Methodology/Approach: Recently; the "Washer Dryer" type washing machines with horizontal or slant drums are becoming popular in Japan. We measured and analyzed posture while using the washing machines with 3 dimensional motion capture measurement devices. Subjective Kansei and usability questionnaires were also used. After the measurement; measured working postures were analyzed with the human kinematic model (3D SSPP) that can estimate theoretical value of the muscle tension and loads on the lumber vertebrae; knees and ankles. Three types of washers (European type; box shape and horizontal drum; Conventional Japanese type; a vertical drum; New type; slant drum with higher profile) were used for the experiment. 12 female participants aged between 22 and 43 took evaluation.
On electrics shaver; electromyogram of lower arm and pressure to the face was measured.
Findings: On Washer-dryer; theoretical muscular forces (%MVC; percent of maximum voluntary contraction which is a percentage of the maximum muscular force of 50 percentile female) on elbow; hip; knee and ankle were estimated. Sum of the %MVC of the new type was 116; European type was 133 (knee tension is high) and conventional Japanese type was 284 (ankle tension is 110; which exceeds the limit). The new type requires only 40% of the muscular force required for the conventional Japanese type. From the subjective evaluation; the new type was better than the European type washer and conventional type on subjective fatigue evaluation and general evaluation; with statistical significance with one-way ANOVA.
On shaver; EMG was reduced 20% from conventional shape and it was and statistically significant. Pressure force to the face skin was reduced 85% and also significant.
Originality/Value of paper: The practical case examples of improvement with Kansei ergonomics; through the commercial product development
Keywords: Kansei ergonomics; product development; washer-dryer machine; electric shaver