Motion Control Shoes: Are they Useful?
A very high methodological quality study was recently published in the British Journal of Sport Medicine. The authors monitored 372 recreational runners during 6 months for injuries (average weekly training = 2 x 9km at 6min/km or 10min/mile). Runners were randomized to either neutral cushioned shoes or to motion control shoes. The study concludes that runners with pronated feet show a decreased risk of injury while wearing motion control shoes compared with neutral cushioned footwear.
Before all shoe retailers go wild saying “I knew it!”, so they can justify their selling strategy for the last 25 years, here is an analysis of the results.
What was known on the topic before this study
- The scientific literature suggested that motion control technologies in footwear was not efficient in reducing the incidence of running injuries (2014-Knapik, 2011-Ryan).
- We don’t know if motion control devices are really efficient in actually reducing pronation, as they seem to have no effect on an individual’s normal pronation (measured barefoot)… but they may have an effect on increased pronation caused by soft cushioning in maximalist shoes (critical analysis of 2011-Cheung).
- It’s not clear whether static foot measures (such as the Foot posture Index –FPI) really predict foot dynamics (a flat foot will not necessarily show more pronation) (2015-Langley).
- Static foot measures (such as the Foot Posture Index - FPI) are not associated with lower limb pathologies (2013-Nielsen, critique de 2014-Neal).
What makes us less confident about the results of this study?
- Three of the authors actually work for the manufacturer that funded the study. Did the manufacturer have a role in the interpretation of results? Or could the manufacturer have an influence on the decision to publish (or not) the study, depending on what the results would say?
- How come the authors’ baseline hypothesis was that motion control footwear would reduce the injury rate (similar to what they reported) while the scientific literature did not support that hypothesis?
- Would the results of this study change the portrait of the current literature if they were included in Knapik’s meta-analysis from 2014, which concluded that motion control technologies do not reduce the incidence of injury, based on 7203 participants? (A meta-analysis is a summary of the literature by grouping studies together)
- The number (and percentage) of runners who did not sustain an injury until the end of the study was no different between neutral and motion control groups… authors could also have concluded that neutral shoes were as efficient as motion control in keeping runners uninjured. :)
- Would a firmer medial midsole (only by 15%) really influence injury rate that much… explaining almost 50% of injuries in this cohort?
- If we consider the results from this study as a portrait of the reality, motion control shoes may reduce the extra-pronation caused by soft neutral maximalist shoes, and may be interesting for: 1. Runners used to cushioned maximalist shoes; 2. Who present with a “pronator foot”; 3. Who don’t want to transition to firmer and more minimalist shoes; 4. And who are more at risk of specific injuries. Thus, even considering this study as THE reference while ignoring the 4 other studies published on the topic, The Running Clinic’s clinical recommendations would remain unchanged.
- This RCT was not registered in any database beforehand (potential modifications of reported outcomes following statistical analyses)… usually, this is mandatory to publish in high-ranked journals like BJSM.
- The dropout rate was really high… and higher (which would have been statistically significant if reported) in the motion control group (31%) compared with neutral (18%). Causes of dropout were not reported in details, although discomfort and pain were part of them (information obtained directly from the authors). This could have greatly influenced the results, but was not even discussed in the paper.
Based on this single study, will shoe retailers and manufacturers, who keep the motion control paradigm alive against all science since 25 years, justify and perpetuate their recommendations?