Skip to content

Nerve Conduction Studies: Interpretation

A clinician teaching reference: how to read NCS/EMG, representative normal values, and condition patterns.

Overview — what NCS/EMG can and cannot answer; the localisation mindset

Electrodiagnostic studies — nerve conduction studies (NCS) plus needle electromyography (EMG) — are an extension of the clinical examination, not a stand-alone diagnosis. Read alongside the history and examination they answer a small number of focused questions: is there a lesion of the peripheral nervous system, where is it, what is its pathophysiology (axon loss versus demyelination), how severe is it, and how old is it? [1][2] They cannot, on their own, tell you the aetiology (compression, trauma, inflammation, ischaemia all look broadly similar), and a normal study never fully excludes a small-fibre, very proximal, or very recent lesion.

The discipline that makes the report useful to a surgeon is the localisation mindset. Every abnormality is interpreted as a question of "where along the pathway?" — anterior horn cell, root, plexus, trunk, or named nerve; and within a named nerve, which segment. The single most powerful localising principle in the upper limb is the relationship of the lesion to the dorsal root ganglion (DRG): because the sensory cell body sits in the DRG (in the intervertebral foramen, distal to the root), a lesion proximal to the DRG — a root avulsion or radiculopathy — leaves the peripheral sensory axon in continuity and the sensory nerve action potential (SNAP) is preserved, whereas a lesion distal to the DRG (plexus or nerve) abolishes it. This is the lever that distinguishes radiculopathy from plexopathy, and it is developed in the condition-pattern section below. [1][3][8]

Two practical caveats frame everything that follows. First, EDX is operator- and technique-dependent; the numbers in a report are only as good as electrode placement, distances, and temperature control. Second, the study is most reliable when read comparatively — symptomatic versus asymptomatic side, one nerve against its neighbour, distal against proximal — because each patient is, in effect, their own control.

The measurements and what they mean — onset/peak latency, amplitude, conduction velocity, F-waves, H-reflex

A motor study stimulates a nerve and records the compound muscle action potential (CMAP) over the target muscle; a sensory study records the SNAP over the nerve itself (orthodromic or antidromic). Four primary measurements, plus the late responses, carry the information. [1][2]

  • Onset latency — time (ms) from stimulus to the first deflection of the response. It reflects conduction in the fastest fibres and the distal-most segment, and is the value used for distal motor latency and median–ulnar comparisons. [1][2]
  • Peak latency — time to the peak of the SNAP; more reproducible than onset for sensory studies and conventionally used for sensory distal latencies and median–ulnar/median–radial comparisons. [4][7]
  • Amplitude — CMAP in millivolts (mV), SNAP in microvolts (µV). Amplitude is a semi-quantitative measure of the number of functioning axons (and, for the CMAP, muscle fibres) contributing to the response. Low amplitude is the signature of axon loss. [1][2]
  • Conduction velocity (CV) — m/s, computed from the latency difference between two stimulation sites divided by the inter-site distance (motor) or from latency and distance (sensory). CV reflects myelination and the integrity of the largest, fastest fibres. Marked slowing implies demyelination. [1][2]

Late responses interrogate the proximal segments that routine distal stimulation cannot reach:

  • F-waves — a small late motor response produced by antidromic activation of the anterior horn cell that "backfires" orthodromically to the muscle. F-wave latency samples the entire motor axon including the root, and is prolonged or absent in proximal demyelination (e.g. early Guillain–Barré) and in radiculopathy/plexopathy, though it is a relatively non-specific and insensitive localiser. [1][2]
  • H-reflex — the electrophysiological analogue of the monosynaptic stretch reflex (Ia afferent → spinal cord → motor efferent), routinely elicited from soleus (S1) and used mainly in the lower limb; upper-limb (flexor carpi radialis, C6/C7) H-reflexes are technically harder and less routine. Normal soleus H-reflex latency is on the order of ~28–35 ms (height-dependent). [1][2]

The mnemonic that survives contact with a real report: amplitude ≈ axon number; latency/CV ≈ myelination. Keep the two channels separate when you read.

