected to prevent plantarflexion and allow dorsiflexion, thus improving first, second, and third rocker. The orthoses were compared through objective gait analysis, including 3D kinematics and kinetics. All orthoses successfully improved the gait pattern and only small differences were noted between the configurations of the different orthoses. The CFO®, however, allowed a more physiological third ankle rocker compared with the Orteam®/PLS. Although the PLS ensured the highest correction at the ankle around initial contact, the CFO® created a significantly higher maximal hip flexion moment in stance. In general, the results of this study indicated a substantial functional flexibility of the CFO®.

Is an Instrumented Spasticity Assessment an Improvement Over Clinical Spasticity Scales in Assessing and Predicting the Response to Integrated Botulinum Toxin Type A Treatment in Children With Cerebral Palsy

OBJECTIVE To compare responsiveness and predictive ability of clinical and instrumented spasticity assessments after botulinum toxin type A (BTX) treatment combined with casting in the medial hamstrings (MEHs) in children with spastic cerebral palsy (CP). DESIGN Prospective cohort study. SETTING Hospital. PARTICIPANTS Consecutive sample of children (N=31; 40 MEH muscles) with CP requiring BTX injections. INTERVENTION Clinical and instrumented spasticity assessments before and on average ± SD 53±14 days after BTX. MAIN OUTCOME MEASURES Clinical spasticity scales included the Modified Ashworth Scale and the Modified Tardieu Scale. The instrumented spasticity assessment integrated biomechanical (position and torque) and electrophysiological (surface electromyography) signals during manually performed low- and high-velocity passive stretches of the MEHs. Signals were compared between both stretch velocities and were examined pre- and post-BTX. Responsiveness of clinical and instrumented assessments was compared by percentage exact agreement. Prediction ability was assessed with a logistic regression and the area under the receiver operating characteristic (ROC) curves of the baseline parameters of responders versus nonresponders. RESULTS Both clinical and instrumented parameters improved post-BTX (P≤.005); however, they showed a low percentage exact agreement. The baseline Modified Tardieu Scale was the only clinical scale predictive for response (area under the ROC curve=0.7). For the instrumented assessment, baseline values of root mean square (RMS) electromyography and torque were better predictors for a positive response (area under the ROC curve=.82). Baseline RMS electromyography remained an important predictor in the logistic regression. CONCLUSIONS The instrumented spasticity assessment showed higher responsiveness than the clinical scales. The amount of RMS electromyography is considered a promising parameter to predict treatment response.

The Intra- and Inter-Rater Reliability of an Instrumented Spasticity Assessment in Children with Cerebral Palsy

Aim Despite the impact of spasticity, there is a lack of objective, clinically reliable and valid tools for its assessment. This study aims to evaluate the reliability of various performance- and spasticity-related parameters collected with a manually controlled instrumented spasticity assessment in four lower limb muscles in children with cerebral palsy (CP). Method The lateral gastrocnemius, medial hamstrings, rectus femoris and hip adductors of 12 children with spastic CP (12.8 years, ±4.13 years, bilateral/unilateral involvement n=7/5) were passively stretched in the sagittal plane at incremental velocities. Muscle activity, joint motion, and torque were synchronously recorded using electromyography, inertial sensors, and a force/torque load-cell. Reliability was assessed on three levels: (1) intra- and (2) inter-rater within session, and (3) intra-rater between session. Results Parameters were found to be reliable in all three analyses, with 90% containing intra-class correlation coefficients >0.6, and 70% of standard error of measurement values <20% of the mean values. The most reliable analysis was intra-rater within session, followed by intra-rater between session, and then inter-rater within session. The Adds evaluation had a slightly lower level of reliability than that of the other muscles. Conclusions Limited intrinsic/extrinsic errors were introduced by repeated stretch repetitions. The parameters were more reliable when the same rater, rather than different raters performed the evaluation. Standardisation and training should be further improved to reduce extrinsic error when different raters perform the measurement. Errors were also muscle specific, or related to the measurement set-up. They need to be accounted for, in particular when assessing pre-post interventions or longitudinal follow-up. The parameters of the instrumented spasticity assessment demonstrate a wide range of applications for both research and clinical environments in the quantification of spasticity.

