Feet and Footwear: Applying Biological Design and Mismatch Theory to Running Injuries

by Wilkinson M, Stoneham R, Saxby L

International Journal of Sports and Exercise Medicine 4:090

The Endurance-Running hypothesis proposes that natural selection has shaped humans into endurance-running specialists. Running-related-injury rates between 20-79% suggests modern humans are prone to injury in this species-specific movement pattern. This opinion piece offers a novel perspective on high-injury prevalence in human endurance running, focussing on evolutionary mismatch between modern athletic footwear and evolved foot structure and function. We propose that non-anatomically shaped, structured, cushioned footwear can lead to maladapted foot structure and loss of biologically-normal function including stability, elasticity, sensory feedback and subsequent movement control. The structure and function of the human foot and its possible impairment by modern footwear has received little attention in running-related literature, but could provide a new area of enquiry and potential solutions for many running-related injuries.

https://www.clinmedjournals.org/articles/ijsem/international-journal-of-sports-and-exercise-medicine-ijsem-4-090.php?jid=ijsem


Form determines function: Forgotten application to the human foot?

by Mick Wilkinson, PhD and Lee Saxby, BSc.

The Foot and Ankle Online Journal 9 (2): 5

There has been and continues to be much debate about the merits and detriments of barefoot and minimal-shoe running. Research on causes of running-related injury is also characterised by equivocal findings. A factor common to both issues is the structure and function of the foot. Comparatively, this has received little attention. This perspective piece argues that foot function and in particular, how foot structure determines function, has largely been overlooked, despite basic principles of physics dictating both the link between structure and function and the importance of function for stability in locomotion. We recommend that foot shape and function be considered in the interpretation of existing findings and be incorporated into future investigations interested in running mechanics, injury mechanisms and the effects of footwear on both.

http://faoj.org/2016/06/30/form-determines-function-forgotten-application-to-the-human-foot/


Textured insoles reduce vertical loading rate and increase subjective plantar sensation in overground running

by Michael Wilkinson, Alistair Ewen, Nicholas Caplan, David O'Leary, Neil Smith, Richard Stoneham & Lee Saxby

European Journal of Sport Science

The effect of textured insoles on kinetics and kinematics of overground running was assessed. 16 male injury-free-recreational runners attended a single visit (age 23 ± 5 yrs; stature 1.78 ± 0.06 m; mass 72.6 ± 9.2 kg). Overground 15-m runs were completed in flat, canvas plimsolls both with and without textured insoles at self-selected velocity on an indoor track in an order that was balanced among participants. Average vertical loading rate and peak vertical force (Fpeak) were captured by force platforms. Video footage was digitised for sagittal plane hip, knee and ankle angles at foot strike and mid stance. Velocity, stride rate and length and contact and flight time were determined. Subjectively rated plantar sensation was recorded by visual scale. 95% confidence intervals estimated mean differences. Smallest worthwhile change in loading rate was defined as standardised reduction of 0.54 from a previous comparison of injured versus non-injured runners. Loading rate decreased (−25 to −9.3 BW s−1; 60% likely beneficial reduction) and plantar sensation was increased (46–58 mm) with the insole. Fpeak (−0.1 to 0.14 BW) and velocity (−0.02 to 0.06 m s−1) were similar. Stride length, flight and contact time were lower (−0.13 to −0.01 m; −0.02 to−0.01 s; −0.016 to −0.006 s) and stride rate was higher (0.01–0.07 steps s−1) with insoles. Textured insoles elicited an acute, meaningful decrease in vertical loading rate in short distance, overground running and were associated with subjectively increased plantar sensation. Reduced vertical loading rate could be explained by altered stride characteristics.

https://www.tandfonline.com/doi/full/10.1080/17461391.2018.1444094