握力・鍵ピンチ力1回測定の信頼性と真の変化をどう判断するか

Reliability applicability of single-trial grip and key pinch strength measurements

要旨：本研究では，20歳以上の健常学生の男性40名，女性40名を対象に，握力，鍵ピンチ力の1回測定について2日間に分け，性別，左右別に信頼性とその真の変化をどう判断するか検証した．両測定ともに本測定1回目と2回目に有意差はなく，信頼性を示す級内相関係数ICC（1，1）は0.80〜0.93，系統誤差も認めず良好な結果であった．測定時間や測定者および対象者の負担から判断しても，3回測定に比べ1回測定のメリットは大きい．また，最小可検変化量MDC 95は，13.5〜18.9％の範囲であり，真の変化（改善もしくは悪化）を判断する際，統計学的には20％を目安にすることが有用と考える．

　This study attempts to verify the reliability of single-trial measurements of grip and key pinch strength and show how resulting data should be used to infer when meaningful changes have occurred in a subject. Data for the study were collected from 40 male and 40 female, healthy university students over 20 years old and were divided according to both the subjects' gender and each of the hands. Results were favorable for both measurements, with no significant difference between the first day of measurement and the second. There was a range of reliability Intraclass correlation coefficients (ICC) (1, 1) of 0.80-0.93, and no system errors. When considered from the standpoint of time and burden placed on the subjects and testers, the merits of a single-trial method compared to a three-trial method are even greater. The Minimal Detectable Change 95 (MDC 95) ranged from 13.5-18.9%. Therefore, when inferring the change (improvement or worsening) in a subject, 20% should be a statistically useful rough value to bear in mind.