A systematic way to read a study — sensory then motor; distal vs proximal; side-to-side; amplitudes; CV/latency; late responses; then needle EMG

A report is best read in a fixed order so nothing is missed: [1][2][4]

  1. Sensory studies first. SNAPs are the most sensitive early marker of an axonal lesion distal to the DRG and the key discriminator for the radiculopathy-versus-plexopathy question. Check each SNAP is present, then its amplitude, then its peak latency/CV.
  2. Motor studies. For each nerve check distal motor latency, CMAP amplitude (distal), and forearm/across-elbow CV. CMAP amplitude loss lags sensory loss in many compressive lesions.
  3. Distal versus proximal. Compare the response on stimulating distally and proximally along the same nerve. A drop in CMAP amplitude/area from proximal to distal stimulation (with preserved distal latency) defines conduction block — the hallmark of a focal demyelinating lesion between the two stimulation sites (e.g. ulnar block across the elbow). Disproportionate temporal dispersion (a longer, lower, more polyphasic proximal response) points to differential slowing across the segment.
  4. Side-to-side. For a unilateral problem, the contralateral nerve is the most useful normal reference; inter-side differences in latency or amplitude are often more informative than absolute values against a population range.
  5. CV/latency are then interpreted as a block: focal slowing or block localises; uniform slowing across many nerves suggests a generalised demyelinating process; near-normal CV with low amplitudes suggests axon loss.
  6. Late responses (F-waves, H-reflex) add proximal information when distal studies are normal or borderline.
  7. Needle EMG is the final and often most localising step. Assess, in each muscle: spontaneous activity at rest (fibrillation potentials and positive sharp waves — markers of active denervation; complex repetitive discharges, fasciculations, myokymia, myotonia), motor-unit action potential (MUAP) morphology (large, long, polyphasic units indicate chronic reinnervation; small, short units suggest myopathy), and recruitment (reduced/discrete recruitment with a fast firing rate indicates neurogenic axon/motor-unit loss). The distribution of abnormal muscles — sampled across nerves and across roots/myotomes, including paraspinals — is what converts EMG findings into an anatomical localisation. [1][2][3]

Axonal vs demyelinating — the core dichotomy

Almost every electrodiagnostic interpretation reduces to placing the lesion on the axonal–demyelinating axis, because the two have different mechanisms, prognoses, and (for the surgeon) implications. [1][2][5]

Axon loss (the typical picture in chronic compression that has progressed, traction injury, axonotmesis, and most toxic/metabolic neuropathies): - Low amplitude is the cardinal finding — SNAP first, then CMAP. - Latency and CV are relatively preserved (mild slowing only, because the fastest surviving fibres still conduct near-normally; CV typically stays above ~70–80% of the lower limit of normal). - Needle EMG shows fibrillations/positive sharp waves (after the denervation delay) and, later, reinnervation changes (large polyphasic MUAPs, reduced recruitment). - Prognosis depends on axon regrowth (~1 mm/day) and is generally slower and less complete.

Demyelination (focal entrapment with block, inflammatory demyelinating neuropathies, some hereditary neuropathies): - Slowing out of proportion to amplitude loss — prolonged distal latencies, slow CV, prolonged/absent F-waves. - Conduction block (amplitude/area drop on proximal vs distal stimulation across the affected segment) and temporal dispersion are specific for acquired segmental demyelination and are highly localising. - Needle EMG is often relatively normal early (no axon loss = no fibrillations), or shows only reduced recruitment due to block. - Prognosis is generally good and fast if remyelination occurs (no axon loss to regrow).

A further axis is uniform versus segmental. Uniform slowing across all nerves and segments suggests a hereditary demyelinating process (e.g. CMT1); patchy, segmental slowing with block and dispersion suggests an acquired (often inflammatory) demyelinating process. Most surgically relevant entrapments produce focal demyelination at the entrapment site, sometimes with superimposed axon loss once the lesion is chronic. [1][2][5]

Typical normal values (representative)

