Tendon architecture is an interesting study in and of itself.
For example, the flexor digitorum superficialis tendons run superficial to the flexor digitorum profundus tendons , but yet inserts on the middle phalanx while the profundus inserts on the distal phalanx. It turns out that the superficialis tendon splits at the level of the proximal phalanx and allows the deeper profundus to pass through on its course to the distal phalanx. Such complex architecture is not uncommon in the hand. On the dorsal side of the hand, the extensor tendons passing through to the fingers possess a complex network of inter-tendon connections that tend to make these tendons function as a single unit. For example, the tendon of the extensor digiti minimi blends with a tendon of the extensor digitorum at the level of the metacarpals.