Motor Accident Injuries: Does a Low-Speed Collision Materially Aggravate Pre-existing Spinal Conditions to Constitute a Non-Threshold Injury Exceeding 10% Whole Person Impairment?
Introduction
Based on the authentic Australian judicial case Shiba v Allianz Australia Insurance Limited [2025] NSWPICMP 42, this article disassembles the Court’s judgment process regarding evidence and law. It transforms complex judicial reasoning into clear, understandable key point analyses, helping readers identify the core of the dispute, understand the judgment logic, make more rational litigation choices, and providing case resources for practical research to readers of all backgrounds.
Chapter 1: Case Overview and Core Disputes
Basic Information:
* Court of Hearing: Personal Injury Commission (Review Panel)
* Presiding Member: Member Nolan (Chair), Medical Assessor Couch, Medical Assessor Assem
* Cause of Action: Review of a Medical Assessor’s Certificate regarding “threshold injury” and “degree of permanent impairment” under the Motor Accident Injuries Act 2017 (NSW).
* Judgment Date: 21 January 2025
* Core Keywords:
* Keyword 1: Authentic Judgment Case
* Keyword 2: Motor Accident Injuries Act 2017 (NSW)
* Keyword 3: Threshold Injury
* Keyword 4: Radiculopathy
* Keyword 5: Permanent Impairment
* Keyword 6: Material Aggravation
Background:
The Claimant was involved in a low-speed rear-end motor vehicle collision while stationary at traffic lights. Following the accident, the Claimant reported significant neck pain radiating to the right arm with symptoms of radiculopathy, lumbar spine pain radiating to the left leg with radiculopathy, and right shoulder pain. Radiological investigations revealed pre-existing degenerative changes in the cervical and lumbar spine, which the Claimant asserted became symptomatic and severely aggravated by the motor accident. The Insurer contended that the injuries were “threshold injuries” and did not cause permanent impairment exceeding the statutory threshold, arguing that the symptoms were primarily due to pre-existing conditions and the low-impact nature of the collision.
Core Disputes and Claims:
The central legal focus of the dispute was:
1. Whether the cervical spine injury (right C6 radiculopathy) and lumbar spine injury (left L5 radiculopathy) sustained by the Claimant were “threshold injuries” for the purposes of the Motor Accident Injuries Act 2017 (NSW).
2. Whether the right shoulder injury constituted a “threshold injury.”
3. Whether the degree of permanent impairment of the injured person as a result of the injuries caused by the motor accident was greater than 10% Whole Person Impairment (WPI).
The Claimant sought a determination that his cervical and lumbar spine injuries were non-threshold due to radiculopathy and that his overall permanent impairment exceeded 10% WPI. The Insurer sought to uphold the original Medical Assessor’s finding that all injuries were threshold and resulted in 0% WPI.
Chapter 2: Origin of the Case
The Claimant, Alan Shiba, a large-framed man employed full-time as an Employer Liaison Consultant since 2007, was known for his fitness and even held a second casual job as a VIP Host/Customer Liaison Officer prior to the motor accident. This history underscored his active lifestyle and lack of significant functional limitations before the incident.
On 18 February 2020, at approximately 3:00 pm, the Claimant was driving his silver 2011 Toyota Corolla towards his office in Merrylands. He was stationary at a red traffic light on Polding Street, Fairfield Heights, positioned behind several other vehicles. Crucially, the Claimant observed no vehicles behind him in his rear-view mirror. As the lights turned green, the vehicle directly ahead did not immediately move. The Claimant momentarily released his foot from the brake before reapplying it. In that decisive moment, his vehicle was struck from the rear with a “significant force,” accompanied by a loud bang. He experienced an immediate sensation as if his “head had exploded,” suffering severe pain in the back of his head, neck, and left leg. He did not recall hearing any warning sounds prior to the impact.
The other driver, operating a grey 2018 Toyota Prado, stated that they had accelerated from a stationary position as the lights turned green, but the Claimant’s vehicle braked unexpectedly, leading to the collision. The Insured driver estimated their impact speed to be less than 20 km/h, describing the collision as “not severe” and resulting in only minor damage to their vehicle.
Following the impact, the Claimant was able to exit his car unassisted, initially believing he was “alright.” However, after moving his car to a side street and buying some water, he was overwhelmed by severe neck and lower back pain, feeling his head “was going to explode.” This rapid deterioration in his condition prevented him from driving further, highlighting the immediate and dramatic impact of the collision. This abrupt shift from a state of shock to debilitating pain marked the genesis of his legal claim.
