Does the relation-back rule apply to add an additional plaintiff?

On the other hand, in Bartalo v. Superior Court (1975) 51 Cal.App.3d 526, 124 Cal.Rptr. 370, the plaintiff added in the amended complaint was not able to take advantage of the relation-back rule. In that case, a woman timely sued for personal injuries. After the statute of limitations ran, she attempted to add her husband as an additional plaintiff, alleging his loss of consortium. Because a new and different injury was consequently alleged, the husband's amended complaint did not relate back to the original complaint.

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