Dynamic Foot Model for Impact Investigation - Computational Biomechanics of the Musculoskeletal System - page 69

LE, Min. Principal
(Avg: 100%)
0.000
0.000
-0.040
-0.080
-0.120
-0.160
-0.200
-0.240
-0.280
-0.320
-0.360
-0.400
-0.534
FIgure 5.6 (See color insert.) Predicted maximal plantar fat pad deformation and compressive strain at
heel strike.
The indentation test combined with the computational approach can provide patient-specific fat
pad deformation and internal stress/strain information for foot pathologies and therapeutic footwear
designs (Erdemir et al. 2006). In this study, quantitative analysis of internal and contact stress of
fat pad tissue using the dynamic FE foot model could help to address heel pain during walking or
running.
FE analysis of shock attenuation period using dynamic-implicit algorithms is challenging and
still undergoing constant improvement. Preliminary predicted results showed that the heel fat pad
under impact force could induce large deformation and stress concentration on soft tissues under
the calcaneus, which could affect the medial calcaneal nerve during heel strike, while similar
heel pain location could have different pathophysiologic mechanisms and biomechanics patterns
(Saggini et al. 2007). Moreover, in this study, we did not consider the venous plexus effect on fat
pad damping stiffness, which could decrease impact force about 1.8% at 0.4 m/s (Weijers, Kessels,
and Kemerink 2005). The simulation could further be tested and parametrically studied with dif-
ferent fat pad and sole material stiffness and thickness, striking velocities, striking angles, and
proximal loads.
aCknowledgmentS
This work was supported by the Research Grant Council of Hong Kong (GRF Project no.
PolyU5326/11E) and the National Natural Science Foundation of China (11272273, 11120101001).
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