The Effect of Materials on Performance: A Kinematic Analysis of Eating

Abstract

Objectives. This research replicates and extends part of a study by Mathiowetz (1991) and Mathiowetz & Wade (1995). Using kinematic analysis, this study examined the effect of materials (i.e. applesauce, saucer and spoon) on subsequent occupational performance (i.e. eating). Three conditions varying the materials present were studied, including materials-based occupation (MBO) (i.e. applesauce, spoon, saucer present), partial imagery-based occupation (PIBO) (i.e. spoon, empty saucer present) and imagery-based occupation (IBO) (i.e. no materials present).Method. Using a repeated measures counterbalanced design, the eating performance of 47 female college students aged 21–26 years (mean = 21.6, SD = 1.7) was analysed using equipment from Motion Analysis, Inc. Dependent variables included movement time, movement units, maximum displacement, amplitude of peak velocity, the percentage of reach in which peak velocity occurred and indicators of the vertical axis at various phases of the movement. Displacement × time, velocity × time and velocity × displacement graphs were generated from each condition for a random sample of 30 participants and were compared by two raters to carry out categorical judgement analyses.Results. The MBO condition elicited a slower, less smooth movement with lower peak velocity and lower percentage of reach in which peak velocity occurred when compared to both the PIBO and IBO conditions. The MBO condition was different from the others on six additional variables involving analysis of the movement in three distinct phases. Compared to the IBO condition, the PIBO condition elicited a slower, less smooth movement with less maximum displacement and lower peak velocity. The categorical judgement analyses supported differences between the MBO and IBO graphs, but not between the PIBO vs. IBO and MBO graphs.Conclusion. These results indicate that materials produce movements that are significantly different in multiple ways from movements produced in the absence of materials.