Is there an over-the-counter insert that would help with metatarsal pain? (behind the 2nd-3rd toes) What causes this? It seems to be worst at the push-off point. Do I need more height at the back of the shoe (i.e. heel lift), midfoot (arch support), front? I'm not to mechanically inclined. Are there exercises to help this injury? Rest is not an option. Thanks in advance.