Final answer:
Flexibility of joints can vary from person to person due to the structural classification and the support from ligaments and muscles.
Step-by-step explanation:
Flexibility can vary from joint to joint in the same person.
Each synovial joint of the body is specialized to perform certain movements. The movements that are allowed are determined by the structural classification for each joint. For example, a multiaxial ball-and-socket joint has much more mobility than a uniaxial joint. However, the ligaments and muscles that support a joint may place restrictions on the total range of motion available.
Thus, the ball-and-socket joint of the shoulder has little in the way of ligament support, which gives the shoulder a very large range of motion. In contrast, movements at the hip joint are restricted by strong ligaments, which reduce its range of motion but confer stability during standing and weight-bearing.