Which joint is located at the posterior aspect of the pelvis?

The sacro-iliac joint is the correct answer because it is indeed located at the posterior aspect of the pelvis, serving as the connection between the sacrum at the base of the spine and the iliac bones of the pelvis. This joint plays a crucial role in weight-bearing and shock absorption during activities such as walking and running, making it significant for both mobility and stability in the pelvic region.

The symphysis pubis, while also a joint, is located at the anterior aspect of the pelvis where the two pubic bones meet. The temporomandibular joint is found in the jaw, connecting the mandible to the temporal bone of the skull, which is far removed from the pelvic region. Lastly, the acromion process is a bony projection on the scapula (shoulder blade), unrelated to the pelvis entirely. Thus, the sacro-iliac joint is the only joint mentioned that accurately fits the specified location in the question.