Parameters of the ellipses describing the region of variability of the position of the centre of gravity for selected operational parameters of the wheelchairs and three wheelchair tilt angles β, where test—Independent measuring test, α—Inclination of the axis of the ellipse, a—Horizontal axis of the ellipse, b—Vertical axis of the ellipse, M—Average value, SD—Standard deviation, x_CG—Average position of the centre of gravity on x-axis, y_CG—Average position of the centre of gravity on y-axis, ρ—The number of measured points inside the ellipse.

Parameters of the ellipses describing the region of variability of the position of the centre of gravity for selected operational parameters of the wheelchairs and three wheelchair tilt angles β, where test—Independent measuring test, α—Inclination of the axis of the ellipse, a—Horizontal axis of the ellipse, b—Vertical axis of the ellipse, M—Average value, SD—Standard deviation, xCG—Average position of the centre of gravity on x-axis, yCG—Average position of the centre of gravity on y-axis, ρ—The number of measured points inside the ellipse.