Thomas试验（髋关节屈曲挛缩试验）指的是一项体格检查试验，是以一个英国骨外科医生Hugh Owen Thomas（1834-1891）的名字来命名的，用来排除髋关节屈曲挛缩。

病人仰卧检查台上，其一侧膝髋关节尽量弯曲，而另一条腿保持伸展状态。如果患者具有以下指征，即为Thomas征阳性。

髋关节屈曲挛缩如果在最开始的3个月内自行消失则可能是髋关节发育不良的迹象。它可以用来发现单侧的髋关节有屈曲挛缩畸形。

该测试包括3个步骤：

The Thomas test (Hugh Owen Thomas well leg raising test) is a physical examination test, named after Dr. Hugh Owen Thomas (1834–1891), a British orthopaedic surgeon, used to rule out hip flexion contracture and psoas syndrome. Often associated with runners, dancers, and gymnasts who complain of hip "stiffness" and reported "snapping" feeling when flexing at the waist.