The adductors will always be comparatively weak to the quads and hams. The small muscles and connective tissue are often the weak links, which is why I explain gear as something akin to extra connective tissue.
The method I found is something known as ELDOA. It's a French acronym from Guy Voyer and is kinda like ME yoga. The best thing to do is to look it up on YouTube as it's impossible to explain without video.
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