The study’s objective was to investigate the effects of foliage plants on prefrontal cortex activity and subjective assessments of psychological relaxation. In a crossover experimental design, 24 male university students in their 20s observed a container with and without foliage plants for 3 minutes while oxyhemoglobin (oxy-Hb) concentration in the prefrontal cortex was continuously measured with a portable near-infrared (NIR) spectroscopy device. Afterward, subjective evaluations of emotions were obtained via two self-report questionnaires: a modified semantic differential (SD) method and the Profile of Mood State questionnaire (POMS). Oxy-Hb concentration in the right prefrontal cortex was significantly lower in subjects who viewed the foliage plants than in those who did not, indicating a physiologically relaxed state. The subjects also reported in the SD method significantly more positive emotions (e.g., comfortable, natural, and relaxed) associated with viewing the foliage plants. In the POMS, a significant positive effect on psychological relaxation when subjects viewed the foliage plants was shown. Thus, we conclude that foliage plants have both physiological and psychological relaxation effects in males even after only short exposure.
Sin-Ae Park, Chorong Song, Ji-Young Choi, Ki-Cheol Son, and Yoshifumi Miyazaki
Dong Sik Yang, Svoboda V. Pennisi, Ki-Cheol Son, and Stanley J. Kays
Twenty-eight ornamental species commonly used for interior plantscapes were screened for their ability to remove five volatile indoor pollutants: aromatic hydrocarbons (benzene and toluene), aliphatic hydrocarbon (octane), halogenated hydrocarbon [trichloroethylene (TCE)], and terpene (α-pinene). Individual plants were placed in 10.5-L gas-tight glass jars and exposed to ≈10 ppm (31.9, 53.7, 37.7, 46.7, and 55.7 mg·m−3) of benzene, TCE, toluene, octane, and α-pinene, respectively. Air samples (1.0 mL) within the glass containers were analyzed by gas chromatography–mass spectroscopy 3 and 6 h after exposure to the test pollutants to determine removal efficiency by monitoring the decline in concentration over 6 h within sealed glass containers. To determine removal by the plant, removal by other means (glass, plant pot, media) was subtracted. The removal efficiency, expressed on a leaf area basis for each volatile organic compound (VOC), varied with plant species. Of the 28 species tested, Hemigraphis alternata, Hedera helix, Hoya carnosa, and Asparagus densiflorus had the highest removal efficiencies for all pollutants; Tradescantia pallida displayed superior removal efficiency for four of the five VOCs (i.e., benzene, toluene, TCE, and α-pinene). The five species ranged in their removal efficiency from 26.08 to 44.04 μg·m−3·m−2·h−1 of the total VOCs. Fittonia argyroneura effectively removed benzene, toluene, and TCE. Ficus benjamina effectively removed octane and α-pinene, whereas Polyscias fruticosa effectively removed octane. The variation in removal efficiency among species indicates that for maximum improvement of indoor air quality, multiple species are needed. The number and type of plants should be tailored to the type of VOCs present and their rates of emanation at each specific indoor location.
A-Young Lee, Sin-Ae Park, Hye-Gyeong Park, and Ki-Cheol Son
The objective of this study was to assess the physical and psychological effects of an 18-session horticultural therapy (HT) program based on task-oriented training in stroke patients and investigate patient satisfaction. The HT program consisted of horticultural activities including the motions such as reaching–grasping, squatting, stepping, and stooping. A total of 31 stroke inpatients (16 males, 15 females) at B rehabilitation hospital in Seongnam, South Korea, participated in this study. Fourteen stroke patients participated in a thrice weekly HT program (6 weeks, ≈60 minutes per session) between Aug. and Sept. 2016, whereas another 17 stoke patients comprised the control group. At the completion of the 18-session HT program, upper limb function [manual function test (MFT)], grip strength (hydraulic hand dynamometer), pinch force (hydraulic pinch gauge), fine motor skills (9-hole pegboard), balance [Berg Balance Scale (BBS)], and activities of daily living (Modified Barthel Index) were evaluated in both groups. In addition, depression [The Korean version of the short form of Geriatric Depression Scales (SGDS-K)], rehabilitation stress (Rehabilitation Stress Scales), rehabilitation motivation (Rehabilitation Motivation Scales), and fall efficacy (The Korean version of the Falls Efficacy Scale) were evaluated. Stroke patients in the HT group showed significantly improved upper limb function, hand force, balance, fall efficacy, activities of daily living, and decreased depression (P < 0.05). By contrast, no significant change was noted in the control group. In addition, 85.7% of the stroke patients in the HT group reported being very satisfied or satisfied with the HT program. In conclusion, the HT program based on task-oriented training improved the patients’ physical and psychological function after stroke rehabilitation. These study results suggest that implementing an HT program in a rehabilitation hospital will effectively contribute to functional recovery after stroke.
