Original Research ArticlesSonographic Evaluation of the Optimal Needle Insertion Site in the Biceps Femoris Short HeadShin, Seyoung MD; Kim, Ki Hoon MD, PhD; Kim, Dong Hwee MD, PhDAuthor Information From the Department of Physical Medicine and Rehabilitation, Korea University, Ansan Hospital, Gyeonggi-do, Korea. All correspondence should be addressed to: Dong Hwee Kim, MD, PhD, Department of Physical Medicine and Rehabilitation, Korea University, Ansan Hospital, 123 Jeokgeum-ro, Danwon-gu, Ansan 15355, Republic of Korea. This study is supported by Korea University Grant (K1824851). This study was previously presented in an abstract form in the 2019 annual meeting of Korean Academy of Rehabilitation Medicine on October 18, 2019, Seoul Dragon City. Seyoung Shin is in training. Financial disclosure statements have been obtained, and no conflicts of interest have been reported by the authors or by any individuals in control of the content of this article. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s Web site (www.ajpmr.com). American Journal of Physical Medicine & Rehabilitation: February 2021 - Volume 100 - Issue 2 - p 147-152 doi: 10.1097/PHM.0000000000001537 Buy SDC Metrics Abstract Objective The aim of the study was to identify the optimal needle placement for electromyographic examination of the biceps femoris short head muscle in relation to the biceps femoris long head tendon through sonographic evaluation. Design This cross-sectional observational study involved 36 lower limbs of 18 healthy volunteers. The distances and angles indicating the relationships between the common fibular nerve and the medial or lateral border of the biceps femoris long head tendon were measured at 5 and 7 cm proximal to the tip of the fibular head (P1 and P2, respectively) using ultrasonography. Results The median values of the distance between the biceps femoris long head tendon and the common fibular nerve were significantly longer in the lateral approach than in the medial approach at the P1 and P2 levels. The median values of the angles between the vertical line to the biceps femoris long head tendon and the common fibular nerve were significantly larger in the lateral approach than in the medial approach at both levels. Conclusions The common fibular nerve is located just below the medial border of the biceps femoris long head tendon at a near-vertical degree from the skin. It is strongly recommended that the needle should be inserted on the lateral side of the biceps femoris long head tendon during needle electromyographic examination of the biceps femoris short head muscle. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.