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Research Article  |   June 1998
Effects of Object Affordances on Reaching Performance in Persons With and Without Cerebrovascular Accident
Author Affiliations
  • Ching-yi Wu, ScD, OTR, is Assistant Professor, Department of Occupational Therapy, College of Medicine, Chang Gung University, Tao-yuan, Taiwan
  • Catherine A. Trombly, ScD, OTR, FAOTA, is Professor, Department of Occupational Therapy, Boston University, Sargent College of Health and Rehabilitation Sciences, Boston, Massachusetts
  • Keh-chung Lin, ScD, OTR, is Associate Professor, School of Occupational Therapy, College of Medicine, National Taiwan University, 7 Chung-shan South Road, Taipei, Taiwan
  • Linda Tickle-Degnen, PhD, OTR/L, is Assistant Professor, Department of Occupational Therapy, Boston University, Sargent College of Health and Rehabilitation Sciences, Boston, Massachusetts
Article Information
Neurologic Conditions / Stroke / Special Issue on Occupation-Centered Research
Research Article   |   June 1998
Effects of Object Affordances on Reaching Performance in Persons With and Without Cerebrovascular Accident
American Journal of Occupational Therapy, June 1998, Vol. 52, 447-456. doi:10.5014/ajot.52.6.447
American Journal of Occupational Therapy, June 1998, Vol. 52, 447-456. doi:10.5014/ajot.52.6.447
Abstract

Objective. This study investigated whether affording objects with different levels of functional support would have an impact on reaching performance in patients after cerebrovascular accident (CVA) and in adults who were neurologically intact. Reaching performance was quantitatively analyzed, using several kinematic variables.

Method. Two groups, 14 participants after CVA and 24 age-matched adults who were neurologically intact, performed a food chopping task under two conditions: enriched affordances and impoverished affordances. Enriched affordances involved reaching forward to a chopper and pushing down on the handle to chop afresh mushroom. Impoverished affordances involved reaching forward to a simulated chopper (i.e., a chopper covered with cardboard) without anything in it and then pushing the handle down. Reaching movement was measured by a three-dimensional motion analysis system.

Results. For the CVA group, the enriched condition of reaching to chop the mushroom resulted in more efficient, direct, smooth, and preplanned movement than the impoverished condition of reaching to push on the chopper handle. The neurologically intact group responded similarly except that the participants’ movement was equally smooth, as measured by movement unit, between the two testing conditions. Force generation, as characterized by peak velocity, was similar for both conditions for both groups.

Conclusion. The finding that enriched affordances had a positive effect on movement kinematics in both CVA and neurologically intact groups suggests that providing natural objects for completing a task and providing functional information on the objects may enhance the functional performance of persons who have had a CVA. These findings should be replicated and extended to confirm the validity of these effects and allow for generalization.