Domain: Healthcare — Anthropotomy
Target concept: Composition and Arrangement of the Foot Bones

Video generation prompt: A set of foot bones is placed on the table for observation of the number, morphology, and arrangement pattern of the tarsal, metatarsal, and phalangeal bones.

Evaluation guide:
(i) Target concept: A static, macroscopic, anatomically accurate physical arrangement of the 26 human foot bones on a planar surface for structural observation.
Minimum mechanism: Dry, isolated, unpainted, unarticulated (non-ligamented) bony elements must retain species- and region-specific morphology and be positioned to reveal their natural spatial hierarchy without occlusion or distortion.
(ii)Storyline: Frame 1→10: Fixed overhead or oblique frontal view captures entire arrangement; tarsals enter field of view as a cohesive medial unit; metatarsals appear distal and parallel, directly abutting tarsal bases; phalanges extend distally from metatarsal heads in natural toe splay (hallux slightly medial, little toe lateral); no motion occurs, only sustained stillness; all bones remain fully visible with no occlusion; lighting is diffuse and shadow-consistent; viewpoint is locked with no parallax shift.

Manual:
Experimental Procedure
1. Place a complete set of dry, disarticulated (unarticulated) human foot bones on a neutral-colored table.
2. Arrange them anatomically: tarsals grouped medially/proximally, metatarsals aligned distally in parallel rows, phalanges attached distally to each metatarsal head.
Observation of Experimental Phenomena
- 7 tarsal bones visible as irregular short bones in compact cluster.
- 5 metatarsal bones visible as elongated shafts in distal parallel alignment.
- 14 phalanges visible as segmented cylinders: 2 for hallux, 3 each for digits 2–5.
Summary of Experimental Principles
The foot skeleton comprises tarsals (proximal short bones), metatarsals (intermediate long bones), and phalanges (distal segmented bones); their arrangement reflects weight-bearing architecture and joint mobility.

Prompt Grounding rubric:
level_1: No foot bones appear on the table; or only non-bone objects (shoes, feet, diagrams) are shown; or no table surface is visible; or there is no still arrangement of bone pieces at all.
level_2: At least one bone-shaped object appears, but it doesn't read as any recognizable tarsal, metatarsal, or phalanx (e.g., misshapen, fused into a single blob, cartoonish); or the bones are not resting on a table; or the layout is fully disordered: piled up, scattered off the table edge, or embedded in soft tissue.
level_3: A set of separate, whitish bone pieces rests on a flat table; at least three separate bone groupings are visible (a tarsal cluster, a metatarsal row, and a phalangeal chain), but one whole category is missing (no tarsals, or no phalanges shown at all), or the groups are placed in the wrong order (e.g., phalanges sit directly beside tarsals with no metatarsal row between them).
level_4: All three bone groups are present as separate, whitish pieces on the table (a cluster of seven tarsal bones, a row of five metatarsals, and a full set of phalanges across the five toes), with tarsals sitting closest to the ankle end, metatarsals extending from the tarsals, and phalanges extending from the metatarsal ends; one small flaw remains, such as a single phalanx tipped out of plane or two tarsals touching/overlapping without being fused together.
level_5: All 26 bones (the tarsal cluster, five metatarsals, and full phalangeal chains) are present as separate, whitish, recognizably bone-shaped objects laid out on a plain table in correct sequence: the tarsal cluster sits proximally/medially, the five metatarsals extend from it in parallel toward the toes, and each toe's phalangeal chain extends distally from its metatarsal head in a natural line matching the toe's spread (big toe closest to the midline); no bones overlap, none are fused together, no bone is rotated so it blocks another from view, and no shadows or extra objects hide any piece.

Scientific and Causal Correctness rubric:
level_1: The 'bones' look like soft tissue, cartilage, or fluid rather than bone; or they're colored (red, blue, translucent) instead of bone-white; or their shape doesn't read as bone at all (e.g., smooth spheres, branching or sponge-like porous structures); or the visible bone count clearly contradicts human anatomy (e.g., more than 7 tarsal-looking pieces, or fewer than 5 metatarsal-looking pieces).
level_2: The bone color is off-white in the wrong way (yellowed, gray, stained) rather than bone-white; or at least one bone type has the wrong basic shape (a metatarsal shown as a short cube, a phalanx shown as a smooth rod with no joint ends); or the total bone count is off by 5 or more from 26; or bones are arranged in a way that's anatomically impossible (phalanges sitting proximal to the tarsals).
level_3: All the pieces look bone-white and rigid; the total count is roughly right (26 ± 2); tarsals appear as a cluster of short bones, metatarsals as elongated shafts, and phalanges as segmented cylinders, but one category gets its joints wrong (phalanges shown fused into single solid rods with no segment breaks, or tarsals lined up in a straight row instead of an irregular cluster), or it's unclear which end of the layout is proximal versus distal.
level_4: All the pieces are bone-white, rigid, and shaped correctly: tarsals show irregular, blocky shapes bunched together medially; metatarsals show a consistent elongated shape with a wider base end and narrower head end; phalanges show clear segment divisions (three segments per toe, except the big toe's two); the tarsal-to-metatarsal and metatarsal-to-phalanx junctions look like they're touching in sequence, but one small anatomical detail is off, such as the big toe shown with three phalanges instead of two, or the navicular bone placed on the outer (lateral) side instead of the inner side.
level_5: All the pieces are bone-white, rigid, and anatomically precise: the tarsal cluster clearly shows seven distinguishable bones varying in size and contour (talus, calcaneus, navicular, cuboid, and three cuneiforms); the five metatarsals are elongated and roughly parallel, their bases touching the tarsals and their heads pointing toward the toes; each toe shows the correct phalanx count (two segments for the big toe, three each for the other four toes), with rounded joint ends; every joint contact point (tarsal-to-tarsal, tarsal-to-metatarsal, metatarsal-to-phalanx) looks like a close, precise touch with no visible gap or overlap.

Spatiotemporal Consistency rubric:
level_1: Bones jump to new positions between frames with no motion connecting them; a bone vanishes and reappears without being moved by anything visible; the tabletop cracks or splits apart; the lighting suddenly flips from deep shadow to full brightness between frames; a bone visibly snaps into a new rotation, melts, or stretches.
level_2: One or more bones flicker or visibly hop to a slightly different spot without any smooth path connecting the positions; the table edge bends or warps unnaturally; the shadow a bone casts doesn't line up with where the light is coming from, or points a different way than the other bones' shadows; the spacing between bone groups (e.g., the tarsal cluster) shrinks or grows for no reason.
level_3: Every bone stays in the same spot relative to the table for the whole clip, with no teleporting, deforming, or flickering; shadows stay put and point the same direction as each other; the tabletop stays flat and unbroken, but a small flaw remains, such as one bone casting no shadow at all while its neighbors do, or a slight lens-perspective warp making the metatarsal row look faintly non-parallel in a single frame (a camera artifact, not an anatomical error).
level_4: Every bone keeps a fixed position and orientation on the table for the whole clip with no drifting; shadows are present under every bone, point the same direction, and scale sensibly with each bone's height; the table stays rigid, flat, and unbroken; the lighting stays even and steady, but one small flaw remains, such as a brief overall brightness flicker between two frames, or a visible seam where two bone pieces meet without being fused.
level_5: No positional slips anywhere: every bone stays perfectly still with no visible drift, rotation, or resizing across the whole clip; every bone's shadow falls the same direction and softness as the others throughout; the tabletop looks uniformly flat with no warping, seams, or odd reflections; the lighting stays even everywhere with no hot spot or gradient; the camera viewpoint never pans, tilts, zooms, or refocuses for the entire clip.