A system comprising a magnetically encoded shaft and magnetic field detecting system, characterised by : the magnetically encoded shaft comprises: first, second, third and fourth magnetically encoded bands spirally encircling the shaft , each band comprising first magnetically encoded regions having a first magnetic polarity alternating with second magnetically encoded regions having a second magnetic polarity; the first band comprising first dead zones , the second band comprising second dead zones , the third band comprising third dead zones and the fourth band comprising fourth dead zones , the dead zones being defined in each band between successive first and second magnetically encoded regions; the first and second bands spaced apart by a first distance and the third and fourth bands spaced apart by the first distance, a second distance greater than the first distance between the first and third and bands and between the second and the fourth bands; first magnetically encoded regions opposite second magnetically encoded regions in the first and second bands and defining a first force-sensitive region therebetween; first magnetically encoded regions opposite second magnetically encoded regions in the third and fourth bands and defining a second force-sensitive region therebetween; the first force-sensitive regions spaced opposite third and fourth dead zones in the third and fourth bands; the second force-sensitive regions spaced opposite first and second dead zones in the first and second bands; and the magnetic field detecting system comprising sensors mounted proximate the shaft for detecting magnetic fields surrounding the first and second force-sensitive regions , wherein a force exerted on one or both of the first and second force-sensitive regions alters the magnetic field surrounding the respective first and second force-sensitive regions , the alterations indicative of the force exerted. first, second, third and fourth magnetically encoded bands spirally encircling the shaft , each band comprising first magnetically encoded regions having a first magnetic polarity alternating with second magnetically encoded regions having a second magnetic polarity; the first band comprising first dead zones , the second band comprising second dead zones , the third band comprising third dead zones and the fourth band comprising fourth dead zones , the dead zones being defined in each band between successive first and second magnetically encoded regions; the first and second bands spaced apart by a first distance and the third and fourth bands spaced apart by the first distance, a second distance greater than the first distance between the first and third and bands and between the second and the fourth bands; first magnetically encoded regions opposite second magnetically encoded regions in the first and second bands and defining a first force-sensitive region therebetween; first magnetically encoded regions opposite second magnetically encoded regions in the third and fourth bands and defining a second force-sensitive region therebetween; the first force-sensitive regions spaced opposite third and fourth dead zones in the third and fourth bands; the second force-sensitive regions spaced opposite first and second dead zones in the first and second bands; and the magnetic field detecting system comprising sensors mounted proximate the shaft for detecting magnetic fields surrounding the first and second force-sensitive regions , wherein a force exerted on one or both of the first and second force-sensitive regions alters the magnetic field surrounding the respective first and second force-sensitive regions , the alterations indicative of the force exerted. <EOS>