Some important factors of female work are analysed, and the importance and use of knowledge about maximum muscular strength of women in theory and praxis of Ergonomics, Biomechanics is demonstrated. With the term of maximum isometric muscular strength of position isodynes are defined as curves which join points of application of forces within the arm reach and which indicate strengths of the same type and amount. Isodynes are used for complex describing the dynamo-metric structure of the arm reach. Some examples of isodyne-diagrams demonstrate their practical applicability for work study practitioners and designers of work places and layout.