Resisted Isometric Muscle Test¶
A clinical examination that holds a specified muscle action against resistance and interprets pain or force as limited evidence about musculoskeletal function.
Core Idea¶
A resisted isometric muscle test is a musculoskeletal examination: the person attempts a specified action while the examiner opposes it and the relevant joint position stays essentially held. The examiner observes pain, force, or both and interprets the response as limited evidence for a clinical question. The four necessary parts are the question and target action, held position and resistance, observed response, and bounded interpretation. Rowlands and colleagues observed several muscles active during an empty-can test,[^ref-4318c6498db0] while Itoi and colleagues found that pain and weakness criteria gave different diagnostic results.[^ref-adbdf891e19f] The procedure therefore does not perfectly isolate one muscle or by itself diagnose a lesion.
Use Within the Domain¶
The same procedure can be used at unlike body regions while the anatomical action and meaning of the response change. Empty- and full-can shoulder tests have been studied for possible supraspinatus tendon tear; a separate study used maximal isometric manual resistance during examinations of painful knees.[ref-adbdf891e19f][ref-b9b4b92bb484] Diagnostic accuracy and examiner agreement belong to the particular maneuver and clinical question, not to the whole family.
Clarity¶
Record the action attempted, position held, resistance applied, pain or strength observed, and conclusion being considered. Pain and weakness are different response criteria; Itoi and colleagues found that the criterion chosen changed the accuracy of the can tests in their study.[^ref-adbdf891e19f] A moving resisted action has not met the held-position boundary simply because it is resisted.
Manages Complexity¶
The four-part record makes a bedside finding easier to compare with other findings without hiding uncertainty. More than one muscle was active in an empty-can electromyography study, and a painful-knee study reported limited between-examiner agreement under its conditions.[ref-4318c6498db0][ref-b9b4b92bb484] Those limits matter when one result appears to point to a single structure.
Abstract Reasoning¶
Move from a specified question to a held resisted action, then from the observed sign to a conditional revision of the clinical differential. Ask whether the position was held, whether the reported sign matches the intended response criterion, and what other causes could produce it. Itoi and colleagues found criterion-dependent can-test accuracy,[^ref-adbdf891e19f] and the AAOS rotator-cuff guideline favors combinations of clinical tests over an isolated one for its stated question.[^ref-198965fd2e55] A positive sign is a clue whose weight depends on the maneuver, population, and corroborating findings.
Knowledge Transfer¶
The shoulder and knee cases share the question → stationary resisted effort → pain/strength observation → bounded interpretation sequence without sharing anatomy or one diagnostic threshold.[ref-adbdf891e19f][ref-4318c6498db0][ref-6f120313fbc2][ref-b9b4b92bb484] An isometric sports strength task may share the contraction but lacks this clinical question and differential interpretation.
Example¶
In a held empty- or full-can shoulder examination, the specified effort is resisted while pain or manual weakness is recorded. Itoi and colleagues compared response criteria for tear detection, and separate studies examined held empty-can resistance and maximal isometric contractions in both can positions.[ref-adbdf891e19f][ref-4318c6498db0][^ref-6f120313fbc2] The response can inform the shoulder question without proving that only supraspinatus was tested. In painful-knee examinations, Hayes and Petersen used standardized positions and maximal isometric manual resistance, recorded pain and strong/weak classifications, and studied their agreement between examiners. The accessible abstract does not name the exact knee motions or establish a unique lesion diagnosis.[^ref-b9b4b92bb484]
Neighborhood in Abstraction Space¶
Resisted Isometric Muscle Test sits in a sparse region of the domain-specific corpus (100th percentile for distinctiveness): few abstractions share its structure, so a faithful description tends to retrieve it precisely.
Family — Biomedical Signal Sensing & Recording (21 abstractions)
Nearest neighbors
- Modified Ashworth scale — 0.75
- Diagnostic Percussion — 0.73
- Self-buckling — 0.71
- Depolarizing Prepulse — 0.70
- Brodie–Trendelenburg percussion test — 0.70
Computed from structural-signature embeddings · 2026-10-17
Not to Be Confused With¶
This is the resisted-isometric branch of selective tissue tension examination, not that whole paradigm of active, passive, resisted, and palpation findings.[^ref-ba69a3a1e6ba] It is not every provocation test, a calibrated force measurement by definition, or a unique-muscle isolation claim. A Cozen comparator in a cited elbow study lacks proof of a held isometric protocol and is not counted as a positive example here.[^ref-915b3e666c8f]
References¶
[^ref-adbdf891e19f]: Itoi, E., Kido, T., Sano, A., Urayama, M., & Sato, K. (1999). "Which is more useful, the full can test or the empty can test, in detecting the torn supraspinatus tendon?". American Journal of Sports Medicine, 27(1), 65–68. Original comparative clinical study; PubMed abstract consulted for methods, response criteria and study-specific results.
[^ref-4318c6498db0]: Rowlands, L. K., Wertsch, J. J., Primack, S. J., Spreitzer, A. M., & Roberts, M. M. (1995). "Kinesiology of the empty can test". American Journal of Physical Medicine & Rehabilitation, 74(4), 302–304. Original EMG study; PubMed abstract consulted for maintained resisted position and multi-muscle activation.
[^ref-6f120313fbc2]: Timmons, M. K., Lopes-Albers, A. D., Borgsmiller, L., Zirker, C., Ericksen, J., & Michener, L. A. (2013). "Differences in scapular orientation, subacromial space and shoulder pain between the full can and empty can tests". Clinical Biomechanics, 28(4), 395–401. Original comparison; PubMed abstract consulted for maximal isometric contractions in both positions and pain observation.
[^ref-b9b4b92bb484]: Hayes, K. W., & Petersen, C. M. (2003). "Reliability of classifications derived from Cyriax’s resisted testing in subjects with painful shoulders and knees". Journal of Orthopaedic & Sports Physical Therapy, 33(5), 235–246. Original reliability study; PubMed abstract consulted. Exact knee motions are not named in the accessible abstract.
[^ref-ba69a3a1e6ba]: Franklin, M. E., Conner-Kerr, T., Chamness, M., Chenier, T. C., Kelly, R. R., & Hodge, T. (1996). "Assessment of exercise-induced minor muscle lesions. The accuracy of Cyriax’s diagnosis by selective tension paradigm". Journal of Orthopaedic & Sports Physical Therapy, 24(3), 122–129. Original construct-validity study; PubMed abstract consulted for the active, passive, resisted and palpation components and their limits.
[^ref-198965fd2e55]: American Academy of Orthopaedic Surgeons. (2025). "Management of Rotator Cuff Injuries Evidence-Based Clinical Practice Guideline". Professional guideline; Diagnosis (Clinical Examination) recommendation and rationale consulted. Its accuracy finding concerns rotator-cuff assessment.
[^ref-915b3e666c8f]: Greene, C., Droppelmann, G., García, N., Jorquera, C., & Verdugo, A. (2022). "A new test for the advanced diagnosis of lateral elbow tendinopathy with concomitant intrasubstance tear: Failure to Resist Extension Effort (the Free test)". Orthopedic Research and Reviews, 14, 495–503. Original comparative study; publisher PDF consulted for the Cozen comparator and the new Free index test. It does not establish an isometric Cozen protocol.