The values below are representative adult upper-limb figures drawn from widely used reference compilations and the AANEM Normative Data Task Force review. They are not absolute. Every reference range is laboratory- and technique-specific and varies with limb temperature (a cool limb slows conduction and prolongs latency, roughly 1.5–2.5 m/s and ~0.2 ms per °C), inter-electrode distance, the patient's age and height, and the recording montage. Always interpret a result against the issuing laboratory's own reference range and, ideally, the patient's asymptomatic side — never against the table alone. [1][4][5][6][7]

Study (adult, surface, ~32–34 °C) Typical normal limit Parameter
Median motor (wrist→APB) distal latency ≤ ~4.2–4.4 ms onset latency
Median motor CMAP ≥ ~4 mV amplitude
Median motor forearm CV ≥ ~49–50 m/s conduction velocity
Median F-wave ≤ ~31 ms (height-dependent) minimum F latency
Ulnar motor (wrist→ADM) distal latency ≤ ~3.3–3.6 ms onset latency
Ulnar motor CMAP ≥ ~6 mV amplitude
Ulnar motor forearm CV ≥ ~49–51 m/s conduction velocity
Ulnar motor across-elbow CV ≥ ~50 m/s (and < 10 m/s slower than forearm) conduction velocity
Ulnar F-wave ≤ ~32 ms (height-dependent) minimum F latency
Radial motor (forearm→EIP) distal latency ≤ ~3.0 ms onset latency
Radial motor CMAP ≥ ~2–3 mV amplitude
Median sensory (digit II/III, 14 cm) peak latency ≤ ~3.5 ms peak latency
Median SNAP ≥ ~20 µV (antidromic) amplitude
Median sensory CV ≥ ~50 m/s conduction velocity
Ulnar sensory (digit V, 14 cm) peak latency ≤ ~3.1 ms peak latency
Ulnar SNAP ≥ ~10–17 µV (antidromic) amplitude
Ulnar sensory CV ≥ ~50 m/s conduction velocity
Radial sensory (snuffbox→thumb) peak latency ≤ ~2.7 ms peak latency
Radial SNAP ≥ ~15–20 µV amplitude

Sources for the table: the AANEM Normative Data Task Force literature review (Chen et al. 2016; Dillingham et al. 2016), Buschbacher's reference-value studies, and the value ranges tabulated in Preston & Shapiro and Kimura. [4][5][6][7] Amplitude lower limits in particular vary substantially between montages and references — treat them as orientation, not thresholds.

Condition patterns — what they look like

Carpal tunnel syndrome (median neuropathy at the wrist)

The earliest and most sensitive abnormality is prolonged median sensory (and palmar/mixed) distal latency — focal slowing across the carpal tunnel — because sensory fibres are affected before motor fibres. As severity increases, the median motor distal latency prolongs (distal latency > ~4.2 ms is supportive), then SNAP and CMAP amplitudes fall as axon loss supervenes. [1][7][9]

The most useful early test is a comparison study that controls for temperature and technique by pitting the median nerve against an adjacent normal nerve over the same distance — typically the median–ulnar (ring-finger sensory or mixed palmar) latency difference or the median–radial (thumb) difference. A difference > ~0.4–0.5 ms is abnormal and raises sensitivity from roughly 75% to ~95%. [7][9] Conventional severity grading runs: mild (abnormal sensory/comparison latency only, normal motor); moderate (abnormal sensory and motor distal latency, preserved amplitudes); severe (the above plus reduced SNAP and/or CMAP amplitude, with needle-EMG denervation/reinnervation in APB). A genuinely normal, well-performed median sensory study and comparison study make clinically significant CTS unlikely. [7][9]

Ulnar neuropathy at the elbow (UNE)

Localising the ulnar nerve to the elbow rests on focal slowing or conduction block across the elbow segment, studied with the elbow flexed (~90°) and an adequate measured across-elbow distance (~10 cm). The classic AANEM/AAEM criteria are: across-elbow motor CV reduced below ~50 m/s; an across-elbow segment > 10 m/s slower than the below-elbow (forearm) segment; > ~20% CMAP amplitude/area drop from below-elbow to above-elbow stimulation (conduction block); and a significant change in CMAP configuration (temporal dispersion) above versus below the elbow. [3][10] When routine studies are inconclusive, short-segment incremental stimulation ("inching") at ~1–2 cm intervals across the elbow localises an abrupt latency jump or amplitude drop to the entrapment point and is the most sensitive method. [3][10] Needle EMG of FDP (ulnar head) and FCU helps separate elbow from wrist lesions and grades axon loss.

