Development of the Hypertonia Assessment Tool (HAT): a discriminative tool for hypertonia in children

Aim The aim of this study was to develop a tool to identify paediatric hypertonia subtypes. Method Items generated by experts were subscaled (spasticity, dystonia, rigidity). The tool was administered to 34 children (19 males, 15 females, mean age 8y 2mo, range 2y 5mo–18y 7mo) with hypertonia and cerebral palsy (CP) in Gross Motor Function Classification System (GMFCS) levels: I, n=7; II, n=5; III, n=7 level IV, n=7; and level V, n=8 level. Kuder–Richardson Formula 20 determined internal consistency. To assess reliability, two physicians administered the tool to 25 additional children with CP (15 males, 10 females; mean age 10y 8mo; GMFCS levels I, n=4; II, n=3; III, n=7; IV, n=4; and V, n=7) on two occasions, 2 weeks apart. To evaluate validity, a third physician diagnosed the hypertonia by neurological examination. Results The internal consistency of the spasticity items was moderate (α=0.58), and dystonia was high (α=0.79). Item reduction eliminated seven of the 14 original items. The agreement of the spasticity and rigidity subscales was adequate (prevalence‐adjusted bias‐adjusted kappa [PABAK] ranging from moderate [0.57] to excellent [1.0]) for validity, test–retest reliability, and interrater reliability. For dystonia agreement was lower, with PABAK ranging from fair (0.30) to good (0.65). Eighty‐seven per cent had spasticity and 78% had dystonia. Interpretation The Hypertonia Assessment Tool has good reliability and validity for identifying spasticity and the absence of rigidity, and moderate findings for dystonia.     

Reliability and validity of a new dexterity questionnaire (DextQ-24) in Parkinson's disease

BackgroundPatients with Parkinson's disease exhibit disturbed dexterity. Validated self-reported outcomes for dexterity in Parkinson's disease are lacking. The aim of this study was to investigate the reliability, content and construct validity of a new Dexterity Questionnaire 24.MethodsOne hundred and three patients with Parkinson’s disease completed the Dexterity Questionnaire 24 (score range 24–96), at baseline and four weeks later. The internal consistency was determined. Test-retest reliability was assessed in a subgroup (N = 44). Standard error of measurements and the minimal detectable change were defined. The construct validity was examined in the whole group (N = 103). Floor and ceiling effects were investigated.ResultsThe internal consistency of the Dexterity Questionnaire 24 was high (α = 0.91). High test-retest reliability was found (Intra Class Correlation Coefficient = 0.91, Confidence interval: 0.84–0.95). Standard error of measurement was 2.9 and minimal detectable change was 8 points. (i.e., 11%). Good structural, convergent and divergent validity of the Dexterity questionnaire 24 was found (r = 0.73 with Activities of Daily Living-subscale of the Parkinson's Disease Questionnaire-39, and r = 0.66, and r = 0.50, p-values all < 0.0001, respectively with the subscales II and III of the Movement Disorders Society-Unified Parkinson Disease Rating Scale). Low not significant correlations were found between the Dexterity Questionnaire 24 and the subscales stigma and social support (r = 0.20, and r = 0.14 respectively). No floor or ceiling effects were found for the total Dexterity Questionnaire 24.ConclusionThe Dexterity Questionnaire 24 is valid and reliable for evaluating dexterity in patients with Parkinson's disease.     

Selective Control Assessment of the Lower Extremity (SCALE): development,validation, and interrater reliability of a clinical tool for patients with cerebral palsy

Normal selective voluntary motor control (SVMC) can be defined as the ability to perform isolated joint movement without using mass flexor/extensor patterns or undesired movement at other joints, such as mirroring. SVMC is an important determinant of function, yet a valid, reliable assessment tool is lacking. The Selective Control Assessment of the Lower Extremity (SCALE) is a clinical tool developed to quantify SVMC in patients with cerebral palsy (CP). This paper describes the development, utility, validation, and interrater reliability of SCALE. Content validity was based on review by 14 experienced clinicians. Mean agreement was 91.9% (range 71.4–100%) for statements about content, administration, and grading. SCALE scores were compared with Gross Motor Function Classification System Expanded and Revised (GMFCS‐ER) levels for 51 participants with spastic diplegic, hemiplegic, and quadriplegic CP (GMFCS levels I – IV, 21 males, 30 females; mean age 11y 11mo [SD 4y 9mo]; range 5–23y). Construct validity was supported by significant inverse correlation (Spearman's r=‐0.83, p<0.001) between SCALE scores and GMFCS levels. Six clinicians rated 20 participants with spastic CP (seven males, 13 females, mean age 12y 3mo [SD 5y 5mo], range 7–23y) using SCALE. A high level of interrater reliability was demonstrated by intraclass correlation coefficients ranging from 0.88 to 0.91 (p<0.001).     

