Abstract: Abstract:  Linkages in the plane are know to have geometrically interesting configuration spaces M.  
One can describe the dynamics of some simple idealized  linkages in terms of the geodesic flow on M, for an  appropriate Riemannian metric. We describe how to associate to the linkage the curvature of this metric, which has a direct bearing on the dynamics of geodesic  flow, and thus of the linkage.