Plantar Fat Pad Thickness And Its Impact On Ankle Biomechanics In Amateur Runners

The plantar fat pad, also known as the heel fat pad, is a specialized structure located beneath the calcaneus, composed of fibrous and adipose tissue. It serves as a natural cushion, playing a crucial role in shock absorption during weight-bearing activities. Despite its recognized importance, the influence of plantar fat pad thickness on ankle biomechanics during running remains unclear. A thicker plantar fat pad could potentially contribute to better shock absorption and reduce the overall stress on the ankle joint, which might indirectly affect ankle torque. PURPOSE: To investigate the impact of plantar fat pad thickness on ankle biomechanics during running. METHODS: Fourteen young healthy amateur runners participated in the study, running on a 10-meter walkway at their preferred speed in a biomechanics lab. Lower leg kinematics were recorded using eight Vicon cameras, and three force platforms captured ground reaction forces. MRI scans of the right foot and ankle were obtained with a 3.0-Tesla MRI scanner using a 16-channel foot coil, while participants lay supine with a neutral ankle position. The thickness of the plantar pad was independently measured by two researchers from the medial calcaneal tuberosity of the calcaneus to the boundary between the superficial fat pad and the dermis on sagittal T2-weighted MRI. Correlation coefficients were calculated to assess the relationship between plantar fat pad thickness and 3D ankle biomechanics. Results: a moderate correlation between plantar fat pad thickness and the peak plantarflexion torque during the stance phase of running was observed (R2 = 0.446, P = 0.009). CONCLUSION: A thicker plantar fat pad might indirectly reduce peak plantarflexion torque during the stance phase of running. This finding implies that variations in plantar fat pad thickness may influence ankle biomechanics and could potentially play a role in shock absorption during weight-bearing activities such as running.Dr. Kim was partially supported by the LSU Provost's Fund for Innovation in Research, First Kinesiology Research Grants, and CHSE Faculty Research Grant.