Final answer:
Synovial rib attachments might be replaced by syndesmoses to provide increased movement. Syndesmoses connect bones with connective tissue, as seen in the interosseous membranes of the forearm and leg, facilitating rotation in the former and stability in the latter.
Step-by-step explanation:
Synovial rib attachments might be replaced by syndesmoses to allow for a greater range of movement than what is provided by the original synovial connections. A syndesmosis joint is characterized by bones that are connected by bands of connective tissue, thereby allowing for more movement relative to sutures.
For instance, the interosseous membranes of the forearm and leg serve as syndesmoses to unite parallel bones like the radius and ulna in the forearm, and tibia and fibula in the leg, thus preventing their separation. In the case of the forearm, this allows for the necessary rotation of the radius bone during movement. Conversely, the stability of the tibiofibular syndesmosis in the leg supports weight-bearing activities, as it firmly locks the talus bone between the tibia and fibula at the ankle joint, providing strength and stability.