Chapter 3: Key Evidence and Core Disputes
Applicant’s Main Evidence and Arguments:
* Claimant’s Account: Consistent reports of immediate neck pain radiating to the occipital region, progressing to right shoulder and arm pain with numbness/tingling in the thumb, index, and middle fingers (C6 dermatome consistent), indicating cervical radiculopathy. Persistent lower back pain radiating to the left leg and foot with numbness (L5 distribution), indicating lumbar radiculopathy. Right shoulder pain with restricted movement.
* Medical Reports:
* Dr Ian Farey (Spinal Surgeon): Multiple reports (April 2020 – October 2021) consistently diagnosing cervical and lumbar radiculopathy, attributing symptoms to the motor accident, and recommending conservative management initially, progressing to recommending C5/6 ACDF surgery for cervical symptoms and noting lumbar microdiscectomy was performed.
* Associate Professor Peter Papantoniou (Orthopaedic Surgeon): Multiple reports (May 2020 – November 2021) diagnosing L5 radiculopathy due to disc bulges and an annular tear at L4/5, directly linking these to the accident. Performed L5/S1 microdiscectomy in February 2021.
* Dr James Bodel: Report (November 2022) diagnosing persisting cervical and lumbar radiculopathy, attributing 35% WPI to the injuries, criticising reliance on low-impact biomechanics, and asserting significant neurological involvement. Supplementary report (March 2023) defending causation and necessity of surgery, rebutting biomechanical opinions.
* Associate Professor Mark Sheridan: Report (June 2022) documenting persistent C6 cervical radiculopathy and L5 lumbar radiculopathy, recommending ACDF, and attributing symptoms to accident-related aggravation of pre-existing conditions.
* Radiological Evidence (Post-accident):
* CT Cervical Spine (February 2020): Right paracentral disc protrusion at C5/6 with uncovertebral joint changes, possible encroachment on right C6 nerve root.
* MRI Cervical Spine (February & October 2020, June 2022): Moderate disc protrusion/extrusion at C5/6, affecting spinal cord/nerve root, straightening of cervical lordosis.
* MRI Lumbar Spine (April & June 2020, June 2022): Broad-based disc extrusion at L4/5, annular tear at L4/5, disc bulges at L4/5 and L5/S1, left foraminal protrusion at L4/5 contacting exiting left L4 nerve root, post-surgical scarring at L5/S1.
* Ultrasound Right Shoulder (March 2020): Supraspinatus tendinosis and subacromial bursitis (no tears).
* CT-guided Epidural/Foraminal Blocks (September 2020, March 2021): Therapeutic and diagnostic efficacy, confirming nerve root irritation.
* Argument: The injuries, particularly radiculopathy, are neurological/structural, making them non-threshold. The motor accident materially aggravated pre-existing asymptomatic degenerative conditions, leading to severe and persistent symptoms, functional limitations, and requiring surgical interventions.
Respondent’s Main Evidence and Arguments:
* Insured Driver’s Account: Low-speed rear-end impact (estimated <20km/h), claimant braked unexpectedly, minimal vehicle damage.
* Medical Reports:
* Dr Gregor Bruce: Reports (November 2020, March 2023) noting degenerative changes, but concluding no new acute traumatic injury. Symptoms attributed to aggravation of pre-existing asymptomatic spondylosis. No substantial neurological impairment found in 2020.
* Associate Professor Michael Shatwell: Multiple reports (February 2023 – November 2023) concluding cervical spine injury was minor soft tissue strain/sprain, C5/6 disc extrusion was degenerative and pre-existing, lumbar findings (disc bulges, annular tears) were age-related and unrelated to the accident. No evidence of radiculopathy attributable to the accident. Right shoulder injury due to degenerative changes/illness behaviour. Critiqued other experts.
* Radiological Evidence (Pre-accident):
* X-rays Lumbar Spine, Right Hip, Right Lower Limb (December 2017): Lumbar spine normal, right hip moderate degenerative changes, right lower limb no bony abnormalities. This establishes pre-existing degeneration without acute symptoms.
* Biomechanical Analysis Reports:
* Patrick McDonald (Forensic Accident Investigator): Report (February 2023) confirming low-speed impact (Delta-V: Prado 4.4km/h, Corolla 7.9-14km/h), consistent with minor rear-end accident. Insufficient force for significant injury. Seatbelts/headrests mitigated impact.
