In the literature it has been shown that gibbons are able to brachiate with very low mechanical costs on a horizontal, rigid substrate. They do this by pendular movements, where potential and kinetic energy are exchanged to create an optimum energy conservation. Moreover they must minimize their collisional energy losses by ensuring that the passage between two movements happens smoothly without abrupt change in the path of body center of mass. Although the animals appear to succeed to do this in uniform, predictable experimental circumstances, this can not offer a thorough insight in the degree of coordination and control which these animals might show in their habitual, more complex, surroundings.
In this research it will be assessed, by means of a gradually increased degree of complexity, what the impact is of compliance of branches and their heterogeneous spacing on the mechanical costs of brachiation and whether and how kinesiological adaptations are realised. Moreover it will be examined whether siamangs show a motor learning process or not. If a learning process would exist, we expect reduction of the mechanical costs after familiarisation to a specific set-up. To examine all this thoroughly, anatomical, kinematic and dynamic analysis are carried out.