Grasp modelling with a biomechanical model of the hand

Abstract

The use of a biomechanical model for human grasp modelling is presented. A previously validated biomechanical model of the hand has been used. The equilibrium of the grasped object has been added to the model through the consideration of a soft contact model. A grasping posture generation algorithm has been also incorporated to the model. All the geometry has been represented using a spherical extension of polytopes (s-topes) for efficient collision detection.The model has been used to simulate an experiment in which a subject was asked to grasp two cylinders of different diameter and weight. Different objective functions have been checked to solve the indeterminate problem. The normal finger forces estimated by the model have been compared to the ones experimentally measured. The popular objective function sum of the squared muscle stresses has been shown not suitable for the grasping simulation, requiring at least being complemented by task dependent grasp quality measures.

Hand Posture Prediction Using Neural Networks within a Biomechanical Model

“…The authors have previous experience in human grasping and have carried out several studies in the field of biomechanics [48][49][50][51][52][53]. These works have focused on the experimental characterization of common grasps in daily life, including not only grasping postures but also the forces produced by the different hand segments.…”

Assessment of the risk and biomechanical consequences of lateral epicondylalgia by estimating wrist and finger muscle capacities in tennis players

“…The understanding of hand biomechanics during object or handle manipulation has significantly improved over the last decade, mostly through numerous ergonomic and clinical studies (Kong & Lowe, 2005;Sancho-Bru et al, 2014;Wu, Dong, McDowell, & Welcome, 2009). In particular, the estimation of muscle forces using musculoskeletal models confirmed that wrist extensors are highly involved when grasping handle (Goislard de Monsabert et al, 2012) and when performing tennis strokes (Rossi et al, 2014), supporting the idea that a weakness of extensor muscles relative to flexor muscles could increase the risk of occurrence of lateral epicondylalgia.…”

Evaluation of Human Prehension Using Grasp Quality Measures

“…A brief description of the model is presented here but the detailed explanation can be found in [1], [27].…”

“…This index needs the estimation of the muscle forces from the use of the biomechanical model of the hand, as is described in Section 2.3.1. It has units of [force] x [area] -1 , its lower limit is 0 and its upper limit is the sum of the maximum stresses Smax the muscles can bear, which has been considered as the same for all of the muscles [1]. We propose to normalize the index as: QE1N = 1-(QE1 /(m Smax 2 )).…”

“…First of all, inside biomechanical human hand models, it could be used as a tool for assisting in the prediction of grasping postures or as a criterion to solve the indeterminate problem of finding the contact forces needed to grasp an object in a given posture [1]. Second, it can be applied in the design of hand-held products [2,3].…”