Comparison of two musculoskeletal models to evaluate glenohumeral joint kinematics and dynamics

The musculoskeletal models have been used to estimate simultaneously the internal forces
and the joint kinematics during motion to avoid intrusive methods to diagnose
glenohumeral instability. The Holzbaur model and the Wu model have the main algorithms
to calculate the joint kinematics and dynamics that are used in most of the musculoskeletal
models to evaluate mobility and instability. No research has been done to compare the two
main shoulder models’ algorithms to evaluate shoulder mobility and have been reported
to evaluate stability. The estimation of range of motion and the joint reaction forces are
fundamental to find quantitative parameters to evaluate stability and mobility. The
shoulder mobility has been evaluated with standardized motion. From these, standardized
motions, abduction has been used as a clinical test to evaluate kinematic patterns to
differentiate from healthy subjects and subjects with anterior-posterior instability.
Nevertheless, the lack of evidence of the comparison of both models has not been enough
to find what model is better to evaluate joint kinematics and dynamics. The joint kinematics
and dynamics are essential to differentiate between healthy and pathological subjects.
Through the use of musculoskeletal models, the computation algorithms are used to
estimate the joint joint kinematics, moments, and joint contact forces that are calculated
based on experimental data. Nevertheless, the musculoskeletal models need to be ranked,
and evaluated with experimental data to identify the best models to evaluate joint
kinematics and dynamics. The direct measurement of joint reaction forces with biomodular
implants [1] are essential to compare the joint reaction forces that are estimated with both
models. The biomodular implants have been evaluated in patients with total shoulder
replacement to have a better approach to estimate the joint contact forces with
musculoskeletal models. The comparison of musculoskeletal models will help to evaluate
joint kinematics and dynamics for healthy subjects and patients with other surgical
procedures. This research is designed to verify the models’ capability to estimate joint
contact forces with the aim of improving the accuracy to improve the detection of
quantitative parameters to assess glenohumeral joint instability.
The diagnosis of glenohumeral joint instability has been quantified with the estimation of
joint kinematics and dynamics with musculoskeletal models. The comparison of the joint
reaction forces between the two models can improve the methods to detect the
algorithm’s ability to evaluate glenohumeral instability and other motion related
pathologies.