Chapter 1: Anatomy‑Aware Plates & Straps

Created by Sarah Choi (prompt writer using ChatGPT)

Anatomy‑Aware Plates & Straps

Armor looks believable when it cooperates with bones, muscles, and the way people actually move. Plates should protect without jamming joints; straps should transfer load to skeletal structures rather than throttling soft tissue. This article gives character concept artists a practical grammar for anatomy‑aware plate and strap design—from light to heavy kits, across fantasy and sci‑fi—plus the production details that help 3D, rigging, and tech art bring those designs to life.

Principles: Protect What Gets Hit; Free What Must Move

Start with threat/motion maps: blunt, cut, puncture, fall, crawl; sprint, climb, roll, kneel, mount. Coverage belongs on high‑risk bony regions and soft‑tissue bullseyes; clearance belongs over hinge lines and muscle bellies. Every plate should answer three questions: where does it stop, where does it slide, and where does it hand its load to the skeleton? Keep silhouettes clean and repeat a few consistent rules (edge chamfers, shingle direction, anchor spacing) so the language reads from camera distance.

Landmark Atlas: Strap & Plate Waypoints

Use palpable landmarks to anchor hardware and plate edges:

  • Clavicle & acromion (shoulder cap shelf): pauldron pivots, harness bridges.
  • Sternum & costal margin: breastplate edge and buckle avoidance zone (breathing).
  • Scapular spine & inferior angle: shoulder blade glide window—avoid pinning here.
  • Axilla (armpit) & lat seam: no hard edges; route straps behind the axillary line.
  • Iliac crest & ASIS (hip shelf): ideal belt/yoke load transfer to pelvis.
  • Greater trochanter (lateral hip bump): brace overlap and holster standoff.
  • Olecranon (elbow point) and patella (knee cap): cap centers with donut padding.
  • Pisiform & thenar web: gauntlet flare and palm freedom.
  • C7 & T7 (neck base and scapular plane): collar and cape attachment logic.

Joint Ranges & Hinge Corridors

Design plate gaps along real arcs:

  • Shoulder: ~0–180° abduction, ~0–160° flexion, axial rotation; maintain a floating pauldron on a yoke with rear elastic bridges. Leave a crescent clearance above the deltoid.
  • Elbow: ~0–145° flexion; three‑lame couter (elbow cap) that shingle toward the wrist with a keyhole slot accommodates forearm rotation.
  • Wrist: ~80° flex/70° extend; brace the dorsal side lightly, leave palm soft for grip. Flare gauntlet edges away from pisiform.
  • Hip: ~120° flex; leave inguinal crease clear. Float tassets on elastics so thighs lift without catching.
  • Knee: ~0–145° flex; tri‑segment poleyn (knee) with donut pad and side wings; shin clamshell opens opposite hinge side.
  • Ankle: dorsiflex for stairs; leave Achilles and malleoli clearance; greave flare at top and bottom prevents bite.

Plate Segmentation by Region

  • Torso: Breast/back with central spine channel; abdominal lames overlap downward for crunch. Side elastics under rib plates permit breathing.
  • Shoulder/Upper arm: Dome pauldron, secondary biceps cop that tucks under, with scapular cutout. Avoid pinning the scapula.
  • Forearm: Clamshell bracer on hinge webbing; closure opposite hinge. Keep wrist flex window.
  • Hip/Tassets: Independent panels hung from a pelvic yoke; slotted to clear thigh front during flexion.
  • Thigh/Shin: Thigh plates float from belt; greaves as two shells with hinge on medial or posterior line to avoid tibial crest.
  • Neck: Split collars with notch at trachea; rolling lames at the back for nodding.

Strap Systems: Routing, Tension, and Buckles

Goal: move mass to the pelvis and axial skeleton, avoid compressing vessels/nerves.

  • Shoulder harness: X‑or H‑yokes that terminate at hip belt. Route straps over clavicle, not against neck. Add sternum connector to prevent slip.
  • Hip belt: Sits on iliac crest; primary anchor for tassets, holsters, and thigh plates. Use dual‑pull buckles for symmetric cinch.
  • Thigh/arm straps: Place over tendinous zones (IT band, triceps long head) rather than muscle bellies. Angle to counter plate spin.
  • Buckles: Position off midlines (no sternum crunch, no spinal bumps); use quick‑releases where don/doff speed matters. For stealth, convert to covered cams or toggles.
  • Elastic bridges: Between plate and yoke to decouple breathing/stride from shell motion; document stretch length and travel in callouts.

Padding, Standoff, and Comfort

Energy management requires distance. Use foam donuts at patella/olecranon, spacer mesh under large plates for airflow, and leather facings at edges. Maintain standoff (10–25 mm) where impact is expected; too little standoff turns plates into blunt hazards. Mark padding thickness, density, and vent windows in your orthos.

