Exploring Kinetic and Kinematic Finger Individuation Capability in Children With Hemiplegic Cerebral Palsy

Abstract

While fine manual dexterity develops over time, the extent to which children show independent control of their digits in each hand and the impact of perinatal brain injury on this individuation have not been well quantified. Our goal in this study was to assess and compare finger force and movement individuation in 8–14 year old children with hemiplegic cerebral palsy (hCP; n = 4) and their typically developing peers (TD; n = 10). We evaluated finger force individuation with five independent load cells and captured joint movement individuation with video tracking. We observed no significant differences in individuation indices between the dominant and non-dominant hands of TD children, but individuated force and movement were substantially reduced in the paretic versus non paretic hands of children with hCP ( p < 0.001). In TD participants, the thumb tended to have the greatest level of independent control. This small sample of children with hCP showed substantial loss of individuation in the paretic hand and some deficits in the non-paretic hand, suggesting possible benefit from targeted training of digit independence in both hands for children with CP.

Developmental and acquired brain injury have opposite effects on finger coordination in children

“…Previous studies of grasping have shown that children with CP do not develop typical force coordination patterns ( Eliasson et al, 1991 ), and the kinematics of their reaching movements are more segmented and do not show anticipatory shaping of the fingers ( Rönnqvist and Rösblad, 2007 ). Children with CP also show less individuation between the fingers in the paretic hand ( McCall et al, 2022 ). A recent study compared an adult CP group to healthy controls ( Kong et al, 2019 ), and found that the CP group showed smaller maximal forces and higher indices of finger interdependence (enslaving) (i.e., less individuated finger force production in the CP group), while the indices of multi-finger synergies stabilizing total finger forces were not significantly different from those of a control group.…”

Quantifying Hand Strength and Isometric Pinch Individuation Using a Flexible Pressure Sensor Grid

“…Hand function is one of the most complex components of the human motor system [1][2][3][4][5]. Grasping objects, for example, often begins with visual perception and generation of a motive to reach [6][7][8].…”

“…However, this technique is a gross assessment that does not detect subtle deficits in hand function [25][26][27]. Moreover, there is no commercially available digital dynamometer designed to measure dexterous modulation of individual finger strength, which is a core component of tasks required for daily living [1,2,[28][29][30][31][32][33].…”

“…To better quantify assessments of hand dexterity, we and others have previously developed techniques to score kinematic finger individuation, or the ability to flex a single digit in isolation [1,2,29,[34][35][36][37][38][39][40]. Since isometric kinetic components of force generation are also critical but involve slightly different neural pathways [41][42][43], others have applied similar techniques to study isometric finger individuation [1,2,29,34]. Quantification of isometric finger individuation is essential, as grasping and manipulating objects between the thumb and another digit is integral to everyday interactions with our environment [1,2,34,40].…”

“…Since isometric kinetic components of force generation are also critical but involve slightly different neural pathways [41][42][43], others have applied similar techniques to study isometric finger individuation [1,2,29,34]. Quantification of isometric finger individuation is essential, as grasping and manipulating objects between the thumb and another digit is integral to everyday interactions with our environment [1,2,34,40].…”