CMUL e-Book Database CMUL e-Book Database
account_balance Home > Book

Interaction of arch type and footwear on running mechanics


Description

High arch and low arched runners are more prone to overuse injuries of the lower extremity than normal arched runners. This is thought to be attributed to higher loading exhibited in high arched runners and excessive rearfoot motion in low arched runners (Williams et al., 2001). Running shoes are specifically designed for these arch types to reduce injury rates (motion control shoes for low arched runners and cushioning shoes for high arched runners). Recently, it was reported that a footwear intervention program reduced lower extremity injury rates at a military base (Knapik et al., 1999). However, the biomechanical changes associated with running in the recommended footwear were not examined. The overall goal of this work was to therefore examine lower extremity mechanics when high and low arched run in the shoe that is recommended for their foot type. In order to accomplish this, a valid and reliable method of determining arch height was needed. Williams et al. (2000) reported on an arch height index measurement that was established to be valid and reliable. However, this index was based on several measurements taken with a set of hand held calipers. The Arch Height Index Measurement System was developed in order to improve the ease of this measure (Richards et al., 2001). Intra- and inter-rater reliability of the device was evaluated by determining the Intra-class correlation coefficients (ICC) for the arch height index (AHI), as described by Williams et al. (2000). These ICCs ranged between 0.96 & ndash;0.99 for all measures. Secondly, the distribution of the AHI was reported for a group of healthy recreational runners between the ages of 18 & ndash;40 who ran more than 10 miles per week. No differences were noted when comparing genders or between the sides of individuals. The AHI for all of the subjects was 0.340 +/ & minus; 0.030. Based on this distribution, subjects with AHI greater than 1.5 standard deviations above the mean value were invited to be part of the high arch (HA) group. Runners with AHI greater than 1.5 standard deviations below the mean value were invited to be in the low arch (LA) group. The next part of the investigation involved the study of the interaction of arch type and footwear during overground running. Twenty HA and twenty LA runners ran in both a motion control (MC) shoe and cushioning (CT) shoe. Rearfoot kinematics and tibial shock were analyzed in the different footwear conditions. There was an interaction of arch type and footwear for instantaneous loading rate which was lowest in the recommended shoe for each arch type. (Abstract shortened by UMI.).