These joints are classified as (or polyaxial) because they permit motion around an indefinite number of axes, all sharing a common center.
For further reading, these sources provide deep dives into both the anatomical and regenerative aspects: spheroid joint
: The Radiopaedia guide to ball and socket joints offers a concise medical reference on structure and motion limits. These joints are classified as (or polyaxial) because
: They allow for movement with 3 degrees of freedom—flexion/extension, abduction/adduction, and rotation. spheroid joint