In a newborn infant, torticollis resulting from a tissue tumor most likely involves which of the following muscles?

It would involve the muscle called the sternoclei-domastoid.

Habit 1: be proactive  habit 2: begin with the end in mind  habit 3: put first things first  habit 4: think win-win  habit 5: seek first to understand, then to be understood  habit 6: synergize  habit 7: sharpen the saw