Applied anatomy of the first plantar lumbrical muscle / 中华显微外科杂志

ABSTRACT

Objective To investigate the anatomical structure of the first plantar lumbrical muscle in the foot and to measure the relevant data which could provide anatomical basis for repairing thumb and finger defects with the transplantation of toes accompanied with the first lumbrical muscle,and to explore the marphological function of the first lumbrical muscle of the foot.Methods From March,2016 to January,2018,a systematic and detailed dissection of the 50 formalin-fixed feet was performed to observe the exact position of the starting and ending points of the first lumbrical muscle,and a Vernier caloper was used to measure the relevant record data.Results The first lumbrical muscle originates from the medial portion of the flexor digitorum lungus tendon of the second toe,and the length of the ventral muscle was [55.87±8.67(79.30-41.16] mm.There were 2 endpoints in the tendon.The first one was in the medial tubercle of the proximal phalanges.The second one was aponeurosis of the dorsal toe and the tendon was divided into proximal and distal segments with the medial tubercle as the mark point.The length of the proximal segment was [15.34±4.81(5.52-25.18] mm,the width of the proximal segment was [2.31±1.12(3.28-1.21)] mm,the thickness was [0.44±0.14(0.28-0.68)] mm;the length of the distal segment was [11.51±4.06(3.46-14.90)] mm,the width was [6.10±1.44(9.36-3.70)] mm,and the thickness was [0.18±0.09(1.10-0.38)] mm.The length and thickness of the proximal segment was signifantly larger than those of the distal segment (P＜0.05).Conclusion The first lumbrical muscle has the function of maintaining the balance and stability of both the toe and the arch during movement,flexuring the metatarsophalangeal joint,extending the interosseous joint of the extensor phalangeal,adducting the second toe;also the function of preventing the second toe from pronation during foots' movement.