The effects of imagery-based occupation on duration of prone extension in four-and five-year old children

Objective. This study was designed to test the effects of added imagery on the performance of children assuming prone extension posture. Imagery was used to add purpose for maintaining prone extension, a posture considered important for sensory integration. Method. Fourand five-year-old children (N = 36) were randomly assigned to the imagery condition or the rote condition, with 31 completing all procedures. Each participant was asked to hold the prone extension posture for as long as possible. In the imagery-based condition, the child was asked to fly like an airplane to Disneyland. This group had a picture of Disneyland and famous characters placed in the visual field. In the rote condition, the instructions given were to hold this type of body posture. Each child was videotaped. Results. A 2-way analysis of variance (experimental condition X gender) revealed that there was not a statistically significant difference between the imagery-based condition and the rote condition, F (1, 27) = . 02, p = . 88. Girls performed better than boys, F (1, 27) = 5.9, p = . 02. By chance assignment, there were more girls (10) than boys (5) in the rote condition and more boys (11) than girls (5) in the imagery condition. Conclusion. This study does not support the hypothesis that imagery elicits better occupational performance, but the results might be due to an unexpected disproportioning by gender through random assignment. Duration of Prone Extension 3 The Effects of Imagery-Based Occupation on Duration of Prone Extension in Fourand Five-Year Old Children Occupational therapy is unique among professions in regards to the use of purposeful doing or occupation since being founded in 1917. Bird T. Baldwin (1919), an advocate for the importance of purposeful occupation, suggested occupationally embedded exercise increased one’s endurance and willingness to participate in comparison to exercise alone. He viewed the person as complex with many intricate systems that are enhanced by voluntary involvement in therapeutic occupation. Nelson (1988) asserted that an occupation must have meaning in order to be purposeful for the individual. Meaning is an interaction between a person and an occupational form. It is one’s interpretation of an occupational form that leads to purpose. Purpose is a felt emotion and causes the person to desire an outcome. Nelson and Peterson (1989) indicated the significance of meaning in their analysis of enhancing therapeutic exercise through occupation. A person finding meaning in an occupation will in turn have a sense of purposefulness. In one of many research studies, Yoder, Nelson, and Smith (1989) focused on embedding exercise within an occupation to encourage a rotating arm motion. The subjects who were told that they had been stirring cookie dough to make cookies performed more repetitions than those in the group told to stir for the purpose of exercise alone. There are different ways to classify occupational forms that can be of an advantage to patients (Lang, Nelson, & Bush, 1992). One way is in terms of naturalistic, simulated, and imagery-based occupations (Nelson & Peterson, 1989). Naturalistic occupational forms involve exercise that occurs spontaneously as a result of one’s daily Duration of Prone Extension 4 occupations. An example of this would be the exercise a person experiences while painting the sides of a house. In simulated occupational forms, the environment has been altered by the therapist to mimic naturalistic forms in some way. Imagery-based occupation is another approach to enhancing therapeutic exercise. Nelson and Peterson defined imagery-based occupation as verbal or pictorial stimuli that elicit imagined or visualized movement or performance even though little physical support (material) is present in the immediate environment. An example of this might include reaching one’s arm up and back down while pretending to put dishes away in the cupboard. Although no dishes are present, the patient imagines the task, contributing to an increase in the range of motion in the shoulder. There are several studies that have analyzed the individual effects of materials-, imagery-, and rote-exercise based occupational forms. Lang et al. (1992) compared these occupational forms among nursing home residents. This study focused on the number of repetitions completed during material-based occupation (kicking a balloon), imagerybased (imagining kicking a balloon), and rote exercise (kicking motion). The results of the study indicate more repetitions from the participants when taking part in the materials-based occupation than in the imagery-based and rote exercise conditions. DeKuiper, Nelson, and White (1993) completed a follow up to this study and measured not only exercise repetitions but also the vertical distance and speed of movement. The results agreed with the findings of Lang et al. Thomas (1996) developed a similar study by