I have had this heel pain before and have had plantar fascitis. I used both arch support and good shoes. If you have the arch support without the good shoes it can be counter productive and you'll be looking at the arch support as not doing the job intended. Also, usually its a good idea to get some shoes that have a good midsole ( knowledgeable shoe retailer can tell you about this ). Good combination of doctor and retailers with training in shoe comfort is a good bet. It helped me tremendously.
Crwstar
Thanks for using the forum. I am happy to address your questions, and my answer will be based on the information you provided here. Please make sure you recognize that this forum is for educational purposes only, and it does not substitute for a formal office visit with your doctor.
Without the ability to review your brother in law's history and examine him personally, I can not comment on the cause of his heel pain. However, I will try to provide you with general information regarding heel pain that radiates up the leg.
One of the most common causes of heel pain is called plantar fascitis. The plantar fascia is the tissue in the sole/mid foot among the tendons. Plantar fascitis is inflammation of this tissue. The pain typically occurs in the inner side of the heel. The pain typically occurs after taking the first few steps in the morning and improves with continued walking. The pain may radiate up the leg. Causes are mechanical, often due to abnormal inward turning of the foot due to poorly fitting shoes, walking for a prolonged time on uneven surfaces, etc.
Treatment for plantar fascitis consists of arch support, anti-inflammatory medications, ice massage and stretching. Injections and surgical treatment are reserved for severe cases that rail conservative management.
Other rarer causes of heel pain include a nerve root problem (a problem that affects the nerves as they come out of the spine; this is most often associated with pain in areas besides the heel), or a problem called tarsal tunnel which is a nerve entrapment syndrome similar to carpal tunnel syndrome but much less rare, other nerve entrapment syndromes, and small stress fractures. Rarely, infections can cause heel pain.
This would be best evaluated by a general practitioner who can then determine if referral to a neurologist or other specialist is necessary.
Thank you for this opportunity to answer your questions, I hope you find the information I have provided useful, good luck.