Basically what your DH is is an athlete. However, because he is a manager and in the public eye, he can't just pop on a pair of Air Jordans. What he might want to investigate are shoes that give him a good arch support and good ankle support. Gel or air insoles might be an added benefit but might be expensive. Although if he can find a good, well-made pair of shoes, they could last much longer than a month or so as you indicated and be well worth the $$ investment. There are others on this board who can probably give you better advice but, from my experience from being on my feet for long periods of time, these are my suggestions.
Other things he might want to investigate are posture, back support and weight distribution. Does he need to lose a few pounds? These could contribute to his overall discomfort.
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