Award Date

2009

Degree Type

Thesis

Degree Name

Master of Science in Kinesiology

Department

Kinesiology and Nutrition Sciences

Advisor 1

John Mercer, Committee Chair

First Committee Member

Janet Dufek

Second Committee Member

Richard Tandy

Graduate Faculty Representative

Edward Neumann

Number of Pages

96

Abstract

The purpose of this study was to determine whether certain ground reaction force parameters such as impact force (F1), second maximum force (F2), loading rate, stance time and average vertical ground reaction force (Fzavg) differ when 11-13 year old children run in a neutral shoe (Nike Air Pegasus+ 25) that is either a child or adult style.

Shoes were impact tested in an impact test instrument to determine any performance differences between the two shoes. Next, 10 healthy female subjects aged 12.03 ± 1.14 years with a height of 154.6 ± 4.90 cm and a mass of 46.18 ± 14.33 kg with a shoe size between 3.5 and 7 youth were recruited from the Las Vegas area to run 9 meters, a maximum of 40 times in the two shoes over a force platform. Loading rate was calculated using two methods: (1) rate of change in force between ground contact and F1, and (2) rate of change of force within 10 ms bin between ground contact and 50 ms. In addition to recording biomechanical parameters, after each condition subjects filled out a survey to determine personal comfort for each shoe.

Dependent variables (shoe impact data, F1, F2, Fzavg, stance time and loading rate) were analyzed using paired t-tests. Loading rate bins were analyzed using a 2 (shoe) x 5 (bin) repeated measures ANOVA. Survey data were analyzed using a paired t-test.

From the mechanical impact test analysis, it was determined that there were significant differences in force, peak acceleration and percent energy between shoes (p<.001). From the running test, it was determined that, loading rate was different (p=.009) between shoe conditions whereas F1, F2, stance time, or average vertical ground reaction force were not different between shoes (p>.01). It was also determined that there was no difference in loading rate between bins (p>.05). From the survey data, it was determined that heel cushioning was the only parameter that was different (p=.004) between shoes.

In order to prevent overuse injuries, it has been reported that a lower loading rate can prevent possible overuse injuries. Because a larger loading rate was observed while running in the children's shoes it is concluded that the lower loading rate for the subject wearing the adult shoe may reduce overuse injury and is the better shoe choice for girls aged 11-13 years old (Nigg, 1997).

Keywords

Children; Ground reaction forces; Running; Shod; Shoes

Disciplines

Kinesiology

Language

English


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Kinesiology Commons

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