The effect of socks on vertical and anteroposterior ground reaction forces in walking and running

Abstract

Background: Previous research suggests that socks may have the potential for injury protection through the absorption and/or redistribution of impact forces. However, there is limited research regarding the shock attenuation qualities of athletic socks in sporting populations and previously observed pressure reductions have not been quantified using a force plate.

Objective: Firstly to identify the effect of specialist athletic socks on vertical and anteroposterior ground reaction forces (GRFs) during walking and running. Secondly, to compare GRFs between specialist socks, non-specialist socks and barefoot walking and running conditions.

Methods: Following ethical approval participants (n=5) completed five walking (1.52-1.68 m s(-1)) and running (3.8-4.2 m s(-1)) trials, unshod, over a force plate. This was completed before and after a 5000 m run (3.2 m s(-1)) in their own trainers in three conditions; barefoot, non-specialist socks and specialist running socks.

Results: Significant differences were identified between barefoot and specialist sock conditions for pre-intervention time to impact peak (F=3.110((2)), P=.05, r=.11) and maximum propulsive force (F=8.126((2)), P=.001, r=.25) when walking. Post hoc analysis identified an increase of .0016 s in time to impact peak when walking barefoot compared to the specialist sock condition (T=-7.402((4)), P=.002, r=.71). During walking the specialist sock also demonstrated a significant decrease of .075 BWs in maximum propulsive force when compared to the barefoot condition (T=-7.624((4)), P=.002, r=.79). Both significant effects diminished following the 5000 m run.

Conclusion: Findings suggest that the specialist running sock has limited effects on GRFs and therefore may be responsible for a limited degree of shock attenuation experienced during walking.