Worse exercise for plantar plate when building uphill strength

I just had a conversation with a runner who has a plantar plate injury. 

He got the plantar plate sprain trying to build his uphill running strength in preparation for a trail race. 

This is no rookie mistake. He is a longtime ultra marathoner with lots of experience. But he made a common mistake determined runners can make. 

Today on the Doc On The Run Podcast, we're talking about one of the worst exercises you can do if you have a plantar plate sprain and you've been trying to build your uphill running strength for a trail race.