A shoulder arthrometer for measuring glenohumeral joint translation upon application of a force to an arm of a patient. It includes an arm attachment assembly, a force measurement gauge, a translation measurement gauge assembly, and a girdle assembly. The arm attachment assembly is capable of being secured to the arm of a patient. The force measurement gauge is operably engaged with the arm attachment assembly for measuring a force applied to the arm attachment assembly in anterior-posterior directions and the inferior direction. The translation measurement gauge assembly is operably engaged with the arm attachment assembly. It is capable of measuring anterior-posterior translations and inferior translations relative to the arm of a patient and includes a girdle connecting element. The girdle assembly is operably engageable with the girdle connecting element. The girdle assembly is capable of being secured to the torso of the patient to provide a fixed point of reference. During application of either an anterior-posterior force or an inferior force to an arm of a patient, glenohumeral joint displacement is measured, the amount of force being registered by the force measurement gauge, while the amount of translation is registered via the translation measurement gauge assembly.