Association between upper limb clinical tests and accelerometry metrics for arm use in daily life in children with unilateral cerebral palsy.

Purpose: To evaluate the association between upper-limb (UL) clinical tests and UL accelerometry-derived metrics in children with unilateral Cerebral Palsy (CP).

Methods: In this cross-sectional study, twenty children with unilateral CP and Manual Ability Classification System level I-III were included. Outcomes of the Assisting Hand Assessment, Box and Block-Test and accelerometry metrics were collected in the clinical setting and in daily life. UL asymmetry index (i.e., the ratio between the well-functioning UL and the affected UL use) was evaluated in different physical activity levels and relative use of UL was evaluated during daily living. Spearman's correlation was used to determine the association between UL clinical tests and accelerometry metrics in a clinical setting and in daily life.

Results: The strongest negative association was between the Assisting Hand Assessment units and accelerometry metrics during the sedentary time in daily life (r_s = -0.64). The asymmetries between ULs were highest during the child's sedentary time (asymmetry index: 45.15) compared to when the child was in light (asymmetry index: 23.97) or higher intensity physical activity (asymmetry index: 13.39). The children used both ULs simultaneously for 44% of the time during daily life.

Conclusion: Accelerometry metrics may provide additional objective information to clinical tests by quantifying the amount of UL movements and the amount of asymmetry between the upper limbs in daily life.