Gross motor function, functional level, physical performance, and muscle strength in preschool children newly diagnosed with cancer: Data from the RePlay trial

Children with cancer experience treatment-related physical disruptions; however, these disruptions for preschool children newly diagnosed with cancer are poorly characterized. This study aimed to quantify gross motor function, functional level, physical performance, and muscle strength in preschool children aged 1-5 years newly diagnosed with cancer, and to compare these with age-expected normative values. This cross-sectional study includes data from the baseline assessment of 83 children (49% girls, 39 ± 16 months old) enrolled in the Rehabilitation including structured active Play for preschoolers with cancer (RePlay) trial. Gross motor function was evaluated using the Peabody Developmental Motor Scales-Second Edition (PDMS-2); functional level was assessed using the Pediatric Evaluation of Disability Inventory (PEDI); physical performance was assessed using the 6-min walk test; and muscle strength was assessed using the KLS Martin Vigorimeter for handgrip strength. Mean gross motor quotient was 78.9 [95% CI: 73.6-84.2], indicating poor overall performance; 76% of the children performed below average or worse. Most children had difficulties with locomotion, with a mean standard score of 5.7 [95% CI: 4.8-6.6], indicating poor performance; 81% of the children performed below average or worse. PEDI mobility data were available for 83 children, with a mean normative standard score of 23.2 [95% CI: 20.0-26.3], indicating decreased functional level; 69% of the children scored below average. Mean handgrip strength was below average compared to healthy children; 0.17 [95% CI: 0.12-0.22]. CONCLUSION: These results show that preschoolers newly diagnosed with cancer have gross motor function, functional level, and muscle strength impairments, underlining the importance of targeted physical rehabilitation. CLINICALTRIALS: gov: NCT04672681. WHAT IS KNOWN: • Research has shown that children newly diagnosed with cancer have markedly impaired muscle strength, cardiorespiratory fitness, physical performance, and gross motor functions. • Gross motor function development is fundamentally important for preschoolers. However, research on gross motor function in children with cancer is limited, and existing studies often include broad age ranges (1-18 years), hindering clear evidence specific to preschoolers aged 1-5 years. WHAT IS NEW: • Preschool children newly diagnosed with cancer have clinically significant impairments of gross motor function and functional level. • Data on physical performance and muscle strength are limited, indicating poor feasibility for preschoolers with cancer.