One of the strongest arguments for properly fitted shoes is a condition known as hammer toe. Hammer toe occurs when pressure or trauma to a toe's knuckle causes the entire digit to bend downward. The muscles surrounding the toe joints contract, leading to intense pain and a raised area prone to callous and corn formation. Some cases of hammer toe are classified as flexible, because the toe can be stretched back into normal shape. Other cases are classified as rigid, meaning the muscles have become so atrophied that normal movement is impossible.
Although any toe is susceptible to the deforming effects of hammer toe, it is primarily seen in the second toe. For many people, this second toe is actually longer than the 'big toe' used for informal shoe fittings. If the shoe's toe compartment does not allow at least 1/2 inch of space in front of the longest toe, the pressure can lead to hammer toe. Shoes that narrow towards the front can also create trauma to the second toe, and high heels only intensify the problems of hammer toe.
There is also evidence of some genetic predisposition towards hammer toe formation. Other cases of hammer toe may be caused by physical trauma, such as a misplaced kick or stubbing accident. Nerve damage to the foot area may also cause an involuntary contraction of individual toes. Hammer toe can seriously affect a sufferer's walking gait, but many people learn to compensate.
There are various treatments for hammer toe, ranging from manipulation of the toe itself to surgical correction. A podiatrist may recommend a change in footwear to give the toes more room to flex. Over-the-counter treatments of hammer toe often include adhesive gel pads and shoe inserts to reduce the friction between the affected toe and the upper portion of the shoe. Surgery may be considered if the toe becomes inflexible and atrophied to the point of constant pain.