* Professor Robert Anderson: Biomechanical analysis (June 2022) concluding low-speed impact with insufficient force for significant spinal injuries. Degenerative changes pre-existed and were not causally related to the collision.
* Grant Johnston (Engineering Analysis): Report (March 2023) confirming low-speed rear-end impact (9-20km/h), minimal property damage. Forces compared to daily activities. Spinal restraint systems effective. Degenerative findings pre-existed and were unrelated to trauma.
* Argument: All injuries are threshold injuries, primarily caused by pre-existing degenerative conditions, not the low-speed motor accident. Biomechanical evidence shows insufficient force for significant trauma or aggravation. No objective signs of radiculopathy attributable to the accident. Permanent impairment does not exceed 10% WPI.
Core Dispute Points:
1. Causation: Did the low-speed motor accident cause the Claimant’s cervical, lumbar, and right shoulder injuries, or merely render symptomatic pre-existing asymptomatic degenerative conditions, and if so, was that a “material aggravation”?
2. Threshold Injury Classification: Do the Claimant’s symptoms, particularly the reported radiculopathy in the cervical and lumbar spine, meet the statutory criteria to be classified as “non-threshold injuries” under the Motor Accident Injuries Act 2017 (NSW)?
3. Permanent Impairment: Does the combination of injuries (assuming some are non-threshold) result in a Whole Person Impairment (WPI) greater than 10%?
Chapter 4: Statements in Affidavits
The specific content of affidavits is not detailed in the provided RTF, but the general context highlights their role in presenting the parties’ factual narratives and supporting evidence. The Claimant’s affidavit would have meticulously detailed his immediate and progressive symptoms post-accident, emphasising the contrast with his pre-accident active and asymptomatic state, and incorporating his treating doctors’ opinions. He would likely have described the “blacking out” and the “head exploding” sensation to underscore the severity of the impact. The Insurer’s affidavit would likely have focused on the low-speed nature of the collision, the minimal damage to vehicles, and the Claimant’s pre-existing degenerative conditions as identified in the 2017 imaging, arguing that these were the primary cause of his symptoms, with the accident playing a negligible role. The strategic intent behind the Judge’s procedural directions regarding the affidavits would typically be to identify precise factual disputes, streamline the evidence presentation, and narrow the issues for determination, particularly concerning the onset and causation of symptoms versus pre-existing conditions.
Chapter 5: Court Orders
The RTF does not detail specific interim procedural orders beyond the referral of the Medical Assessor’s Certificate (MAC) to a Review Panel. The President’s Delegate ordered the referral to the Review Panel upon finding “reasonable cause to suspect that the original medical assessment was materially incorrect,” particularly due to the Medical Assessor’s failure to engage adequately with expert medical opinions indicating persistent radiculopathy. This indicates an initial procedural order for a fresh assessment of the medical dispute.
Chapter 6: Hearing Scene: Ultimate Showdown of Evidence and Logic
The ultimate showdown of evidence and logic occurred during the re-examination conducted by Medical Assessor Couch, with Member Nolan present for the history taking. This re-examination served as a critical opportunity to re-evaluate the Claimant’s subjective complaints against objective clinical signs, contrasting the conflicting medical and biomechanical narratives presented by both parties.
Process Reconstruction: Live Restoration:
The Claimant presented as a man visibly affected by pain, walking with a slow and symmetrical gait, yet showing good effort and cooperation during the physical examination. His distress when recalling the immediate post-accident pain, particularly the sensation of his head “exploding,” underscored the subjective severity of his experience. His denial of any prior significant musculoskeletal issues despite documented degenerative changes in 2017 was a point of tension, as was his obtaining Endone from his brother. The examination itself was meticulous, with repeated measurements and tests to verify objective signs. During the interview, the Claimant displayed marked sleep disturbance and low mood, stating his life “has been turned upside down.” He was able to sit for 45 minutes but was seen walking stiffly afterwards, demonstrating the ongoing impact of his condition.
Core Evidence Confrontation:
The confrontation hinged on several key areas:
1. Cervical Spine Radiculopathy: The Claimant’s persistent neck pain radiating to the right arm, coupled with numbness and tingling in the right index and middle fingers, was a central claim. Objectively, the Panel found muscle wasting in the right upper arm (40.5cm vs 42cm left), a depressed right biceps jerk, slight weakness in right elbow flexion and wrist extension, and diminished light touch/blunt pinprick sensation in the right C6 dermatome. These findings directly challenged the original Medical Assessor’s conclusion of no radiculopathy.