Cervical radiculopathy

The signature is a near-normal NCS with abnormal needle EMG in a myotomal pattern. Because the lesion is proximal to the DRG, the peripheral sensory axon stays in continuity and SNAPs are preserved even when the dermatome is numb — the single most important teaching point, and the discriminator from plexopathy. [1][3][8] Motor studies are usually normal unless there is substantial anterior-root axon loss (then the relevant CMAP may be low). The diagnosis is made on needle EMG: denervation/reinnervation in two or more muscles supplied by the same root but different peripheral nerves, plus, importantly, the cervical paraspinal muscles (innervated by the posterior primary ramus, which leaves the root very proximally — paraspinal abnormality places the lesion at/near the root and is often the earliest finding). [3][8]

Polyneuropathy

The typical acquired pattern is length-dependent and symmetric — abnormalities appear first and worst in the longest nerves (lower limb/sural before upper limb), with a distal-to-proximal gradient. Classify on the axonal–demyelinating axis: axonal polyneuropathy shows low-amplitude SNAPs/CMAPs with relatively preserved CV (the common diabetic/toxic/metabolic picture); demyelinating polyneuropathy shows marked slowing, prolonged distal latencies and F-waves, conduction block and temporal dispersion with relatively preserved amplitudes. Uniform slowing suggests hereditary disease; patchy slowing with block suggests acquired inflammatory disease (e.g. CIDP). [1][2][5]

The key cross-cutting teaching point: a preserved SNAP in an anaesthetic dermatome localises the lesion proximal to the DRG (root) and rules out a post-ganglionic (plexus/nerve) cause for that sensory loss — the cleanest single discriminator between radiculopathy and plexopathy. [1][3][8]

Common pitfalls and caveats

  • Temperature. The commonest source of spurious "slowing." A cool limb prolongs latencies, slows CV and increases amplitude. Maintain and document limb temperature (≥32 °C upper limb); warm a cold hand before believing a borderline-slow median latency. [1][4][5]
  • Anomalous innervation — Martin–Gruber anastomosis (MGA). A median-to-ulnar crossover in the forearm (~15–30% of people) produces confusing patterns: an unexpectedly high ulnar CMAP on proximal stimulation, a "too-fast" or initially-positive median forearm response, and apparent ulnar conduction block that is really a crossover artefact. Recognise it before over-calling an elbow lesion. [1][2]
  • Volume conduction / co-stimulation. An initial positive deflection of a CMAP, or an unexpectedly large response, may be a distant muscle picked up by volume conduction or inadvertent co-stimulation of an adjacent nerve — not the target. Check montage and stimulus intensity. [1][2]
  • Timing after injury. EDX has a built-in delay and must be timed to the question. After an acute axonal injury, motor Wallerian degeneration takes ~7–11 days (and sensory a few days longer) before distal stimulation reveals the full amplitude loss — a study done too early underestimates the lesion or can falsely suggest a (recoverable) conduction block. Fibrillation potentials on needle EMG do not appear until ~2–3 weeks post-denervation (proximal muscles earlier, distal later). For a traumatic nerve injury, a baseline at ~3–4 weeks and a repeat at ~3 months are usually the most informative. [1][2]
  • Numbers versus the clinical picture. A value just outside a population range in an asymptomatic territory, or a normal study in a clearly symptomatic patient, must be reconciled with the examination — not reported in isolation. EDX refines and localises a clinical hypothesis; it does not replace it. [1][2]

