The three goals of this research were to investigate how normal subjects move while seated, how paraplegic patients move while seated, and whether seated movements can be modeled using a hemi-ellipsoid shape. Pressure readings were recorded at 11 Hz using a 36 by 36 sensor pressure map by XSENSOR. Subjects were instructed to move or perform pressure relief as they normally would while seated. Analysis was performed using Microsoft Excel with Solver and Matrix.xla add-ins and automated with VBA code. Major movements and time intervals between movements were calculated by locating the area of maximum pressure on each hemi-buttock for 20 normal and 6 paraplegic subjects. Statistical analysis revealed movements followed a normal distribution while time intervals followed a lognormal distribution. For both the normal (p=0.041) and paraplegic groups (p=0.007) the number of movements significantly increased from the first hour of recording to the second hour. The time interval between major movements decreased but not significantly for neither the normal subjects nor the paraplegics. No significant differences were identified between the normal and paraplegic groups over the first hour or second hour for number of movements or time intervals. Time series analysis with plotting, trend lines, ARIMA, and periodograms did not reveal patterns in the data. Preference for a side was shown. Next, all areas of identified major movements for one subject and one frame for each of the paraplegic patients were modeled as a hemi-ellispoid shape using minimization with Solver. Eigenvalues were calculated in order to obtain the lengths of the x, y, and z axis of the hemi-ellipsoid with an average error of 39.87% for the normal subject and an error range of 5.10% to 2701.81% for the paraplegic patients.

Background: Rowing is a demanding sport where extreme positions and high physical loads are obtained. This leads to injury risks, especially in the lower back. Another issue relates to comfortability. When rowing, the buttocks are the pivot point, and lots of pressure is placed on the sitting bones and surrounding tissues. For para-rowers, these issues can be even more prominent and important to consider. Purpose and aim: The purpose of this project was to develop a solution that enhances the enjoyment and comfortability for para-rowers. To do that, this project aimed to develop an individualized add-on product for rowing seats, with an included method to translate individual measurements into the design. Method: The Double Diamond Model was used to guide the project, where both qualitative and quantitative methods were included to reach the aim and purpose. To discover and define the problem, data was collected with literature review, benchmarking, and semi-structured interviews. With that data as a base, concepts were developed and selected, and the selected concept was tested with regards to pressure distribution. Results: The final concept was based on one individual and includes a seating area that has the exact shape of that individual. It does also include an increased back support and sideways support. To get measurements to design the individualized seat, a method consisting of scanning a vacuum pillow was used. Conclusion: The findings indicate that a perfectly fitted seat will spread out pressure more evenly around the buttocks, which enhances comfortability. There is, though, still much to consider and evaluate before this product can reach the market.