Physiological Response to the 6-Minute Frame Running Test in Children and Adults With Cerebral Palsy.

PURPOSE: To determine the physiological response and association to peak oxygen uptake of the 6-minute Frame Running test (6-MFRT) in persons with cerebral palsy (CP). METHODS: Twenty-four participants with CP, Gross Motor Function Classification System II/III/IV, performed the 6-MFRT. Distance, peak heart rate (HR peak ), peak respiratory exchange ratio (RER peak ), and peak oxygen uptake ( O 2peak ) were measured. RESULTS: HR peak ranged from 146 to 201 beats per minute, RER peak from 0.94 to 1.49, 6-MFRT distance from 179 to 1220 m and O 2peak from 0.62 to 2.18 L/min. HR peak was achieved in 63%, RER peak in 71%. A strong correlation was observed between 6-MFRT and O 2peak . CONCLUSIONS: The 6-MFRT represented a (near) maximum effort for 75% of the participants and the 6-MFRT can be used to estimate oxygen consumption on an individual basis.

Improvements in Muscle Strength Are Associated With Improvements in Walking Capacity in Young Children With Cerebral Palsy: A Secondary Analysis.

PURPOSE: To evaluate whether changes in lower-limb muscle strength explain changes in walking capacity during 14-week periods of usual care, power training and follow-up for children with spastic cerebral palsy. METHODS: Secondary analysis of a previously conducted double-baseline controlled trial of 22 children with spastic cerebral palsy. Generalized estimating equations were used to evaluate the relationships between within-subject changes in isometric muscle strength and walking capacity over 3 periods. RESULTS: Changes in hip abductor strength were associated with changes in the Muscle Power Sprint Test, changes in gastrocnemius and hip abductor strength were associated with changes in the Shuttle Run Test, and changes in gastrocnemius strength were associated with changes in the 1-minute walk test. All associations supported better walking capacity with increased strength. CONCLUSION: Walking capacity, especially sprint capacity, can be improved by increasing strength by functional power training in this population.

Development curves of communication and social interaction in individuals with cerebral palsy.

AIM: To determine development curves of communication and social interaction from childhood into adulthood for individuals with cerebral palsy (CP). METHOD: This Pediatric Rehabilitation Research in the Netherlands (PERRIN)-DECADE study longitudinally assessed 421 individuals with CP, aged from 1 to 20 years at baseline, after 13 years (n=121 at follow-up). Communication and social interactions were assessed using the Vineland Adaptive Behavior Scales. We estimated the average maximum performance limit (level) and age at which 90% of the limit was reached (age90 ) using nonlinear mixed-effects modeling. RESULTS: One-hundred individuals without intellectual disability were aged 21 to 34 years at follow-up (39 females, 61 males) (mean age [SD] 28y 5mo [3y 11mo]). Limits of individuals without intellectual disability, regardless of Gross Motor Function Classification System (GMFCS) level, approached the maximum score and were significantly higher than those of individuals with intellectual disability. Ages90 ranged between 3 and 4 years for receptive communication, 6 and 7 years for expressive communication and interrelationships, 12 and 16 years for written communication, 13 and 16 years for play and leisure, and 14 and 16 years for coping. Twenty-one individuals with intellectual disability were between 21 and 27 years at follow-up (8 females, 13 males) (mean age [SD] 24y 7mo [1y 8mo]). Individuals with intellectual disability in GMFCS level V showed the least favourable development, but variation between individuals with intellectual disability was large. INTERPRETATION: Individuals with CP and without intellectual disability show developmental curves of communication and social interactions similar to typically developing individuals, regardless of their level of motor function. Those with intellectual disability reach lower performance levels and vary largely in individual development. WHAT THIS PAPER ADDS: Communication and social interactions in individuals with cerebral palsy without intellectual disability develop similarly to typically developing individuals. Communication and social interactions of individuals with intellectual disability develop less favourably and show large variation.

