ball and socket

基本解释

In the diseased hip, the "ball and socket" become irregular, rough, and deformed, causing pain and decreased range of motion (Figure 1).
在髋关节病变的“球窝”变成不规则，粗拙，变形，导致疼痛和关节活动范围减小（图1）。
They made joints in stone keeping the lintels in place horizontally using a tongue and groove joint and subsequently fixing the upright and lintel with a ball and socket joint or mortice and tenon.
石匠们用楔口连接法将楣石水准放置，将石块连接起来，然后将这些直立的石块和楣石用球窝接头或楔口接头来固定。
They made joints in stone keeping the lintels in place horizontally using a tongue and groove joint and subsequently fixing the upright and lintel with a ball and socket joint or mortice and tenon .
石匠们用楔口连接法将楣石水平放置，将石块连接起来，然后将这些直立的石块和楣石用球窝接头或楔口接头来固定。

Seeing exactly how certain joints work was a good refresher for me (remember learning the difference between hinged joints for the elbow, and ball-and-socket, like the hips?), and following the blood flow into and out of the heart always makes me wonder at the fine-tuned machinery of the human body.
FORBES: Google Body lets you explore what's under your skin