1.   A. Those joints will always work loose because of their design.

2.   Perhaps the greatest benefit of longer-lasting artificial hips and knees is for people whose original joints never worked.

3.   The joint works properly when commands are transmitted over secondary lines.

4.   The joint had been working properly when commands were sent over secondary lines, but managers decided to replace it before station assembly missions later this year.

5.   Unless you add wire supports, which keep the leg assembly tight, the joints will work loose no matter what you do.