CURVAS DE DESARROLLO DE COMUNICACIÓN E INTERACCIÓN SOCIAL EN NIÑOS CON PARÁLISIS CEREBRAL: OBJETIVO: Determinar las curvas de desarrollo de la comunicación y la interacción social desde la infancia hasta la edad adulta para las personas con parálisis cerebral (PC). MÉTODO: Esta Investigación de Rehabilitación Pediátrica en el Estudio de los Países Bajos (PERRIN)-DECADE evaluó longitudinalmente 421 individuos con PC, de 1 a 20 años en el inicio, después de 13 años (n=121 en el seguimiento). La comunicación y las interacciones sociales se evaluaron utilizando la Escala de comportamiento adaptativo de Vineland. Estimamos el límite promedio de rendimiento máximo (nivel) y la edad a la que se alcanzó el 90% del límite (edad90 ) utilizando un modelo no lineal de efectos mixtos. RESULTADOS: Cien individuos sin discapacidad intelectual tenían entre 21 y 34 años en el seguimiento (39 mujeres, 61 varones; edad media [DS] 28 y 5 meses [3 años y 11meses]). Los límites de las personas sin discapacidad intelectual, independientemente del nivel del Sistema de Clasificación de la Función Motora Gruesa (GMFCS), se acercaron a la puntuación máxima y fueron significativamente superiores a los de personas con discapacidad intelectual. Edad 90s entre 3 y 4 años para la comunicación receptiva, 6 y 7 años para la comunicación expresiva y las interrelaciones, 12 y 16 años para la comunicación escrita, 13 y 16 años por juego y ocio, y 14 y 16 años por sobrellevarlo. Veintiún individuos con discapacidad intelectual tenían entre 21 y 27 años en seguimiento (8 mujeres, 13 hombres; edad media [DS] 24 años y 7 meses [1 año y 8 meses]). Las personas con discapacidad intelectual en el nivel V de GMFCS mostraron el desarrollo menos favorable, pero la variación entre las personas con discapacidad intelectual fue grande. INTERPRETACIÓN: Las personas con PC sin discapacidad intelectual muestran curvas de desarrollo de comunicación e interacciones sociales similares a las personas con desarrollo típico, no considerando su nivel de función motora. Las personas con PC y discapacidad intelectual alcanzan niveles de rendimiento más bajos y varían en gran medida en el desarrollo individual.

CURVAS DE DESENVOLVIMENTO DA COMUNICAÇÃO E INTERAÇÃO SOCIAL EM CRIANÇAS COM PARALISIA CEREBRAL: OBJETIVO: Determinar as curvas de desenvolvimento e interação social da infância para a adolescência para indivíduos com paralisia cerebral (PC). MÉTODO: Este estudo Europeu de Reabilitação Pediátrica na Holanda (PERRIN)-DECADE avaliou longitudinalmente 421 indivíduos com PC, com idades de 1 a 20 anos na linha de base, após 13 anos, (n=121 no acompanhamento). A comunicação e interação social foram avaliadas usando as Escalas Vineland de Compartamento Adaptativo. Estimamos o limite máximo de desempenho médio (nível) e idade em que 90% do limite foi atingido (idade90 ) usando modelos não-lineares de efeitos mistos. RESULTADOS: Cem indivíduos sem deficiência intelectual com idades entre 21 e 34 anos no acompanhamento (39 do sexo feminino, 61 do sexo masculino; média de idade [DP] 28a 5m [3a 11m]). Os limites de indivíuduos sem deficiência intelectual, independente do nível do Sistema de Classificação da Função Motora Grossa (GMFCS), se aproximou da pontuação maxima e foram significativamente maiores do que os valores de indivíduos com deficiência intelectual. A idade 90s variou entre 3 e 4 anos para comunicação receptiva, 6 e 7 anos para comunicação expressiva e intercomunicações, 12 e 16 anos para comunicação escrita, 12 e 16 years para brincadeiras e lazer, e 14 e 16 anos para adaptabilidade. Vinte e um indivíduos com deficiência intelectual estavam entre 21 e 27 anos no acompanhamento (8 do sexo feminino, 13 do sexo masculino; média de idade [DP] 24a 7m [1a 8m]). Indivíduos com deficiência intelectual no nível GMFCS V mostraram o desenvolvimento menos favorável, mas a variação entre indivíduos com deficiência intelectual foi grande. INTERPRETAÇÃO: Indivíduos com PC com e sem deficiência intelectual mostram curvas desenvolvimentais de comunicação e interação social similares a indivíduos com desempenho típico, independente do nível de função motora. Aqueles com deficiência intelectual tiveram menores níveis de performance e variaram amplamente no desenvolvimento individual.

Fatigue in Children and Young Adults With Physical Disabilities: Relation With Energy Demands of Walking and Physical Fitness.

