Permanent impairment ratings
that hold up under scrutiny
Dr. Lloyd performs AMA impairment ratings as a QME-certified chiropractor, translating injury severity into defensible whole-person impairment percentages that strengthen demand packages and withstand cross-examination.
Understanding Impairment
What is an impairment rating?
After a patient reaches maximum medical improvement -- the point at which further treatment is not expected to produce significant functional gains -- a permanent impairment rating quantifies the lasting loss of function caused by the injury. It is not a measure of pain or disability. It is an objective, standardized assessment of how much normal function has been permanently lost.
In California, permanent impairment ratings are performed using the AMA Guides to the Evaluation of Permanent Impairment, 5th Edition. The resulting whole-person impairment (WPI) percentage becomes a critical factor in determining both settlement value in personal injury cases and benefit levels in workers' compensation claims.
An accurate, defensible impairment rating can be the single most influential piece of evidence in a demand package. Insurance adjusters assign dollar value based on the WPI percentage. Defense attorneys build their strategy around challenging it. Mediators use it as a reference point for settlement negotiations. When the rating is performed correctly and documented thoroughly, it becomes very difficult to attack.
Dr. Lloyd is one of the few chiropractors in Petaluma and Sonoma County who serves as both a treating provider and a Qualified Medical Evaluator authorized to perform these ratings. This dual role means the provider who knows your client's injury history best is the same provider performing the final impairment evaluation -- creating a seamless clinical narrative from initial injury through permanent rating.
Methodology
DRE vs. ROM: Two approaches
The AMA Guides 5th Edition defines two distinct methodologies for rating spinal impairment. The selection of the appropriate method depends on the specific clinical findings and the nature of the injury.
Diagnosis-Related Estimates (DRE)
The DRE method is the primary method used for rating spinal impairment under the AMA Guides 5th Edition. It assigns impairment categories based on specific, verifiable clinical findings rather than subjective measurements.
- Assigns categories based on radiculopathy, loss of motion segment integrity, and alteration of motion segment integrity
- Requires objective findings such as electrodiagnostic abnormalities, documented muscle atrophy, and imaging evidence of structural damage
- Categories range from DRE Category I (no significant clinical findings) to DRE Category V (severe impairment)
- Most appropriate when there are objective, verifiable clinical findings directly tied to the injury
- Preferred by the AMA Guides as the default approach for spinal ratings
Range of Motion (ROM)
The ROM method may be used when the DRE method is not applicable or when the condition is not specifically addressed by the DRE categories. It captures functional limitations through measured motion loss.
- Based on measured loss of range of motion compared to published norms for each spinal region
- Requires standardized measurement using inclinometry (dual inclinometer technique) per AMA protocol
- Each spinal region has specific impairment values corresponding to degrees of motion loss
- Can capture functional limitations that DRE categories may not fully reflect
- Combined with neurological impairment and other factors for final WPI calculation
Why It Matters
How ratings translate to settlement value
The whole-person impairment percentage functions as a multiplier in case valuation. Even small differences in the final WPI number -- a percentage point or two -- can significantly affect the total demand value. This is why the accuracy and defensibility of the rating matters more than almost any other element in the clinical record.
Insurance adjusters and defense attorneys will scrutinize the rating methodology, the clinical findings supporting it, and whether the evaluation was performed by a qualified provider. An impairment rating from a QME-certified provider carries substantially more weight than one from a provider without that credential. Ratings performed using incorrect methodology or without thorough documentation will be challenged -- and potentially dismissed entirely -- through peer review or at deposition.
- ✓ A well-documented rating with supporting clinical findings, measurements, and imaging correlation is far harder to attack on cross-examination or through independent medical examination
- ✓ Complete methodology chain in every report Dr. Lloyd's reports include initial clinical findings, treatment records documenting the trajectory of recovery, MMI determination, and the final rating calculation
- ✓ This creates a defensible narrative from the moment of injury through permanent impairment -- not an isolated rating disconnected from the clinical history
- ✓ Cases originating from accidents on Highway 101, Lakeville Highway, and throughout the Petaluma area benefit from having a local provider who can correlate treatment records with the final rating, rather than an outside evaluator reviewing records cold
- ✓ Attorneys Who work with a treating provider and QME at the same practice eliminate the gap between treatment documentation and final impairment evaluation
The Process
Our impairment rating process
A structured, five-step process that produces defensible impairment ratings backed by the complete clinical record.
Maximum Medical Improvement
The patient must first reach MMI, meaning further treatment is not expected to significantly improve their condition. Dr. Lloyd determines MMI based on objective clinical criteria -- plateaued range of motion measurements, stable neurological findings, and consistent functional capacity -- not arbitrary timelines or insurance-driven endpoints. The MMI determination is itself documented and defensible.
Comprehensive Examination
A dedicated rating examination separate from routine treatment visits. This includes detailed range of motion measurements using the dual inclinometer technique required by the AMA Guides, neurological testing including dermatomal sensory mapping and deep tendon reflex grading, orthopedic assessment of each affected spinal region, and review of all diagnostic imaging including MRI, CT, and plain film radiographs.
Records Analysis
Complete review of the entire treatment record to establish the trajectory from initial injury through recovery to MMI. This includes the initial examination findings, progress notes documenting objective changes at each visit, imaging reports, referral correspondence, and any outside treatment records. This creates the clinical narrative that supports and contextualizes the final rating.
Rating Calculation
Application of either DRE or ROM methodology -- or both when clinically appropriate -- per the AMA Guides 5th Edition. When multiple spinal regions or body parts are involved, individual impairment values are combined using the Combined Values Chart rather than simple addition, as required by the Guides. Each step of the calculation is shown and explained in the final report so that the methodology can be verified and reproduced.
Written Report
A detailed report documenting the entire rating process: the clinical findings supporting each determination, the methodology selection rationale, the specific AMA Guides sections and tables applied, and the resulting whole-person impairment percentage. Reports are delivered within 48 hours and are formatted for direct inclusion in demand packages. See our personal injury reports page for more on documentation standards.
Conditions
Common conditions we rate
Impairment ratings for musculoskeletal and neurological injuries resulting from motor vehicle collisions, workplace injuries, and other trauma.
Cervical Spine Injuries
Whiplash, disc herniation, disc bulge, cervical spondylosis with traumatic aggravation
Lumbar Spine Injuries
Disc bulge, disc herniation, compression fracture, lumbar strain/sprain
Thoracic Spine Injuries
Thoracic disc injury, costovertebral dysfunction, compression fracture
Radiculopathy
Cervical and lumbar nerve root compression with dermatomal deficits
Shoulder Injuries
Rotator cuff tears, labral injuries, restricted range of motion post-trauma
Post-Concussion Syndrome
Persistent cognitive, neurological, and vestibular symptoms following head injury
Request an impairment rating
QME-certified evaluations using AMA Guides 5th Edition. 48-hour report turnaround. Serving Petaluma, Rohnert Park, Novato, and Sonoma County.
3100 Lakeville Hwy, Ste D, Petaluma, CA 94954