Hardware to Detect EMG or Skin Resistance
That technique won't work - there is no relationship between skin resistance and finger position when measured between the finger tip and the elbow. You aren't measuring it correctly, anyway. You need silver/silver chloride electrodes with electrode jelly, high-gain amplifiers, and a lot of filtering and screening. Abrading the skin with electrode jelly and paper towel helps.

EMG won't work, either.

The DataGloves we used when I worked on advanced cockpit research at BAe used fibre optics. Strain on the optic fibre (it had a small cut in it) running along each finger over the knuckles reduced the intensity of the transmitted light. Detecting and amplifying the change gave the degree of flexure of each finger. A 3D electro-magnetic sensor attached to the back of the hand in conjunction with a magnetic field generator gave us the position of the hand and how it was moving (X, Y, Z, and roll, pitch and yaw).