PURPOSE: To examine whether general fatigue and fatigue during or after walking are related to energy demands during walking and physical fitness in children and young adults with physical disabilities. METHODS: Sixty-eight individuals with physical disabilities participated. General fatigue (Checklist Individual Strength [CIS8R] questionnaire), walking-induced fatigue (OMNI [OMNIwalk] scale after walking for 6 min), gross and net energy costs (ECs) of walking, physical strain of walking, and aerobic and anaerobic fitness were measured. RESULTS: Regression analyses showed no relations with the CIS8R. For all participants, a higher net EC was weakly related to an increased OMNIwalk. For teenagers only, low anaerobic fitness and high physical strain of walking values were moderately related to high OMNIwalk scores. CONCLUSION: Low anaerobic fitness and high physical strain values partly explain fatigue after walking in teenagers with cerebral palsy, but not in younger children. General fatigue was not explained by low fitness levels or high energy demands of walking.

Intraobserver Reliability and Construct Validity of the Squat Test in Children With Cerebral Palsy.

PURPOSE: This study evaluated intraobserver reliability and construct validity of the squat test to assess lower extremity strength in children with cerebral palsy (CP) and spastic diplegia. METHODS: Children with CP performed 2 trials of the squat test and calculated the intraclass correlation coefficient to evaluate intraobserver reliability. Correlations between outcomes of hand-held dynamometry (HHD) of knee extensor strength and an 8-repetition maximum (8RM) leg press test and the squat test were calculated to evaluate construct validity. RESULTS: Excellent intraobserver reliability was observed for the squat test. Correlations between squat test performance and HHD knee extension and 8RM leg press test demonstrated good construct validity. CONCLUSIONS: The squat test is a reliable and valid tool to assess lower extremity strength in children with CP and spastic diplegia. The squat test is inexpensive and less time-consuming, and therefore particularly suitable for clinicians.

Lower limb muscle fatigue during walking in children with cerebral palsy.

AIM: To investigate whether more prominent signs of muscle fatigue occur during self-paced walking in children with cerebral palsy (CP) compared to typically developing peers. METHOD: In this case-control study, 13 children with CP (four males, nine females; mean age [SD] 11y 4mo [3y 8mo]; nine in Gross Motor Function Classification System [GMFCS] level I, three in GMFCS level II, and one in GMFCS level III) and 14 typically developing peers (nine males, five females; mean age [SD] 9y 10mo [1y 10mo]) walked 5 minutes overground at a self-selected walking speed. Electromyography (EMG) median frequency and root mean square (RMS) were identified per gait cycle from EMG recordings of the tibialis anterior, gastrocnemius medialis, soleus, rectus femoris, and semitendinosus. Rate of change in those variables was analysed using mixed linear model analyses. RESULTS: The decrease in EMG median frequency of gastrocnemius medialis and soleus and increase in EMG-RMS of tibialis anterior, gastrocnemius medialis, and soleus were significantly larger in the most affected leg of children with CP compared with typically developing peers. INTERPRETATION: Increased selective muscle fatigue of the lower leg muscles was observed during self-paced walking in children with mild-to-moderate severe CP. This could contribute to and account for limited walking capacity. WHAT THIS PAPER ADDS: Children with cerebral palsy (CP) show more signs of lower leg muscle fatigue than typically developing peers. No signs of muscle fatigue were observed in upper leg muscles of children with CP.

Long-term course of difficulty in participation of individuals with cerebral palsy aged 16 to 34 years: a prospective cohort study.

AIM: To determine the long-term course of difficulty in participation of individuals with cerebral palsy (CP) without intellectual disability between 16 years and 34 years of age. METHOD: One hundred and fifty-one individuals with CP aged 16 to 20 years were included (63% male, 37% female; Gross Motor Function Classification System [GMFCS] levels I-IV; without intellectual disability). The Assessment of Life Habits questionnaire 3.0 general short form was used up to three times biennially and at 13-year follow-up (13-year follow-up: n=98). Scores (range 0-10) reflect difficulty and assistance in participation in housing, education and employment, interpersonal relationships, recreation, community life, and responsibilities. Multilevel models were used to determine the course of difficulty in participation by GMFCS level. RESULTS: Despite high average participation levels, 41% to 95% of adolescents and young adults with CP experienced difficulty. Difficulty in participation in housing and interpersonal relationships increased from age 16 years onwards and in most other life areas in the mid- and late 20s. In adolescents in GMFCS levels III and IV, participation in recreation and community life improved up to age 23 years. INTERPRETATION: Individuals with CP experience increasing difficulties in participation in their mid- and late 20s. Clinicians should systematically check for participation difficulties in young adults with CP and offer timely personalized treatment. WHAT THIS PAPER ADDS: Many individuals with cerebral palsy (CP) aged 16 to 34 years experience difficulty in participation. Difficulty in participation increases in the mid- and late 20s for individuals with CP. Participation in recreation/community life improves before age 23 years for those in Gross Motor Function Classification System levels III and IV.

