My friend and I felt it would hinder her from moving very fast.
Walkers stumble and generally move slowly(with exception) so we questioned how she seemingly 'just there'.
We see Andrea struggling on the ground in a fairly open, fairly flat if wooded area and then *slice* the hooded figure is just suddenly there. How exactly did she just appear? Seems Andrea should've seen her at some point in that final stretch before she ends up on her back struggling with the one Walker.