Abstract
[Purpose] To investigate the reproducibility of the lateral reach test (LRT) and the relationships between LRT and FRT, and FRT of both upper limbs (dual FRT); and to examine their applicability in the evaluation of dynamic balance. [Subjects and Methods] The subjects were 21 healthy male and female adults. Using a functional reach measuring instrument, we measured bilateral LRT, bilateral FRT, and dual FRT, and calculated the intraclass correlation coefficients (ICC) of LRT and dual FRT. We also investigated the relationship between them, and compared the variation in the distance of each reach. [Results] Measures of LRT and dual FRT had high reproducibility with ICCs of 0.907 and 0.977, respectively. Also, LRT, FRT, and dual FRT showed significant correlations, and also correlated with height. When normalized for height, LRT and FRT each showed strong bilateral correlations, but no correlation was found between LRT and FRT or dual FRT. As functional characteristics of LRT and FRT, it was found that LRT showed bilateral symmetry and FRT bilateral asymmetry. Further, the dominant hand made no difference to LRT, while it had a significant effect on FRT. [Conclusion] The results show LRT is highly reproducible and bilaterally symmetrical. LRT and FRT provide different evaluations of motor function, and the results show that LRT may potentially be more suitable for measuring lateral dynamic balance than FRT. Regarding the evaluation of dynamic balance, it appears necessary to measure both LRT and FRT or dual FRT for anterior and bilateral evaluation.