Physical Strain: A New Perspective on Walking in Cerebral Palsy.

OBJECTIVES: To describe (1) physical strain of walking, (2) the proportion of participants walking above the anaerobic threshold, and (3) 4 phenotypes of physical strain of walking on the basis of deviations in aerobic capacity and walking energy cost (EC) in children and adolescents with cerebral palsy (CP). DESIGN: Cohort study. SETTING: Academic medical center. PARTICIPANTS: A sample (N=57) of participants (n=37; mean age, 13.5±4.0y) with CP (Gross Motor Function Classification System [GMFCS] levels I [n=13], II [n=17], and III [n=7]) and typically developing (TD) participants (n=20; mean age, 11.8±3.5y). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Oxygen consumption (Vo2walk), speed, and EC were determined during walking at a comfortable speed. Peak oxygen consumption (Vo2peak) and anaerobic threshold were measured during a maximal cycling exercise test. Aerobic capacity was reduced if lower than the 10th percentile, and EC was increased if higher than 3SD. Physical strain was defined as follows: (Vo2walk/Vo2peak)×100. RESULTS: Participants with CP had a higher physical strain (GMFCS level I, 55%±12% GMFCS level II, 62%±17%; GMFCS level III, 78%±14%) than did TD participants (40%±11%) (P<.001). Forty-three percent of participants with CP showed a Vo2walk at or above their anaerobic threshold as compared with 10% of TD participants (P=.007). Phenotypes showed that a reduced Vo2peak (n=9) or an increased EC (n=9) lead to an 18% to 20% higher physical strain, whereas a combination (n=12) leads to a 40% increase. CONCLUSIONS: Children and adolescents with CP walk at a high physical strain, approximating intense exercise and a considerable proportion walks close to or above their anaerobic threshold, probably explaining fatigue and reduced walking distance. Both an increased EC and a reduced Vo2peak contribute to high physical strain in children or adolescents with CP. The different causes of high physical strain in individuals with CP require different intervention strategies.

Reliability and Construct Validity of the 6-Minute Racerunner Test in Children and Youth with Cerebral Palsy, GMFCS Levels III and IV.

AIM: To determine the test-retest reliability and construct validity of a novel 6-Minute Racerunner Test (6MRT) in children and youth with cerebral palsy (CP) classified as Gross Motor Function Classification System (GMFCS) levels III and IV. The racerunner is a step-propelled tricycle. METHODS: The participants were 38 children and youth with CP (mean age 11 y 2 m, SD 3 y 7 m; GMFCS III, n = 19; IV, n = 19). Racerunner capability was determined as the distance covered during the 6MRT on three occasions. The intraclass correlation coefficient (ICC), standard error of measurement (SEM), and smallest detectable differences (SDD) were calculated to assess test-retest reliability. RESULTS: The ICC for tests 2 and 3 were 0.89 (SDD 37%; 147 m) for children in level III and 0.91 for children in level IV (SDD 52%; 118 m). When the average of two separate test occasions was used, the SDDs were reduced to 26% (104 m; level III) and 37% (118 m; level IV). For tests 1 to 3, the mean distance covered increased from 345 m (SD 148 m) to 413 m (SD 137 m) for children in level III, and from 193 m (SD 100 m) to 239 m (SD 148 m) for children in level IV. CONCLUSIONS: Results suggest high test-retest reliability. However, large SDDs indicate that a single 6MRT measurement is only useful for individual evaluation when large improvements are expected, or when taking the average of two tests. The 6MRT discriminated the distance covered between children and youth in levels III and IV, supporting construct validity.

Effectiveness of Functional Power Training on Walking Ability in Young Children With Cerebral Palsy: Study Protocol of a Double-Baseline Trial.

