The current research doesn't venture many details on the elbows/radius/ulna and locomotion biomechanics.
For the moment they just say the elbow was "slightly flexible" and that the bones were transitioning towards a round shape.
You can research deep into the resources and will perhaps find more.
Here are a resource which give context, found via &...
This article by Baier seem to support that the knee and elbow joint in sprawling locomotion supports movement perpendicular to the simple hinge joint in erect locomotion, which is exactly what question is asking. The joints in sprawlers also supports flexion/extension axis though, and the question could have been a bit clearer on that. If I misinterpret ...
This article shows a lefthanded bias for climbing and eating, with one bat species:
Paolo Zucca, Alessandra Palladini, Luigi Baciadonna, Dino Scaravelli.
"Handedness in the echolocating Schreiber's Long-Fingered Bat (Miniopterus schreibersii)"
Volume 84, Issue 3,
Four winged insect's ancestors were lucky because they had the sky all to themselves for perhaps 50 million years, giving them valuable time to develop more complex wings which can compete with simpler forms of flight. The first terrestrial insects came 380 million years ago, and the first dragonflies are from 300 million years ago. The high oxygen at the ...
The "bump" on an earthworm (i.e., a worm species of the order Opisthopora) is a clitellum. Clitella are only visible on earthworms when they're sexually mature [Sources: 1, 2, 3]. So the absence of a clitellum does not preclude your specimen from being a member of this order.
The species in your photo is almost undoubtedly some species of earthworm....