A handheld probe device capable of indentation of bone comprising: a housing having a housing mass, the housing comprising: an inner housing comprising a ledge and a groove ; and an outer housing holding a set screw , the outer housing moveable relative to the inner housing with the set screw travelling in the groove ; a force generator configured to apply a predetermined force for a predetermined period of time, the force generator in the form of an impact generator comprising an impact transfer assembly comprising an impact transfer rod and an impact transfer rod adjustment screw ; a hypodermic sized test probe having a proximal end operatively coupled to the force generator ; an impact mass driven by a primary spring towards the impact transfer assembly , the impact mass retained on the ledge against the driving of the primary spring ; a force generator trigger configured to initiate the force generator to impart the predetermined force for the predetermined time when a force greater than a threshold value is applied to the housing , the force generator trigger comprising a trigger ball configured to push the impact mass off the ledge in response to a push from the set screw such that the impact mass is driven by the primary spring to impact the impact transfer assembly ; and, a measurement device consisting of a flexure assembly consisting of a flexure made of Beryllium Copper and a plurality of strain gauges , the measurement device being configured to monitor the displacement of the test probe upon actuation of the trigger ; wherein; the housing mass is such that when a predetermined force of 10 to 20 Newtons is applied by the force generator , for a predetermined amount of time of 1 millisecond to the test probe, the inertia of the housing results in an error caused by movement of the housing of less than one percent. a housing having a housing mass, the housing comprising: an inner housing comprising a ledge and a groove ; and an outer housing holding a set screw , the outer housing moveable relative to the inner housing with the set screw travelling in the groove ; an inner housing comprising a ledge and a groove ; and an outer housing holding a set screw , the outer housing moveable relative to the inner housing with the set screw travelling in the groove ; a force generator configured to apply a predetermined force for a predetermined period of time, the force generator in the form of an impact generator comprising an impact transfer assembly comprising an impact transfer rod and an impact transfer rod adjustment screw ; a hypodermic sized test probe having a proximal end operatively coupled to the force generator ; an impact mass driven by a primary spring towards the impact transfer assembly , the impact mass retained on the ledge against the driving of the primary spring ; a force generator trigger configured to initiate the force generator to impart the predetermined force for the predetermined time when a force greater than a threshold value is applied to the housing , the force generator trigger comprising a trigger ball configured to push the impact mass off the ledge in response to a push from the set screw such that the impact mass is driven by the primary spring to impact the impact transfer assembly ; and, a measurement device consisting of a flexure assembly consisting of a flexure made of Beryllium Copper and a plurality of strain gauges , the measurement device being configured to monitor the displacement of the test probe upon actuation of the trigger ; wherein; the housing mass is such that when a predetermined force of 10 to 20 Newtons is applied by the force generator , for a predetermined amount of time of 1 millisecond to the test probe, the inertia of the housing results in an error caused by movement of the housing of less than one percent. <EOS>