Fine motor skills and effects of methylphenidate in children with attention-deficit-hyperactivity disorder and developmental coordination disorder

The aims of this study were to investigate fine motor skills of children with both attention-deficit-hyperactivity disorder (ADHD) and developmental coordination disorder (DCD) and those of a control group, and to examine the effects of methylphenidate on these skills. A group of 12 children with ADHD-DCD (11 males, one female; mean age 9y 8mo [SD 1y 7mo]) and 12 age- and sex-matched controls (mean age 9y 7mo [SD 1y 2 mo]) participated. The manual dexterity subtests of the Movement Assessment Battery for Children, the concise assessment method for children's handwriting, and a computerized graphomotor task were used. Results demonstrated that children with ADHD-DCD performed more poorly on the manual dexterity subtests, had poorer quality of handwriting, and drew more rapidly, more fluently, but less accurately than controls on the graphomotor task. On methylphenidate, manual dexterity and quality of handwriting improved, and strokes on the graphomotor task became less fluent but more accurate. ADHD is characterized by persistent symptoms of inattention, impulsivity, and hyperactivity, affecting 3 to 5% of school-age children. Up to 50% of children with ADHD also have motor coordination problems that are severe enough to meet criteria for DCD. In DCD, children demonstrate functional motor performance deficits not explained by the child's (chronological) age or intellect, or by other neurological or psychiatric disorders.     

Construct validity of the Quality of Upper Extremity Skills Test for children with cerebral palsy

Aim The aim of the study was to investigate the construct validity of the Quality of Upper Extremity Skills Test (QUEST) in children with cerebral palsy (CP). Method A total of 170 QUEST assessments from a convenience sample of 94 children with CP involved in clinical and research treatment programmes (54 males, 40 females; mean age 6y 10mo, SD 2y 11mo, range 2–16y; Gross Motor Function Classification System levels I–V) were reviewed. Results The QUEST was not unidimensional; many items demonstrated poor fit when total scores were analysed; goodness of fit improved when domains were considered independently and limbs separately examined. QUEST items involving elbow flexion and/or forearm in pronation were easily achieved, thus reducing test sensitivity. Postures items in the grasp domain behaved erratically, with little total score relationship. Interpretation Calculating total scores is discouraged. Reporting QUEST results separately for domains and each limb is recommended. Posture items in the grasp domain had little relationship with total scores and it is recommended that they be removed from the test.     

Performance on Functional Strength Measurement and Muscle Power Sprint Test confirm poor anaerobic capacity in children with Developmental Coordination Disorder

BackgroundThere is little and conflicting information about anaerobic performance and functional strength in children with Developmental Coordination Disorder (DCD).AimsTo investigate anaerobic capacity and functional strength in children with a clinical diagnosis of DCD (clin-DCD) and if differences were larger in older (age 7–10 years) compared to younger children (age 4–6 years). Furthermore to determine the percentage of children with clin-DCD that scored <15th percentile on the norm-referenced Functional Strength Measurement.MethodA clin-DCD group (36 boys, 11 girls, mean age: 7y 1mo, SD = 2y 1mo) and a typically developing group (TD) (57 boys, 53 girls, mean age: 7y 5mo, SD = 1y 10mo) were compared on Muscle Power Sprint Test (MPST) and Functional Strength Measurement (FSM).ResultsChildren with clin-DCD performed poorer on the MPST and FSM, especially on the muscle endurance items of the FSM. The differences were larger in the older children compared to the younger on the cluster muscle endurance and the FSM total score. Over 50% of clin-DCD group scored <15th percentile on the FSM.InterpretationDifferences between children with clin-DCD and TD children are even more pronounced in the older children, especially when tested on items requiring fast repetitive movements.     

