I think the term "soft shell" refers more to degree of water proofness vs. breathability. For example, a really water proof (OK, resistant, GoreTex is never fully water proof) GoreTex jacket is referred to as a "hard shell." Something like wind bloc fleece is far more breathable but far less water resistant and is referred to as a "soft shell." A lot of mountaineer and climber types like the "soft shells" for winter travel. They don't get sweated out like a hard shell but offer some moisture protection from snow and the like. That's my understanding.

The mentions subungal hematoma, which I believe means bruises under the toenails, but doesn't say much about what to do about it.