Date Published: July 3, 2017
Publisher: Public Library of Science
Author(s): Lisa Mailleux, Ellen Jaspers, Els Ortibus, Cristina Simon-Martinez, Kaat Desloovere, Guy Molenaers, Katrijn Klingels, Hilde Feys, Miklos S. Kellermayer.
The clinical application of upper limb (UL) three-dimensional movement analysis (3DMA) in children with unilateral cerebral palsy (uCP) remains challenging, despite its benefits compared to conventional clinical scales. Moreover, knowledge on UL movement pathology and how this relates to clinical parameters remains scarce. Therefore, we investigated UL kinematics across different manual ability classification system (MACS) levels and explored the relation between clinical and kinematic parameters in children with uCP.
Fifty children (MACS: I = 15, II = 26, III = 9) underwent an UL evaluation of sensorimotor impairments (grip force, muscle strength, muscle tone, two-point discrimination, stereognosis), bimanual performance (Assisting Hand Assessment, AHA), unimanual capacity (Melbourne Assessment 2, MA2) and UL-3DMA during hand-to-head, hand-to-mouth and reach-to-grasp tasks. Global parameters (Arm Profile Score (APS), duration, (timing of) maximum velocity, trajectory straightness) and joint specific parameters (angles at task endpoint, ROM and Arm Variable Scores (AVS)) were extracted. The APS and AVS refer respectively to the total amount of movement pathology and movement deviations of wrist, elbow, shoulder, scapula and trunk.
Longer movement durations and increased APS were found with higher MACS-levels (p<0.001). Increased APS was also associated with more severe sensorimotor impairments (r = -0.30-(-0.73)) and with lower AHA and MA2-scores (r = -0.50-(-0.86)). For the joint specific parameters, stronger movement deviations distally were significantly associated with increased muscle weakness (r = -0.32-(-0.74)) and muscle tone (r = 0.33-(-0.61)); proximal movement deviations correlated only with muscle weakness (r = -0.35–0.59). Regression analysis exposed grip force as the most important predictor for the variability in APS (p<0.002). We found increased movement pathology with increasing MACS-levels and demonstrated the adverse impact of especially muscle weakness. The lower correlations suggest that 3DMA provides additional information regarding UL motor function, particularly for the proximal joints. Integrating both methods seems clinically meaningful to obtain a comprehensive representation of all aspects of a child’s UL functioning.
Unlike gait analysis, the clinical application of upper limb (UL) three-dimensional movement analysis (3DMA) remains challenging in children with unilateral cerebral palsy (uCP). In children with uCP, UL function has thus far been extensively studied using reliable and valid clinical scales for bimanual performance or unimanual capacity such as the Assisting Hand Assessment  or the Melbourne Assessment , respectively. Notwithstanding their clinical and scientific value, these clinical scales lack quantitative data as their scores are based on visual observations and they only provide limited information on selective anatomical motions and movement patterns at the individual joint levels. In contrast, a more detailed and objective description can be obtained by means of 3DMA with which the amount of movement pathology can be captured .
In this study, we assessed UL clinical and kinematic parameters in a large cohort of children with uCP with varying levels of manual abilities to attain a better understanding of the intricate relationship between sensorimotor impairments, activity measures and the specific kinematic deviations. Such insights are crucial to set individualized therapy goals and thus optimize the child’s UL functional potential. We found significant differences in UL movement pathology between children with different manual ability levels and demonstrated the adverse impact of muscle weakness, muscle tone and sensory deficits on UL kinematics, as well as the negative relation between aberrant UL kinematics and bimanual performance and unimanual capacity.
We found increased UL movement pathology in children with poorer manual abilities and demonstrated the adverse impact of muscle weakness, muscle tone and sensory deficits on UL kinematics, especially at the level of the wrist and elbow. Moreover, aberrant UL kinematics were associated with poor bimanual performance and unimanual capacity. Results further highlighted the importance of muscle strengthening as a treatment modality to decrease UL movement pathology as supported by the stronger correlations between muscle weakness and UL kinematics. Finally, the overall low to moderate correlations between joint kinematics and the different clinical measures suggest that a 3DMA provides added information regarding UL motor function, particularly for the proximal joints. Hence, integrating both methods seems clinically meaningful to obtain a comprehensive representation of all aspects of a child’s UL functioning.