Clinical use of the Mayo-Portland Adaptability Inventory in rehabilitation after paediatric acquired brain injury

The Mayo-Portland Adaptability Inventory (MPAI; designed to be administered by clinicians) is a popular measure of disability following head injury in adults. Its acceptability, validity, and reliability were assessed for use with children. There were 335 children and adolescents (215 males, 120 females) aged between 1 and 19 years at injury (median age 9y 8mo [SD 5y]) in our sample. The test was acceptable to respondents, rapidly and easily administered, and required only small modifications. It demonstrated validity against client and parent reports of major symptoms. It demonstrated test-retest reliability within the limitations of our data and excellent interrater accord. Consequently, the MPAI is recommended for paediatric use for evaluating rehabilitation needs and therapy outcome.     

Normative values and the effects of age, gender, and handedness on the Moberg Pick-Up Test

The Moberg Pick-Up Test is a standardized test for assessing hand dexterity. Although reduction of sensation in the hand occurs with aging, the effect of age on a subject's performance of the Moberg Pick-Up Test has not been examined. The primary goal of this study was to examine the impact of aging and, secondarily, the impact of gender and handedness, on performance of the Moberg Pick-Up Test in 116 healthy subjects. The average time to complete each of the four subsets of the test was analyzed using the Kruskal-Wallis, Mann-Whitney U, and Wilcoxon signed-rank tests. The results show that hand dexterity of the subjects was significantly affected by age, with young subjects being the fastest and elderly subjects the slowest. Women accomplished the test faster than men, and task performance with the dominant hand was faster than with the non-dominant hand. Use of normative values established based on age and gender is a valuable objective tool to gauge hand function in patients with different neurologic disorders.     

Assessment of unilateral spatial neglect in children using the Teddy Bear Cancellation Test

The purpose of the study was to provide normative data for the Teddy Bear Cancellation Test (TBCT) and to evaluate prospectively the frequency of unilateral spatial neglect (USN) in children with acquired brain injury (ABI). In the control group (n = 419; 218 males, 201 females; mean age 5y 1mo [SD 1y 4mo]; range 3 to 8y) omissions were rare and decreased with age. A left displacement of the first three teddy bears cancelled was observed with increasing age. This preferential left-to-right cancelling strategy was interpreted as learned under the influence of reading habits. The same test was used prospectively in 41 children with ABI (24 males, 17 females; mean age 5y 5mo [SD 2y]; range 3 to 8y) admitted to a paediatric rehabilitation department specializing in acquired brain lesions. In patients and controls, children under 6 years of age omitted more items than older children. The localization of omissions was skewed significantly to the left in children with right-sided lesions compared with children with left-sided lesions. USN was observed in seven patients with ABI. Left USN was found in three of the 10 patients with right-sided ABI. Right USN was present in two of the patients with 15 left-sided ABI and two of the 16 patients with non-lateralized ABI. Left USN is frequent in children after right-sided brain injury. The relatively high incidence of right spatial neglect in children is discussed in relation to the development of hemispheric specialization.     

A repeated course of constraint-induced movement therapy results in further improvement

A recent therapeutic intervention, constraint-induced movement therapy (CIMT), has been shown to improve movement efficiency and quality of movement in the involved hand of children with hemiplegic cerebral palsy (CP). In the present study, we investigate the long-term effects of CIMT and the effect of a second course on involved limb function using an ABABA design. Eight children with mild to moderate hemiplegic CP (six males, two females; mean age 8y 7mo [SD 2y 6mo]; range 5-11y), who had received a CI therapy intervention 12 months before this study, participated in a second intervention. In both interventions, the children wore a sling on their non-involved upper extremity for 6 hours per day during 10 out of 12 consecutive days and were engaged in play and functional activities that provided structured practice using the involved upper extremity. The results indicated initial improvements in movement efficiency, as measured by the Jebsen-Taylor Test of Hand Function, the Speed and Dexterity subtest (no. 8) of the Bruininks-Oseretsky Test of Motor Proficiency, and caregivers' perceptions of amount of use and quality of movement of the involved limb, were retained 12 months after the first intervention. The second intervention resulted in further improvement on these measures. Results indicate that intensive practice associated with CIMT may be retained long term, and that continued improvements may occur after a second intervention dose.     

