Mean values (SD) of kinematic and dynamic variables at the different events of the task.

<p>Mean values (SD) of kinematic and dynamic variables at the different events of the task.</p

Example of typical recordings of the step down task in one participant.

<p>Top panel: phases of the task (first swing, first double support (FDS), second swing and last double support (LDS)) with images corresponding to the initial position of each phase. Inset: Isometric (posterior left) view of the Grip-Lift Manipulandum (GLM). The direction of the grip force (GF) and load force (LF) are shown by its vectors following the reference frame where x, y and z corresponds to the vertical, mediolateral and posteroanterior axes respectively. In the panels, the following traces are shown as function of time: (A) vertical displacement of the hand and sacrum, (B) vertical Ground Reaction Force (vGRF), (C) Load Force (LF) and (D) Grip Force (GF). The short vertical dotted lines mark the different phases of the task in all traces. The straight long vertical line mark t₀ in all four traces. The dashed horizontal line in panel B shows the subject weight. The circles highlights the events observed in the forces during the task: vGRF_fc, value of the vGRF at foot contact; vGRF_max, maximum value observed for vGRF during the task; LF_min, minimum value observed for LF during the task; LF_max, maximum value observed for LF during the task; GF_min, minimum value observed for GF during the task; and GF_max, maximum value observed for GF during the task.</p

Comparison of kinematic and dynamic variables between female and male groups.

<p>Comparison of kinematic and dynamic variables between female and male groups.</p

Mean values (SD) of temporal variables of the whole sample during the task.

<p>Mean values (SD) of temporal variables of the whole sample during the task.</p

Example of two subjects’ traces corresponding to each groups mean values.

<p>Female subject (S5) is presented in grey and male subject (S7) in black. The traces display the vertical position of the hand (straight traces) and the sacrum (line-dot-dot traces) as function of time, starting from t₀, showing the difference in the vertical displacement of the hands and the sacrum between groups. The vertical cut lines mark vGRF_fc and LF_max events in each subject’s trial.</p

The Two-Arm Coordination Test: Maturation of Bimanual Coordination in Typically Developing Children and Deficits in Children with Unilateral Cerebral Palsy

<p><b>Background:</b> Tools to assess bimanual coordination are scant. We aimed to: 1) provide normative data of maturation of bimanual coordination in tipically developing (TD) children measured by the Two Arm Coordination Test (TACT), and 2) validate the TACT as an instrument to specifically discriminate impairment of bimanual coordination in children with unilateral cerebral palsy (UCP). <b>Procedure:</b> Cross-sectional observational study. 252 TD children and 26 children with UCP performed 8 trials of TACT (following a star pattern with a pointer steered by coordinated movements of both arms). Number of errors and time were combined in a performance index of motor learning.<b>Results:</b> In TD children, bimanual coordination improved with age (F(7,244)=36.888, p<.001). Children with UCP had a poorer bimanual coordination than TD children (all t>24.25, all p<.01). TACT scores were correlated moderately to manual dexterity and manual ability (all r>-.452, all p<.039), showing the capacity of the TACT to provide information on different aspects of hand function. <b>Conclusion:</b> TACT is a valid instrument to assess bimanual coordination.</p

Diagram of a child holding the Manipulandum while performing the task from initial to ending position.

<p>LF, load force; GF, grip force. X, Y, and Z represent the vertical, mediolateral, and anteroposterior axes, respectively.</p

Results of dynamic variables in function of the events (LF_min, GF_min, LF_max and GF_max).

<p>A) Mean Load force. B) Mean Grip force. C) Mean GF/LF ratio. The four conditions are presented in colour code as follow: blue = more affected hand, cyan = less affected hand, green = nondominant hand and yellow = dominant hand. Error bars represent the standard error. * indicates p-value <0.050.</p

Mean values of temporal and dynamic variables.

<p>Mean values of temporal and dynamic variables.</p

Mean values of maximum voluntary contraction and percentage of maximum voluntary contraction for the grip force.

<p>Mean values of maximum voluntary contraction and percentage of maximum voluntary contraction for the grip force.</p