Clonus (ankle/patellar)

For: Cervical myelopathy

Compression of the spinal cord in the neck, usually from degenerative narrowing. It can cause clumsy hands, unsteady walking, symptoms in both arms or the legs, and brisk reflexes, though these signs are often absent early.

Best used to rule in

Sensitivity7%

Specificity99%

LR+ (positive)5.49

LR− (negative)0.94

LR+ as given by Jiang et al. 2024, which fits the study's underlying counts; the rounded 7% and 99% shown would give about 7. The original paper prints 5.4.

Caution: Single study: only about 6 of 88 myelopathy patients were positive, so the figure is very imprecise.

What the numbers mean

Positive result: a moderate rule-in: a positive result makes the diagnosis clearly more likely.
Negative result: barely informative: a negative result changes little.

Source

Cook C, Brown C, Isaacs R, Roman M, Davis S, Richardson W. Clustered clinical findings for diagnosis of cervical spine myelopathy. J Man Manip Ther. 2010;18(4):175–180. Journal article (DOI) · single study
Also cited: Jiang Z, Davies B, Zipser C, et al. The value of clinical signs in the diagnosis of degenerative cervical myelopathy: a systematic review and meta-analysis. Global Spine J. 2024;14(4):1369-1394. Full text (PubMed Central) · likelihood ratios as recalculated in this review

Figures as they will appear in Rule It In, Rule It Out (Trokos, forthcoming). If a newer or better study changes them, this page changes with the book. Figures last updated from the book on 2 October 2026.

Get the book for the neck questions that matter: nerve root or referred pain, which myelopathy signs count, and when a neck after trauma needs imaging

This page gives the published figures. Rule It In, Rule It Out adds how to do this test, what counts as positive, how to read the result, and, where studied, whether combining it with other tests helps.

Coming in late 2026 as a PDF and a paperback. Join the list to hear when it's out