There certainly has been a lot of comments in recent years about how ineffective that running shoes actually are supposed to be at controlling motion and I have sort have gone along with that as that is probably what the preponderance of data was showing. I did take a brief look at this earlier this year (Can running shoes control motion?). Every retailer I ask about this tell me that they can put a runner into one shoe and then another and see differences between the shoes in the amount of motion, specifically in “overpronation“. So how does that gel with the preponderance of the research? Are the anecdotes from the retailers wrong or is the research wrong?
My interpretation of the preponderance of the research on the ability of running shoes to control motion is that systematically, they either don’t or if they do, the change is very small; certainly smaller than what is seen at the retail level when trying different shoes. The important point is the word ‘systematically’ – this means that if you delve into the actual data in the studies you do see some runners who respond in one direction to a design feature, and some runners who respond in the other direction and some runners who show no difference or a very small difference in either direction. This means that the average or ‘systematic’ response is no difference. This also means that the response to a specific design feature is subject specific. I did address that issues in this post: Timing of ‘heel off’ in different running shoes. This to me means that, yes certain design features (or running shoe models) can control motion in some runners, but not others and that will be different for each runner. There could be any number of explanations and we can only speculate what the reasons might be. It could be variations in joint axes positions which will affect the lever arm that a design feature has to mechanically achieve a kinematic or kinetic change (see this discussion). It could be, if we want to talk about “overpronation”, that different causes of “ovepronation” respond differently to different design features. There are a lot of different causes of “overpronation” and some can be affected by the design features in a running shoe and others probably can not be. I am sure you can see the problematic nature if a running shoe study included all “overpronators” in a study and then found no differences.
What triggered me to pen the above thoughts was this study:
Changes in talocrural and subtalar joint kinematics of barefoot versus shod forefoot landing
Mako Fukano and Toru Fukubayashi
Journal of Foot and Ankle Research 2014, 7:42 doi:10.1186/s13047-014-0042-9
Synergetic talocrural and subtalar joint movements allow adaptation to different footwear and/or surface conditions. Therefore, knowledge of kinematic differences between barefoot and shod conditions is valuable for the study of adaptations to footwear conditions. The objective of this study was to assess the kinematic differences in the talocrural and subtalar joints during barefoot and shod landing.
Seven healthy participants (4 males and 3 females) participated in a landing trial under barefoot and shod conditions. Fluoroscopic images and forceplate data were collected simultaneously to calculate the talocrural and subtalar joint kinematics and the vertical ground reaction force.
Upon toe contact, the plantarflexion angle of the talocrural joint during the barefoot condition was significantly larger than that during the shod condition (barefoot, 20.5 ± 7.1°, shod, 17.9 ± 8.3°, p =0.03). From toe contact to heel contact, the angular changes at the talocrural and subtalar joint were not significantly different between the barefoot and shod conditions; however, the changes in the subtalar eversion angles in the barefoot condition, from heel contact to 150 ms after toe contact, were significantly larger than those in the shod condition.
These results suggest that footwear was able to reduce the eversion angle of the subtalar joint after heel contact during landing; the effect of wearing footwear was quite limited. Therefore, induced rearfoot kinematic alterations to prevent or manage injuries by neutral-type footwear are likely to be impractical.
One of the problems with studies on kinematics and kinetics of running shoes is that the motion analysis systems use markers either on the shoe (do they represent foot motion?) or on the foot (and the skin moves, so does it really reflect foot motion? And a hole has to be cut in the shoe so this may affect the integrity of the design features being tested). What was really cool about this study was that they used a fluoroscope to look at rearfoot motion rather than a marker based system. This allowed them to watch what the bones were actually doing.
A couple of issues with the study in that they only looked at forefoot landing, so not sure if it can be extrapolated beyond that. The viewing field of the fluoroscope did limit the landing height that was used in the study.
What they found was that, yes the shoes used with the design features in the shoe that was used in the study (Adidas Response Cushion) did systematically reduce eversion of the rearfoot. That systematic change was small, but statistically significant. I also assume that the shoe used is more of a neutral/cushioning shoe with limited motion control features.
This is all prefaced by the assumption that we do want to actually control motion. Obviously in some circumstances we do.
As always, I go where the evidence takes me until convinced otherwise, and this study tells me that when there is a clinical need (or any other reason) to reduce eversion, that this can be achieved with a shoe with the design features used in the above study.
Fukano, M., & Fukubayashi, T. (2014). Changes in talocrural and subtalar joint kinematics of barefoot versus shod forefoot landing Journal of Foot and Ankle Research, 7 (1) DOI: 10.1186/s13047-014-0042-9