Electro-conductive yarns can be used to create electrically active areas in textile structures to develop wearable strain gauges. The electromechanical properties of the strain gauge have been studied. Three lab experiments have been conducted: the first analyses the electrometrical properties of the yarns which were used to produce knitted sensors; the second investigates the properties of a single stitch to understand the effect of contact points between yarns on the electrical properties of knitted fabric. Finally, the electrical properties of the knitted fabrics which contain electrically active conductive areas, i.e. knitted sensors, were tested.