Original Article: PDF OnlyThe Accurate Segmental Motor Innervation of the Skeletal Muscles of the Lower Extremity in Human BeingsZhu, Lei MD*; Lin, Hao-dong MD, PhD*; Ma, Bei MD, PhD†; Chen, Ai-min MD, PhD*Author Information *Department of Orthopedic Trauma Surgery, Changzheng Hospital †Department of Physiology, The Second Military Medical University, Shanghai, China L.Z. and H.-d.L. contributed equally. Supported by the National Natural Scientific Foundation of China (grant NSFC 81171161). L.Z. has full access to all the data in the study and take responsibility for its accuracy. The authors declare no conflict of interest. Reprints: Ai-min Chen, MD, PhD, The Department of Orthopedic Trauma Surgery, Changzheng Hospital, 415 Feng Yang Rd., Huang Pu District, Shanghai, China (e-mail: [email protected]). Neurosurgery Quarterly: November 15, 2013 - Volume Publish Ahead of Print - Issue - doi: 10.1097/WNQ.0000000000000018 Buy PAP Metrics Abstract Our knowledge of the accurate segmental motor innervation of the skeletal muscles of the lower extremity in human beings is inadequate. All the 15 subjects with unilateral fracture of the sacrum and sacral nerve injury underwent internal fixation and decompression of the sacral nerve. The L4-S4 nerve roots of the uninjured side were stimulated during operation. The motor innervation was determined by stimulating the spinal nerves with supramaximal intensity. We found that the gluteus medius and the gluteus maximus were mainly innervated by L5 and S1. Moreover, we found that the nerve fibers that innervated the extensor digitorum brevis, the abductor hallucis, and the flexor digitorum brevis were mainly from S2 and S3. Our findings have provided the electrophysiological mapping of the segmental anatomy of the muscles of the lower extremity, which is of meaningful clinical value in diagnosis and treatment of nerve injury and neurogenic diseases. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.