See Also

References

  1. Preston DC, Shapiro BE. Electromyography and Neuromuscular Disorders: Clinical–Electrophysiologic–Ultrasound Correlations. 4th ed. Philadelphia: Elsevier; 2021.
  2. Kimura J. Electrodiagnosis in Diseases of Nerve and Muscle: Principles and Practice. 4th ed. New York: Oxford University Press; 2013.
  3. Ramani PK, Lui F, Arya K. Nerve Conduction Studies and Electromyography. In: StatPearls. Treasure Island (FL): StatPearls Publishing; 2024. Available from: https://www.ncbi.nlm.nih.gov/books/NBK611987/
  4. Chen S, Andary M, Buschbacher R, Del Toro D, Smith B, So Y, et al. Electrodiagnostic reference values for upper and lower limb nerve conduction studies in adult populations. Muscle Nerve. 2016;54(3):371–7.
  5. Dillingham T, Chen S, Andary M, Buschbacher R, Del Toro D, Smith B, et al. Establishing high-quality reference values for nerve conduction studies: a report from the Normative Data Task Force of the American Association of Neuromuscular & Electrodiagnostic Medicine. Muscle Nerve. 2016;54(3):366–70.
  6. Buschbacher RM, Prahlow ND. Manual of Nerve Conduction Studies. 2nd ed. New York: Demos Medical Publishing; 2006.
  7. Rosario NB, De Jesus O. Electrodiagnostic Evaluation of Carpal Tunnel Syndrome. In: StatPearls. Treasure Island (FL): StatPearls Publishing; 2024. Available from: https://www.ncbi.nlm.nih.gov/books/NBK562235/
  8. Dillingham TR. Electrodiagnostic Evaluation of Cervical Radiculopathy. In: StatPearls. Treasure Island (FL): StatPearls Publishing; 2024. Available from: https://www.ncbi.nlm.nih.gov/books/NBK563152/
  9. American Association of Neuromuscular & Electrodiagnostic Medicine; American Academy of Neurology; American Academy of Physical Medicine and Rehabilitation. Practice parameter for electrodiagnostic studies in carpal tunnel syndrome: summary statement. Muscle Nerve. 2002;25(6):918–22.
  10. American Association of Electrodiagnostic Medicine, Campbell WW. Practice parameter for electrodiagnostic studies in ulnar neuropathy at the elbow: summary statement. Muscle Nerve. 1999;22(3):408–11.

Creative Commons BY-NC 4.0

CC Creative Commons licence
BY Attribution — you must credit the source
NC NonCommercial — not for commercial use

Attribution-NonCommercial 4.0 International

Creative Commons Corporation ("Creative Commons") is not a law firm and does not provide legal services or legal advice. Distribution of Creative Commons public licenses does not create a lawyer-client or other relationship. Creative Commons makes its licenses and related information available on an "as-is" basis. Creative Commons gives no warranties regarding its licenses, any material licensed under their terms and conditions, or any related information. Creative Commons disclaims all liability for damages resulting from their use to the fullest extent possible.

Using Creative Commons Public Licenses

Creative Commons public licenses provide a standard set of terms and conditions that creators and other rights holders may use to share original works of authorship and other material subject to copyright and certain other rights specified in the public license below. The following considerations are for informational purposes only, are not exhaustive, and do not form part of our licenses.

Considerations for licensors: Our public licenses are intended for use by those authorized to give the public permission to use material in ways otherwise restricted by copyright and certain other rights. Our licenses are irrevocable. Licensors should read and understand the terms and conditions of the license they choose before applying it. Licensors should also secure all rights necessary before applying our licenses so that the public can reuse the material as expected. Licensors should clearly mark any material not subject to the license. This includes other CC- licensed material, or material used under an exception or limitation to copyright. More considerations for licensors: wiki.creativecommons.org/Considerations_for_licensors

Considerations for the public: By using one of our public licenses, a licensor grants the public permission to use the licensed material under specified terms and conditions. If the licensor's permission is not necessary for any reason--for example, because of any applicable exception or limitation to copyright--then that use is not regulated by the license. Our licenses grant only permissions under copyright and certain other rights that a licensor has authority to grant. Use of the licensed material may still be restricted for other reasons, including because others have copyright or other rights in the material. A licensor may make special requests, such as asking that all changes be marked or described. Although not required by our licenses, you are encouraged to respect those requests where reasonable. More considerations for the public: wiki.creativecommons.org/Considerations_for_licensees

Creative Commons Attribution-NonCommercial 4.0 International Public License

By exercising the Licensed Rights (defined below), You accept and agree to be bound by the terms and conditions of this Creative Commons Attribution-NonCommercial 4.0 International Public License ("Public License"). To the extent this Public License may be interpreted as a contract, You are granted the Licensed Rights in consideration of Your acceptance of these terms and conditions, and the Licensor grants You such rights in consideration of benefits the Licensor receives from making the Licensed Material available under these terms and conditions.

