Anatomical Pattern of Dorsal Metatarsal Arteries in a Black Kenyan Population

Introduction Knowledge of anatomical variations in the origin and in the course of the dorsal metatarsal arteries (DMTAs) is valuable for many procedures, including reconstructive surgeries and flap selection. However, there is a paucity of data on these arteries among black Africans. Materials and Methods The present study studied the origin and the location of DMTAs in 30 formalin-fixed cadaveric feet of adult black Kenyans at the Department of Human Anatomy of the University of Nairobi, Nairobi, Kenya. Results Dorsal metatarsal arteries were present in all of the cases. Of the right dorsalis pedis artery (DPA), in the majority of the cases, the 1st DMTA arose as the continuation of the DPA, while the 2nd to 4th DMTAs were given off as branches from the arcuate artery (AA). On the left feet, in the majority of the cases, the 1st DMTA arose as the continuation of the DPA, while the rest were given off as branches from the AA. In relation to the dorsal interossei muscles, all of the the arteries were either within the muscle fibers (53%) or beneath them (47%), on the right side. On the left side, the 1st DMTA was above the muscles in 40% of the cases; within the muscles in 53%; and beneath the muscles in 7%. The 2nd and 3rd DMTAs were above the muscles in 57% and in 53% of the cases, respectively. Conclusion These results reveal that the DMTAs show variation in their origin and position relative to the dorsal interossei muscles. These variations display bilateral asymmetry.

Presentation of an intermetatarsal ganglion

Ganglia have occurred in almost all areas of the foot, but most often associated with capsular or tendinous structures. They are fluid-filled masses which often present themselves radiographically as increases in soft tissue density. Ganglia exhibit high intensity magnetic resonance imaging and must be clinically and pathologically differentiated from other masses, such as, but not limited to, neuromas, granulomas, and neurilemomas. The authors present a rare occurrence of an intermetatarsal ganglionic cyst associated with the third dorsal interossei muscle, which was large enough to cause bony deformation of the adjacent metatarsals. It is unusual for ganglia to cause alterations in bone unless they are intraosseus in nature. Bone deformation and invasion are usually associated with aggressive tumors.

Identification of a Frequency Response Model of Joint Rotation

A second order, linear oscillator transfer function model is fit to the measured transfer function relating the abduction-adduction rotation of the first finger to the applied moment. Nearly constant isometric contractions of the first palmar and dorsal interossei are maintained by the subjects during the measurements. The stiffness and damping components of the identified models increase significantly with increasing isometric contraction when compared to those recorded under relaxed contraction. Muscle fatigue causes the natural frequency, damping ratio and stiffness of the joint rotation to decrease under full isometric contraction, and it causes the natural frequency and stiffness to increase when the muscles are relaxed.