The 2015 American College of Sports Medicine annual meeting is on this week in San Diego. I always enjoy perusing the abstract book for this meeting as there are usually more than a few gems of relevance to my interests. This year was no exception. Rather than review a select few in detail like previous years, I will just mention the key finding reported from the relevant ones with a few comments. The detailed review can perhaps wait until the paper is published in full.
Flanagan et al measured physiological and psychological variables in runners using traditional and minimalist running shoes during a 2 mile time trail. There were no differences between the groups in the physiological variables or time to complete the 2 miles. However, those with the minimalist shoes felt better indicating a psychological advantage.
Griffen et al reported that there is no correlation between arch height and foot strength. That makes it 7 studies now that have shown the same thing (see the comments I made here).
Kwon et al reported that there was an improvement over 3 days in balance in those with functional ankle instability using kinesio tape.
Rice et al recruited 15 runners (5 shod rearfoot strikers; 5 shod forefoot strikers; and 5 minimally shod forefoot strikers) and measured vertical loading rates. They concluded “These early results suggest that running with a FFS pattern reduces the rate of both vertical and resultant loading experienced by the body, to a greater extent in minimally shod compared with traditionally shod runners.” This, of course is predicated in the assumption that vertical loading rates are something that is important and that is far from clear that it is.
Lewinson et al tested a “commercially available non-custom athletic footwear (AF) insole” in 15 runners measureing a whole lot of parameters and found “No significant differences were observed between the CON and AF insole conditions for knee abduction angular impulses (CON: 10.3±5.4 Nms, AF insole: 9.6±4.7 Nms, p=0.26), peak foot eversion angles (CON: 11.1±4.5 deg, AF insole: 10.8±4.3 deg, p=0.64) or peak foot eversion velocities (CON: 378±108 deg/s, AF insole: 408±122 deg/s, p=0.06). However, individually, many participants (7/15 for knee abduction angular impulse, 11/15 for peak foot eversion and eversion velocity) experienced relevant biomechanical changes of ±10% or more with the AF insole. ” Nothing surprising there are that is pretty much what we see in most kinetic and kinetic studies of inserts/insoles/orthotics – ie the response are subject specific and not systematic.
Ruder et al tested 5 subjects in highly cushioned and traditional running shoes and found no differences in the ground reaction force variables.
Zdziarski et al reported (as have others) just how poor runners are at determining their own foot strike pattern, concluding “Accurate perception of foot strike pattern was impaired in nearly half of all runners, irrespective of experience. This misperception may be caused by proprioceptive dampening from the shoe or a lack of understanding of what the different foot strikes actually feel like. There is the potential for increased prevalence of lower extremity injury if the perceived and actual running mechanics do not match or if the strike pattern is inappropriate for a lighter shoe.”.
Gruber et al reported on an issue which may affect the interpretation of ground reaction forces for studies; concluding “The results indicate that the foot-ground collision generates frequencies associated with an impact load, regardless of the portion of the foot that makes initial contact with the ground. The motion of the ankle joint during forefoot running may delay the time course of maximum signal power of this impact energy by ~9% compared with rearfoot running. Thus, the vertical impact peak in forefoot running may be visually obscured in the time domain by the active peak rather than it not occurring at all. Future studies should use caution quantifying the vertical impact peak magnitude and loading rate from the time domain when comparing rearfoot running and forefoot running .”
Lundstrom et al showed that “Competitive runners are more economical than recreational runners and run closer to the marathon finish times predicted by shorter races. Within each category, runners with better running economy tend to run closer to their predicted times in the marathon. Running economy may be a more important predictor of performance in the marathon than in races of shorter distances“.
Leuchanka recruited 9 traditionally shod runners and transitioned them with a 10 week barefoot running program. Their 5km time trial time improved by 3.1%, but there were no changes in physiological parameters (eg VO2). The results could either be explained by changes in biomechanical parameters or the Hawthorne effect. There was no control group.
Lee et al showed that the regular use of the foam roller using a crossover study design in 8 trained runners that the foam rolling decreased leg muscle soreness but did not affect running performance.
A number of recent studies have reported on proximal issues in medial tibial stress syndrome (eg), but the study reported by Soria et al no differences in hip abductor and adductor strength between injured and non-injured runners.
Magyari et al tested 73 runners in a shoe and barefoot, having them run at a self selected speed; for 8 minutes; running time and heart rate were measured; they found no differences between the two conditions.
Du Bois et al tested 22 runners in different footwear and barefoot conditions and pretty much found teh same as what everyone else seems to be reporting: “Similar to previous research, there was an increase in the demands at the ankle across all foot strike patterns while only MFS runners presented with reduced demands at the knee and hip. FFS runners demonstrated a trend towards reduced knee demands suggesting that adopting a FFS or MFS when running barefoot can reduce knee injury risk. However, due to the increased demands at the ankle, it is important that all habitually shod runners gradually transition to barefoot running.” ie different running techniques load different tissues differently in different runners.
Paquette et al looked at the relationship between foot strike pattern and biomechanical parameters finding that the strike index “was positively correlated to internal hip rotation ROM (r=0.55, p=0.03) but, negatively correlated to ankle eversion velocity (r=-0.56, p=0.005), and knee flexion ROM (r=-0.75, p<0.001)“.
I would like to have been at the meeting to find out more on these studies; maybe next year.
As always, I go where the evidence takes me until convinced otherwise….