Estimating Tibial Stress throughout the Duration of a Treadmill Run

Abstract

Introduction: Stress fractures of the tibia are a problematic injury amongst runners of all levels. Quantifying tibial stress using a modelling approach provides an alternative to invasive assessments that may be used to detect changes in tibial stress during running. This study aimed to assess the repeatability of a tibial stress model and to use this model to quantify changes in tibial stress that occur throughout the course of a 40-minute prolonged treadmill run. Methods: Synchronised force and kinematic data were collected during prolonged treadmill running from fourteen recreational male rearfoot runners on two separate occasions. During each session, participants ran at their preferred speed for two consecutive 20-minute runs, separated by a 2-minute pause. The tibia was modelled as a hollow ellipse and bending moments and stresses at the distal 1/3 of the tibia were estimated using beam theory combined with inverse dynamics and musculoskeletal modelling. Results: Intraclass correlation coefficients indicated good-to-excellent repeatability for peak stress values between sessions. Peak anterior and posterior stresses increased following 20 minutes of prolonged treadmill running and were 15% and 12% greater respectively after 40 minutes of running compared with the start of the run. Conclusion: The hollow elliptical tibial model presented is a repeatable tool that can be utilised to assess within-participant changes in peak tibial stress during running. The increased stresses observed during a prolonged treadmill run may have implications for the development of tibial stress fracture.

Combining wearable sensor signals, machine learning and biomechanics to estimate tibial bone force and damage during running

“…As described previously , we have confidence in lab-based estimates of tibial compression force. There is less agreement in the literature about other loading directions (e.g., tibial bending, (Derrick et al, 2016;Haris Phuah et al, 2010;Meardon et al, 2015;Rice et al, 2019;Sasimontonkul et al, 2007;Scott & Winter, 1990;Yang et al, 2014)). Nevertheless, there may be value to exploring algorithms for estimating these other loading directions, or for estimating damage due to the combined loading from axial compression and bending.…”

Tibial stress during running following a repeated calf‐raise protocol

“…A customized Matlab (R2017a, MathWorks) program was written to estimate tibial stress and has been detailed by Rice et al 7 In brief, segment center of mass accelerations and joint reaction forces were calculated. Bending due to muscular forces was calculated from nine muscles that span the cross section at the distal third of the tibia: Tibialis Anterior; Soleus; Tibialis Posterior; Extensor Digitorum Longus; Flexor Digitorum Longus; Flexor Hallucis F I G U R E 1 Sample of a digitized tibial cross section utilizing a customized Matlab script.…”

“…The bending at the centroid due to the external reaction forces included the contributions from both the knee joint reaction force and the knee joint moment (termed contact forces). As in Rice et al, 7 stance phase axial and bending forces due to the external reaction forces and internal muscular forces were vector summed to represent the resultant axial force and resultant bending moments acting at or about the centroid at the distal third of the tibia. Normal stresses at the posterior, anterior, lateral, and medial peripheries were calculated as axial stress ± bending stress.…”

“…7,[12][13][14] Beam theory modeling was shown to be a repeatable approach for quantifying within-participant changes in tibial stress. 7 Previous beam theory approaches have modeled a cross-section of the tibia as a hollow ellipse, using literature-based geometric properties or image-based estimates of bone geometry and assuming symmetry in the cross section. 7,[12][13][14] The accuracy of stress calculated using beam theory could be improved by using participant-specific bone geometry and assuming asymmetry of the cross section.…”

“…7 Previous beam theory approaches have modeled a cross-section of the tibia as a hollow ellipse, using literature-based geometric properties or image-based estimates of bone geometry and assuming symmetry in the cross section. 7,[12][13][14] The accuracy of stress calculated using beam theory could be improved by using participant-specific bone geometry and assuming asymmetry of the cross section. Bone geometry has been proposed to be important when understanding risk of stress injury as measures of geometry, including cross-sectional area, section modulus, and area moment of inertia, have been inversely associated with risk of stress fracture in military populations.…”