Handgrip Strength, Trunk Muscle Endurance, and Functional Mobility in Adolescents With Mild Intellectual Disability

This comparative, cross-sectional observational study examined handgrip strength, trunk muscle endurance, and functional mobility in adolescents aged 12-18 years with mild intellectual disability and compared their performance with typically developing peers. A total of 51 participants were evaluated during a single assessment session, including 24 adolescents with mild intellectual disability and 27 typically developing adolescents. Handgrip strength was measured using a digital hand dynamometer, trunk muscle endurance was assessed using the McGill trunk endurance test battery, and functional mobility was evaluated using the Timed Up and Go Test and the Timed Up and Down Stairs Test. The study also examined the relationships among handgrip strength, trunk muscle endurance, and functional mobility.

Inclusion Criteria * Adolescents aged 12-18 years. * For the mild intellectual disability group: a clinical diagnosis of mild intellectual disability according to DSM-5 criteria. * Ability to understand and follow simple verbal instructions. * Ability to complete the assessment procedures safely. * For the typically developing group: no diagnosis of intellectual disability, neurodevelopmental disorder, neurological disease, orthopedic condition, or serious systemic disease that could affect assessment performance. * Written informed consent obtained from the participant's legal guardian. * For participants with mild intellectual disability, verbal assent obtained using an age- and cognition-appropriate explanation. Exclusion Criteria * An orthopedic or neurological limitation preventing completion of the assessments. * An additional medical or comorbid condition that could substantially affect assessment performance. * Inability or unwillingness to complete the assessment session.