Comment on 'Soft-tissue contributions to impact forces simulated using a four-segment wobbling mass model of forefoot-heel landings'

摘要

The purpose of this comment is to seek clarification from the authors regarding the model's assumptions and choice of parameters. The mass of the model appears to be inconsistent with the mass of the subject used to derive the model.In the first paragraph of the Methods section of the paper by Gittoes, Brewin, and Kerwin (2006), the authors write: "The planar model (Fig. 1) represented both sides of the body using a single foot, shank, thigh and upper body segment. The foot was modelled as a single rigid body. The shank, thigh and upper body segments were each sub-divided into a wobbling and a rigid mass." In the first sentence of Section 2.2, the authors note that the mass and inertial characteristics (MIC) are based on a single 22 year-old female with mass 69.0 kg. The derivation of the mass and inertial parameters was referenced to Gittoes and Kerwin (2006), where it was stated that the predicted total body mass of the subject was 67.94 kg (1.54% less than the actual mass). The MIC of Gittoes et al. (2006) are repeated below in Table 1. The sums of the rigid and wobbling masses for the shank, thigh, and upper-body segments are 6.425,14.442, and 34.447 kg, respectively.