2. Lumbar Spine Radiculopathy: The Claimant’s reports of low back pain radiating to the posterolateral left thigh and front of the shin were crucial. The Panel found dysmetria (reduced lateral flexion to the left), a depressed left ankle jerk, moderately reduced power of left extensor hallucis longus (Grade 4/5), and diminished light touch/pinprick sensation over the dorsum of the left foot (L5 distribution). Straight-leg-raising was reduced to 20 degrees on the left with reproduction of radicular pain, indicating neural tension. These objective signs of left L5 radiculopathy directly contradicted the initial assessment.
3. Right Shoulder Pathology: The Claimant described severe pain on elevating the right arm and difficulty sleeping. While imaging showed tendinosis and bursitis (soft tissue), the Panel noted restricted active range of motion (AROM) in the right shoulder, which was more marked than the left.
4. Causation vs. Pre-existing Degeneration/Biomechanics: The medical experts (Dr Farey, Prof Papantoniou, Dr Bodel, Assoc Prof Sheridan) largely argued for causation or material aggravation by the motor accident, citing the temporal onset of symptoms and the necessity of surgical interventions. Conversely, Assoc Prof Shatwell and the biomechanical engineers (McDonald, Anderson, Johnston) maintained that the low-speed impact was insufficient to cause significant injury, attributing symptoms to pre-existing degeneration. The Panel was tasked with reconciling these diametrically opposed views.
Judicial Reasoning:
The Panel ultimately sided with the Claimant’s expert medical opinions, finding objective clinical signs consistent with radiculopathy in both the cervical and lumbar spine. The Panel highlighted the critical importance of these objective findings, particularly the presence of nerve root dysfunction, in overriding the initial Medical Assessor’s determination.
The Court held:
“Upon examination by the Panel, there were definite signs of Whiplash Associated Disorder Grade 3 of the cervical spine, with muscle guarding, dysmetria, and objective signs of right C6 radiculopathy. This condition involves nerve root dysfunction and exceeds the definition of a threshold injury.”
“The Panel’s examination revealed definite abnormalities in the lumbar spine, including dysmetria, positive neural tension in the left lower limb, weakness, and sensory impairment in the left L5 distribution. These findings conform to a diagnosis of left L5 radiculopathy. Such radiculopathy involves nerve dysfunction and is excluded from the definition of a threshold injury.”
These statements were determinative because they directly established the presence of radiculopathy in both spinal regions. According to the Motor Accident Injuries Act 2017 (NSW) and the Motor Accident Injuries Regulation 2017, an injury to the spinal nerve root manifesting in neurological signs (other than radiculopathy) is a threshold injury, but if radiculopathy is present, it is explicitly excluded from the definition of a threshold injury. The Panel’s objective clinical findings directly met the criteria for radiculopathy, fundamentally altering the injury classification. The evidence of muscle wasting, depressed reflexes, and sensory/motor deficits provided the necessary objective basis for this conclusion, overcoming the arguments based on low-impact biomechanics and pre-existing degeneration alone.
Chapter 7: Final Judgment of the Court
The Review Panel revoked the Certificate of Medical Assessor Adam Rapaport dated 23 May 2023.
The Review Panel issued a new certificate determining that:
* The following injuries caused by the motor accident are not threshold injuries:
* cervical spine injury (right C6 radiculopathy); and
* lumbar spine injury (left L5 radiculopathy).
* The following injury caused by the motor accident is a threshold injury:
* right shoulder injury (soft tissue injury).
* The degree of permanent impairment of the injured person as a result of the injuries caused by the motor accident is greater than 10% (30% WPI).
Chapter 8: In-depth Analysis of the Judgment: How Law and Evidence Lay the Foundation for Victory
Special Analysis:
This case holds significant jurisprudential value, particularly in the context of personal injury claims involving pre-existing degenerative conditions and low-speed impacts under the Motor Accident Injuries Act 2017 (NSW). The Panel’s finding that the motor accident materially aggravated the Claimant’s pre-existing asymptomatic conditions, rendering them symptomatic with objective signs of radiculopathy, is a crucial aspect. This outcome provides a pathway for claimants with underlying degeneration to establish non-threshold injuries, even when biomechanical analyses suggest minimal forces. It reinforces that the clinical manifestation of nerve root dysfunction, objectively verified, can supersede arguments centered solely on impact speed or pre-existing radiological findings. The determination also highlights that the definition of “threshold injury” is precisely applied, with specific exclusions like radiculopathy being determinative. The Panel’s detailed re-examination, focusing on subtle yet objective neurological signs, offers a robust framework for overturning previous medical assessments that may have undervalued such clinical evidence.
