The Influence Of Maximal And Minimal Shoes On Walking Biomechanics In Older Individuals

Abstract

Older individuals frequently walk as a means for exercise and often wear running shoes during this activity. Recently there has been increased popularity in older individuals wearing maximal running shoes during walking. Maximal running shoes are unique because they are comprised of a highly cushioned midsole in both the rearfoot and forefoot that is supposed to improve shock attenuation. Minimal running shoes with little cushioning are also used in this population to improve proprioception and balance. Loading in the frontal plane is of particular interest for older individuals since it has been associated with increased risk of knee osteoarthritis. Little is currently known about how maximal and minimal shoes influence walking biomechanics in any age group. PURPOSE: To examine the influence of maximal and minimal running shoes on walking biomechanics in older individuals. METHODS: Walking biomechanics were collected on 16 female participants (age range: 51 – 64 years) using an 8-camera Vicon motion capture system and two embedded force plates. 3D kinematics and kinetics were collected while subjects walked along a 10-meter runway in three different footwear conditions (MAX, MIN, TRAD). Variables of interest included the 1st and 2nd peak of the vertical ground reaction force (Fz1, Fz2), the instantaneous vertical loading rate (IVLR), peak ankle eversion and knee varus angles, and the peak external ankle eversion and knee varus moments. Differences were determined using a repeated measures ANOVA. RESULTS: The external knee varus moment was significantly higher in the maximal shoe compared to the traditional shoe (MAX: 0.55 ± 0.16 Nm/kg, TRAD: 0.49 ± 0.14 Nm/kg, p = .005). The IVLR was significantly higher in the minimal shoe compared to the traditional shoe (MIN: 30.4 ± 3.4 BW/s, TRAD: 21.8 ± 1.8 BW/s, p < .001). No other significant differences were found for the variables of interest. CONCLUSION: The maximal shoe was found to increase the external knee varus moment, which has been linked to increased pain and disease progression in knee osteoarthritis. The IVLR was significantly higher in the minimal shoe, which has also been linked to injury. Based on these findings, there are no clear advantages to wearing a maximal or minimal shoe during walking, and doing so may be detrimental to injury risk. No grant support was provided.