Fifth Metatarsal Stress Fractures in Elite Basketball Players: Evaluation of Forces Acting on the Fifth Metatarsal
Authors:
Joseph H. Guettler MD, Duke
University Medical Center, Durham, NC
Claude T. Moorman III MD, Duke University Medical Center, Durham, NC
Gregory J. Ruskan PT, Duke University Medical Center, Durham, NC
Jeffrey R. Bytomski DO, Duke University Medical Center, Durham, NC
Christopher R. Brown MD, Duke University Medical Center, Durham, NC
Jan K. Richardson PT, PhD, Duke
University Medical Center, Durham, NC
Objective: Stress fracture of the fifth metatarsal is a prevalent injury in basketball players. Successful prevention of this injury is dependent on an understanding of the stresses acting on the fifth metatarsal. The objective of this study was to evaluate the forces acting on the fifth metatarsal during certain maneuvers commonly performed while playing basketball and to determine the effect of medial arch support on these forces.Methods: Eleven male collegiate basketball players were utilized for this study. Electronic pressure sensors capable of dynamic readings were inserted into their shoes, and surface EMG electrodes were placed over the peroneus longus and brevis muscles. The players then performed three maneuvers postulated to place maximal stress on the fifth metatarsal: 1) a one-footed landing following a jump during a simulated lay-up, 2) a 180 degree direction change during a side-to-side shuffle, and 3) a 180 degree pivot during a forward sprint. The maneuvers were first performed in a standard basketball shoe. The maneuvers were then repeated in a shoe with an orthotic that accentuated the medial arch. Maximal force, total work, and time elapsed were recorded beneath the fifth metatarsal during each of these three maneuvers. EMG activity of the peroneus longus and brevis muscles was also recorded.Results: The longest elapsed time and greatest mean total work were encountered beneath the fifth metatarsal during the pivot maneuver. The greatest mean maximal force was experienced upon landing during the lay-up maneuver. The highest mean peak EMG activity was encountered during the shuffle maneuver. The mean maximal force and total work beneath the fifth metatarsal were consistently greater when the three maneuvers were performed without an accentuated medial arch. The orthotic caused a statistically significant (p < 0.05) reduction in maximal force encountered beneath the fifth metatarsal during the lay-up and pivot maneuvers. Mean peak EMG activity of the peroneus longus and brevis muscles was higher during all three maneuvers when the medial arch was accentuated.Conclusions: Support of the medial arch may reduce stresses encountered beneath the fifth metatarsal. This may have important implications relating to the incidence of fifth metatarsal stress fractures in basketball players. Simple shoe modifications may potentially reduce the risk of this season-ending injury.References: Acknowledgements:
