A simulation model for biomechanical analysis was developed in order to calculate the internal loads, such as muscular tension and energy consumption, from measured kinesiological data for various kinds of motion. In this model, the human body is divided into a maximum of nineteen rigid segments connected to each other with ball joints. A maximum of 156 skeletal muscles throughout the body are modeled as tensile force generators which include physiological elements that consume mechanical energy. The component ratio among muscle fiber types, number of body segments and number of degrees of jointfreedom can be changed easily, and according to the alteration of the segment number, the musculoskeletal system is changed automatically. This flexibility is of benefit in application of the method to various motion analyses. Three-dimensional bipedal walking was analyzed using a simplified model, and rowing motions were analyzed using the whole-body model.