Background
Footwear is intended to prevent lower extremity injuries caused by excessive foot-ground impacts and faulty mechanics. However, no clear relationship between shoe habits and injury risk has been established [1]. Many studies have examined barefoot versus shod running kinematics, but the results have been equivocal [2, 3]. A factor in the inconsistent results could be the relationship between foot structure and function. For example, Cobb et al. demonstrated significant walking gait kinematic differences between participants with typical and low arch foot structures using a multi-segment foot model [4]. The purpose of this study was to investigate effects of footwear on multi-segment foot kinematics during running in participants with low arch structure.
Materials and methods
Five healthy participants (26.8 ± 9.01 yrs; 171.5 ± 9.85 cm; 71.61 ± 15.46 kg) with low arch structure completed 10 running trials at 4.0 (±10%) m/s in flat sandal and barefoot conditions. Marker clusters placed on the skin or custom-built wands identified six functional articulations: rearfoot complex (RC), calcaneonavicular complex (CNC), calcaneocuboid joint (CC), medial forefoot (MFF), lateral forefoot (LFF), and 1st metatarsophalangeal complex (MTP). Repeated measures MANOVAs (α ≤ 0.05) were used to analyze within-subject sagittal, frontal and transverse plane range of motion (ROM) and initial contact position differences between footwear conditions for the RC, CNC, and CC articulations. Dependent t-tests (α ≤ 0.05) were performed to assess MTP, MFF and LFF articulation sagittal plane ROM differences between the footwear conditions.
Results
ROM between conditions are shown in Table 1 and initial contact positions are shown in Table 2.
Table 1
ROM mean ± SD results for Sagittal, Frontal and Transverse planes of motion
Barefoot | Flat | |||||
|---|---|---|---|---|---|---|
Sagittal Plane | Frontal Plane | Transverse Plane | Sagittal Plane | Frontal Plane | Transverse Plane | |
RC
| 22.16 ± 3.18 | 8.33 ± 1.72 | 16.99 ± 1.92 | 20.44 ± 5.30 | 8.10 ± 2.92 | 13.98 ± 2.95 |
CNC
| 10.85 ± 2.57 | 8.11 ± 2.67 | 6.35 ± 1.72 | 9.39 ± 4.02 | 6.14 ± 4.33 | 7.44 ± 2.35 |
CC
| 18.66 ± 1.86 | 9.69 ± 2.44 | 8.88 ± 2.92 | 14.48± 5.35 | 7.02 ± 2.75 | 7.45 ± 1.45 |
MFF
| 20.90 ± 4.68 | 20.14 ± 3.60 | ||||
MTP
| 41.35 ± 5.39* | 33.33 ± 1.76* | ||||
LFF
| 7.68 ± 3.19 | 9.34 ± 2.52 | ||||
Table 2
Significant initial contact positions (p < 0.05) mean ± SD results between footwear conditions.
Barefoot | Flat | |||||
|---|---|---|---|---|---|---|
Sagittal Plane | Frontal Plane | Transverse Plane | Sagittal Plane | Frontal Plane | Transverse Plane | |
CNC
| 2.81 ± 4.17 | .38 ± 2.52 | -1.53 ± 3.03* | 1.51 ± 2.67 | .07 ± 5.22 | -4.34 ± 3.38* |
CC
| 5.46 ± 7.60 | -2.08 ± 2.84 | -3.37 ± 3.23* | 3.08 ± 4.03 | 2.60 ± 4.26 | 2.50 ± 1.97* |
MTP
| -14.12 ± 10.38* | -2.54 ± 7.63* | ||||
Conclusions
Runners alter their gait from shod to barefoot running. The ROM differences suggest runners adapt by increasing motion during stance phase. Initial contact positions demonstrate differences in strike pattern. Higher sagittal plane values for barefoot trials may indicate more midfoot/forefoot landing. These data may enhance the understanding of shoe-wear and running-related injuries.
Acknowledgements
This study was supported by a grant from the UW-Milwaukee Graduate School.
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.