Judgment Points:
1. Objective Radiculopathy Findings: The Panel’s re-examination definitively identified objective signs of right C6 radiculopathy (muscle wasting, depressed right biceps jerk, sensory loss, motor weakness) and left L5 radiculopathy (dysmetria, positive neural tension, weakness, sensory impairment). These objective clinical signs were critical in establishing nerve root dysfunction.
2. Material Aggravation of Asymptomatic Conditions: The Panel concluded that while pre-existing degenerative changes were present, the motor accident materially aggravated these asymptomatic conditions, transforming them into symptomatic and debilitating injuries.
3. Causation of Surgical Necessity: The Panel found that both the performed L5/S1 microdiscectomy and the proposed C5/6 discectomy and fusion were medically necessary interventions directly linked to the trauma sustained in the motor accident, despite the underlying degenerative pathology.
4. Threshold vs. Non-Threshold Injuries: The cervical and lumbar spine injuries were classified as non-threshold due to the confirmed radiculopathy, while the right shoulder injury remained a threshold injury, consistent with soft tissue abnormalities without nerve involvement.
5. Permanent Impairment Exceeding Threshold: The combined WPI of 30% significantly exceeded the 10% statutory threshold, opening the door for the Claimant’s entitlement to common law damages.
Legal Basis:
* Section 1.6(2) of the Motor Accident Injuries Act 2017 (NSW): Defines a “soft tissue injury” as one to connective, supportive, or surrounding tissues, but “not an injury to nerves or a complete or partial rupture of tendons, ligaments, menisci or cartilage.”
* Clause 4 of Part 1 of the Motor Accident Injuries Regulation 2017 (MAI Regulation): Explicitly includes within the definition of threshold injury “an injury to the spinal nerve root that manifests in neurological signs (other than radiculopathy).” This implies that if radiculopathy is present, it is not a threshold injury.
* Motor Accidents Guidelines (Version 9.1), Clauses 5.7-5.9: Prescribe the criteria for assessing radiculopathy, requiring two or more objective clinical signs (e.g., loss/asymmetry of reflexes, positive nerve root tension signs, muscle atrophy/weakness, reproducible sensory loss).
* Briggs v IAG Limited Trading as NRMA Insurance [2022] NSWSC 372: Affirmed that causation principles applicable to permanent impairment (Part 6 of the Guidelines) also apply to threshold injury determinations, requiring the accident to be a material contributing cause that is more than negligible.
Evidence Chain:
The Panel’s conclusion was built upon a robust chain of evidence:
1. Pre-accident Medical History: Limited prior complaints despite documented degenerative changes in 2017, indicating asymptomatic status.
2. Temporal Onset of Symptoms: Immediate onset of severe neck pain, followed by progressive development of radicular symptoms in the cervical and lumbar spine, establishing a strong causal link to the accident.
3. Post-accident Imaging: CT/MRI scans showing disc protrusions, extrusions, and annular tears in the context of nerve root encroachment/compression, which became symptomatic post-accident.
4. Expert Medical Opinions: Consistent opinions from treating specialists (Dr Farey, Prof Papantoniou) and medico-legal assessors (Dr Bodel, Assoc Prof Sheridan) confirming radiculopathy, material aggravation of pre-existing conditions, and the medical necessity of surgical interventions.
5. Panel’s Clinical Re-examination: Objective findings of muscle wasting, depressed reflexes, motor weakness, and sensory loss in the specific C6 and L5 dermatomes, definitively establishing radiculopathy according to the Guidelines.
Judicial Original Quotation:
“Upon examination by the Panel, there were definite signs of Whiplash Associated Disorder Grade 3 of the cervical spine, with muscle guarding, dysmetria, and objective signs of right C6 radiculopathy. This condition involves nerve root dysfunction and exceeds the definition of a threshold injury.”
“The Panel’s examination revealed definite abnormalities in the lumbar spine, including dysmetria, positive neural tension in the left lower limb, weakness, and sensory impairment in the left L5 distribution. These findings conform to a diagnosis of left L5 radiculopathy. Such radiculopathy involves nerve dysfunction and is excluded from the definition of a threshold injury.”
