Why is the center of mass ofa 1-m length of pipe at its midpoint whereas this is not true for your arm or leg?

The center of mass of a uniform 1-meter length of pipe is at its midpoint because its mass is evenly distributed along its length. In contrast, the human arm or leg has varying densities and shapes, as they contain bones, muscles, and other tissues, which results in an uneven distribution of mass. Consequently, the center of mass in limbs is located closer to the denser areas, such as the trunk or where the muscles are more concentrated, rather than at the geometric midpoint.