BACKGROUND: Children with cerebral palsy (CP) typically show muscle weakness of the lower extremities, which can be measured with the use of handheld dynamometry (HHD). OBJECTIVE: The purposes of this study were: (1) to determine test-retest reliability and measurement error of isometric lower-extremity strength measurements in children with CP with the use of HHD and (2) to assess implications for measurement design. DESIGN: A test-retest design was used. METHODS: Fourteen children with hemiplegic (n=6) or diplegic (n=8) spastic CP (Gross Motor Function Classification System levels I-III), ages 7 to 13 years, were assessed for isometric strength on 2 separate days (occasions) with the use of HHD, with 3 trials per muscle group. The intraclass correlation coefficient, standard error of measurement, and smallest detectable difference (SDD) were calculated for different measurement designs. RESULTS: Intraclass correlation coefficient values of single measurements for all muscle groups ranged from .70 to .90, and the SDD was large (>30%). Regarding measurement error, the largest source of variability was found for occasion. A 2-occasion mean decreased the SDD by 9% to 14%. For trials, a greater improvement in SDD was found when 2 trials were averaged instead of 3. A measurement design of 2 trials-2 occasions was superior to the often-used approach of 3 trials-1 occasion. LIMITATIONS: The small sample size was the major study limitation. CONCLUSIONS: Handheld dynamometry is reliable and can be used to detect changes in isometric muscle strength in children with CP when using the mean of at least 2 trials. To further improve reliability, taking the average of 2 occasions on separate days is recommended, depending on group size and muscle group.
BACKGROUND:Children with cerebral palsy (CP) typically show muscle weakness of the lower extremities, which can be measured with the use of handheld dynamometry (HHD). OBJECTIVE: The purposes of this study were: (1) to determine test-retest reliability and measurement error of isometric lower-extremity strength measurements in children with CP with the use of HHD and (2) to assess implications for measurement design. DESIGN: A test-retest design was used. METHODS: Fourteen children with hemiplegic (n=6) or diplegic (n=8) spastic CP (Gross Motor Function Classification System levels I-III), ages 7 to 13 years, were assessed for isometric strength on 2 separate days (occasions) with the use of HHD, with 3 trials per muscle group. The intraclass correlation coefficient, standard error of measurement, and smallest detectable difference (SDD) were calculated for different measurement designs. RESULTS: Intraclass correlation coefficient values of single measurements for all muscle groups ranged from .70 to .90, and the SDD was large (>30%). Regarding measurement error, the largest source of variability was found for occasion. A 2-occasion mean decreased the SDD by 9% to 14%. For trials, a greater improvement in SDD was found when 2 trials were averaged instead of 3. A measurement design of 2 trials-2 occasions was superior to the often-used approach of 3 trials-1 occasion. LIMITATIONS: The small sample size was the major study limitation. CONCLUSIONS: Handheld dynamometry is reliable and can be used to detect changes in isometric muscle strength in children with CP when using the mean of at least 2 trials. To further improve reliability, taking the average of 2 occasions on separate days is recommended, depending on group size and muscle group.
Authors: Marije Goudriaan; Benjamin R Shuman; Katherine M Steele; Marleen Van den Hauwe; Nathalie Goemans; Guy Molenaers; Kaat Desloovere Journal: Front Hum Neurosci Date: 2018-01-31 Impact factor: 3.169
Authors: Diego Longo; Marco Lombardi; Paolo Lippi; Daniela Melchiorre; Maria Angela Bagni; Francesco Ferrarello Journal: J Rehabil Med Clin Commun Date: 2021-06-17