In recent years, many mechanisms have been developed to help people with reduced mobility, especially for people who have injuries that do not allow the mobility of the lower body of the human body. In the present work, the properties and mechanical movements of a human being, angles of movement, extension and flexion of the hip, knee, etc. are described. A device has also been designed, using aluminum elements to give lightness and robustness to the exoskeleton. At the same time, an external casing made of PLA plastic has been developed, with all of which it has been tried to make a light exoskeleton with a low volume, with the aim that be of daily use for people with mobility problems. Five young students tested the exoskeleton in laboratory conditions. Different parameters have been evaluated as design, range of movement and the functionality. A series of characteristics has been defined such as the design improvement, functionality and navigation, the operating time, speed and data reading with myoelectric sensors after trials. Keywords: exoskeleton, lower extremities, design, biomechanics.