including elderly females living independently and adding the components of heart rate and self-perceived rest period. Duration of Prone Extension 5 Riccio, Nelson, and Bush (1990) also studied the effects of imagery-based occupations compared to rote exercise in elderly female residents of a nursing home. Participants were told to raise their arms and reach as though they were picking apples and then placing them in a basket on their laps. Instructions were given to practice this motion until the participant was too tired. The subjects also were told to reach down with both arms pretending to be picking up coins that had been dropped and placing them on their laps. The results of the reaching up exercise were statistically significant in support of the study’s hypothesis, that imagery will elicit exercise. The differences in the reaching-down exercise were not statistically significant. Wu, Trombly, and Lin (1994) compared the effects of materials-based, imagerybased, and rote exercise in a study that included female subjects of college age. The participant’s quality of movement was evaluated using the Waterloo Spatial Motion Analysis & Recording Technique (WATSMART). Each participant was asked to a) pick up a pencil from a pencil holder and prepare to write her name (materials-based), b) imagine picking up a pencil from location equal to where the pencil holder was placed and pretend to prepare sign her name (imagery-based), or c) produce the movement of reaching forward in front of the subject (rote exercise). A contrast analysis completed after the omnibus F indicated that the materials-based occupation produced a better quality of movement in terms of less reaction time needed to plan the movement when compared to the imagery-based and exercise conditions. Movement time in seconds and the number of movement units were also significantly lower in the materials-based condition in contrast to the other two conditions. Ross and Nelson (2000) provided further support to this idea. The results of this study indicate a quicker reaction time, a Duration of Prone Extension 6 smoother movement (requiring fewer movement units), more direct movement, and lower amplitude of peak velocity in those subjects participating in the material-based occupation. These findings validate the importance of purposefulness and the role it has on the quality of occupations performed. Hsieh, Nelson, Smith and Peterson (1996) conducted a study of adding purpose to occupations and comparing it to the rote exercise in terms of the number of repetitions. This study of persons with hemiplegia involved the actions bending down, reaching, standing up, and extending the arm. The conditions included using small balls (materials-based) that were thrown at a target, imagining that there are balls on the ground, and the rote exercise condition. The results of the study supported previous studies involving added purpose to increase the number of exercise repetitions in participants. A study completed by Sakemiller and Nelson (1998) focused on adding occupationally embedded exercise to increase functional prone extension in children. Single case experiments on two children with cerebral palsy inquired as to whether adding purpose would increase the range of neck and back extension. A game was introduced to the children, improving neck and back extension in contrast to the baseline established at the beginning of the study. The results further substantiate the use of purposeful occupation as a means to enhance meaning and performance. In review, these studies have provided evidence that materials-based occupational forms add purpose to traditional rote exercise and enhance performance. However, there is not substantial evidence from previous studies that imagery-based occupational forms also add meaning and purpose to occupations. The subjects participating in these studies Duration of Prone Extension 7 mainly consisted of elderly nursing home residents, stroke patients, and healthy college aged students. Sakemiller and Nelson (1998) is the only study to assess functional prone extension in children after adding occupationally embedded exercise. Further research is needed to study the effect of imagery-based exercise on children. One of the methods occupational therapists use to assess children is the prone extension postural test. The prone extension posture first begins to develop when a child is five or six months old (Ayres, 1979). Ayres defines the prone extension posture as the position when a child supports his body weight on his lower abdomen while his head, chest, arms, and legs are raised against gravity. The prone extension posture is essential for inhibiting or integrating the tonic labyrinthine reflex, and is viewed as a significant step in motor development (Ayres, 1972, p. 81). This position is also significant to a child being able to maintain proximal stability (Connor, Williamson, & Siepp, 1978). This type of fundamental postural movement is the basis for motor control (Bobath & Bobath,