A new method for evaluating joint position sense using oral instructions based on body schema

[Purpose] This study investigated the efficacy of our independently developed method for measuring shoulder joint position sense using oral instructions based on body schema ("schema method") and investigated age-related changes. [Participants and Methods] Forty university students, 19 elderly individuals, and 16 elementary school students were included. Active shoulder abduction was measured in an upright sitting position. Target angles for position sense measurement were 45° of abduction (Target 45) and 90° of abduction (Target 90). The schema method consisted of indicating the target angles through oral instructions alone. The reproduction method and the imitation method were also used to measure angles. Abduction angle, absolute error, and variable error were calculated. [Results] A significant difference in abduction angle at Target 45 was observed between the schema method and the reproduction and imitation methods; no significant differences were observed at Target 90. No significant differences in variable error at Target 90 were observed among the three measurement methods. A significant difference in abduction angle was observed between university students and elderly individuals, and a significant difference in variable error was observed between elementary school students and elderly individuals. [Conclusion] Our body schema-based oral instruction method will be useful for evaluating joint position sense or proprioception.