The automotive industry is the largest in the world and its products are among those that influence people's lives the most. The man-machine interface of a vehicle is among the primary - perhaps the primary - factors determining the product's success.

Egress/ Assistive Handle Model

With the ageing population, ingress/egress becomes an increasingly important topic. This egress model demonstrates how the position of an assistive handle on the window frame influences the knee joint forces as well as the muscular effort of egress. For an elderly individual with arthritic knees, this can be of tremendous importance to the usability of the vehicle.

The idea behind the study is that placement of a handle on the window frame might allow car drivers to divide the load of egress between the legs and the arms, thus reducing the maximum load on any of the elements. In such a situation, the AnyBody Modeling System automatically recruits muscles such that the effort is distributed between the body parts and indeed between the individual muscles to share the load between the elements according to their individual strengths.

The parameter study investigates four different positions of the handle as indicated on the figure. The distance between the positions is 0.1 m. The graphs show the muscular effort and the right knee joint forces over the movement for all the handle positions. Notice that in particular the low handle position causes a sharp increase of the knee joint force roughly in the middle of the movement and also causes the highest muscular effort. In terms of effort as well as knee joint force, a high position of the handle is preferable.