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

Abstract

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 (F) 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; 60% likely beneficial reduction) and plantar sensation was increased (46-58 mm) with the insole. F (-0.1 to 0.14 BW) and velocity (-0.02 to 0.06 m s) 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) 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.

Differences in stride length and lower limb moments of recreational runners during over-ground running while barefoot, in minimalist and in maximalist running shoes

“…The gradual decrease in stride length from maximalist shoes through to barefoot could be regulated by plantar-sensory feedback about braking forces. Previous work by Wilkinson et al (2018) found that increased subjective plantar sensation via textured insoles resulted in reduced stride length, increased stride frequency and reduced vertical loading rates. Though speculative, it is possible that plantar sensation of impact force decreases from barefoot to minimalist to maximalist shoe conditions with a resulting increase in stride length and reduction in stride frequency.…”

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“…Evidence suggests that plantar-sensory feedback is used to modify running technique to avoid painful and potentially injurious impacts [24,41,42]. Increasing plantar sensation via textured insoles has recently been shown to reduce vertical loading rate by a magnitude equal to the difference between injured and non-injured runners by reducing stride length [43]. In other work, Gruber, et al [42] investigated whether heel striking, a landing pattern associated with injury [6] and commonly seen in western populations, was related to impaired plantar-sensory feedback.…”

Acute intense fatigue does not modify the effect of EVA and TPU custom foot orthoses on running mechanics, running economy and perceived comfort

“…Wearing CFOs is used to provide foot support and shock absorption during ground contact through re-distribution of plantar loading and a better maintenance of foot stability (Crago et al 2019 ). Prior studies investigating CFOs effects on key biomechanical indicators have reported mixed results with beneficial (Worobets et al 2014 ; Wilkinson et al 2018 ) or unchanged (Lewinson et al 2013 ) adjustments in stride pattern. Discrepant findings may relate to intrinsic properties (i.e., energy return and longitudinal bending stiffness) of tested insoles provoking specific biomechanical modifications in running gait (Sinclair et al 2016 ).…”