2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/151760The effect of rotational constraint on the properties of lattice models like the self-avoiding walk, lattice animals and percolation is discussed. The results obtained so far, using a variety of exact and approximate techniques, are described. Examples of the rotational constraint in real systems are also given.22 pages LaTeX, 5 figures, Lecture Notes in Workshop on Mathematical aspects of Percolation (1996), Indian Statistical Institute, New DelhiStatistical Mechanicstext