For the occupational adaptation and social integration of the intellectually disabled, it is helpful to improve their work performance and interpersonal skills. The purpose of the study was to evaluate the effectiveness of horticultural therapy (HT) programs to improve work performance and interpersonal relationships of persons with intellectual disabilities. Based on observations and analyses of how people with intellectual disabilities work, we have developed a 12-session HT program that includes upper limb movements and physical activities to improve hand function. We recruited, with the consent of their legal guardians, 14 (6 males, 8 females) participants who had intellectual disabilities and were working at a sheltered workshop in K-gu, Seoul, South Korea. The program consisted of twelve sixty-minute sessions that were conducted twice a week at a rooftop garden. For pre- and post-evaluation of the program, the survey of functional adaptive behavior (SFAB), interpersonal negotiation strategies, a horticultural job evaluation (self), hand function tests (pegboard, pinch gauge, fingertips), and blood sample tests for physiological indicators of exercise were conducted. Interpersonal negotiation strategies, functional adaptive behaviors, and physical abilities for job behaviors, including agility and grasping of the hand, improved significantly from before to after the program (p < 0.05). A positive result of VEGF (vascular endothermic growth factor) in blood sample tests implies the need for further research on cognitive changes caused by horticultural activities. This study has limitations due to the small number of participants, but the results suggest that low- to medium-intensity horticultural treatment programs using the upper body and hands could be effective for vocational rehabilitation of the intellectually disabled.
Keywords: gardening; horticultural therapy; intellectual disability; upper limb function; vocational rehabilitation.