Section 1 -- Definitions.

a. Adapted Material means material subject to Copyright and Similar Rights that is derived from or based upon the Licensed Material and in which the Licensed Material is translated, altered, arranged, transformed, or otherwise modified in a manner requiring permission under the Copyright and Similar Rights held by the Licensor. For purposes of this Public License, where the Licensed Material is a musical work, performance, or sound recording, Adapted Material is always produced where the Licensed Material is synched in timed relation with a moving image.

b. Adapter's License means the license You apply to Your Copyright and Similar Rights in Your contributions to Adapted Material in accordance with the terms and conditions of this Public License.

c. Copyright and Similar Rights means copyright and/or similar rights closely related to copyright including, without limitation, performance, broadcast, sound recording, and Sui Generis Database Rights, without regard to how the rights are labeled or categorized. For purposes of this Public License, the rights specified in Section 2(b)(1)-(2) are not Copyright and Similar Rights.

d. Effective Technological Measures means those measures that, in the absence of proper authority, may not be circumvented under laws fulfilling obligations under Article 11 of the WIPO Copyright Treaty adopted on December 20, 1996, and/or similar international agreements.

e. Exceptions and Limitations means fair use, fair dealing, and/or any other exception or limitation to Copyright and Similar Rights that applies to Your use of the Licensed Material.

f. Licensed Material means the artistic or literary work, database, or other material to which the Licensor applied this Public License.

g. Licensed Rights means the rights granted to You subject to the terms and conditions of this Public License, which are limited to all Copyright and Similar Rights that apply to Your use of the Licensed Material and that the Licensor has authority to license.

h. Licensor means the individual(s) or entity(ies) granting rights under this Public License.

i. NonCommercial means not primarily intended for or directed towards commercial advantage or monetary compensation. For purposes of this Public License, the exchange of the Licensed Material for other material subject to Copyright and Similar Rights by digital file-sharing or similar means is NonCommercial provided there is no payment of monetary compensation in connection with the exchange.

j. Share means to provide material to the public by any means or process that requires permission under the Licensed Rights, such as reproduction, public display, public performance, distribution, dissemination, communication, or importation, and to make material available to the public including in ways that members of the public may access the material from a place and at a time individually chosen by them.

k. Sui Generis Database Rights means rights other than copyright resulting from Directive 96/9/EC of the European Parliament and of the Council of 11 March 1996 on the legal protection of databases, as amended and/or succeeded, as well as other essentially equivalent rights anywhere in the world.

l. You means the individual or entity exercising the Licensed Rights under this Public License. Your has a corresponding meaning.

Section 2 -- Scope.

a. License grant.

1. Subject to the terms and conditions of this Public License, the Licensor hereby grants You a worldwide, royalty-free, non-sublicensable, non-exclusive, irrevocable license to exercise the Licensed Rights in the Licensed Material to:

a. reproduce and Share the Licensed Material, in whole or in part, for NonCommercial purposes only; and

b. produce, reproduce, and Share Adapted Material for NonCommercial purposes only.

2. Exceptions and Limitations. For the avoidance of doubt, where Exceptions and Limitations apply to Your use, this Public License does not apply, and You do not need to comply with its terms and conditions.

3. Term. The term of this Public License is specified in Section 6(a).

4. Media and formats; technical modifications allowed. The Licensor authorizes You to exercise the Licensed Rights in all media and formats whether now known or hereafter created, and to make technical modifications necessary to do so. The Licensor waives and/or agrees not to assert any right or authority to forbid You from making technical modifications necessary to exercise the Licensed Rights, including technical modifications necessary to circumvent Effective Technological Measures. For purposes of this Public License, simply making modifications authorized by this Section 2(a) (4) never produces Adapted Material.

