Neuromusculoskeletal (NM) models may help clinicians design better rehabilitation protocols. However, NM models face two challenges. Firstly, NM models greatly simplify the neuromusculoskeletal system. Secondly, the muscle redundancy problem guarantees there are not unique muscle force solutions, making validation of model changes very challenging. Intramuscular pressure (IMP) is the interstitial fluid pressure in muscle and has been shown to have a high correlation with muscle force. This thesis uses a newly-developed IMP sensor to compare the correlation between IMP and muscle force for four muscle models. Correlations were calculated between predicted tibialis anterior force and IMP for seven ankle dorsiflexion/plantarflexion tasks. Muscle model did not significantly affect the correlation between predicted muscle force and IMP. However, the compliant tendon model did have an insignificant increase in joint moment prediction accuracy. This may indicate that a compliant tendon model is appropriate for strong plantarflexor muscles with long tendons.