Bo-Young Kim, Sin-Ae Park, Jong-Eun Song, and Ki-Cheol Son
This study was conducted to determine the effects of a horticultural therapy (HT) program, based on B.F. Skinner’s behavior modification theory and special education science curriculum for Korean children with intellectual disabilities for the improvement of attention and sociality. Twenty-four participants (10 males, 14 females, in grades 1 to 3) with intellectual disabilities were recruited from a special education class at an elementary school in Seoul, South Korea. Twelve children participated in the HT program after-school for 6 months (Mar. to Aug. 2009, once per week, ≈40 min per session); the control group consisted of the remaining 12 children. Before and after the HT program, Conners’ teacher rating scales—revised and the social skills rating system assessments were conducted by parents/caregivers or teachers for each of the children. Analysis of covariance (ANCOVA) and chi square tests were used to compare differences between the two groups. Difference in attention was not significant between groups. Children in the HT group had statistically significant higher sociality scores than those in the control group (P < 0.001). In conclusion, the HT program improved the sociality of children with intellectual disabilities. To maximize the therapeutic effects of the HT program for attention, the program should be revised and supplemented based on the results in this study. A larger sample size and factoring in the level of disability and year in school of the participants would increase the precision in assessing therapeutic effects.
Sin-Ae Park, Sae-Room Oh, Kwan-Suk Lee, and Ki-Cheol Son
This study used electromyographic analysis to investigate specific upper limb and hand muscle activation during 15 common horticultural activities. A total of 30 Korean adults between the ages of 20 and 30 years, with an average age of 24.8 years, were recruited from Konkuk University, Seoul, South Korea. Electromyographic measurements were made using a portable four-channel electromyograph. Bipolar surface electromyography (EMG) electrodes were attached to six upper limb muscles (i.e., upper trapezius, triceps—long head, biceps brachialis, flexor carpi ulnaris, flexor carpi radialis, and brachioradialis) and two hand muscles (i.e., thenar eminence and hypothenar eminence) on the dominant hand. These eight muscles that were selected play a major role in the operation of upper limbs and hand muscles for upper body low-impact activities. Each participant did the 15 horticultural activities on one occasion with two separate sessions. Each activity was performed for 60 seconds followed by a 15-second rest period sitting at a table on a height-adjusted chair between each activity. All eight muscles measured were used together during most of 15 horticultural activities. Upper trapezius, thenar eminence, and hypothenar eminence had higher muscle activity than the other muscles. Triceps—long head displayed very low EMG values compared with the other muscles. The EMG data will facilitate developing scientific and research-based gardening intervention and/or horticultural therapy programs for improving physical health and physical rehabilitation.
A-Young Lee, Sin-Ae Park, Young-Jin Moon, and Ki-Cheol Son
The objective of this study was to analyze the kinematic and kinetic characteristics of eight horticultural activities (HAs): digging, raking, sowing seeds, transplanting plants, near-distance weeding, far-distance weeding, low-height harvesting, and high-height harvesting. Twenty-four male university students (average age, 23.4 ± 2.9 years) participated in this study. Balance and postural stability factors [e.g., center of mass (CoM), ground reaction force (GRF), and center of pressure (CoP)] and postural control strategy factors (e.g., joint angles, joint moment, and muscle activation of the trunk and lower limbs) were assessed using a three-dimensional (3D) motion analysis system, force platform, and surface electromyography. A total of eight HAs were distinguished in three motions: stepping, squatting, and stooping. In performing the eight HAs, CoM shifting occurred and balance of the subjects became unstable. These forced compensatory motor strategies to maintain balance by exertion of GRF from the two feet, movement of the CoP, and a combination of musculoskeletal system exercises of the lower limbs and trunk occurred. The kinematic and kinetic characteristics of lower limb motions were significantly different across the HAs (P = 0.05). The kinematic and kinetic characteristics of HAs were similar to those of the functional tasks during balance improvement training motions and activities of daily living. The current study provides useful reference data for developing a horticultural therapy program for balance improvement in patients who need physical rehabilitation.
Sin-Ae Park, A-Young Lee, Ki-Cheol Son, Wang-Lok Lee, and Dae-Sik Kim
The present study aimed to assess the physical and psychological health benefits of a 15-session gardening intervention in elderly women and to investigate satisfaction of the gardening intervention. Fifty elderly women (age >70 years) at two senior community centers located in Seoul, South Korea, were selected to participate in this study. Twenty-four elderly women at senior community center “A” participated in a twice-weekly gardening intervention (≈50 minutes per session) during the period Sept. to Nov. 2015; 26 elderly women at senior community center “B” comprised a control group. At the completion of the 15-session gardening intervention, physical health parameters such as body composition, physical functional ability, and hand function ability were assessed in both groups. Additionally, psychological health conditions, such as cognitive ability, depression, and sociality, were assessed. The elderly women also answered a questionnaire to assess the amount of physical activity experienced during daily life. Elderly women in the gardening intervention group exhibited significantly improved muscle mass, aerobic endurance, hand dexterity, cognitive ability, and decreased waist circumference (P < 0.05). In contrast, significantly decreased muscle mass and agility and increased depression were observed in the control group (P < 0.05). Moreover, elderly women in the gardening intervention group reported a significantly higher amount of daily physical activity compared with those in the control group (P < 0.05). Additionally, 95.8% of elderly women in the gardening intervention group reported of being very satisfied with the gardening intervention. In conclusion, the gardening intervention maintained and improved the physical and psychological health of elderly women at a senior community center, whereas elderly women in the control group experienced age-related reduced physical and psychological health conditions. More studies are needed to evaluate the effects of a gardening intervention in a larger population of elderly women; in addition, a longer intervention period would provide a better measure of health in elderly women.
