Medical Definition of Arm
Arm: 1. In popular usage, the appendage that extends from the shoulder to the hand. However, the medical definition refers to the upper extremity extending from the shoulder only to the elbow, excluding the forearm, which extends from the elbow to the wrist. The arm contains one bone: the humerus. 2. In a randomized clinical trial, any of the treatment groups. Most randomized trials have two "arms," but some have three "arms," or even more.Source: MedTerms™ Medical Dictionary
Last Editorial Review: 6/9/2016
Medical Dictionary Definitions A - Z
Search Medical Dictionary
- What Is Inherited Lipodystrophy?
- Do You Take Good Care of Your Eyes?
- Tips for a Clean Home & Healthy Cat