THE INSTITUT CATALÀ DEL PEU AND ROAD RUNNING REVIEW CARRY OUT A BIOMECHANICAL STUDY WITH DIFFERENT SPORTING SHOES.

Are there any differences for the runner regarding contact time, flight, etc. among the different top models of running shoes with carbon sheet? A few months ago, our colleagues of Road Running Review, offered us a very interesting proposal. It was about analyzing biomechanical factors and time of footstep and flight of 5 running shoes models with carbon sheet. Fitmetric, the biomechanics team from the Institut Català del Peu, would take over to analyze, with Carles as a runner, which would be for each model the biomechanical responses, footstep and flight time, compression and decompression time of the sole, in order to see which sole is more reactive, muscular activation, etc. and to understand if there are in this high level any differences among the different top models of running shoes with carbon sheet. Coming up, we tell you about the models and the methodology. The analyzed models were the next ones:

• Nike Alphfly Next %2
• Asics Metaspeed Edge +
• Adidas Adizero Adios Pro 2
• Saucony Endorphin Pro 3
• New Balance FuelCell RC Elite v2

Methodology:

• Podiatric examination.
• Functional assessment.
• 11 3D Vicon cameras with retroreflective markers.
• EMG synchronized with movement.
• Treadmill.
• Recording of 2’ at 16 kmh speed (speed of 3’45´´ by km) and rest between running of 3´.

Data to be analyzed:

• Total time of footstep by each model.
• Time of compression (damping) of the sole during the footstep stage (or when resting).
• Time of decompression (reactivity of the sole) of the sole during the footstep stage (or when resting).
• Percentage of damping time during the total time of the footstep.
• Rhythm in time.
• Muscular activity by muscular electromyography.

Results:

• Damping: the New Balance is the one who needs more time of impact during the damping stage. The Adidas requires less damping time. Therefore, we mean that the Adidas is the quickest to compress its sole and then, it will be the most reactive. The order would be as follows:
• Adidas
• Nike
• Asics
• Saucony
• New Balance

Rhythm: the less time is the stride, means that the time between one stride and the another one is less. In a sense, the Saucony is the one with less time, therefore it will provide us more rhythm. Adidas is the one with more time. Therefore, Adidas is the most reactive, however, even though its footstep time is short, its flight time is high, we can move forward a lot but with high stride total time and so with high rhythm. The order from highest to lowest rhythm would be:

• Saucony
• Asics
• Nike
• New Balance
• Adidas

Muscular activation: a priori there are no differences, although it would be necessary a statistical study which would show if there are or not significant differences. What we have seen is that the muscular activity is virtually the same in all muscles and with all the running shoes, but in the soleus with Adidas, which is increased with respect to the other running shoes. Is there any connection with this higher activation in soleus with Adidas running shoes due to its high reactivity and low contact time? The soleus muscles are one of the main muscles for the stability of ankles in the impact and monopodal rest in running. Conclusions:

• ASICS Metaspeed Edge +: probably the most well-balanced of 5. A model which does not stand out for having the highest damping or being the most reactive of all of them, but almost always is on the top 3 of all the analyzed parameters.
• Nike Alphafly Next % 2: it seems to be one of the quickest. The Alphafly Next % 2 gets a great compression decompression ratio at the same time that it is located in the intermediate point if we talk about rhythm.
• Adidas Adizero Adios Pro 2: among the 5, it is theoretically the quickest one and the most reactive, although afterwards we will see how it reduces its rhythm significantly. This means that Lightstrike Pro is located as the most dynamic compound from the 5 analyzed.
• New Balance FuelCell RC Elite v2: were you looking for a competition model which allows you to go more comfortable and damped? New Balance has the solution with its RC Elite v2. A model which at slower rhythms (considering it will not be very slight rhythms) offers more comfort and protection.
• Saucony Endorphin Pro 3: the running shoes with the highest rhythm among the 5. Besides this piece of information, which is important for some people, the Saucony Endorphin Pro 3, is also situated as one of the running shoes with the most comfortable damping.

With these results of the study, we have new questions we would really like to answer on next studies. Regarding the question: Are there any differences for the runner with respect to contact time, flight, etc. among the different top models of running shoes with carbon sheet? It is clear there are differences in such high level and, some day, it will be possible to know about this data of all the running shoes in order to be able to help runners to choose correctly the type of running shoes which suit best for them for its shape or running style.