Can we unmask features of spasticity during gait in children with cerebral palsy by increasing their walking velocity

BACKGROUND AND AIM Spasticity is a velocity dependent feature present in most patients with cerebral palsy (CP). It is commonly measured in a passive condition. The aim of this study was to highlight markers of spasticity of gastrocnemius and hamstring muscles during gait by comparing the effect of increased walking velocity of CP and typical developing (TD) children. METHODS 53 children with spastic CP and 17 TD children were instructed to walk at self-selected speed, faster and as fast as possible without running. Kinematics, kinetics and electromyography (EMG) were collected and muscle length and muscle lengthening velocity (MLV) were calculated. To compare the data of both groups, a linear regression model was created which resulted in two non-dimensional gait velocities. A difference score (DS) was calculated between the high and low velocity values for both groups. RESULTS 103 gait parameters were analyzed of which 16 had a statistically significant DS between TD and CP groups. The spastic gastrocnemius muscle presented at high velocity with a higher ankle angular velocity, plantar flexion moment, power absorption and increased EMG signal during loading response. The spastic hamstrings demonstrated at high velocity a delayed maximum knee extension moment at mid-stance and increasing hip extension moment and hip power generation. The hamstrings also presented with a lower MLV during swing phase. CONCLUSIONS A limited number of gait parameters differ between CP and TD children when increasing walking velocity, giving indirect insight on the effect of spasticity on gait.

Motor endplate‐targeted botulinum toxin injections of the gracilis muscle in children with cerebral palsy

Intramuscular botulinum toxin‐A (BoNT‐A) injections reduce spasticity by blocking neurotransmission at the motor endplate (MEP). The goal of this study was to assess the reduction in spasticity achieved by injecting BoNT‐A at different sites of the gracilis muscle.

Effects of ankle foot orthoses on the gait of cerebral palsy children

Ankle-foot orthoses (AFOs) have been recommended for patients with cerebral palsy (CP) mairdy to correct an equinus gait pattern. A retrospective study was performed on diplegic and hemiplegic patients who had suitable barefoot and AFO gait trials on the same day. The objectives of the present study were to outline the effects of four different types of AF0s (conventional AFOs, fixed AF0s, hinged AFOs and leafsprmgs) on the walking patterns for CP children.

Gait deviations in Duchenne muscular dystrophy—Part 2. Statistical non-parametric mapping to analyze gait deviations in children with Duchenne muscular dystrophy

BACKGROUND Prolonged ambulation is considered important in children with Duchenne muscular dystrophy (DMD). However, previous studies analyzing DMD gait were sensitive to false positive outcomes, caused by uncorrected multiple comparisons, regional focus bias, and inter-component covariance bias. Also, while muscle weakness is often suggested to be the main cause for the altered gait pattern in DMD, this was never verified. RESEARCH QUESTION Our research question was twofold: 1) are we able to confirm the sagittal kinematic and kinetic gait alterations described in a previous review with statistical non-parametric mapping (SnPM)? And 2) are these gait deviations related to lower limb weakness? METHODS We compared gait kinematics and kinetics of 15 children with DMD and 15 typical developing (TD) children (5-17 years), with a two sample Hotellings T2 test and post-hoc two-tailed, two-sample t-test. We used canonical correlation analyses to study the relationship between weakness and altered gait parameters. For all analyses, α-level was corrected for multiple comparisons, resulting in α = 0.005. RESULTS We only found one of the previously reported kinematic deviations: the children with DMD had an increased knee flexion angle during swing (p = 0.0006). Observed gait deviations that were not reported in the review were an increased hip flexion angle during stance (p = 0.0009) and swing (p = 0.0001), altered combined knee and ankle torques (p = 0.0002), and decreased power absorption during stance (p = 0.0001). No relationships between weakness and these gait deviations were found. SIGNIFICANCE We were not able to replicate the gait deviations in DMD previously reported in literature, thus DMD gait remains undefined. Further, weakness does not seem to be linearly related to altered gait features. The progressive nature of the disease requires larger study populations and longitudinal analyses to gain more insight into DMD gait and its underlying causes.