These quotes precisely articulate the Panel’s pivotal findings. The objective clinical signs of muscle guarding, dysmetria, reflex asymmetry, weakness, and sensory impairment, specifically linked to nerve root distributions (C6 and L5), directly satisfy the strict criteria for “radiculopathy” as defined in the Motor Accident Injuries Regulation 2017. This judicial interpretation is a classic example of how detailed clinical examination and the application of statutory definitions can definitively re-classify an injury from “threshold” to “non-threshold,” forming the bedrock of the Claimant’s successful review.
Analysis of the Losing Party’s Failure:
The Insurer’s failure stemmed primarily from:
* Over-reliance on Biomechanical Evidence: While biomechanical reports accurately described the low-speed impact, they were insufficient to conclusively negate causation when confronted with compelling clinical and temporal evidence of injury aggravation. The argument that low-speed impacts “lack sufficient force” was overcome by the finding that the accident materially aggravated pre-existing conditions, making them symptomatic.
* Underestimation of Material Aggravation: The Insurer failed to adequately appreciate that making an asymptomatic pre-existing degenerative condition symptomatic, especially with objective signs of nerve dysfunction, constitutes a material aggravation that can classify an injury as non-threshold. Their focus remained on proving new, acute structural damage, rather than the exacerbation of existing pathologies.
* Inadequate Engagement with Radiculopathy Criteria: The original Medical Assessor, whose decision the Insurer defended, failed to sufficiently engage with expert medical opinions indicating persistent radiculopathy and did not adequately apply the Guidelines’ strict criteria for diagnosing radiculopathy. This oversight was exposed by the Review Panel’s detailed re-examination, which yielded clear objective signs.
* Discounting of Subjective Complaints without Objective Corroboration: The Insurer’s position heavily discounted the Claimant’s subjective reports of severe and persistent pain, attributing them solely to pre-existing conditions. However, the Panel’s re-examination provided objective clinical signs (muscle wasting, reflex changes, weakness, sensory loss) that corroborated the subjective complaints, transforming them into undeniable evidence of nerve root dysfunction.
Implications
1. Your Pre-existing Conditions Matter: Don’t assume a pre-existing condition means you can’t claim. If an accident makes an old, quiet injury suddenly painful and debilitating, the law may recognise this “aggravation” as a new injury.
2. Objective Medical Evidence is Gold: Subjective pain is real, but objective signs (like changes in reflexes, muscle strength, or sensation) are crucial. A thorough and detailed clinical examination is key to proving nerve involvement, which can change your legal outcome.
3. Low-Speed Doesn’t Always Mean Low Impact: Don’t let arguments about minor vehicle damage or low impact speed deter you. Even seemingly minor collisions can severely affect individuals, especially if they have underlying vulnerabilities.
4. Challenge Initial Assessments: If you feel an initial medical assessment doesn’t fully capture your injuries, you have a right to seek a review. A fresh look with more rigorous examination can unveil critical details that were initially missed.
5. Understand Your Rights: Knowing the specific definitions of “threshold injury” and “radiculopathy” under personal injury laws can empower you. These legal nuances can be the difference between limited and comprehensive compensation.
Q&A Session
Q1: What exactly is “radiculopathy” and why is it so important in motor accident claims?
A1: Radiculopathy refers to symptoms caused by the pinching of a spinal nerve root, leading to pain, numbness, tingling, or weakness along the nerve’s path. In Australian motor accident claims, particularly under the Motor Accident Injuries Act 2017 (NSW), radiculopathy is critically important because it’s specifically excluded from the definition of a “threshold injury” (previously “minor injury”). If an injury is found to involve radiculopathy, it automatically becomes a “non-threshold injury,” which can significantly increase a claimant’s entitlement to ongoing statutory benefits and common law damages. Objective clinical signs like changes in reflexes, muscle strength, or sensation are needed to prove it.
Q2: My imaging shows “degenerative changes.” Does this mean my injuries aren’t from the accident?
A2: Not necessarily. As seen in this case, many people have pre-existing degenerative changes in their spine that are asymptomatic (cause no pain or symptoms). A motor accident can “materially aggravate” these conditions, making them symptomatic and debilitating. The key isn’t whether the degeneration was there before, but whether the accident caused or significantly worsened your symptoms to the point of injury, especially if it leads to objective signs of nerve impingement like radiculopathy. Comprehensive medical history and clinical examination contrasting your pre-accident and post-accident functional status are crucial.
