kick over the traces

"I remember that she once said to me, 'Women do get the worst of it when they kick over the traces,'" Hillyard resumed. "And undoubtedly they do. On the other hand you have McKerrel's hard-headed verdict, 'If these poor neurotic bodies had any work to do they wouldn't have so much time to worry about their troubles.' Who shall choose between them? And what does it matter now? Stella's gone. She will strain her poor little unhappy heart no more against the bars."