I tried running today, but after 14 minutes the muscles on the outside of my left shin were too tight to run further, it felt like a lot of pressure in the muscles. I had a period of that some two weeks ago, but thought it had gone away now. So I walked home, feeling very embarrassed, to Google for info and found Clinical Sports Medicine and its chapter about shin pain. I'm pretty sure I suffer from “raised intracompartment pressure”:
… The lower leg has a number of muscle compartments, each enveloped by a thick inelastic fascia. … As a result of overuse/inflammation, these muscle compartments may become swollen and painful, particularly if there is excessive fibrosis of the fascia.
The symptoms are ache, tightness, increasing with exercise, decreasing with rest, usually with minimal tenderness. Exactly what I feel.
I guess anti-inflammatory drugs like Ibuprofen and stretching is in order, but I'm going to call my doctor tomorrow and get a professional opinion.
The tibilis anterior muscle inhabit the anterior compartment – where I feel the pain – in the shin together with the smaller extensor hallucis longus and extensor digitorum longus. I don't know of a good way to stretch that area, and it's not as much the muscles themselves as the membrane between them.