Shoe drop is largely not discussed when looking at running shoes, but it is important to understand the differences and the benefits of a high/low shoe drop. What is it? The difference in stack height from your forefoot to your heel.
High Drop Benefits
High drop shoe is usually something in the 10-12mm drop region. This drop usually means you have a healthy chunk of cushioning under your heel, so if you are particularly heavy on your feet it will help cushion that heel strike when your form starts to drop. Typically a lot of marathon focused shoes will have a higher drop to aid this drop of form over the longer distance.
High Drop Negatives
It encourages poor running form. If you have a large chunk of cushioning in the heel, it will encourage you to land directly on your heel. It is very difficult to land midfoot with a huge wedge of cushioning under your heel. This heel striking puts additional stress through the knees and hips. From a running economy point of view it also is not the most efficient way to run.
Low Drop Benefits
Low drop is typically anything in the region of 0mm to 4mm. It will encourage you to land on your midfoot which usually means less stress on the knees/hips during each stride. Typically a midfoot strike is seen to be a far more efficient running style.
Low Drop Negatives
Your achilles tendon and calf will be under a much higher load. It is very common for a runner who switches from a high drop shoe to a low drop shoe to experience pain in the calf/achilles as they are under a much higher load.
What should you get?
It really depends on your background in running and your previous running injury history. If you are in a constant battle against knee/hip problems it might be worth exploring a lower drop shoe option. On the reverse, if you have a history of achilles tendon/calf problems you are best to stay well away from low drop shoes. The majority of shoe companies stick to somewhere in between 6-8mm region to try and cater for everyone. Next time you get a new pair of shoes it might be worth checking this out.