Ratledge gives two options; a northern route, direct but steeper, and a southern route, less direct but less steep.  Interestingly, there are two points on the southern route where three parishes meet; first, at Park (formerly ‘Home’) Farm, Packington, Ashby-de-la-Zouch and Measham; second, south east of Bramborough (formerly ‘Brambro’) Farm (Ratledge is confident of the route at this point), Ashby-de-la-Zouch, Ashby Woulds and Oakthorpe and Donisthorpe:

https://maps.nls.uk/view/101601957

Surveyed 1881-82

I would suggest that the southern route persisted in use and was extant when the parish boundaries were laid out; there are two points along this short section where three parishes meet.