PURPOSE: To evaluate the effect of functional high-velocity resistance (power) training to improve walking ability of young children with cerebral palsy. METHODS: Twenty-two children with bi- or unilateral spastic cerebral palsy, Gross Motor Function Classification System levels I and II, aged 4 to 10 years will be recruited. A double-baseline design will be used to compare a 14-week functional power training (3 times a week) program with a 14-week usual care period and a 14-week follow-up period. The power exercises will be loaded and performed at 50% to 70% of the maximum unloaded speed. Load will be increased when exercises are performed faster than 70% of the unloaded speed. Primary outcomes will be sprinting capacity (15-m Muscle Power Sprint Test) and goal attainment scaling score of walking-related treatment goals. Secondary outcomes will be walking speed (1-min walk test), endurance (10-m shuttle run test), gross motor function, lower-limb strength, and parent-reported mobility.

Relations between muscle endurance and subjectively reported fatigue, walking capacity, and participation in mildly affected adolescents with cerebral palsy.

AIM: To investigate the relation between muscle endurance and subjectively reported fatigue, walking capacity, and participation in mildly affected adolescents with cerebral palsy (CP) and peers with typical development. METHOD: In this case-control study, knee extensor muscle endurance was estimated from individual load-endurance curves as the load corresponding to a 15-repetition maximum in 17 adolescents with spastic CP (six males, 11 females; age 12-19y) and 18 adolescents with typical development (eight males, 10 females; age 13-19y). Questionnaires were used to assess subjectively reported fatigue (Pediatric Quality of Life Inventory Multidimensional Fatigue Scale) and participation (Life-Habits questionnaire). Walking capacity was assessed using the 6-minute walk test. Relations were determined using multiple regression analyses. RESULTS: Muscle endurance related significantly to subjectively reported fatigue and walking capacity in adolescents with CP, while no relations were found for adolescents with typical development (subjectively reported fatigue: regression coefficient ß [95% confidence intervals] for CP=23.72 [6.26 to 41.18], for controls=2.72 [-10.26 to 15.69]; walking capacity ß for CP=125m [-87 to 337], for controls=2m [-86 to 89]). The 15-repetition maximum did not relate to participation in adolescents with CP. INTERPRETATION: Subjectively reported fatigue and reduced walking capacity in adolescents with CP are partly caused by lower muscle endurance of knee extensors. Training of muscle endurance might contribute to reducing the experience of fatigue and improving walking capacity. Reduced muscle endurance seems to have no effect on participation.

Longitudinal Association Between Gross Motor Capacity and Neuromusculoskeletal Function in Children and Youth With Cerebral Palsy.

OBJECTIVE: To examine associations over longitudinal measurements between neuromusculoskeletal function and gross motor capacity in children and youth with cerebral palsy (CP). DESIGN: A prospective cohort study. SETTING: Rehabilitation departments of university medical centers and rehabilitations centers. PARTICIPANTS: A sample (N=327) consisting of 148 children (aged 5-9y) and 179 youth (aged 11-20y) with CP, Gross Motor Function Classification System level I (n=180), level II (n=44), level III (n=36), level IV (n=34), and level V (n=33). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Gross motor capacity was assessed with the Gross Motor Function Measure-66 over a period of 2 to 4 years in different age cohorts. Neuromusculoskeletal function included selective motor control (SMC), muscle strength, spasticity, and range of motion (ROM) of the lower extremities. RESULTS: Multilevel analyses showed that SMC was significantly associated with gross motor capacity in children and youth with CP, showing higher values and a more favorable course of gross motor capacity in those with better SMC. Strength was only associated with gross motor capacity in youth. Reduced ROM of hip (children) and knee extension (youth) and spasticity of the hip adductors (youth) were additionally-but more weakly-associated with lower values and a less favorable course of gross motor capacity. CONCLUSIONS: Results indicate that children and youth with more severely impaired SMC and youth with reduced muscle strength have a less favorable course of gross motor capacity, while spasticity and reduced ROM are less determinative.

Associations between fitness and mobility capacity in school-aged children with cerebral palsy: a longitudinal analysis.