Light / Medium / Heavy Kit Logic

  • Light: Emphasize mobility and stealth. Hard parts limited to caps (knees, elbows), slim bracers, and a small sternum/shoulder array. Soft armor (aramid textiles, padded gambesons) carries most protection. Straps are minimal and elastic‑biased. Read is close to garment with punctuated hard accents.
  • Medium: Add segmented torso plates, full greaves, and pauldron stacks. Load transfers to hip belts and yokes; overlaps become legible. Moderate noise from straps; balance coverage with articulation windows. Ideal for general infantry/adventurers.
  • Heavy: Max coverage and redundancy. Clamshell torsos, full limb shells with multi‑lame joints, gorgets, and expanded tassets. Weight management via suspenders to hips, multiple anchor clusters, and service seams for donning in parts. Motion sells through designed gaps and pronounced shingling.

Fantasy & Sci‑Fi Translations

  • Fantasy: Material reads (steel, bronze, boiled leather) stay honest. Use heraldic motifs as panel breaks or edge treatments, not overprint. Magic augmentation can justify slimmer plates but keep hinge/overlap logic intact. Cloaks and surcoats route around anchors; avoid trapping cape fabric under plate edges.
  • Sci‑Fi: Mix rigid composites and thermoplastics with soft goods. Exos or servo assists? Show torque arms that terminate at skeletal landmarks (pelvis, scapula plane), not floating in muscle. Insert pockets allow “soft armor” profiles under shells. Hide control cabling along strap channels and inside binding tapes.

Donning, Doffing, and Service Seams

Armor must be wearable. Provide a donning path: hinge sides, order of operations (belt → cuisses → greaves → breast). Add service seams for pad replacement and plate swaps. Put buckles where hands can reach; avoid back‑center closures unless a squire is canonical. Label access flaps in callouts.

Readability & Silhouette Discipline

At mid‑shot, viewers read edges, overlaps, and anchor density. Use larger, coherent plate shapes with consistent chamfer language. Keep strap count legible; terminate straps cleanly with keepers. Show witness tents—tiny cloth dimples between strap anchors—to sell load. Color‑code function sparingly (release pulls, med‑kit tabs) without breaking faction palette.

Failure Modes & Repair Language

Design how plates and straps fail. Metals dent and burr; leather stretches at slots and crazes at radii; composites chip and delaminate; thermoplastics crack at holes. Repairs: riveted doublers near anchor clusters, lace‑in leather scabs, scarfed composite patches, heat‑stapled plastic seams, bar‑tacked web reinforcements. Limit to one or two dominant modes per suit for clarity.

Rigging & Cloth‑Sim Notes

Treat plates as rigid bodies on constraints or bones with limited‑slide over soft yokes. Declare hinge axes and minimum overlaps in your callouts. Increase collision thickness at strap runs and plate edges. For cloth‑sim, mark no‑sim zones under plates and wind‑active gaps at lames and cape hems. Provide three states if relevant: cinched, neutral, and loosened, with strap slack and plate spacing updated.

Production Callouts & Packaging

In orthos: label plate segmentation, material per part, nominal thickness, edge treatment, anchor hardware (rivet diameters, buckle types), strap routing with arrows, padding thickness/density, and standoff distances. Include exploded views for shoulder stack, elbow/knee, hip/tasset yoke, and clamshell bracer. Deliver a threat/motion matrix, hinge/overlap maps, and a don/doff diagram. Add LOD seam maps so detail collapses cleanly while protection language remains.

Case Studies

Light Scout (Fantasy): Quilted gambeson with leather elbow/knee cops, slim bracers, and a split gorget. Hip belt takes quiver/knife; pauldron floats on leather yoke with rear elastic. Straps route away from axilla; cloak rides over a low‑profile collar. Line Soldier (Near‑Future Medium): Composite breast/back with abdominal lames, segmented pauldron, clamshell greaves. Hip‑anchored thigh plates; insert pockets for soft armor under shell. Sternum buckle offset; quick‑release cam buckles at hips. Spacer‑mesh padding vents heat. Siege Breaker (Heavy Fantasy‑Tech): Full clamshell torso with locking spine, multi‑lame elbows/knees, extended tassets on a pelvic yoke. Double anchor clusters triangulate loads to the hips; gorget protects throat without tracheal pressure. Don/doff in modules via service seams.

Workflow: From Brief to Package

  1. Map threats and moves; 2) Place plates by bone landmarks and motion arcs; 3) Route straps to the pelvis/axial skeleton; 4) Choose light/medium/heavy coverage and material set; 5) Lock hinge/overlap rules and donning path; 6) Paint wear/failure language; 7) Package orthos, exploded stacks, hinge/overlap maps, rig notes, and LOD seam plans.

Closing Thought

Armor that respects anatomy doesn’t just look right—it animates right. When edges clear joints, straps talk to bones, and overlaps follow motion, the suit sells protection without sacrificing performance, across fantasy plate and sci‑fi shells alike.