Kanta Matsuzawa1, Mutsuaki Edama2,3, Masahiro Ikezu2, Fumiya Kaneko2, Ryo Hirabayashi2, Ikuo Kageyama3. 1. Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata City, Niigata, 950-3198, Japan. hpm19009@nuhw.ac.jp. 2. Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata City, Niigata, 950-3198, Japan. 3. Department of Anatomy, School of Life Dentistry at Niigata, Nippon Dental University, Niigata, Japan.
Abstract
PURPOSE: The flexor digitorum superficialis muscle (FDS) is considered the most important of the forearm flexors for maintaining elbow valgus stability. However, the relationships between the origin structure of each finger of the FDS and the anterior oblique ligament (AOL) of the ulnar collateral ligament and the common tendon (CT) in the proximal part, and morphological features are unclear. The purpose of this study was to clarify the relationships between the origin structure of each finger of the FDS and the AOL and the CT, as well as to clarify the morphological features of the muscle belly of each finger of the FDS. METHODS: This study examined 20 elbows. The origin of each finger was examined. Muscle mass, muscle fiber bundle length, and the pennation angle of each finger were also measured. RESULTS: In all cases, the third and fourth digits originated from the radius, the anterior common tendon (ACT), and the posterior common tendon (PCT). The second and fifth digits (18 elbows) or an independent fifth digit (2 elbows) originated from the ACT, the PCT, the AOL, and other soft tissues of the elbow. Muscle mass and muscle fiber bundle length in the muscle belly of the third and fourth digits were significantly heavier and longer, respectively, than in the muscle belly of the second and fifth digits. CONCLUSION: Because the second and fifth digits or an independent fifth digit originated from the AOL, their contraction may cause tension in the AOL.
PURPOSE: The flexor digitorum superficialis muscle (FDS) is considered the most important of the forearm flexors for maintaining elbow valgus stability. However, the relationships between the origin structure of each finger of the FDS and the anterior oblique ligament (AOL) of the ulnar collateral ligament and the common tendon (CT) in the proximal part, and morphological features are unclear. The purpose of this study was to clarify the relationships between the origin structure of each finger of the FDS and the AOL and the CT, as well as to clarify the morphological features of the muscle belly of each finger of the FDS. METHODS: This study examined 20 elbows. The origin of each finger was examined. Muscle mass, muscle fiber bundle length, and the pennation angle of each finger were also measured. RESULTS: In all cases, the third and fourth digits originated from the radius, the anterior common tendon (ACT), and the posterior common tendon (PCT). The second and fifth digits (18 elbows) or an independent fifth digit (2 elbows) originated from the ACT, the PCT, the AOL, and other soft tissues of the elbow. Muscle mass and muscle fiber bundle length in the muscle belly of the third and fourth digits were significantly heavier and longer, respectively, than in the muscle belly of the second and fifth digits. CONCLUSION: Because the second and fifth digits or an independent fifth digit originated from the AOL, their contraction may cause tension in the AOL.
Keywords:
Anatomy; Baseball; Rehabilitation; Ulnar collateral ligament; Valgus
Authors: Salvatore J Frangiamore; Gilbert Moatshe; Bradley M Kruckeberg; David M Civitarese; Kyle J Muckenhirn; Jorge Chahla; Alex W Brady; Mark E Cinque; Morten Lykke Oleson; Matthew T Provencher; Thomas R Hackett; Robert F LaPrade Journal: Am J Sports Med Date: 2017-12-21 Impact factor: 6.202