Date of Award
Ph.D. in Health and Kinesiology
Health, Exercise Science, and Recreation Management
John C. Garner
John P. Bentley
Injuries in the workplace pose a significant burden to the health of human beings as well as financial or economic losses to occupational organizations. Slips, trips and an induced loss of balance have been identified as the major causative factor for workplace injuries involving falls (Courtney et al, 2001; Redfern et al, 2001). The bureau of labor statistics reported 15% of a total of 4,693 workplace fatalities and a total of 299,090 cases of non-fatal workplace injuries that were due to slips, trips and falls (BLS, 2011). The purpose of the study was to analyze the biomechanics of human locomotion under normal dry flooring conditions and under slippery flooring conditions with three commonly used alternative casual footwear [thong style flip-flops (ff), crocs with clogs (cc) and slip resistant low-top shoe (lt)]. The study will follow a within-subjects repeated measures design with each participant exposed to all three footwear using a counter balanced design. Eighteen healthy male participants with no orthopedic, cardiovascular or neurological abnormalities completed the study. Participants were required to come in for three testing sessions separated by at least 24 hours of rest interval and an initial familiarization day. On each testing day, participants were provided with an alternative footwear based on a counterbalanced selection and were tested for maximal voluntary contraction for lower extremity muscles and were exposed to a series of walking trails that included a normal dry surface non slip gait trial (ns); unexpected slip (us), alert slip (as) and expected slip (es). A 3 x 4 [3 (ff, cc, lt) x 4 (ns, us, as, es)] within-subjects repeated measures anova was used to analyze the dependent slip parameters (heel slip distance and mean heel slip velocity), kinematic and kinetic gait variables (mean and peak vertical ground reaction forces and lower extremity joint angles) and muscle activity (mean, peak and % maximal voluntary contraction in lower extremity muscles). Significant interactions between the footwear and gait trials were found for the slip parameters, gait parameters and muscle activity variables (p<0.05). Significant interactions were folloup with post-hoc multiple comparisons using a Sidak Bonferroni correction. Based on the results from the study the alternative footwear (cc & ff) had greater slip parameters, reduced ground reaction forces and a plantar flexed foot position at heel strike compared to the lt. The us and as had greater incidence of slips than ng and es and moreover with the a priori knowledge of the slippery flooring conditions (es), the individuals were able to modify the gait kinematic and kinetic parameters rather than lower extremity muscle activity to reduce the potential for a slip. Overall, the most hazardous slips were seen with alternative footwear and during the unexpected slips folloby the alert slips. The lt had lower incidence of slips and maintained a normal gait pattern during all gait trial conditions and demonstrates to be the choice of footwear for maneuvering slippery flooring conditions that exist in both occupational and public places.
Chander, Harish, "Biomechanics Of Slips In Alternative Footwear" (2014). Electronic Theses and Dissertations. 1026.