Final answer:
Greater motion at some joints is due to their structural type, such as the multiaxial ball-and-socket joint of the shoulder, and the amount of support they get from ligaments and muscles, which in turn balances mobility and stability depending on the joint's function.
Step-by-step explanation:
The reason there is greater motion at some joints compared to others is due to their structural design and the amount of support they receive from ligaments and muscles. Synovial joints are specialized to enable specific movements. For instance, a multiaxial ball-and-socket joint, such as the shoulder, provides a broader range of motion because it has less ligament support. Conversely, a ginglymus joint like the elbow offers less mobility but more stability.
Ligaments often limit the movement of joints by providing necessary support and stability. Hence, even if a joint like the hip has the potential for large movement due to its ball-and-socket structure, strong ligaments restrict its range to provide stability, especially during activities like standing and walking. In this regard, the balance between mobility and stability is essential for the function of each joint, depending on its role in the body.