Reach-to-Grasp Co-ordination in the Paretic Limbs of Individuals with Stroke: Insight from a Barrier Paradigm
Nuttakarn Runnarong MS*,**, Jarugool Tretriluxana PhD*, Vimonwan Hiengkaew PhD*, Roongtiwa Vachalathiti PhD*
Affiliation : * Physical Therapy, Mahidol University, Nakhon Pathom, Thailand ** Health Science, Srinakharinwirot University, Nakhon Nayok, Thailand
Objective : Reach and grasp components must be co-ordinated to preserve the optimal reach-to-grasp performance. However,
conflicting results regarding the deficit in reach-to-grasp co-ordination has been reported in the paretic hand of individuals
after stroke. Additionally, investigations have not been undertaken to study more challenging task constraints to induce the
impairment of reach-to-grasp co-ordination. This study aimed to compare reach-to-grasp co-ordination while avoiding an
obstacle in the paretic hand of individuals after stroke with matched non-disabled adults.
Material and Method: Twenty-four participants having mild severity of upper extremity impairment were recruited with an
equal number of non-disabled adults. Kinematic reach-to-grasp movements with obstacle avoidance were analyzed. Reach-
to-grasp co-ordination was quantified using cross-correlation analysis: maximum correlation coefficient represented the
spatial aspect and the time lag represented the temporal aspects.
Results : Individuals after stroke showed a significant disturbance in the temporal aspect of reach-to-grasp co-ordination, but
not the spatial aspect as compared with non-disabled adults.
Conclusion : Among participants, after stroke reach-to-grasp co-ordination was delayed in the temporal aspect of reach-to-
grasp with obstacle avoidance but preserved in the spatial aspect. Specific methods to assess reach-to-grasp co-ordination
and to treat the time delay to improve co-ordination should be considered in individuals after stroke.
Keywords : Motor control, Reach-to-grasp co-ordination, Dexterity
