Table 1 A summary of the five KINARM robot tasks

Visually Guided Reaching R & L

Upper Limb Postural Control

Posture speed (m/s)

Mean hand speed when the hand should be at rest.

Motor Response to a Visual Stimulus

Reaction time (s)

Time from target onset to movement onset.

Feed-forward Control: Initial phase of the movement.

Initial direction error (rad)

Angular deviation between (i) a straight line from the hand position at movement onset to the destination target, (ii) a straight line from the hand position at movement onset to the hand position after the initial phase of movement.

Feed-forward Control: Initial phase of the movement.

Initial distance ratio

Ratio of (i) the distance the hand travelled during the subject’s initial phase of movement to (ii) the distance the hand travelled between movement onset and movement offset (or the end of the trial if the destination target is not reached).

Feed-forward Control: Initial phase of the movement.

Initial speed ratio

Ratio of (i) the maximum hand speed during the subject’s initial phase of movement to (ii) the global hand speed maximum of the trial.

Feedback Control: Movement corrections after the initial motor response.

Speed maxima count

Number of hand speed maxima between movement onset and offset.

Feedback Control: Movement corrections after the initial motor response.

Minimum maximum speed difference (m/s)

Differences between hand speed maxima and minima.

Total Movement

Movement time (s)

Total time elapsed from movement onset to end.

Total Movement

Path length ratio

Ratio of (i) the distance travelled by the hand between the movement onset and movement offset and (i) the straight line distance between the starting and destination targets.

Total Movement

Max speed (m/s)

Global maximum hand speed.

Arm position matching R & L

Position Sense

Variability XY (m)

Root-mean-square (RMS) of X and Y variables: mean value of the variability of the subject’s hand position in the X and Y directions.

Position Sense

Contraction/expansion ratio XY

Ratio of the range of area moved over – arm moved by the subject compared to the arm moved by the robot. Ratio of range of movement in the x and y directions are used in the current ratio.

Position Sense

Shift XY (m)

RMS of the X and Y shifts: mean difference between the mirrored x and y positions of the arm moved by the subject and the x and y positions of the arm (+ lateral shift, - median shift).

Position Sense

Absolute Error XY

The mean absolute distance error across all trials.

Object Hit

Global Performance

Total hits

Number of balls hit off the screen in the opposite direction from it original path.

Global Performance

Hits with left

Number of balls hit with the left (L) hand

Global Performance

Hit with right

Number of balls hit with the right (R) hand

Motor Performance

Hand bias hits

Quantifies which hand is used more often for hitting the balls (hand dominance).

Spatial & Temporal Performance

Miss bias

Quantifies any bias of misses toward one side of the work space or the other (x direction only).

Spatial & Temporal Performance

Hand transition

Shows where the subject’s preference for using one hand over the other switches in the work space.

Motor Performance

Hand selection overlap

Captures how effective subjects are at using both hands and how often they overlap hands (i.e., hit balls with both the R and L hands in the same area of the work space).

Spatial & Temporal Performance

Median error

The percentage of the way through the task when the subject made half their errors.

Motor Performance

Hand speed L (m/s)

The mean L hand speed maintained through the entire task.

Motor Performance

Hand speed R (m/s)

The mean R hand speed maintained through the entire task.

Hand bias

Value from -1 to 1 that describes the bias in hand speed between the hands.

Motor Performance

Movement area L & R (m^2)

Area of space the subject used with each hand during the task.

Motor Performance

Movement area bias

Value from -1 to 1 that describes the bias in movement area between hands.

Object Hit & Avoid

Includes the 14 parameters from Object Hit

Distractor hits L

Number of distractor objects hit with L hand.

Global Performance

Distractor hits R

Number of distractor objects hit with the R hand.

Global Performance

Distractor hits total

Number of distractor objects the subject hit; reported as the % of total distracters dropped.

Trail Making B

Executive Function

Total time (s)

Total time from the targets being illuminated to touching the last target.

Executive Function

Dwell time (s)

Total time spent with the hand feedback dot at the targets.

Time ratio

Time for targets 13/25/time for targets 1–12.

Error count

Number of times an incorrect target was touched.