下肢肌力是個體移行功能的影響因素之一，等速肌力測試儀能夠評估肌肉在各種速度下的力矩值，是最常用以量化肌力的評估工具。使用等速肌力儀探討各族群之下肢肌力，與臨床訓練方式之成效的文獻相當多，因此有關下肢等速肌力評估的信度資訊相當重要。本文針對可能影響下肢等速肌力評估之信度的因素，包括關節部位（髖、膝與踝）、收縮方式（向心與離心收縮）、關節病變與否、測試儀類型(Cybex, Biodex, Lido)以及年齡、性別、測試之間休息與否、參考值選取方式、測試的角速度等，做系統性的文獻回顧。有關於下肢等速肌力評估之再測信度的資料顯示：(1)膝關節的信度最高；(2)伸肌群之信度高於屈肌群之值，但病變關節則屈肌群的信度高於伸肌群之值；(3)低速測試之信度高於高速測試之值；(4)男性之信度高於女性之值；(5)年輕族群之信度高於年長族群之值；(6)Cybex系統的信度稍高於其他系統。以上資料能夠提供臨床治療師及研究人員在使用與設計等速肌力評估時之重要考慮。

Muscular strength of the lower extremity is an important factor that affects human locomotion. Among the various assessments of muscle strength, isokinetic dynamometer is a widely used method to quantify muscle torque under different angular speeds and to examine the training effect. Therefore, the information concerning the reliability of the isokinetic test is important. This article is aimed to review previous studies on the reliability of isokinetic test that examined the influencing factors for reliability such as joints (hip, knee vs. ankle), muscle contraction mode (concentric vs. eccentric contractions), impaired vs. non-impaired joint, age, gender, rest vs. no rest during test interval, muscle torque parameter, angular velocity and machine type (Cybex, Biodex vs. Lido). The results showed that: (1) the knee joint was associated with the highest reliability among the tested joints; (2) the extensors had higher reliability than the flexors, but a reversed trend was observed for the impaired joints, (3) younger age, male gender, and tested under a low angular velocity had higher reliability than those with older age, female gender and tested under high angular velocity; (4) the use of Cybex system was associated with higher reliability than the use of other systems. The data suggested that these influencing factors should be considered when clinicians and researchers apply the isokinetic test for clinical use and study.