Date of Award
Master of Science (MS)
The purpose of this study was to compare the coefficients of static friction of five different pairs of soccer goalie gloves with one soccer ball and to compare the effects of four different glove conditions on the coefficients of static friction. Specifically, the coefficients of static friction were determined and compared for one size 5 soccer ball (Select) with five different pairs of goalie gloves (Nike Vapor Grip 3, Select 88, Uhlsport Aqua, Uhlsport Soft and Uhlsport Hard) and four different glove conditions (new, wet, saliva and dirty). Surrogate wooden fingers were inserted into each glove and the glove was placed on a flattened surface of a soccer ball that was secured to a Bertec force platform. A ten, twenty or thirty pound load was placed on top of the glove and a pulling force was applied to the wrist of the glove. The magnitude of the pulling force was slowly increased until the glove began to slide. The forces exerted by the glove on the ball surface were measured by the force platform. The analog force platform signal was amplified and then converted to digital form at a sampling rate of 600 Hz. The digital data were then input to the Peak Motus 32 version 6.1 motion analysis software that computed the normal contact force and friction force. The maximum friction force just prior to glove movement and the corresponding normal contact force were used to compute the coefficient of static friction between the glove and ball. Five trials were completed for each load. This procedure was completed for each of the five glove types and each of the four conditions. Separate multiple linear regression models were employed to determine if the coefficients of friction for the four glove conditions were statistically different from one another. Load and trial number were also included in these models. The coefficients of friction for brand new gloves were significantly different from the other three conditions. The coefficients of friction for glove in saliva, wet or dirty conditions were not significantly different from one another. Separate multiple linear regression models were employed to determine if the coefficients of friction for the five glove models were statistically different from one another. Again, load and trial number were also included in the models. For the new condition, the Nike Vapor Grip 3 and Select 88 gloves had the highest coefficients of friction and were significantly different from the rest. For the saliva condition, the Uhlsport Aqua and Uhlsport Soft gloves had the highest coefficients of friction and were significantly different from the rest. For the wet conditions, the Uhlsport Soft and Uhlsport Hard gloves had the highest coefficients of friction and were significantly different from the rest. For the dirty condition, the Select 88 glove had the highest coefficients of friction and was significantly different from the rest. These results show that different soccer goalie glove brands and models as well as different conditions all have significantly influence the coefficient of friction between the ball and glove. Soccer goalkeepers should be aware that there are differences in goalie glove brands and differences in how those brands react to different conditions.
Hofmann, Candice, "Factors affecting the coefficient of friction of soccer goalie gloves." (2014). Master's Theses. 112.