Find the turning point in the given data set .

I have this type of data whre first colum is time and second is force. I need to find the turning point as it will give me x and y coordinate for specific number like I need 350 max truning point for this . till now I used teh diff function, I think I am missing something in this . Please help me .

[Adam Danz]

Could you define 'turning point' or show us a plot that depicts a turning point? Could you also give us some data to work with either by attaching a mat file or providing something we can copy-paste into the command window?