Guides to theImpairment Ratingof the Lumbar Spine5th EditionPaul Wakim, D.O., F.A.A.O.O.S. Orthopedic Surgeon, QME, IMEEmile P. Wakim, M.D.Orthopedic Surgeon, QME, IMERobert Ahearn, M.D. Orthopedic Surgery &Disorders of the Spine, QMEKelsey Peterson, M.D. Orthopedic Surgeon M.D.Nader Armanious, M.D. Neurologist, QME, IMEJeffrey Bone, Psy.D. Psychologist-EEG/HEG Neurofeedback, QMEKevyn Dean, M.S.P.T.O.C.S. Physical TherapistSuzanne Ackley, M.D. Orthopedic Surgeon, QME
Definition of Terms: Muscle Spasm/Muscle GuardingAsymmetric Range of MotionNonverifiable Radicular Root PainReflexes/Sensory Loss/AtrophyEMG/NCVAlteration of Motion Segment Integrity
Muscle Spasm/Muscle GuardingA. Muscle Spasm is a sudden involuntary contraction of a muscle ora group of muscles. To differentiate true muscle spasm fromvoluntary muscle contraction, the individual should not be ableto relax the contractions. The spasm should be present standingas well as in the supine position and frequently causes ascoliosis.B. Muscle Guarding is a contraction of a muscle to minimize motionor agitation of the injured or diseased tissue. It is not truemuscle spasm because the contraction can be relaxed. In thelumbar spine, the contraction frequently results in loss of thenormal lumbar lordosis, and it may be associated withreproducible loss of spinal motion.
Asymmetric Range of MotionAsymmetric motion of the spinein one of the three principalplanes is sometimes caused bymuscle spasm or guarding. If anindividual attempts to flex thespine, he or she is unable to doso moving symmetrically;rather, the head or trunk leansto one side To qualify as trueasymmetric motion, the findingmust be reproducible andconsistent and the examinermust be convinced that theindividual is cooperative andgiving full effort.
Nonverifiable Radicular Root PainNonverifiable pain is pain that is in thedistribution of a nerve root but has noidentifiable origin; ie, there are no objectivephysical, imaging, or electromyographicfindings.
Reflexes/Sensory Loss/AtrophyFor Reflex abnormalities to be considered valid, the involved and normallimb(s) should show marked asymmetry between arms or legs onrepeated testingSensory findings must be in a strict anatomic distribution. Motor findingshould be also consistent with the affected nerve structure(s).Atrophy is measuredwith a tape measure atidentical levels on bothlimbs. For reasons ofreproducibility, thedifference incircumference shouldbe 2 cm or greater inthe thigh and 1 cm orgreater in the arm,forearm, or leg.
EMG/NCVUnequivocal electrodiagnostic evidence of acutenerve root pathology includes the presence ofmultiple positive sharp waves or fibrillationpotentials in muscles innervated by one nerveroot.However, the quality of the person performing andinterpreting the study is critical.Electromyography should be performed only by alicensed physician qualified by reason ofeducation, training, and experience in theseprocedures. Electromyography does not detect allcompressive radiculopathies and cannotdetermine the cause of the nerve root pathology.On the other hand, electromyography can detectnoncompressive radiculopathies which are notidentified by imaging studies.
Alteration of Motion Segment IntegrityMotion segment alteration can be either loss ofmotion segment integrity (increased translationalor angular motion) or decreased motionsecondary to developmental fusion, fracturehealing, healed infection, or surgical arthrodesis.An attempt at arthrodesis may not necessarilyresult in a solid fusion but may significantly limitmotion at a motion segment.Motion of the individual spine segments cannot bedetermined by a physical examination but isevaluated with flexion and extensionroentgenograms.
Determining Appropriate Method ofAssessment of Impairment:DRE (diagnosis related estimates) is the principalmethodology used to evaluate an individual whohas had a distinct injury.
Range of MotionROM (range of motion) method is used inseveral situations:220.127.116.11.When an impairment is not caused by an injuryMulti-level involvement in the same spinal regionAlteration of motion segment integrity at multiplelevelsRecurrent radiculopathy caused by a new disk orrecurrent disk in the same spinal region
Diagnosis Related Estimates (DRE):Patient at MMI DRE Lumbar Category I (0% impairment):DRE Lumbar Category II (5-8% whole personimpairment): ADL/Pain above level of impairmentDRE Lumbar Category III (10-13% whole personimpairment):DRE Lumbar Category IV (20-23% whole personimpairment)
DRE Lumbar Category I(0% impairment):No significant clinical findings,no observed muscle guarding or spasm,no documentable neurologic impairment,no documented alteration in structural integrity,andno other indication of impairment related to injuryor illness;no fractures
DRE Lumbar Category II(5-8% impairment):Clinical history and examination findings arecompatible with a specific injury; findings mayinclude significant muscle guarding or spasmobserved at the time of the examination,asymmetric loss of range of motion, ornonverifiable radicular complaints, defined ascomplaints of radicular pain without objectivefindings; no alteration of the structural integrityand no significant radiculopathyRidiculopathy resolved by conservative treatmentCompression Fracture less than 25% of thevertebral body;
DRE Lumbar Category III(10-13% impairment):Significant signs of radiculopathy, such asdermatomal pain and/or in a dermatomaldistribution, sensory loss, loss of relevantreflex(es), loss of muscle strength or measuredunilateral atrophy above or below the kneecompared to measurements on the cotralateralside at the same location; impairment may beverified by electrodiagnostic findings.Radiculopathy resolved by surgery, patient isasymptomatic.Compression Fracture 25-50%
DRE Lumbar Category IV(20-23% impairment):Loss of motion segment integrity defined fromflexion and extension radiographs as at least 4.5mm of translation of one vertebra on another orangular motion greater than 15 degrees at L1-2,L2-3, and L3-4 greater than 20 degrees at L4-5,and greater than 25 degrees at L5-S1; may havecomplete or near complete loss of motion of amotion segment due to developmental fusion, orsuccessful or unsuccessful attempt at surgicalarthrodesisCompression Fractures greater than 50%
DRE Lumbar Category V(25-28% impairment):Meets the criteria of DRE lumbosacral categories IIIand IV; that is, both radiculopathy and alterationof motion segment integrity are present;significant lower extremity impairment is presentas indicated by artophy or loss of reflex(es), pain,and/or sensory changes within an anatomicdistribution (dermatomal), or electromyographicfindings as stated in lumbosacral category III andalteration of spine motion segment integrity asdefined in lumbosacral category IVCompression Fractures greater than 50%
ROM Method:Use of inclimoeters
Specific Spine Disorders
Specific spine disorders
ROM Method: Patient at MMI
ROM Method: Patient at MMICombine above whole personimpairments as per pg. 604, AMAGuides, 5th Edition.
Almaraz/GuzmanAlmaraz/Guzman I: An impairment rating strictlybased on AMA Guides is rebutted by showing thatsuch an impairment rating would result in apermanent disability reward that would beinequitable, disproportionate, and not a fair andaccurate measure of the employee’s permanentdisability. Repealed.Almaraz/Guzman II: Impairment rating may bearrived at by making comparisons and drawinganalogies to scheduled ratings within the fourcorners of the AMA Guides: Anthony Ferras vs.United Airlines.
impairments as per pg. 604, AMA Guides, 5th Edition. ROM Method: Patient at MMI. Almaraz/Guzman. Almaraz/Guzman I: An impairment rating strictly based on AMA Guides is rebutted by