5. Downstream recipients.

a. Offer from the Licensor -- Licensed Material. Every recipient of the Licensed Material automatically receives an offer from the Licensor to exercise the Licensed Rights under the terms and conditions of this Public License.

b. No downstream restrictions. You may not offer or impose any additional or different terms or conditions on, or apply any Effective Technological Measures to, the Licensed Material if doing so restricts exercise of the Licensed Rights by any recipient of the Licensed Material.

6. No endorsement. Nothing in this Public License constitutes or may be construed as permission to assert or imply that You are, or that Your use of the Licensed Material is, connected with, or sponsored, endorsed, or granted official status by, the Licensor or others designated to receive attribution as provided in Section 3(a)(1)(A)(i).

b. Other rights.

1. Moral rights, such as the right of integrity, are not licensed under this Public License, nor are publicity, privacy, and/or other similar personality rights; however, to the extent possible, the Licensor waives and/or agrees not to assert any such rights held by the Licensor to the limited extent necessary to allow You to exercise the Licensed Rights, but not otherwise.

2. Patent and trademark rights are not licensed under this Public License.

3. To the extent possible, the Licensor waives any right to collect royalties from You for the exercise of the Licensed Rights, whether directly or through a collecting society under any voluntary or waivable statutory or compulsory licensing scheme. In all other cases the Licensor expressly reserves any right to collect such royalties, including when the Licensed Material is used other than for NonCommercial purposes.

Section 3 -- License Conditions.

Your exercise of the Licensed Rights is expressly made subject to the following conditions.

a. Attribution.

1. If You Share the Licensed Material (including in modified form), You must:

a. retain the following if it is supplied by the Licensor with the Licensed Material:

i. identification of the creator(s) of the Licensed Material and any others designated to receive attribution, in any reasonable manner requested by the Licensor (including by pseudonym if designated);

ii. a copyright notice;

iii. a notice that refers to this Public License;

iv. a notice that refers to the disclaimer of warranties;

v. a URI or hyperlink to the Licensed Material to the extent reasonably practicable;

b. indicate if You modified the Licensed Material and retain an indication of any previous modifications; and

c. indicate the Licensed Material is licensed under this Public License, and include the text of, or the URI or hyperlink to, this Public License.

2. You may satisfy the conditions in Section 3(a)(1) in any reasonable manner based on the medium, means, and context in which You Share the Licensed Material. For example, it may be reasonable to satisfy the conditions by providing a URI or hyperlink to a resource that includes the required information.

3. If requested by the Licensor, You must remove any of the information required by Section 3(a)(1)(A) to the extent reasonably practicable.

4. If You Share Adapted Material You produce, the Adapter's License You apply must not prevent recipients of the Adapted Material from complying with this Public License.

Section 4 -- Sui Generis Database Rights.

Where the Licensed Rights include Sui Generis Database Rights that apply to Your use of the Licensed Material:

a. for the avoidance of doubt, Section 2(a)(1) grants You the right to extract, reuse, reproduce, and Share all or a substantial portion of the contents of the database for NonCommercial purposes only;

b. if You include all or a substantial portion of the database contents in a database in which You have Sui Generis Database Rights, then the database in which You have Sui Generis Database Rights (but not its individual contents) is Adapted Material; and

c. You must comply with the conditions in Section 3(a) if You Share all or a substantial portion of the contents of the database.

For the avoidance of doubt, this Section 4 supplements and does not replace Your obligations under this Public License where the Licensed Rights include other Copyright and Similar Rights.

Section 5 -- Disclaimer of Warranties and Limitation of Liability.

a. UNLESS OTHERWISE SEPARATELY UNDERTAKEN BY THE LICENSOR, TO THE EXTENT POSSIBLE, THE LICENSOR OFFERS THE LICENSED MATERIAL AS-IS AND AS-AVAILABLE, AND MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND CONCERNING THE LICENSED MATERIAL, WHETHER EXPRESS, IMPLIED, STATUTORY, OR OTHER. THIS INCLUDES, WITHOUT LIMITATION, WARRANTIES OF TITLE, MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NON-INFRINGEMENT, ABSENCE OF LATENT OR OTHER DEFECTS, ACCURACY, OR THE PRESENCE OR ABSENCE OF ERRORS, WHETHER OR NOT KNOWN OR DISCOVERABLE. WHERE DISCLAIMERS OF WARRANTIES ARE NOT ALLOWED IN FULL OR IN PART, THIS DISCLAIMER MAY NOT APPLY TO YOU.

