Culver City, Calif. ? Lifetime’s “Strong Medicine” was originally created to be “about women on both sides of the stethoscope,” says executive producer Tammy Ader.

So why, then, is cable’s longest-running original drama beginning its sixth season at 8 p.m. Sunday with the arrival of Rick Schroder as Dr. Dylan West to partner with Dr. Luisa Delgado (Rosa Blasi-Finn)?

“For ages my own OBGYN, who’s a man, has being saying it can’t be just women who treat women,” Ader explains, “and we’ve always wanted the other partner to be 180 degrees different from Rosa’s character.”

Delgado’s an outspoken single mom, who champions the issues of the underprivileged. Harvard educated Dr. Dana Stowe (Janine Turner) was her partner until the middle of season three; former Army officer Dr. Andy Campbell (Patricia Richardson) then co-ran the Philadelphia-based clinic until the end of last season.

Contemplating what new lead character might provide similar culture-clashing chemistry, Ader realized the true difference was a man.

West’s arrival is, Schroder says, clearly “a shock” when he’s “introduced in the ER in the middle of a tragedy – a train derailment with a lot of injured people.” Delgado in particular is “not too happy” because back in medical school, when he was chief surgical resident and she was an intern, they were often at odds.

Rick Schroder portrays surgeon Dr. Dylan West on Strong

Schroder, now 35, won a Golden Globe as the weeping blond kid in the 1979 remake of the boxing melodrama “The Champ.” During his ‘tween and teen years, he starred as rich and spoiled Ricky Stratton in the sitcom “Silver Spoons.” In 1989, he co-starred in the Western miniseries “Lonesome Dove.” And from 1998 to 2001, he was troubled Detective Danny Sorenson on “NYPD Blue.”

Wanting to present him with a different sort of challenge from the intense, unhappy Sorenson, Ader created West as a much sunnier, more laid-back personality, a single guy with a great sense of humor. She then flew to Phoenix, where Schroder and wife Andrea are raising their four children.

“It’s nice to be wanted,” says Schroder, whose character is “a San Diego beach guy” but “very committed and very enthusiastic toward his job.”

Schroder’s similar attitude about his own work probably helps explain his successful transition from child stardom to a solid adult career that is balanced with a devotion to family and lack of interest in Hollywood hype.

“I love what I do and I bring a great deal of enthusiasm to anything I do. I think there’s a perseverance that wins over talent. I have a lot of perseverance, though I do have some talent,” he says.