ChatGPT o3 on Guides 5 Ex 17-7

As part of our AI and Impairment Rating report, this analysis reviews a two-prompt AI dialog using OpenAI's ChatGPT o3, on the Guides 5 Example 17-7, which concerns a tibia fracture. See the link for more analysis and more examples with other AI providers.

The model was low by -27% of the published WPI. It made a variety of errors. It uniquely made the error of omitting the toe ROM.

This dialog was created with the free plan on May 31, 2025. The text was unedited; the text was reformatted for clarity and consistency. The original source text is available here as a Word document.

How to read the report below

The right hand column is the dialog. It starts with the user's prompt followed by the AI response. The left hand column is our analysis of the response compared to the published Example's rating of 11% WPI. The errors in are highlighted in red. Where appropriate, a reference to the Gudies 5 with page numbers is available.

Best viewed on a Tablet or Desktop to see the dialog text and annotations side-by-side. On mobile the annotations will follow the dialog text in a separate block. In both layouts, an additional text block of annotation details follows at the bottom.

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Written by
Ben Wen
CMO
Category
AI
ChatGPT o3 - Medical Impairment Rating Analysis

LLM5 17-7 ChatGPT o3 - Impairment Rating Analysis

This is the initial request to the LLM. Note the specific reference to the AMA Guides 5th edition
Text from Example 17-7, page 538
LLM erroneously omitted toe ROM in analysis. Using Table 17-14, page 537, there is 3% Foot impairment for each lesser toe. CVC combining the lesser toes we get 12% Foot. However because of the footnote under the table, the lesser toes are capped at 7% Foot. The great toe is 7% Foot. CVC combining the great toe and lesser toes: 7% ⊕ 7% = 13.51% Foot.
Error 1
Incorrect Foot classification
See Error 2 footnote
Wrong combination method
See Error 3 footnote
Incorrect, ankle dorsiflexion Grade 4 function is 17% Foot. Table 17-8, page 532
Error 4
Muscle weakness, atrophy, and ROM cannot be combined per Table 17-2, page 526
Error 5
CVC combining the Foot impairments: 31% ⊕ 13.51% = 40% Foot. Converting that to LEI, by multiplying by 0.7 per Section 17.2a, 28% LEI. Which converts to 11% WPI
Error 6
The atrophy LEI is less than the ROM LEI, so the Final Result is 11%. Example 17-7, page 538
Error 7

User prompt:

I'm working with a friend on the Independent Medical Exam market. This is a sample patient narrative. Can you help me create an impairment rating according to the AMA Guides 5th edition?

Subject: 45-year-old woman.
History: Sustained a tibia fracture in a motor vehicle accident.
Current Symptoms: No pain; stiffness about the ankle and foot, with some swelling of the foot and ankle toward evening. Cannot stand for long periods and cannot use shoes with elevated heels.
Physical Exam: Ankle flexion is 6°; ankle extension is 5°. Toe extension is less than 10° for all toes. 1-cm atrophy of the left calf. It is difficult to determine the strength of the ankle and toe extensors, but a mild weakness is noted.
Clinical Studies: X-rays: healed tibia fracture with no malalignment.
Diagnosis: Healed tibia fracture.

ChatGPT said:

To calculate an impairment rating using the AMA Guides to the Evaluation of Permanent Impairment, 5th Edition, we need to follow the methodology described in Chapter 17: The Lower Extremities. Below is a structured approach based on the provided case:

Patient Summary

  • Age/Sex: 45-year-old woman
  • Injury: Healed tibia fracture from MVA
  • Symptoms: Ankle/foot stiffness, swelling, cannot stand long, no high heels
  • Exam:
    • Ankle flexion: 6° (normal is ~45°)
    • Ankle extension: 5° (normal is ~20°)
    • Toe extension <10° for all toes
    • 1-cm calf atrophy
    • Mild weakness of ankle/toe extensors
  • X-ray: Healed, no malalignment

Step-by-Step Impairment Rating (AMA Guides 5th Edition)

1. Ankle Range of Motion (ROM) Impairment

(Refer to AMA Guides, Table 17-11, page 537)

  • Dorsiflexion (Extension): 5° = 7% Lower Extremity (LE) Impairment
  • Plantarflexion (Flexion): 6° = 7% LE Impairment

✅Combine ROM using Combined Values Chart (CVC):

  • 7% + 7% = 13.51% LE Impairment (CVC result)

2. Muscle Strength Impairment

(Refer to Table 17-8, page 532, and Table 17-10, page 537)

  • Mild weakness in ankle and toe extensors, estimated as Grade 4 strength
  • Key muscles affected:
    • Ankle dorsiflexion = 3% LE
    • Toe extensors = 1% LE

✅ Combine:

  • 3% + 1% = 3.97% LE Impairment

3. Atrophy

(Refer to Table 17-6, page 530)

  • 1-cm calf atrophy = 3% LE Impairment

✅ Add to existing combined values:

  • Use CVC to combine 13.51% (ROM) + 3.97% (Strength) = 16.94% LE
  • Combine 16.94% + 3% (atrophy) = 19.43% LE

Final Impairment Rating

  • Total LE Impairment: ~19% Lower Extremity
  • Convert to Whole Person Impairment (WPI) using Table 17-3 (p. 527):
    • 19% LE × 0.4 = 7.6% WPI

✅ Final Result:

Whole Person Impairment (WPI): ~8%
(Rounded from 7.6%)

Error Footnotes

Further Details

Error 2: Two errors. First plantar flexion should be first accounted for with Foot impairment. Section 17.2a instructs to combine impairments of the foot regionally. Second, 6° Plantarflexion is 21% Foot (which is 15% LEI).

Error 3: Incorrect use of CVC. Here, use addition because both affect the same joint. Separately CVC notation should not be '+'. Using Foot impairments instead of LEI: 10% (Dorsiflexion) + 21% (Plantarflexion) = 31% Foot.