One of the main challenges for wireless body area networks (WBANs) is to evaluate realistic methods to generate channel models for new different purposes and various environments quickly and flexibly. Finite integration technique (FIT) has shown to be promising method for modeling channels characteristics in WBAN deployment scenarios. Applying simulation based channel modeling on the performance evaluations of the concrete-surrounded use scenarios have not been presented in the literature. In this paper, FIT-based channel modeling is applied on the performance evaluation of IEEE 802.15.6 based energy detector (ED) receiver designed for monitoring the symptoms of Parkinson's disease. The first aim of this paper is to assess and compare the simulated channel impulse responses (CIRs) with the data from a measurement campaign. The second aim is to apply the simulated channel on the performance evaluations of the IEEE 802.15.6 based ED receivers. The obtained bit error rate (BER) performances are compared with BERs obtained using channel measurement data in the simulations. It is shown that performance obtained using FIT-based channel modeling corresponds to performance obtained using channel measurement data based channel modeling. The results of this paper further verify the statements that FIT is sufficiently applicable for WBAN channel modeling.