b. TO THE EXTENT POSSIBLE, IN NO EVENT WILL THE LICENSOR BE LIABLE TO YOU ON ANY LEGAL THEORY (INCLUDING, WITHOUT LIMITATION, NEGLIGENCE) OR OTHERWISE FOR ANY DIRECT, SPECIAL, INDIRECT, INCIDENTAL, CONSEQUENTIAL, PUNITIVE, EXEMPLARY, OR OTHER LOSSES, COSTS, EXPENSES, OR DAMAGES ARISING OUT OF THIS PUBLIC LICENSE OR USE OF THE LICENSED MATERIAL, EVEN IF THE LICENSOR HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH LOSSES, COSTS, EXPENSES, OR DAMAGES. WHERE A LIMITATION OF LIABILITY IS NOT ALLOWED IN FULL OR IN PART, THIS LIMITATION MAY NOT APPLY TO YOU.

c. The disclaimer of warranties and limitation of liability provided above shall be interpreted in a manner that, to the extent possible, most closely approximates an absolute disclaimer and waiver of all liability.

Section 6 -- Term and Termination.

a. This Public License applies for the term of the Copyright and Similar Rights licensed here. However, if You fail to comply with this Public License, then Your rights under this Public License terminate automatically.

b. Where Your right to use the Licensed Material has terminated under Section 6(a), it reinstates:

1. automatically as of the date the violation is cured, provided it is cured within 30 days of Your discovery of the violation; or

2. upon express reinstatement by the Licensor.

For the avoidance of doubt, this Section 6(b) does not affect any right the Licensor may have to seek remedies for Your violations of this Public License.

c. For the avoidance of doubt, the Licensor may also offer the Licensed Material under separate terms or conditions or stop distributing the Licensed Material at any time; however, doing so will not terminate this Public License.

d. Sections 1, 5, 6, 7, and 8 survive termination of this Public License.

Section 7 -- Other Terms and Conditions.

a. The Licensor shall not be bound by any additional or different terms or conditions communicated by You unless expressly agreed.

b. Any arrangements, understandings, or agreements regarding the Licensed Material not stated herein are separate from and independent of the terms and conditions of this Public License.

Section 8 -- Interpretation.

a. For the avoidance of doubt, this Public License does not, and shall not be interpreted to, reduce, limit, restrict, or impose conditions on any use of the Licensed Material that could lawfully be made without permission under this Public License.

b. To the extent possible, if any provision of this Public License is deemed unenforceable, it shall be automatically reformed to the minimum extent necessary to make it enforceable. If the provision cannot be reformed, it shall be severed from this Public License without affecting the enforceability of the remaining terms and conditions.

c. No term or condition of this Public License will be waived and no failure to comply consented to unless expressly agreed to by the Licensor.

d. Nothing in this Public License constitutes or may be interpreted as a limitation upon, or waiver of, any privileges and immunities that apply to the Licensor or You, including from the legal processes of any jurisdiction or authority.

Creative Commons is not a party to its public licenses. Notwithstanding, Creative Commons may elect to apply one of its public licenses to material it publishes and in those instances will be considered the “Licensor.” The text of the Creative Commons public licenses is dedicated to the public domain under the CC0 Public Domain Dedication. Except for the limited purpose of indicating that material is shared under a Creative Commons public license or as otherwise permitted by the Creative Commons policies published at creativecommons.org/policies, Creative Commons does not authorize the use of the trademark "Creative Commons" or any other trademark or logo of Creative Commons without its prior written consent including, without limitation, in connection with any unauthorized modifications to any of its public licenses or any other arrangements, understandings, or agreements concerning use of licensed material. For the avoidance of doubt, this paragraph does not form part of the public licenses.

Creative Commons may be contacted at creativecommons.org.