Q3: The other driver says the accident was “low speed” and there was “minimal damage.” Can I still claim significant injuries?
A3: Yes, absolutely. While low-speed impacts and minimal vehicle damage might suggest lower forces, they don’t automatically mean that no significant injury occurred. Individual vulnerability, body position at impact, and pre-existing (even asymptomatic) conditions can all influence injury severity. This judgment highlights that even in a low-speed collision, the accident can materially aggravate underlying conditions to cause non-threshold injuries. The focus shifts from the vehicle damage to the actual impact on the human body, supported by thorough medical and clinical evidence.
Part 3: Appendix – Core Practical Component Library
1. Practical Positioning of This Case
Case Subtype: Personal Injury and Compensation – Motor Accident Spinal Injury (Aggravation of Pre-existing Degenerative Conditions)
Judgment Nature Definition: Final Judgment (Review Panel Determination)
2. Self-examination of Core Statutory Elements
Core Test (Negligence under the Civil Liability Act):
* Was there a Duty of Care owed? (Generally, all drivers owe a duty of care to other road users).
* Was there a Breach of Duty (was the risk foreseeable and not insignificant)? (Did the defendant act reasonably to prevent a foreseeable risk of injury? For instance, failing to keep a proper lookout, driving too close, or failing to brake in time for stationary traffic).
* Did the breach cause the injury (Causation)? (Was the defendant’s breach a necessary condition for the occurrence of the harm? And is it appropriate for the scope of the defendant’s liability to extend to the harm so caused? This includes material aggravation of pre-existing conditions).
Core Test (Damages – Motor Accident Injuries Act 2017 (NSW)):
* Does the Whole Person Impairment (WPI) exceed the statutory threshold (e.g., 10% for non-economic loss in NSW)? (A medical assessor determines the WPI based on the Permanent Impairment Guidelines. This threshold is critical for accessing common law damages).
* Is the injury a “Threshold Injury” (formerly “Minor Injury”)? (Defined under s 1.6 of the MAI Act as including soft tissue injury or a psychological/psychiatric injury that is not a recognised psychiatric illness. An injury to a spinal nerve root that manifests in neurological signs other than radiculopathy is also a threshold injury. If radiculopathy is present, it is not a threshold injury. If an injury is non-threshold, greater compensation and benefits may be available).
* Is there contributory negligence? (Did the claimant’s own actions contribute to their injury? This could reduce the amount of damages recoverable).
3. Equitable Remedies and Alternative Claims
If statutory avenues for compensation under the Motor Accident Injuries Act 2017 (NSW) were exhausted or limited, a party might explore alternative claims in common law negligence, though the Act largely supersedes common law for motor accidents within its scope. However, for disputes not covered or specifically limited by the Act (e.g., if the Act’s coverage was denied due to specific circumstances), common law principles would apply. In this context, the following could be considered:
- Promissory / Proprietary Estoppel (less likely in direct personal injury claims):
- Could apply if there were clear, unequivocal promises made by the at-fault driver or their insurer (e.g., “we will cover all your medical expenses indefinitely”) that induced detrimental reliance by the injured party.
- Result Reference: While not a direct damages claim for personal injury, it might enforce a promise related to care or expenses.
- Unjust Enrichment / Constructive Trust (highly unlikely for a direct motor accident injury claim):
- These principles typically apply in property or contractual disputes where one party has benefited at another’s expense in circumstances where it would be unconscionable to retain that benefit.
- Result Reference: Not directly applicable to securing compensation for personal injury itself, but might be considered in very unusual peripheral circumstances (e.g., mistaken payments for care where no liability is later found).
In the context of the Motor Accident Injuries Act 2017 (NSW), the Act creates its own comprehensive scheme. The primary avenue for challenging determinations is through the internal review mechanisms of the Personal Injury Commission, as demonstrated by this case. Common law claims are typically restricted by the “threshold injury” and “permanent impairment” criteria established by the Act.
4. Access Thresholds and Exceptional Circumstances
Regular Thresholds:
* Threshold Injury Definition (s 1.6 MAI Act): An injury is a threshold injury if it is a soft tissue injury or a recognised psychological/psychiatric injury. An injury to a spinal nerve root manifesting in neurological signs other than radiculopathy is also a threshold injury.
