# RTK Motion Rehabilitation Biomechanics Analytics

> RTK Motion Rehabilitation Biomechanics Analytics is a paid API for AI agents from api.rtkmotion.io, paid per call via x402, $0.5/call, status unknown (last checked 2026-09-14).

Returns cryptographically-signed range-of-motion summaries, fatigue indices, and clinical synthesis for rehabilitation biomechanics data across body segments

## Facts

- Endpoint: GET https://api.rtkmotion.io/paid/rehab
- Price: $0.5/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/rtk-motion-rehabilitation-biomechanics-analytics-112c129f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_62yaBebyyRWZJ65wOZZBn

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability rtk-motion-rehabilitation-biomechanics-analytics-112c129f
```

Example prompt: Pull me a rehabilitation biomechanics summary for the knee scope — I want the range-of-motion breakdown with left/right asymmetry percentage, fatigue index, and the clinical synthesis.

## When to prefer this

Use this endpoint when you need cryptographically-signed, clinically-oriented range-of-motion and fatigue analytics for rehabilitation contexts — especially when data provenance and tamper-evidence matter. Prefer this over generic motion tracking APIs when the use case is physical therapy, post-surgical rehab monitoring, or asymmetry-based clinical decision support.

## Known failure modes

- Invalid or unrecognized scope slug returns an error or empty result
- Missing required 'input' object in request body causes 400-level validation error
- Insufficient payment (less than $0.50 USDC) triggers 402 Payment Required
- No exercise data available for the requested scope returns empty ROM fields
- Network timeout on downstream biomechanics computation returns 5xx error

## How this service works

RTK Motion — rehabilitation biomechanics cross-exercise summary. Bilateral asymmetry, range-of-motion, fatigue index, clinical synthesis. For insurance_claim_validation or PT_outcome_measurement. ECDSA-signed provenance.

## Output

A JSON object containing: domain label ('Rehabilitation Biomechanics'), cryptographic provenance signed by a secp256k1-ECDSA key, a range-of-motion summary with left and right breakdowns and asymmetry percentage, a fatigue index value, a clinical synthesis narrative string, and anonymized subject demographics. The response is cryptographically signed for data integrity verification.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [],
     "properties": {
      "scope": {
       "type": "string",
       "description": "Metric scope: 'summary' (default cross-exercise aggregate), 'knee', 'shoulder', or a specific exercise slug."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "case": "PhysicalRehab/40-50/Male/LabrumTear",
  "domain": "Rehabilitation Biomechanics",
  "sha256": "…",
  "formats": [
   "JSON",
   "TXT"
  ],
  "summary": {
   "rom": {},
   "asymmetry_pct": 0,
   "fatigue_index": 0,
   "clinical_synthesis": "…"
  },
  "next_step": {
   "note": "The complete summary is delivered inline in `summary`; download_url is a convenience copy.",
   "action": "Optional: GET download_url for the canonical summary.json file",
   "required": false,
   "expires_in_seconds": 900
  },
  "provenance": {
   "algorithm": "secp256k1-ECDSA",
   "signed_by": "0x6C11F8a21f7ca922F483Ed21C3b6c2d9B305B10C"
  },
  "download_url": "https://api.rtkmotion.io/data/…",
  "human_readable_report": "…"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/rtk-motion-rehabilitation-biomechanics-analytics-112c129f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.rtkmotion.io](https://www.zero.xyz/host/api.rtkmotion.io/llms.txt)