Inter-rater reliability and test-retest reliability of the Performance and Fitness (PERF-FIT) test battery for children: a test for motor skill related fitness.

BACKGROUND: The Performance and Fitness (PERF-FIT) test battery for children is a recently developed, valid assessment tool for measuring motor skill-related physical fitness in 5 to 12-year-old children living in low-income settings. The aim of this study was to determine: (1) inter-rater reliability and (2) test-retest reliability of the PERF-FIT in children from 3 different countries (Ghana, South Africa and the Netherlands). METHOD: For inter-rater reliability 29 children, (16 boys and 13 girls, 6-10 years) were scored by 2 raters simultaneously. For test-retest reliability 72 children, (33 boys and 39 girls, 5-12 years) performed the test twice, minimally 1 week and maximally 2 weeks apart. Relative and absolute reliability indices were calculated. ANOVA was used to examine differences between the three assessor teams in the three countries. RESULTS: The PERF-FIT demonstrated excellent inter-rater reliability (ICC, 0.99) and good test-retest reliability (ICC, ≥ 0.80) for 11 of the 12 tasks, with a poor ICC for the Jumping item, due to low spread in values. A significant difference between first and second test occasion was present on half of the items, but the differences were small (Cohen's d 0.01-0.17), except for Stepping, Side jump and Bouncing and Catching (Cohen's d 0.34, 0.41 and 0.33, respectively). Overall, measurement error, Limits of Agreement and Coefficient of Variation had acceptable levels to support clinical use. No systematic dissimilarities in error were found between first and second measurement between the three countries but for one item (Overhead throw). CONCLUSIONS: The PERF-FIT can reliably measure motor skill related fitness in 5 to 12-year-old children in different settings and help clinicians monitor levels of fundamental motor skills (throwing, bouncing, catching, jumping, hopping and balance), power and agility.

Field-Based Tests of Strength and Anaerobic Capacity Used in Children With Developmental Coordination Disorder: A Systematic Review.

OBJECTIVE: Children with developmental coordination disorder (DCD) are reported to have lower levels of strength and anaerobic capacity. The purpose of this study was to (1) identify field-based tests for strength and anaerobic capacity used in studies comparing children with DCD and children who were typically developing (TD), (2) examine the methodological quality of studies reporting psychometric properties and rate the psychometric properties of the examined test, and (3) summarize available evidence by combining the methodological quality of the studies and the quality of the psychometric properties of the test. METHODS: An electronic search was conducted in July 2019 in 4 electronic databases. For purpose 1, primary studies were included with no exclusion of study design in which children aged 4 to 18 years with DCD were compared with children who were TD on strength and/or anaerobic capacity measures. For purpose 2, primary studies were included with no exclusion of study design in which a psychometric property was investigated. The Consensus-Based Standards for Selection of Health Measurement Instruments (COSMIN) was used to evaluate the methodological quality of the 34 studies and rate the psychometric properties of the tests used. RESULTS: Hand-held dynamometer, bent knee push-up, vertical jump, standing long-jump, functional strength measurement, fitness test, and test battery can be recommended for TD, and the shuttle run item of the Bruininks-Oseretsky Test of Motor Proficiency-Second Edition and 10 m × 5 m sprints (straight and slalom) can be recommended for DCD. CONCLUSION: Information regarding psychometric properties of field-based tests for strength and anaerobic capacity in children with DCD is lacking. IMPACT: Information about the psychometric properties of field-based tests for strength and anaerobic capacity in children with DCD is lacking. More information is available on TD children, but it is also not complete; information regarding validity and responsiveness, especially, is missing. When using measures in children with DCD, it is important to keep in mind this lack of evidence for the validity and reliability of the outcomes for this target group.

Reliability and Validity of the Ladder Agility Test Among Children.

