# Balance And Posture

> Cross-cutting rules that keep any generated pose physically plausible — feet grounded, a sensible center of mass, human joint limits, and symmetric defaults. Use this as a CHECK on every Action, especially for big motions like reaching, leaning, bending, lifting a leg, squatting, or standing on one leg.

- **Type:** Skill
- **Install:** `agentstack add skill-sumitaich1998-slavex-balance-and-posture`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [sumitaich1998](https://agentstack.voostack.com/s/sumitaich1998)
- **Installs:** 0
- **Category:** [AI & ML](https://agentstack.voostack.com/c/ai-and-ml)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [sumitaich1998](https://github.com/sumitaich1998)
- **Source:** https://github.com/sumitaich1998/slavex/tree/master/.cursor/skills/balance-and-posture

## Install

```sh
agentstack add skill-sumitaich1998-slavex-balance-and-posture
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# balance-and-posture

This is a **modifier / sanity skill**: apply it on top of the motion skills so the
result looks like a real body that won't tip over or snap a joint. It rarely emits
joints by itself; instead it constrains the numbers the other skills produce.

## Core rules
1. **Keep feet grounded.** Unless the command is explicitly a jump, at least one
   foot stays on the floor. When you lower the body (squat, crouch, sit, kneel),
   drop `root.y` so the feet stay near the floor instead of the legs clipping
   through it:
   - stand: `root.y = 0`
   - small dip / half-squat: `root.y ≈ -0.25 .. -0.30`
   - deep squat / sit: `root.y ≈ -0.45`
   - kneel / crouch low: `root.y ≈ -0.35`
2. **Center of mass over the base of support.** When one leg lifts (knee raise,
   kick, balance), shift weight over the planted foot: a small torso lean toward
   the support side (`Spine`/`Chest` Z ~ ±8–12) and keep that `*Foot` at rest
   `[90,0,0]`.
3. **Counterbalance big reaches/bends.** A deep forward bow (`move-torso` X large)
   or a long forward reach moves mass forward — add a slight hip/knee counter-flex
   (`UpLeg`/`Leg` a few degrees) and/or shift `root` slightly so it doesn't look
   like it's falling.
4. **Respect human joint limits** (angles are hard-clamped to [-180,180], but stay
   well inside realistic ranges):
   - Elbow / knee: flex one way only, `0..150`; never hyperextend (no negative).
   - Shoulder: ~`|180|`; hip flexion ~`-30..120`, abduction ~`45`.
   - Neck: yaw `|80|`, pitch `|55|`, tilt `|35|`. Spine: flex `|80|`, lean `|35|`,
     twist `|45|`. Fingers: each segment `0..90` (curl), no sideways/backward.
   - Ankle: ~`60..120` around the `[90,0,0]` rest.
5. **Symmetric defaults.** For "both"/whole-body commands, mirror left↔right using
   the sign rules (arms: LEFT raises with more-negative Z, RIGHT with more-positive
   Z; legs/abduction mirror on Z). Don't leave one side dangling unless asked.
6. **Return to rest cleanly.** "relax", "stand normally", "reset" → emit the rest
   pose (`*UpperArm` `[0,0,±90]`, `*UpLeg:[0,0,180]`, `*Foot:[90,0,0]`, torso/neck
   `[0,0,0]`) with `root.y:0`.

## Quick checklist before emitting an Action
- Is a foot on the ground (or is `root.y` dropped to match a lowered pose)?
- Are both sides handled for "both/whole-body" commands?
- Is every angle inside the human range above?
- Does the center of mass look supported (lean/counterflex for big moves)?
- Only the joints that should change are present (others omitted → stay as-is).

## Example: balanced one-leg knee raise
`{"durationMs":800,"pose":{"RightUpLeg":[90,0,0],"RightLeg":[90,0,0],"Spine":[0,0,-8],"Chest":[0,0,-6]},"say":"Balancing."}`
(right knee up; slight lean over the planted left foot to keep balance.)

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [sumitaich1998](https://github.com/sumitaich1998)
- **Source:** [sumitaich1998/slavex](https://github.com/sumitaich1998/slavex)
- **License:** MIT

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** yes
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-sumitaich1998-slavex-balance-and-posture
- Seller: https://agentstack.voostack.com/s/sumitaich1998
- Browse the marketplace: https://agentstack.voostack.com/browse

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