Apparatus and method for muscle movement training

An apparatus, comprising:

• a first retractor device, wherein the first retractor device comprises:
• a first torsion spring;
• a first cable that comprises an extendable and retractable first cord;
• and
• a first tapered drum that is attached to the first cable, wherein the first tapered drum comprises a conical shape, wherein the first cable is wound in a spiral around the first tapered drum, wherein the first retractor device provides a first constant non-variable load and a first constant resistance to the first cable in a first direction;
• a second retractor device, wherein the second retractor device comprises:
• a second torsion spring;
• a second cable that comprises an extendable and retractable second cord;
• and
• a second tapered drum that is attached to the second cable, wherein the second tapered drum comprises a conical shape, wherein the second cable is wound in a spiral around the second tapered drum, wherein the second retractor device provides a second constant non-variable load and a second constant resistance to the second cable in a second direction that is opposite to the first direction, wherein the first constant non-variable load is the same as the second constant non-variable load, and wherein the first constant resistance is the same as the second constant resistance;
• and
• a body gear unit for engaging a human, wherein the body gear unit is attached to the first retractor device and the second retractor device.