Obstetric brachial plexus palsy (OBPP) arises from perinatal injury to the brachial plexus, resulting in varying degrees of motor and sensory impairment in the upper extremity. While existing assessment instruments primarily target unilateral limb function, they frequently overlook bimanual capabilities, which are essential for functional independence. This study aims to investigate the utility of the Duruöz Hand Index (DHI) as a reliable, valid, and practical instrument for evaluating functional limitations in individuals with OBPP. A cohort of 21 pediatric patients (aged 6-18 years) with OBPP was recruited from a tertiary university hospital in Turkey. Functional assessment included grip and pinch strength, range of motion, and upper extremity performance, measured using the Modified Mallet Classification, Brachial Plexus Outcome Measure (BPOM), Pediatric Outcomes Data Collection Instrument (PODCI), and DHI

Inclusion Criteria:

• Aged 6 to 18 years
• All diagnosed with OBPP who were followed up at the Physical Medicine and Rehabilitation outpatient clinic of a tertiary university hospital in Turkey.

Exclusion Criteria:

• A history of trauma or surgery affecting the function of the affected extremity (other than OBPP)
• The presence of systemic diseases that could impair hand function (such as polyneuropathy)
• Cognitive impairments that could affect comprehension.

The study cohort consisted of patients who were under regular follow-up at our tertiary care hospital and met the inclusion criteria.

The individual participant data (IPD) collected during this study will be shared in an anonymized format. All identifying information will be removed to ensure participant confidentiality, and only de-identified datasets underlying the study results will be made available to qualified researchers upon request

De-identified individual participant data (IPD) and supporting documents will be available starting from the date of publication of the main study results and will remain accessible for 5 years.

IPD and supporting information will be accessible to qualified researchers for academic or scientific purposes. Access requests can be submitted via email to the corresponding author, and data will be shared after approval and signing of a data use agreement to ensure confidentiality and ethical use.