Assessment of upper‐limb capacity,performance, and developmental disregard in children with cerebral palsy: validity and reliability of the revised Video‐Observation Aarts and Aarts module: Determine Developmental Disregard (VOAA‐DDD‐R)

Aim To investigate the validity and reliability of the revised Video‐Observation Aarts and Aarts module: Determine Developmental Disregard (VOAA‐DDD‐R). Method Upper‐limb capacity and performance were assessed in children with unilateral spastic cerebral palsy (CP) by measuring overall duration of affected upper‐limb use and the frequency of specific behaviours during a task in which bimanual activity was demanded (‘stringing beads’) and stimulated (‘decorating a muffin’). Developmental disregard was defined as the difference in duration of affected upper‐limb use between both tasks. Raters were two occupational and one physical therapist who received 3 hours of training. Construct validity was determined by comparing children with CP with typically developing children. Intrarater, interrater, and test–retest reliability were determined using the intraclass correlation coefficient. Standard errors of measurement and smallest detectable differences were also calculated. Results Twenty‐five children with CP (15 females, 10 males; mean age 4y 9mo [SD 1y 7mo], range 2y 9mo–8y; Manual Ability Classification System levels I–III) scored lower on capacity (p=0.052) and performance (p<0.001), and higher on developmental disregard (p<0.001) than 46 age‐ and sex‐matched typically developing children (23 males; mean age 5y 3mo [SD 1y 5mo], range 2y 6mo–8y). The intraclass correlation coefficients (0.79–1.00) indicated good reliability. Absolute agreement was high, standard errors of measurement ranged from 4.5 to 6.8%, and smallest detectable differences ranged from 12.5 to 19.0%. Interpretation The VOAA‐DDD‐R can be reliably and validly used by occupational and physical therapists to assess upper‐limb capacity, performance, and developmental disregard in children (2y 6mo–8y) with CP.     

Cerebral sinus venous thrombosis in Swiss children

Aim To describe the characteristics of paediatric cerebral sinus venous thrombosis (CSVT) in Switzerland. Method Data on clinical features, neuroimaging, risk factors, and treatment were collected for all children in Switzerland younger than 16 years of age who had CSVT between January 2000 and December 2008. A follow‐up examination and a cognitive assessment were performed (mean follow‐up period 26mo). Differences between neonates and children (patients older than 28d) were assessed and predictors of outcome were determined. Results Twenty‐one neonates (14 males, seven females; mean age 9d, SD 8d) and 44 children (30 males, 14 females; mean age 8y 7mo, SD 4y 5mo) were reported. The incidence of paediatric CSVT in Switzerland was 0.558 per 100 000 per year. In neonates, the deep venous system was more often involved and parenchymal injuries were more common. The strongest predictor of poor outcome was neonatal age (odds ratio 17.8, 95% confidence interval 0.847–372.353). Most children showed global cognitive abilities within the normal range, but impairments in single cognitive subdomains were frequent. Interpretation Paediatric CSVT is rare. Its outcome is poor in neonates. Most children have good neurological outcomes, but some patients have individual neuropsychological impairments.     

Assessing educational outcomes in middle childhood: validation of the Teacher Academic Attainment Scale

Aim Assessing educational outcomes in high‐risk populations is crucial for defining long‐term outcomes. As standardized tests are costly and time‐consuming, we assessed the use of the Teacher Academic Attainment Scale (TAAS) as an outcome measure. Method Three hundred and forty three children in mainstream schools aged 10 to 11 years (144 males, 199 females; 190 extremely preterm and 153 term; mean age 10y 9mo, SD 5.5mo, range 9y 8mo–12y 3mo) were assessed using the reading and mathematics scales of the criterion standard Wechsler Individual Achievement Test, 2nd (UK) edition (WIAT‐II). Class teachers completed the TAAS, a seven‐item questionnaire for assessing academic attainment. The TAAS was also completed at 6 years of age for 266 children. Results Cronbach’s alpha 0.95 indicated excellent internal consistency, and the correlation between TAAS scores at 6 and 11 years indicated good test–retest reliability (r=0.77, p<0.001). Significantly higher TAAS scores for term vs preterm children demonstrated discriminative validity. TAAS scores at 6 and 11 years were significantly correlated with WIAT‐II reading (r=0.69 and 0.75, p<0.001) and mathematics (r=0.75 and 0.82, p<0.001) scores, demonstrating good predictive and concurrent validity respectively. TAAS scores of <2.5 were good predictors of learning difficulties. Interpretation The TAAS is a brief, psychometrically sound teacher‐report of academic attainment that yields continuous and categorical outcomes. It provides a cost‐ and time‐efficient outcome measure for large‐scale studies.     

