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 (500, 506, 500A, 506A) having a first magnetic polarity alternating with second magnetically encoded regions (504, 502, 504A, 502A) 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 (509, 509A), wherein a force exerted on one or both of the first and second force-sensitive regions (509, 509A) alters the magnetic field surrounding the respective first and second force-sensitive regions (509, 509A), 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 (500, 506, 500A, 506A) having a first magnetic polarity alternating with second magnetically encoded regions (504, 502, 504A, 502A) 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 (509, 509A), wherein a force exerted on one or both of the first and second force-sensitive regions (509, 509A) alters the magnetic field surrounding the respective first and second force-sensitive regions (509, 509A), the alterations indicative of the force exerted.