PURPOSE: This study aimed (1) to evaluate the test-retest reliability of a new agility test among children and (2) to determine the physical performance and anthropometric variables that may influence agility performance in this population. METHODS: For aim 1, participants (n = 34) completed the Ladder Agility Test (LAT) twice, with a 2-week interval between the first and second test occasions. For aim 2, participants (n = 125) were assessed on the LAT as well as other measures thought to be necessary for agility such as motor coordination, explosive power of the lower extremity, dynamic balance, age, and body mass index. RESULTS: Intraclass correlation coefficient of the LAT total score was .94 (95% confidence interval, .88-.97). Cronbach alpha of .85 was found between the 4 test items. An R2 of .466 was found to represent the explained variance of the LAT total score by the predicting variables. Dynamic balance (2-legged side jumps) (P < .001), motor coordination (P < .01), and age (P < .06) were found to be the major predictors of the LAT total score. CONCLUSIONS: This study shows that the LAT is a reliable and valid field-based test that can be used to evaluate agility performance in children. Factors such as dynamic balance, motor coordination, and age may influence agility performance.

Psychometric properties of field-based anaerobic capacity tests in children with Developmental Coordination Disorder.

Background: Assessment of anaerobic capacity in children with Developmental Coordination Disorder (DCD) is essential for treatment planning. However, available field-based measures have no established validity and reliability in this population. Purpose: To examine the psychometric properties of selected field-based anaerobic capacity tests in children with and without DCD. Methods: School-aged children (6-16 years) with and without DCD participated in the study. The children completed the shuttle run sub-item of the Bruninks-Oseretsky test of motor proficiency-second edition, the 10 × 5 m sprint tests (straight and slalom) and the muscle power sprint test (MPST). Results: The shuttle run test item of the Bruninks-Oseretsky test of motor proficiency-second edition and 10 × 5 m sprint tests possess good construct validity and test-retest reliability in children with DCD. The 10 × 5 m sprint test-slalom was found to be the most responsive test among children with DCD. However, the MPST was less reliable in children with DCD compared to their typically developing peers, leading to a very large Smallest Detectable Difference. Conclusions: The findings suggest that the selected anaerobic capacity measures have sound psychometric properties among children with DCD with the exception of the MPST. Clinicians working on children with DCD could use these tests in their practice, especially in situations where logistical resources are limited. Implications for Rehabilitation Field-based anaerobic capacity tests are suitable measures for assessing anaerobic capacity in children with Developmental Coordination Disorder, particularly in situations where laboratory assessments are not feasible. The shuttle run test item of the Bruninks-Oseretsky test of motor proficiency-second edition and the 10 × 5 sprint tests (straight and slalom) have good construct validity in this population. The 10 × 5 sprint test (slalom) is the most sensitive anaerobic capacity test among children with Developmental Coordination Disorder.

Functional strength measurement in cerebral palsy: feasibility, test-retest reliability, and construct validity.

Purpose: No instrument exists that measures functional strength in both lower and upper extremities in children with cerebral palsy (CP). Therefore, the functional strength measurement (FSM) was tested for feasibility, test-retest reliability and validity in CP. Methods: Thirty-seven children with CP (aged 4-10 years, Gross Motor Function Classification System I and II) participated. The most common compensations for CP were described; new item descriptions were standardized, and one item was removed. Test-retest reliability was examined. To measure convergent validity, correlations between the FSM-CP and isometric muscle strength measured with the handheld dynamometer (HHD) were determined. Results: Test-retest reliability was considered high for all items (intra-class correlation coefficient 0.79-0.95). Significant correlations between the HHD and FSM-CP ranged from r = 0.36 to 0.75. Conclusion: The FSM-CP is feasible, reliable, and valid to use in children with CP. The FSM-CP can be considered as a helpful tool in clinical practice of physical examination of children with CP.

Subtyping children with developmental coordination disorder based on physical fitness outcomes.

PURPOSE: Children with Developmental Coordination Disorder (DCD) are known to have poor physical fitness. However, differentiating homogenous subgroups of DCD using fitness performance has not yet been established. Therefore the purpose of this study was to identify subtypes in children with and without DCD using measures of physical fitness. METHOD: Children (aged 6-10 years, n = 217) constituted the sample for this study. They were assessed on 1) aerobic fitness (20m Shuttle Run test), 2) anaerobic fitness (Muscle Power Sprint Test), 3) isometric muscle strength (handheld dynamometry) 4) functional upper and lower body strength (Functional Strength Measurement) and 5) motor coordination [Movement Assessment Battery for Children-2nd edition (MABC-2) test]. The Ward method was used to identify the various clusters. RESULTS: Five subtypes emerged in the entire sample. In the typically developing (TD) children mainly 2 subtypes (number 5 and 2) were found containing 89% of the TD children (n = 55), with the largest group demonstrating above average performance on all measures (cluster 5). Children in subtype 2 had just above average motor coordination and good aerobic fitness but lower muscle strength. Subtypes 1, 3 and 4 were clearly "DCD" clusters, however they showed difference in fitness performance. Subtype 1 contained children with DCD who showed poor performance on all fitness outcomes (n = 45). Children with DCD in subtype 3 had poor aerobic but average strength and anaerobic fitness (n = 48). Subtype 4 contained children with DCD (n = 45) who had good muscle strength and anaerobic fitness. Of these, 36% were at risk of DCD while 24% had definite motor coordination problems. CONCLUSION: Our findings indicate that children with and without DCD demonstrate heterogeneous physical fitness profiles. The majority of the children (66%) with DCD belonged to subtypes with lower fitness performance. Further studies are needed to confirm these findings in other samples of DCD children.

