Ball-of-the-foot pain (metatarsalgia) occurs when one of the metatarsal joints becomes inflamed and painful. The pain usually centers on one or more of the five bones (metatarsals) in this middle of the foot.

Causes
Metatarsalgia is often caused by arthritis, foot injury, continuous walking/running on hard surfaces, or improper footwear (high-heels, stiff boots). As you age, the ball of your foot becomes thinner and more susceptible to pain or injury.
 
Treatment
Sometimes just a change of shoes will result in pain relief. When choosing the right footwear, it's best to find shoes that offer ample support as well as unload pressure from the ball of the foot. Custom orthotics may be prescribed to treat severe cases.