We investigated the use of a sorting box to obtain a quantitative assessment of upper limb motor function in children with cerebral palsy. In our study, children with and without cerebral palsy placed and removed geometrical objects of a sorting-box while their wrist position was monitored by a camera-based, motion-tracking system. We analyzed three different smoothness metrics (logarithmic dimensionless jerk, spectral arc-length and number of peaks) together with time to task completion. Our results suggest that smoothness metrics are an effective tool to distinguish between impaired and non-impaired subjects, as well as to quantify differences between the affected and less-affected sides in children with hemiparetic cerebral palsy.

Cerebral Palsy (CP) is a group of permanent pre, post and perinatal disorders of the motor and posture development due to non-progressive alterations in brain’s natural development caused by injuries in the Central Nervous System. Due to the importance of the daily use of the upper limb members, it’s important to consider more efficient ways to evaluate the performance in patients diagnosed with CP. One way to obtain an evaluation of the performance of the thoracic member is recording defined movements and calculating the smoothness, using an instrumented sorting block box. Our objective is to create a protocol of valuation for the upper member that is objective, efficient and that gives a quantitative feedback of the grade of the motor affectation of child with PC in a clinical environment.