AFAA Personal Trainer Certification Practice Exam

What type of joint is the subtalar joint classified as?

1. Hinge joint

2. Ball-and-socket joint

3. Planar joint

4. Synovial joint

The correct answer is: Synovial joint

The subtalar joint is classified as a synovial joint, which is characterized by a joint cavity filled with synovial fluid, allowing for a greater range of movement than other types of joints. The subtalar joint, located between the talus and calcaneus bones in the foot, allows for movement primarily in the form of inversion and eversion. While it is indeed a synovial joint, it specifically exhibits characteristics of a complex joint with multiple movement capabilities, including those related to the ankle's mobility. Understanding that it is a synovial joint helps clarify its function and importance in activities that require foot and ankle movement, such as walking, running, and jumping. The other classifications listed do not accurately represent the subtalar joint's structure or function. Hinge joints allow movement primarily in one plane, like the elbow or knee. Ball-and-socket joints provide a wide range of motion in multiple planes, such as the shoulder or hip. Planar joints, also known as plane joints, allow for gliding movements but are not the primary function of the subtalar joint. Recognizing the subtalar joint as a synovial joint helps in understanding its role in dynamic movements and overall foot biomechanics.