Muscle strength and muscle fatigue during maximal isometric grip tasks in children with unilateral cerebral palsy

Abstract

The first objective of this study was to compare maximal hand and pinch grip strength and muscle fatigue between children with unilateral cerebral palsy (CP) and typically developing (TD) children. Secondly, we aimed to investigate the influence on muscle fatigue of characteristics such as age, gender, MACS level and maximal muscle strength. Sixty-one children with unilateral CP (33 males, 28 females; mean age 11y, SD 3y1m) and 61 age and gender matched TD children were included. Hand and pinch grip strength of the non-dominant hand (NDH) was in the CP group 47% and in the TD group 3% lower than in the dominant hand (DH). Hand grip strength in the DH and NDH was respectively 7% and 40% lower in children with CP compared to TD children. The pinch grip strength in the NDH was 53% lower in children with CP in comparison with TD children, but in the DH a similar pinch grip strength was found between groups. In the CP group, the SFI of hand and pinch grip was higher in the NDH compared to the DH, except for the SFI of hand grip. The SFI of hand and pinch grip was in both hands lower in the TD group compared to the CP group. The regression model showed that maximal muscle strength predicted 7% to 14% of the SFI, meaning that a higher maximal strength is related with lower muscle fatigue. Further research is warranted to optimize the measurement protocol of muscle fatigue and to investigate the influencing factors and underlying mechanism of muscle fatigue.