Design, development and validation of an artificial muscle biomechanical rig (AMBR) for finite element model validation

Abstract

In modern physiological research the focus has advanced from the mechanostat theory to the functional muscle-bone-unit, investigating the relationship between muscle and bone. A recent study yielded in vivo data on the deformation of the human tibia and an inverse FE algorithm, which was developed to calculate the muscle forces triggering these deformations. In this context an Artificial Muscles Biomechanical Rig (AMBR) was developed, in order to validate the methods used and obtain further data on the relationship of muscle forces and bone deformations. With AMBR the biomechanical behavior of the human tibia can be simulated, comparable to the FE simulation. It is a custom-made mechanical platform including pneumatic actuators combined with a control system to simulate the lower leg muscles. The specimen tested is a biomechanical replica of the tibia. For validation and verification with AMBR, tests focused on the accuracy and repeatability of data acquisition of the specimen deformation during force application by using a motion capture system. The rig was able to serve its purpose by validating the inverse FE algorithm. Its further applications might comprise of profounder studies on various mechanical effects of muscles on bones and create new biomechanical insights for prevention and rehabilitation.