Abstract:
The aim of this study was to evaluate the benefits and limitations of using three
dimensional (3D) musculoskeletal modelling (LifeModeler™) in assessing the safety and
efficacy of exercising on a seated biceps curl resistance training machine. Three
anthropometric cases were studied, representing a 5th percentile female, 50th percentile
and 95th percentile male. Results indicated that the LifeModeler™ default model was not
adequate to solve the forward dynamics simulations. Therefore adjustments had to be
made to the default model to successfully complete the forward dynamics simulations.
The software was able to sufficiently highlight the shortcomings of the biceps curl
machine’s engineered adjustability in relation to the anthropometric dimensions of the
studied cases, as the 5th percentile female could not be accommodated suitably on the
machine. High lumbar spine anterior/posterior shear forces for all anthropometric cases
and maximum muscle tensions for the female and 50th percentile male indicate that the
seated biceps curl exercise may pose risks for injuries. To conclude, it appears that 3D
musculoskeletal modelling can be used to evaluate resistance training equipment such
as the seated biceps curl machine. However the limitations as indicated by this study
must be taken into consideration, especially when using the default LifemodelerTM
model.