* Permanent Impairment (s 7.23 MAI Act): The degree of permanent impairment must be greater than 10% WPI to access common law damages for non-economic loss.
* Statutory Benefit Duration (s 3.24 MAI Act): Statutory benefits for loss of earnings and treatment expenses generally cease after 26 weeks if the injury is a threshold injury.
Exceptional Channels (Crucial):
* Radiculopathy (Clause 4, MAI Regulation): This is a key exceptional channel. If a spinal nerve root injury manifests in neurological signs including radiculopathy (meeting the specific objective clinical signs criteria outlined in the Guidelines, such as reflex asymmetry, muscle weakness, and sensory loss in a nerve root distribution), it is not a threshold injury. This case is a prime example of successfully using this channel.
* Serious Injury Exceeding WPI Threshold: While this case directly addresses the 10% WPI threshold, other personal injury claims might have higher thresholds (e.g., 15% for non-economic loss in some jurisdictions prior to the Motor Accident Injuries Act 2017). Establishing a WPI above the relevant threshold is essential for common law access.
* Aggravation of Pre-existing Conditions: Demonstrating that a motor accident “materially aggravated” a pre-existing asymptomatic condition, making it symptomatic and causing ongoing impairment (especially radiculopathy), is a powerful exceptional channel, as evidenced by Shiba.
Suggestion: Do not abandon a potential claim simply because you do not meet the standard time or conditions. Carefully compare your circumstances against the exceptions above, as they are often the key to successfully filing a case. Robust medical evidence, particularly a detailed clinical examination, is paramount in establishing radiculopathy and causation.
5. Guidelines for Judicial and Legal Citation
Citation Angle:
It is recommended to cite this case in legal submissions or debates involving:
* The interpretation and application of “threshold injury” definitions under the Motor Accident Injuries Act 2017 (NSW), particularly concerning spinal nerve root injuries.
* Cases where a motor accident is alleged to have “materially aggravated” pre-existing asymptomatic degenerative spinal conditions, leading to symptomatic radiculopathy.
* The evidentiary weight of objective clinical signs of radiculopathy in overturning a previous medical assessment based on biomechanical evidence or an over-reliance on pre-existing radiological findings.
* Cases where a low-speed impact is argued to have caused significant injury due to aggravation of pre-existing conditions.
Citation Method:
* As Positive Support: When your matter involves an injured person with pre-existing asymptomatic spinal degeneration who develops objective signs of radiculopathy following a motor accident (even a low-speed one), citing Shiba v Allianz Australia Insurance Limited can strengthen your argument that the injury is non-threshold and warrants a higher WPI.
* As a Distinguishing Reference: If the opposing party cites this case to argue that pre-existing conditions negate causation, you should emphasize any uniqueness of the current matter where objective signs of radiculopathy are absent, or where the aggravation is not material. Conversely, if Shiba is cited against you, and your client’s injuries genuinely fall into the “threshold” category, you would distinguish it based on the lack of objective radiculopathy findings.
Anonymisation Rule: Do not use the real names of the parties; strictly use professional procedural titles such as Claimant / Insurer or Appellant / Respondent.
Conclusion
The Shiba judgment underscores a critical principle in motor accident law: a thorough and objective clinical examination can decisively determine the nature and severity of injuries, especially when pre-existing conditions are present. The Panel’s meticulous re-examination and finding of objective radiculopathy highlights that even in cases of low-speed impact, the legal outcome hinges on the material aggravation of injuries, rather than solely on impact mechanics. This case empowers individuals to understand that their unique physical responses to trauma, when medically substantiated, can challenge and overturn initial assessments.
Everyone needs to understand the law and see the world through the lens of law. The in-depth analysis of this authentic judgment is intended to help everyone gradually establish a new legal mindset: True self-protection stems from the early understanding and mastery of legal rules.
Disclaimer
This article is based on the study and analysis of the public judgment of the Personal Injury Commission of New South Wales (Shiba v Allianz Australia Insurance Limited [2025] NSWPICMP 42), aimed at promoting legal research and public understanding. The citation of relevant judgment content is limited to the scope of fair dealing for the purposes of legal research, comment, and information sharing.
The analysis, structural arrangement, and expression of views contained in this article are the original content of the author, and the copyright belongs to the author and this platform. This article does not constitute legal advice, nor should it be regarded as legal advice for any specific situation.
Please consult a qualified legal professional for advice tailored to your specific circumstances.
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