A fall arrester (100) for reducing injuries of a user (108) thereon when falling comprising a rotatable spool (314) with webbing (200) wound thereon, the webbing (200) being protracted from and retracted back upon the spool (314), a torsion bar (310) operationally connected to the webbing (200) through the spool (314) to generate a generally constant reaction force on the spool (314) as the torsion and bar and spool (314) rotate to absorb kinetic energy of the fall; the fall arrester (100) according to claim 1 further including a counting mechanism (500) to maintain a reserve amount of webbing (200) on the spool (314) to enable the torsion bar (310) to twist through its operational range without encountering an end-of-webbing condition.