Visual assessment in children with cerebral palsy: implementation of a functional questionnaire

Aim The aim of this study was to evaluate an interdisciplinary visual assessment for multiply challenged children diagnosed with cerebral palsy (CP). Method A comprehensive ophthalmological assessment together with a visual classification scale (VCS) and a questionnaire evaluating daily visual function were completed regarding 77 children (41 females, 36 males; age range 3–20y; mean age 8y 3mo [SD 4y 3mo]; Gross Motor Function Classification System [GMFCS] level V; Manual Ability Classification System level V) who were diagnosed with CP (79.2% spastic quadriplegia, 6.5% athetoid quadriplegia, 10.4% mixed type, 3.9% hemiplegia). All participants had severe to profound motor and intellectual disability and an inability to communicate consistently through either verbal or assisted communication. The interrater and test–retest reliability of the questionnaire and its validity in comparison with the VCS were examined. In addition, the contribution of ophthalmological testing in predicting daily visual function was assessed. Results The ophthalmological examination revealed three diagnostic subgroups: a group with cerebral visual impairment (CVI), a group with optic atrophy, and a group without visual impairment. The questionnaire was found to have high values of interrater reliability (interclass correlation coefficient [ICC]=0.873; 95% confidence interval [CI] 0.762–0.935) and test–retest reliability (ICC=0.988; 95% CI 0.964–0.996). Validity was established for the questionnaire factors: task‐orientated visual function (r=0.802; 95% CI 0.669–0.885) and basic visual skills (r=0.691; 95% CI 0.504–0.816). The questionnaire provided information about daily visual performance not available from one‐time ophthalmological testing, particularly for participants diagnosed with CVI. The visual performance scale significantly predicted daily visual function for all groups. Interpretation This study highlights the benefits of implementing a diagnostic performance scale as well as a reliable functional questionnaire to achieve a precise visual assessment of children with severe neurological impairment.     

Standardized finger-nose test validity for coordination assessment in an ataxic disorder

OBJECTIVES: Evaluation of coordination with the Finger-Nose Test is an essential part of the neurological examination. This study explored the convergent and discriminant construct validity of the Standardized Finger-Nose Test (SFNT) in a neuromuscular disorder with ataxic features. METHOD: A cross-sectional study was carried out with 24 participants with recessive spastic ataxia of Charlevoix-Saguenay. Convergent construct validity was tested by correlating the SFNT with other upper extremity function tests, a functional independence measure and social participation. Upper extremity function tests included gross and fine dexterity (Box and Block Test and Purdue Pegboard), upper extremity strength (dynamometry) and global upper extremity performance (TEMPA). The Functional Independence Measure (FIM) and the Assessment of Life Habits scale (LIFE-H) measured functional independence and social participation respectively. Discriminant construct validity was explored by comparing performance on the SFNT between two age groups (< 40 years and > or = 40 years). RESULTS: Convergent validity of the SFNT was demonstrated by moderate to strong correlations with gross and fine finger dexterity (r = 0.82-0.84), global upper extremity performance (0.74-0.79), functional independence (r = 0.74) and social participation (r = 0.78). Upper extremity coordination of the older group was significantly lower than in the younger group, suggesting the ability of the SFNT to discriminate between different levels of function. CONCLUSION: This study demonstrated the convergent and discriminant construct validity of the SFNT in a neuromuscular disorder with ataxic features.     

Grip force coordination during bimanual tasks in unilateral cerebral palsy

Aim The aim of the study was to investigate coordination of fingertip forces during an asymmetrical bimanual task in children with unilateral cerebral palsy (CP). Method Twelve participants (six males, six females; mean age 14y 4mo, SD 3.3y; range 9–20y;) with unilateral CP (eight right‐sided, four left‐sided) and 15 age‐matched typically developing participants (five males, 10 females; mean age 14y 3mo, SD 2.9y; range 9–18y,) were included. Participants were instructed to hold custom‐made grip devices in each hand and place one device on top of the other. The grip force and load force were recorded simultaneously in both hands. Results Temporal coordination between the two hands was impaired in the participants with CP (compared with that in typically developing participants), that is they initiated the task by decreasing grip force in the releasing hand before increasing the force in the holding hand. The grip force increase in the holding hand was also smaller in participants with CP (involved hand/non‐dominant hand releasing, p<0.001; non‐involved hand/dominant hand releasing, p=0.007), indicating deficient scaling of force amplitude. The impairment was greater when participants with CP used their non‐involved hand as the holding hand. Interpretation Temporal coordination and scaling of fingertip forces were impaired in both hands in participants with CP. The non‐involved hand was strongly affected by activity in the involved hand, which may explain why children with unilateral CP prefer to use only one hand during tasks that are typically performed with both hands.     

