Athletic footwear affects balance in men.

Abstract

Stable equilibrium during locomotion is required for both superior performance of sports and prevention of injuries from falls. A recent report indicated that currently available athletic footwear impairs stability in older men. Since this discovery, if confirmed, seems important to both competitive athletes and the physically active general public, we performed an experiment using similar methods on a younger population. We tested the hypothesis that midsole thickness is negatively, and hardness positively related to dynamic equilibrium, in 17 healthy adult men (mean(s.d.) age 33(11.13) years) via a balance beam method. Subjects walked along a 9-m long beam at 0.5 m sl once barefoot and six times wearing identical pairs of experimental shoes which differed only in midsole hardness and thickness which spanned the respective ranges currently available in footwear. Falls from the beam (balance failures) were quantified. Balance failures varied significantly in relation to midsole hardness and thickness, and there was a strong trend toward interaction of these variables (P = 0.09). Midsole hardness was positively related to stability, and midsole thickness was negatively related, which confirms the previous report. Hence, shoes with thick-soft soles, similar to modem athletic footwear and 'walking shoes', destabilize men, and shoes with thin-hard soles provide superior stability. The pair with the poorest stability (A 15 -thick; 12.34 balance failures per 100 m) produced 217% more balance failures than those associated with the best stability (A 50 -thin; 3.89 balance failures per lOOm).Since most types of athletic footwear and many other shoes incorporate midsoles with hardness and thickness associated with poor stability, we conclude that both athletic performance and public safety could be enhanced through stability optimized footwear. Footwear that incorporates expanded polymer foam of a certain range of thickness and hardness, which includes most commercially available athletic footwear, and presently popular 'walking shoes', has recently been reported substantially to impair equilibrium in older men. For example, these authors have shown that differences in fall frequency from a balance beam varied by an amazing 128%, when comparing footwear associated with the best stability with that of the poorest8. Since stability differences of this magnitude must have major health and athletic performance effects, products providing poor stability are currently being marketed to the general public specifically for use in performing physical activity (walking shoes and athletic footwear), and no safety standards are in force that can provide the public with relative stability with the use of these products. Further examination of the relation between footwear soles and stability seems justified.The previous report examined footwear midsole hardness and thickness exclusively in an older male cohort8. It seems unwise to assume that their results apply to the general population without testing a younger group. Accordingly, ...

Influence of footwear midsole material hardness on dynamic balance control during unexpected gait termination

“…They include midsole material hardness, height of heel collar and outer sole slip resistance (frictional properties). The largest collection of work has been done on midsole material and control of balance by Robbins et al [3][4][5][6]. His investigations have involved both walking on a narrow beam and detecting ankle angle position in footwear that varied in hardness levels from soft (Shore A Scale 15) to hard (Shore A Scale 50).…”

The effect of different unstable footwear constructions on centre of pressure motion during standing

“…However, a direct comparison between both studies is not possible because of different mid-sole densities and methods to evaluate balance. It is possible that the extra thickness (compared to the other shoes tested) and softness of the mid-sole of the SU resulted in sensory insulation [13] by reducing afferent input to the brain regarding foot position. The FF was the thinnest of the shoe constructions and this may help explain in part why there were no significant differences in stability when wearing this shoe even though it specifically has a low-density foam mid-foot portion.…”

“…By combining these two (thickness and softness vs. thinness and hardness) balance failure increased by 217%. [13] Contrary to Robbins et al [13], Lord et al [14] reported no association between firmness (hard-soled; Shore A58 or softsoled; Shore A42) of shoe sole and balance ability. However, a direct comparison between both studies is not possible because of different mid-sole densities and methods to evaluate balance.…”

“…The SU had the greatest mid-sole thickness (45-48 mm) made of a fairly soft foam material (we did not measure the Shore scale on our footwear). Robbins et al [13] reported a change in mid-sole thickness from thin (13 mm thick at heel) to thick (27 mm thick at the heel) resulted in an increased balance failure of 54%. Balance failure was defined as the participant's inability to traverse a beam with a cross-section outer diameter width of 7.8 cm, a height of 3.9 cm, and a length of 9 m. A change in firmness from hard (Shore A50) to soft (Shore A15) also resulted in an increased balance failure of 77%.…”

The impact of different footwear characteristics, of a ballet flat pump, on centre of pressure progression and perceived comfort

“…Footwear stability is most frequently researched within the areas of athletic and high-heeled shoes, with papers mainly focusing on medial and lateral foot stability and postural sway [18][19][20]. The way the sole is constructed and the sole material properties have been shown to influence stability and comfort in elderly populations with a thick-soled shoe reducing stability and a thinner firmer sole material being more preferable [21].…”