AIM: The aim of this study was to determine the longitudinal associations among fitness components and between fitness and mobility capacity in children with cerebral palsy (CP). METHOD: Forty-six children (26 males, 20 females; mean age 9y 7mo [SD 1y 8mo]) with a bilateral (n=24) or a unilateral spastic CP (n=22) participated in aerobic and anaerobic fitness measurements on a cycle ergometer and isometric muscle strength tests (Gross Motor Function Classification System [GMFCS] level I [n=26], level II [n=12], level III [n=8]). Mobility capacity was assessed with the gross motor function measure (GMFM) and a walking capacity test. Associations over longitudinal measurements (three or four measurements over 1y) were determined since longitudinal data allow a more accurate estimation. The associations were determined using a mixed model with fixed effects (mobility capacity as dependent variables and fitness components as independent variables) and a random intercept. RESULTS: In children with bilateral CP, changes in aerobic fitness were associated with changes in anaerobic fitness (p<0.001), and changes in aerobic fitness showed an association with changes in muscle strength (p<0.05). Anaerobic fitness was not associated with muscle strength. No associations between fitness components were found in unilateral CP. Anaerobic fitness and muscle strength were significant determinants for GMFM and walking capacity in bilateral but not in unilateral CP. INTERPRETATION: The longitudinal associations between aerobic and anaerobic fitness and mobility indicate that increasing either aerobic or anaerobic fitness is associated with improvements in mobility in children with bilateral CP. While increasing anaerobic fitness might be beneficial for mobility capacity in children with bilateral CP, this is less likely for children with unilateral CP.

Developmental trajectories of receptive and expressive communication in children and young adults with cerebral palsy.

AIM: The aim of this study was to determine the developmental trajectories of expressive (speech) and receptive (spoken and written language) communication by type of motor disorder and intellectual disability in individuals with cerebral palsy (CP). METHOD: The development of 418 participants (261 males, 157 females; mean age 9y 6mo [SD 6y 2mo], range 1-24y; Gross Motor Function Classification System (GMFCS) level I [n=206], II [n=57], III [n=59], IV [n=54], V [n=42]) was followed for 2 to 4 years in a longitudinal study. Communication performance was measured using the Vineland Adaptive Behavior Scales. The type of motor disorder was differentiated by type of CP as unilateral spastic (USCP, n=161), bilateral spastic (BSCP, n=202), and non-spastic (NSCP, n=55), while intellectual disability was determined by IQ or school type (regular or special). A multilevel analysis was then used to model the developmental trajectories. RESULTS: The most favourable development of expressive communication was seen in USCP (vs BSCP ß [SE]-2.74 [1.06], NSCP ß [SE]-2.67 [1.44]). The difference between the development trajectory levels of children with and without intellectual disability was smaller for children with USCP than for those with BSCP and NSCP. For receptive communication, the most favourable development was found for all children with USCP and for BSCP or NSCP without intellectual disability (vs intellectual disability ß [SE]-4.00 [1.16]). Development of written language was most favourable for children without intellectual disability (vs intellectual disability ß [SE]-23.11 [2.85]). INTERPRETATION: The development of expressive communication was found to be most closely related to type of motor disorder, whereas the development of receptive communication was found to be most closely related to intellectual disability.

Assessment of muscle endurance of the knee extensor muscles in adolescents with spastic cerebral palsy using a submaximal repetitions-to-fatigue protocol.

OBJECTIVE: To compare muscle endurance in adolescents with spastic cerebral palsy (CP) with typically developing (TD) peers using a submaximal repetitions-to-fatigue (RTF) protocol. DESIGN: Cross sectional. SETTING: Human motion laboratory. PARTICIPANTS: Adolescents with spastic CP (n=16; Gross Motor Function Classification System levels I or II) and TD adolescents (n=18) within the age range of 12 to 19 years old. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Each participant performed 3 RTF tests at different submaximal loads, ranging from 50% to 90% of their maximal voluntary knee extension torque. The relation between the number of repetitions (repetition maximum [RM]) and imposed submaximal relative (percent of maximal voluntary torque [%MVT]) and absolute (Nm/kg) torque was quantified. To compare adolescents with CP with TD adolescents, a mixed linear model was used to construct load endurance curves. Surface electromyography of quadriceps muscles was measured to assess changes in normalized amplitude and median frequency (MF) as physiological indicators of muscle fatigue. RESULTS: Adolescents with CP showed a larger decrease in %MVT per RM than TD adolescents (P<.05). TD adolescents showed substantial higher absolute (Nm/kg) load endurance curves than adolescents with CP (P<.001), but they did not show a difference in slope. Electromyographic normalized amplitude increased significantly (P<.05) in the quadriceps muscles in all tests for both groups. Electromyographic MF decreased significantly (P<.05) in tests with the low and medium loads. Electromyographic responses did not differ between groups, indicating that similar levels of muscle fatigue were reached. CONCLUSIONS: Adolescents with CP show slightly lower muscle endurance compared with TD adolescents on a submaximal RTF protocol, which is in contrast with earlier findings in a maximal voluntary fatigue protocol. Accordingly, adolescents with CP have a reduced capacity to endure activities at similar relative loads compared with TD adolescents.

