Unravelling age-related gait decline in cerebral palsy: insights into physiological changes and functional implications through an observational study-a French study protocol in a laboratory setting.

introductionCerebral palsy (CP) presents a complex neurodevelopmental disorder with a spectrum of motor impairments stemming from early brain injury. Whereas CP is traditionally viewed as a non-progressive condition, emerging evidence suggests a progressive decline in mobility and function, particularly in adulthood. Despite the prevalence of self-reported age-related gait decline in adults with CP, objective evidence supporting this phenomenon remains limited. Moreover, mechanistic insights into these functional alterations and their comparison with typically developing (TD) peers are lacking. To address this gap, our study aims to objectively assess age-related changes in gait performance among individuals with CP while examining physiological differences compared with TD peers. METHODS AND ANALYSIS: This protocol will compare the mobility of individuals with and without CP within two age groups (18-25 and 35-50 years old). Participants at Gross Motor Function Classification System levels I-II at age 18 will be invited to partake in the study. Every participant will be invited to complete four visits investigating a wide range of mobility related measures: walking performance, muscle strength, cardiopulmonary performance, fatigability, cost of walking and quantitative gait analysis. Through this comprehensive analysis encompassing gait performance metrics, self-reported outcomes, muscle strength, biomechanics and metabolical cost of walking, and fatigability, we seek to elucidate the underlying mechanisms driving age-related gait decline in adults with CP and inform targeted interventions to maintain function and quality of life. ETHICS AND DISSEMINATION: The study has been approved by the French ethics board (#2022-A02510-43) and will be communicated through conferences, articles and to participants through layman terms. TRIAL REGISTRATION NUMBER: NCT06163950.