Refractive errors in infancy predict reduced performance on the movement assessment battery for children at 3 1/2 and 5 1/2 years

We have previously reported that significant hyperopia at 9 months predicts mild deficits on visuocognitive and visuomotor measures between 2 years and 5 years 6 months. Here we compare the motor skills of children who had been hyperopic in infancy (hyperopic group) with those who had been emmetropic (control group), using the Movement Assessment Battery for Children (Movement ABC). Children were tested at 3 years 6 months (hyperopic group: 47 males, 63 females, mean age 3 y 7 mo, SD 1.6 mo; control group: 61 males, 70 females, mean age 3 y 7 mo, SD 1.2 mo) and at 5 years 6 months (hyperopic group: 43 males, 56 females, mean age 5 y 4 mo, SD 1.7 mo; control group: 51 males, 62 females, mean age 5 y 3 mo, SD 1.6 mo). The hyperopic group performed significantly worse at both ages, overall and on at least one test from each category of motor skill (manual dexterity, balance, and ball skills). Distributions of scores showed that these differences were not due to poor performance by a minority but to a widespread mild deficit in the hyperopic group. This study also provides the first normative data on the Movement ABC for children below 4 years of age, and shows that it provides a useful measure of motor development at this young age.     

Validation of the Virtual MET as an assessment tool for executive functions

The purpose of this study was to establish ecological validity and initial construct validity of a Virtual Multiple Errands Test (VMET) as an assessment tool for executive functions. It was implemented within the Virtual Mall (VMall), a novel functional video-capture virtual shopping environment. The main objectives were (1) to examine the relationships between the performance of three groups of participants in the Multiple Errands Test (MET) carried out in a real shopping mall and their performance in the VMET, (2) to assess the relationships between the MET and VMET of the post-stroke participant's level of executive functioning and independence in instrumental activities of daily living, and (3) to compare the performance of post-stroke participants to those of healthy young and older controls in both the MET and VMET. The study population included three groups; post-stroke participants (n = 9), healthy young participants (n = 20), and healthy older participants (n = 20). The VMET was able to differentiate between two age groups of healthy participants and between healthy and post-stroke participants thus demonstrating that it is sensitive to brain injury and ageing and supports construct validity between known groups. In addition, significant correlations were found between the MET and the VMET for both the post-stroke participants and older healthy participants. This provides initial support for the ecological validity of the VMET as an assessment tool of executive functions. However, further psychometric data on temporal stability are needed, namely test–retest reliability and responsiveness, before it is ready for clinical application. Further research using the VMET as an assessment tool within the VMall with larger groups and in additional populations is also recommended.     

Development and validation of item sets to improve efficiency of administration of the 66‐item Gross Motor Function Measure in children with cerebral palsy

Aim To develop an algorithmic approach to identify item sets of the 66‐item version of the Gross Motor Function Measure (GMFM‐66) to be administered to individual children, and to examine the validity of the algorithm for obtaining a GMFM‐66 score. Method An algorithmic approach was used to identify item sets of the GMFM‐66 (GMFM‐66‐IS) using data from 95 males and 79 females with cerebral palsy (CP; mean age 14y 7mo, SD 1y 8mo, range 12y 7mo to 17y 8mo). The GMFM‐66‐IS scores were then validated using combined data from three Dutch studies involving 134 males and 92 females with CP (mean age 7y, SD 4y 6mo, range 1y 4mo to 13y 8mo), representing all levels of the Gross Motor Function Classification System. Results The final algorithm contains three decision items from the GMFM‐66 that determine which one of four item sets to administer. The GMFM‐66‐IS has excellent agreement with the full GMFM‐66 both at a single assessment (intraclass correlation coefficient [ICC]=0.994, 95% confidence intervals [CI] 0.993–0.996) and across repeat assessments (ICC=0.92, 95% CI 0.89–0.95). Interpretation The GMFM‐66‐IS is a promising alternative to the full GMFM‐66. Users should be consistent in their choice of measure (GMFM‐66 or GMFM‐66‐IS) on repeat testing and clearly identify which method was used.