How do changes in motor capacity, motor capability, and motor performance relate in children and adolescents with cerebral palsy?

OBJECTIVE: To investigate the relations between changes in motor capacity (can do, in standardized environment), motor capability (can do, in daily environment), and motor performance (does do, in daily environment) among children with cerebral palsy (CP). DESIGN: Prospective longitudinal study. After baseline measurements (at the age of 18 mo, 30 mo, 5 y, 7 y, 9 y, 11 y, or 13 y), 2-year follow-up measurements were performed. Change scores were calculated, and Pearson correlations were used for change score relations. SETTING: Outpatient clinic. PARTICIPANTS: Toddlers, school-age children, and adolescents with CP (N=321; 200 boys, 121 girls). Levels of severity according to the Gross Motor Function Classification System included level I (42%), level II (15%), level III (17%), level IV (13%), and level V (13%). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Change in motor capacity was assessed with the Gross Motor Function Measure-66. Changes in motor capability and motor performance were assessed with the Pediatric Evaluation of Disability Inventory using the Functional Skills Scale and Caregiver Assistance Scale, respectively. RESULTS: Within the total group, change score correlations were moderate (.52-.67) and significant (P<.001). For age groups, correlations were significantly higher in toddlers than school-age children and adolescents. For severity levels, correlations were significantly higher in children at level III than level I, IV, and V. CONCLUSIONS: Results imply that change in motor capacity does not automatically translate to change in motor capability and change in motor capability does not automatically translate to change in motor performance. Results also show different relations for clinically relevant subgroups. These are important insights for clinical practice because they can guide evidence-based interventions with a focus on activities.

Long-term trajectories of health-related quality of life in individuals with cerebral palsy: a multicenter longitudinal study.

OBJECTIVES: To (1) determine the long-term trajectory of health-related quality of life (HRQOL) for the dimensions of physical complaints and motor, psychological, and social functioning for groups of individuals with cerebral palsy (CP) aged 1 to 24 years; (2) assess the variability in HRQOL within individuals with CP over time; (3) assess the variability in HRQOL between individuals with CP; and (4) compare the HRQOL in individuals with CP to reference data of typically developing individuals. DESIGN: Multicenter prospective longitudinal study. SETTING: Rehabilitation departments of 3 university medical centers and various rehabilitation centers in The Netherlands. PARTICIPANTS: Dutch individuals with CP (N=424; age, 1-24y). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The HRQOL dimensions of physical complaints and motor, psychological, and social functioning. Each individual visited the rehabilitation department for 3 or 4 measurements. The time between measurements was 1 or 2 years. RESULTS: Individuals with CP experience an HRQOL that, on average, remains fairly stable over time. Variability in HRQOL within individuals with CP was similar to that within typically developing individuals. Variability between individuals with CP could be explained by type of CP (motor functioning), Gross Motor Function Classification System level (physical complaints and motor and social functioning), and intellectual disability (physical complaints and social functioning). Finally, individuals with CP experienced a lower HRQOL than did typically developing individuals, especially for the dimensions of motor and social functioning. CONCLUSIONS: Many changes take place in the psychosocial development of the individual with CP, which accordingly change their expectations and those of their caregivers, peers, and professionals. As a result, perceived physical complaints and motor, psychological, and social functioning remain fairly stable over many years.

The effectiveness of a physical activity stimulation programme for children with cerebral palsy on social participation, self-perception and quality of life: a randomized controlled trial.

