Therapeutic exercise has previously been shown to alter the static height of the medial longitudinal arch (MLA). It is still unknown, however, if these effects carry over into dynamic activities. PURPOSE: To determine if an 8-week foot strengthening exercise program increases static arch height and reduces vertical deformation of the MLA during mid-stance in running.METHODS: Thirty-four recreational runners (17 males, 17 females) have completed this ongoing study (age 24.06 Â± 3.61 years, body mass 68.63 Â± 12.95 kg, and height 173.34 Â± 9.54 cm). To date, 22 subjects have been assigned to the control group (8 weeks of normal running) and 12 to the foot strengthening group (8 weeks of foot strengthening, along with normal running). Static arch height (SAH) and dynamic arch drop (DAD) were measured at baseline and following the 8-week intervention using Vicon motion analysis. Reflective markers were placed on the proximal and distal ends of the 1st and 5th metatarsals. These 4 markers were recorded in static double leg stance to estimate SAH, and in single leg mid-stance to give a measure of DAD during treadmill running at a self-selected pace. Ten-second trials were recorded at minutes 3 and 4 during running and DAD was evaluated for right and left feet by comparing arch height in mid-stance to the SAH. Following the intervention, data for SAH and DAD were compared across time points and statistical analysis performed to identify differences in the amount of change in SAH and DAD between groups. RESULTS: There was no difference noted in DAD between the groups as a whole, but the change in DAD from baseline to the end of week 8 was statistically significant for those in the foot strengthening group with an initial DAD of â‰¥ 3.80 mm (p < .028). There was also a statistically significant increase in SAH in the foot strengthening group compared to the control group (p = .013). CONCLUSIONS: These preliminary data suggest that the foot strengthening intervention was effective in increasing SAH compared to the control group. The intervention was most effective at decreasing DAD in those with the largest amount of DAD at baseline. At this time it is unknown whether this decrease in arch drop is associated with performance benefits or decreased injury risk in the recreational runner, and further research is needed to determine the clinical significance of these findings.
College and Department
Life Sciences; Exercise Sciences
BYU ScholarsArchive Citation
Bridges, Jarom, "The Effect of Foot Strengthening Exercise on Dynamic Function of the Medial Longitudinal Arch in Runners: A Preliminary Report" (2015). All Theses and Dissertations. 5626.
therapeutic exercise, biomechanics, arch height