Insights in static and dynamic fatigability in the upper limb in typically developing children and children with unilateral Cerebral Palsy

Abstract

Abstract Background In Cerebral Palsy (CP), fatigability in the upper limb (UL) is important for daily life. Aim To investigate (1) the difference between static and dynamic motor fatigability (SMF, DMF) using grip between Unilateral CP (UCP) and typically developing (TD) children and (2) the relation between SMF and DMF and UL functioning in UCP. Participants Thirty-eight UCP children and 38 age and gender matched TD children were included in the first research question and 63 UCP children in the second research question, all aged between 6-18 years old. Measurements Motor fatigability was measured in power grip and key pinch. SMF was expressed as the Static Fatigue Index (SFI) and the ratio of decrease in mean force (ratio Fmean). For DMF, the ratio Fmean and the ratio of decrease in peaks (ratio peaks) were calculated. UL functioning was measured using maximal grip and key pinch strength (Fmax), UL maximal isometric strength, unimanual capacity and bimanual performance. Conclusion Overall, children with UCP showed more motor fatigability compared to TD children. However, differences in motor fatigability were inconsistent. Significant correlations were found in static fatigability and maximal grip and key pinch strength. Correlations with the activity level were limited. Further research with larger groups is indicated.