OBJECTIVE: To determine the effects of a six-month physical activity stimulation programme on social participation, self-perception and quality of life in children with cerebral palsy. DESIGN: Multicentre randomized controlled trial with concealed allocation, blinded assessments and intention-to-treat analysis. SETTING: Paediatric physiotherapy practices, special schools for children with a disability, and the child's own home. SUBJECTS: Forty-nine children with spastic cerebral palsy (28 male), aged 7-13 years, able to walk with and without walking aids. INTERVENTIONS: The intervention group followed a six-month physical activity stimulation programme involving counselling through motivational interviewing, home-based physiotherapy and four months of fitness training. The control group continued regular paediatric physiotherapy. MAIN MEASURES: Outcomes included social participation in domestic life, social participation in recreation and leisure (Life-Habits for Children questionnaire and Children's Assessment of Participation and Enjoyment questionnaire), self-perception (Harter's Self-Perception Profile for Children) and parent-reported quality of life (Cerebral Palsy Quality of Life Questionnaire). Assessments were performed at baseline, at six months (except quality of life) and at twelve months. RESULTS: Intervention resulted in a positive effect on social participation in domestic life at twelve months (mean between-group difference = 0.9, 95% confidence interval (CI) = 0.1 to 1.7 [1-10 scale], P = 0.03), but not at six months. No significant effects were found for social participation in recreation and leisure, self-perception at six months and twelve months or for quality of life at twelve months. CONCLUSIONS: The combination of counselling, home-based physiotherapy and fitness training was not effective in improving social participation in recreation and leisure, self-perception or quality of life, but did show a potential for improving social participation in domestic life over the longer term.

Longitudinal development of gross motor function among Dutch children and young adults with cerebral palsy: an investigation of motor growth curves.

AIM: The aim of this study was to describe patterns for gross motor development by level of severity in a Dutch population of individuals with cerebral palsy (CP). METHOD: This longitudinal study included 423 individuals (260 males, 163 females) with CP. The mean age at baseline was 9 years 6 months (SD 6y 2mo, range 1-22y). The level of severity of CP among participants, according to the Gross Motor Function Classification System (GMFCS), was 50% level I, 13% level II, 14% level III, 13% level IV, and 10% level V. Participants had been assessed up to four times with the Gross Motor Function Measure (GMFM-66) at 1- or 2-year intervals between 2002 and 2009. Data were analysed using non-linear mixed effects modelling. For each GMFCS level, patterns were created by contrasting a stable limit model (SLM) with a peak and decline model (PDM), followed by estimating limits and rates of gross motor development. RESULTS: The SLM showed a better fit for all GMFCS levels than the PDM. Within the SLM, significant differences between GMFCS levels were found for both the limits (higher values for lower GMFCS levels) and the rates (higher values for GMFCS levels I-II vs level IV and for GMFCS levels I-IV vs level V) of gross motor development. INTERPRETATION: The results validate the existence of five distinct patterns for gross motor development by level of severity of CP.

Systematic review of the clinimetric properties of laboratory- and field-based aerobic and anaerobic fitness measures in children with cerebral palsy.

OBJECTIVE: To systematically evaluate the level of evidence of the clinimetric properties of measures of aerobic and anaerobic capacity used for children with cerebral palsy (CP). DATA SOURCES: A systematic search of databases PubMed, Embase, SPORTDiscus, and PsycINFO through April 2011 was performed. STUDY SELECTION: Two independent raters identified and examined studies that reported laboratory- or field-based measures of maximal aerobic or anaerobic capacity in children with CP aged 5 to 14 years. DATA EXTRACTION: The COnsensus-based Standards for the selection of health status Measurement INstruments (COSMIN) checklist was used by 2 independent raters to evaluate the methodologic quality of the included clinimetric studies and to identify measures used in these studies. DATA SYNTHESIS: Twenty-four studies that used a maximal aerobic or anaerobic capacity measure were identified. Five studies reported clinimetric properties for 5 measures (2 aerobic and 3 anaerobic measures). Methodologic quality was excellent in 3 studies, showing good validity and reliability of field-based aerobic (Shuttle Run Test) and anaerobic (Muscle Power Sprint Test) measures. The studies on laboratory-based measures were rated fair, mainly because of inadequate statistics. The level of evidence was strong for good validity and reliability of the field-based tests. The level of evidence was unknown for validity and low to moderate for good reliability of laboratory-based tests. CONCLUSIONS: There is a paucity of research on the clinimetric properties of measurement instruments to assess aerobic and anaerobic capacity for children with CP. Further clinimetric studies of laboratory-based measures in children with CP at all Gross Motor Function Classification System (GMFCS) levels, and clinimetric studies of field-based measures in children who are classified as GMFCS levels III to V are required.