Plantar loading during jumping while wearing a rigid carbon graphite footplate

Fifth metatarsal stress fractures are common in sports and often result in delayed and non-union. The purpose of this study was to examine the effect of a rigid carbon graphite footplate (CGF) on plantar loading during take-off and landing from a jump. Nineteen recreational male athletes with no history of lower extremity injury in the past 6 months and no foot or ankle surgery in the past 3 years participated in this study. Subjects completed 7 jumping tasks while wearing a standard running shoe and then the shoe plus the CGF while plantar loading data was recorded. A series of paired t-tests were used to examine differences between the two footwear conditions independently for both takeoff and landing (α=0.05). The contact area in the medial midfoot (p<.001) and forefoot (p=.010) statistically decreased when wearing the CGFP. The force-time integral was significantly greater when wearing the CGFP in the middle (p<.001) and lateral forefoot (p=.019). Maximum force was significantly greater beneath the middle (p<.001) and lateral forefoot (p<.001) when wearing the CGFP, while it was decreased beneath the medial midfoot (p<.001). During landing, the contact area beneath the medial (p=.017) and lateral midfoot (p=.004) were significantly decreased when wearing the CGFP. The force-time integral was significantly decrease beneath the medial midfoot (p<.001) when wearing the CGFP. The maximum force was significantly greater beneath the medial (p=.047) and middle forefoot (p=.001) when the subject was wearing the CGFP. The maximum force beneath the medial midfoot (p<.001) was significantly reduced when wearing the carbon graphite footplate. The results of the study indicate that the CGF is ineffective at reducing plantar loading during jumping and landing. © 2013 Elsevier B.V

Plantar Loading During Cutting While Wearing a Rigid Carbon Fiber Insert.

Context : Stress fractures are one of the most common injuries in sports, accounting for approximately 10% of all overuse injuries. Treatment of fifth metatarsal stress fractures involves both surgical and nonsurgical interventions. Fifth metatarsal stress fractures are difficult to treat because of the risks of delayed union, nonunion, and recurrent injuries. Most of these injuries occur during agility tasks, such as those performed in soccer, basketball, and lacrosse. Objective : To examine the effect of a rigid carbon graphite footplate on plantar loading during 2 agility tasks. Design :  Crossover study. Setting : Laboratory. Patients or Other Participants : A total of 19 recreational male athletes with no history of lower extremity injury in the past 6 months and no previous metatarsal stress fractures were tested. Main Outcome Measure(s) :  Seven 45° side-cut and crossover-cut tasks were completed in a shoe with or without a full-length rigid carbon plate. Testing order between the shoe conditions and the 2 cutting tasks was randomized. Plantar-loading data were recorded using instrumented insoles. Peak pressure, maximum force, force-time integral, and contact area beneath the total foot, the medial and lateral midfoot, and the medial, middle, and lateral forefoot were analyzed. A series of paired t tests was used to examine differences between the footwear conditions (carbon graphite footplate, shod) for both cutting tasks independently (α = .05). Results : During the side-cut task, the footplate increased total foot and lateral midfoot peak pressures while decreasing contact area and lateral midfoot force-time integral. During the crossover-cut task, the footplate increased total foot and lateral midfoot peak pressure and lateral forefoot force-time integral while decreasing total and lateral forefoot contact area. Conclusions : Although a rigid carbon graphite footplate altered some aspects of the plantar- pressure profile during cutting in uninjured participants, it was ineffective in reducing plantar loading beneath the fifth metatarsal