Joint position sense in elderly fallers: a preliminary investigation of the validity and reliability of the SENSERite measure

OBJECTIVES: To establish the validity and reliability of the SENSERite system and to determine and compare proprioceptive acuity thresholds (PATs) among 3 groups. DESIGN: Between groups, repeated measures, with randomized sequence. SETTING: University research laboratory. PARTICIPANTS: Forty-six adults recruited into 1 of 3 groups: group 1, 10 healthy young adults (mean age, 22.20y); group 2, 22 healthy older adults (mean age, 73.12y); and group 3, 14 older adults with a history of falls (mean age, 73.21y). INTERVENTIONS: The validity of SENSERite's joint position measure was determined by comparing the system's performance with a validated goniometer measure. The test-retest reliability was determined by repeatedly measuring the established joint positions for the neutral, inversion, eversion, plantarflexion, and dorsiflexion on 2 separate occasions, approximately 24 hours apart. In addition, PATs were measured to determine group differences. Data were analyzed by means of a univariate analysis of variance (ANOVA), intraclass correlation coefficient (ICC(2,k)), and paired t tests. MAIN OUTCOME MEASURES: Error in active reproduction of position and PAT derived from the 5 respective joint position sense tests. RESULTS: Excellent clinical goniometer and SENSERite correlation (ICC(2,k)=1.0, P<.05) was found. The test-retest reliability for the 5 respective position sense tests were excellent (ICC(2,k) range, .88-.99; P<.05). ANOVA revealed a significant difference in PATs among the 3 groups. Post hoc analysis indicated that PAT was greater in groups 2 and 3 than in group 1. No significant difference in PAT was observed between groups 2 and 3. CONCLUSIONS: The ability of the SENSERite to measure joint angular position was as good as that of a clinical goniometer; it had an adequate reliability when tested on 2 separate occasions. The device detected differences between elderly and young subjects, but it did not discriminate differences between fallers and nonfallers. This finding indicates that there is no significant difference between the fallers and nonfallers in proprioceptive acuity.