Mung Hwa Yoo, Youn Jung Kwon, Ki-Cheol Son, and Stanley J. Kays
Foliage plants of Hedera helix L. (english ivy), Spathiphyllum wallisii Regal (peace lily), Syngonium podophyllum Schott. (nephthytis), and Cissus rhombifolia Vahl. (grape ivy) were evaluated for their ability to remove two indoor volatile organic air pollutants, benzene and toluene. Removal was monitored when the aerial portion of plants was exposed singly to 1 μL·L-1 or to 0.5 μL·L-1 of each gas in a closed environment over 6-hour periods during the day and the night. Selected physiological processes were assessed before and immediately after treatment to determine the effect of the gases on the plants. The effectiveness of plants in the removal of air pollutant(s) varied with species, time of day, and whether the gases were present singly or as a mixture. When exposed to a single gas, S. wallisii, S. podophyllum, and H. helix displayed higher removal efficiencies (ng·m-3·h-1·cm-2 leaf area) of either gas than C. rhombifolia during the day. The efficiency of removal changed when both gases were present; H. helix was substantially more effective in the removal of either benzene or toluene than the other species, with the removal of toluene more than double that of benzene. When exposed singly, the removal of both compounds was generally higher during the day than during the night for all species; however, when present simultaneously, H. helix removal efficiency during the night was similar to the day indicating that stomatal diffusion for english ivy was not a major factor. The results indicated an interaction between gases in uptake by the plant, the presence of different avenues for uptake, and the response of a single gas was not necessarily indicative of the response when other gases are present. Changes in the rates of photosynthesis, stomatal conductance, and transpiration before and after exposure indicated that the volatiles adversely affected the plants and the effects were not consistent across species and gases. Deleterious effects of volatile pollutants on indoor plants may be critical in their efficacy in improving indoor air quality and warrant further study.
Sin-Ae Park, Ho-Sang Lee, Kwan-Suk Lee, Ki-Cheol Son, and Candice A. Shoemaker
The metabolic cost of 10 gardening tasks was measured in children to determine the exercise intensities associated with these tasks. Seventeen children [(mean ± sd) aged 12.4 ± 0.7 years and body mass index 21.6 ± 4.0 kg·m−2] participated in this study. The children performed the 10 gardening tasks at a garden previously established in Cheongju, Chungbuk, South Korea. They visited the garden twice and performed five different tasks on each visit. Five minutes were provided to complete each gardening task and a 5-minute rest was allowed between each task. The children wore a portable telemetric calorimeter and a heart rate monitor for measurement of oxygen uptake and heart rate during the gardening tasks. The results show that the 10 gardening tasks represented moderate- to high-intensity physical activity for the children [4.3 ± 0.5 to 6.6 ± 1.6 metabolic equivalents (MET)]. Digging (6.6 ± 1.6 MET) and raking (6.2 ± 1.5 MET) were high-intensity physical activities, and digging was more intense than the other gardening tasks performed in this study (P < 0.05). Tasks such as weeding (5.8 ± 1.1 MET), mulching (5.5 ± 1.3 MET), hoeing (5.3 ± 0.7 MET), sowing seeds (5.0 ± 1.1 MET), harvesting (4.8 ± 0.6 MET), watering (4.6 ± 1.1 MET), mixing growing medium (4.4 ± 0.6 MET), and planting transplants (4.3 ± 0.5 MET) were moderate-intensity physical activities. The MET data for the gardening tasks will facilitate the development of garden-based exercise interventions for children, which can promote health and physically active lifestyle.
Sin-Ae Park, A-Young Lee, Kwan-Suk Lee, and Ki-Cheol Son
The objective of this study was to determine the exercise intensities of 10 gardening tasks for men and women in their 20s. Fifteen university students [(mean ± SD) age 24.7 ± 1.4 years and body mass index 23.5 ± 4.1 kg·m−2] participated in this study. On two occasions, the subjects completed 10 gardening tasks in a high tunnel and a grassy area with weeds located near the high tunnel in Cheongju, Chungbuk, South Korea. They performed five gardening tasks randomly ordered on each occasion. Subjects did each gardening task for 5 minutes and then sat and rested in a chair for 5 minutes before the next task. Each subject wore a portable telemetric calorimeter and respired into the facemask during the gardening tasks and resting periods to measure their oxygen uptake. The subjects also wore a heart rate monitor under their breast to record heart rate data during the gardening tasks and resting periods via radiotelemetry. The 10 gardening tasks performed by the subjects were determined to be moderate- to high-intensity physical activities [3.5 ± 0.5 to 6.3 ± 1.2 metabolic equivalents (MET)]. In conclusion, the exercise intensity of gardening tasks should be useful information for developing garden exercise programs that meet the recommended physical activity for health benefits in adults.