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

BACKGROUND: There is little and conflicting information about anaerobic performance and functional strength in children with Developmental Coordination Disorder (DCD). AIMS: To 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. METHOD: A 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). RESULTS: Children 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. INTERPRETATION: Differences 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.

Reliability and Structural and Construct Validity of the Functional Strength Measurement in Children Aged 4 to 10 Years.

BACKGROUND: Adequate muscle strength, power, and endurance are important in children's daily activities and sports. Various instruments have been developed for the assessment of muscle function; each measures different aspects. The Functional Strength Measurement (FSM) was developed to measure performance in activities in which strength is required. OBJECTIVE: The study objective was to establish the test-retest reliability and structural and construct validity of the FSM. DESIGN: A cross-sectional descriptive study was conducted. METHODS: The performance of 474 children with typical development on the FSM was examined. Test-retest reliability (n=47) was calculated with the intraclass correlation coefficient (2.1A) for agreement. Structural validity was examined with exploratory factor analysis, and internal consistency was established with the Cronbach alpha. Construct validity was determined by calculating correlations between FSM scores and scores obtained with a handheld dynamometer (HHD) (n=252) (convergent validity) and between FSM scores and scores on the Movement Assessment Battery for Children-2 (MABC-2) (n=77) (discriminant validity). RESULTS: The test-retest reliability of the FSM total score ranged from .91 to .94. The structural validity revealed one dimension, containing all 8 FSM items. The Cronbach alpha was .74. The convergent validity with the HHD ranged from .42 to .74. The discriminant validity with MABC-2 items revealed correlations that were generally lower than .39, and most of the correlations were not significant. Exploratory factor analysis of a combined data set (FSM, HHD, and MABC-2; n=77) revealed 2 factors: muscle strength/power and muscle endurance with an agility component. LIMITATIONS: Discriminant validity was measured only in children aged 4 to 6 years. CONCLUSIONS: The FSM, a norm-referenced test for measuring functional strength in children aged 4 to 10 years, has good test-retest reliability and good construct validity.

Physical fitness in children with developmental coordination disorder: measurement matters.

Children with Developmental Coordination Disorder (DCD) experience considerable difficulties coordinating and controlling their body movements during functional motor tasks. Thus, it is not surprising that children with DCD do not perform well on tests of physical fitness. The aim of this study was to determine whether deficits in motor coordination influence the ability of children with DCD to perform adequately on physical fitness tests. A case-control study design was used to compare the performance of children with DCD (n=70, 36 boys, mean age=8 y 1 mo) and Typically Developing (TD) children (n=70, 35 boys, mean age=7 y 9 mo) on measures of isometric strength (hand-held dynamometry), functional strength, i.e. explosive power and muscular endurance (Functional Strength Measurement), aerobic capacity (20 m Shuttle Run Test) and anaerobic muscle capacity, i.e. muscle power (Muscle Power Sprint Test). Results show that children with DCD were able to generate similar isometric forces compared to TD children in isometric break tests, but were significantly weaker in three-point grip strength. Performance on functional strength items requiring more isolated explosive movement of the upper extremities, showed no significant difference between groups while items requiring muscle endurance (repetitions in 30s) and items requiring whole body explosive movement were all significantly different. Aerobic capacity was lower for children with DCD whereas anaerobic performance during the sprint test was not. Our findings suggest that poor physical fitness performance in children with DCD may be partly due to poor timing and coordination of repetitive movements.