Physical examination maneuver

Physical Exam

Knee Strength

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How to Perform

Test knee strength against resistance in flexion and extension, comparing sides. Grade strength and note any pain or give-way weakness.

How to Interpret

Showing 1 of 8 findings

Functional Neurologic Disease

Give-way (collapsing) weakness on resisted strength testing
Rule in
Very helpfulNo CI
Rule out
Somewhat helpfulNo CI
Evidence:Moderate

Related Bedside Tests

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Patellar Deep Tendon Reflex
aka Knee jerk
Rule in:VHLumbosacral Radiculopathy, VHPeripheral Neuropathy, IECerebellar Disease +5 more
Rule out:SHPeripheral Neuropathy, ICLumbosacral Radiculopathy, IECerebellar Disease +5 more
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Hip Strength
Rule in:VHFunctional Neurologic Disease, VHGluteal Tendinopathy, VHLumbosacral Radiculopathy +6 more
Rule out:HGluteal Tendinopathy, HLumbosacral Radiculopathy, SHFunctional Neurologic Disease +6 more
🎬Video coming soon
Achilles Deep Tendon Reflex
aka Ankle jerk
Rule in:VHPeripheral Neuropathy, SHHypothyroidism, NHLumbosacral Radiculopathy +5 more
Rule out:VHPeripheral Neuropathy, MHHypothyroidism, NHLumbosacral Radiculopathy +5 more
🎬Video coming soon
Calf Circumference
Rule in:HLumbosacral Radiculopathy, SHSarcopenia, MHDeep Vein Thrombosis +1 more
Rule out:SHSarcopenia, MHDeep Vein Thrombosis, NHLumbosacral Radiculopathy +1 more
🎬Video coming soon
Straight Leg Raise
aka Lasègue sign
Rule in:SHLumbosacral Radiculopathy, NHLumbar Disc Herniation, IECauda Equina Syndrome
Rule out:SHLumbar Disc Herniation, NHLumbosacral Radiculopathy, IECauda Equina Syndrome
🎬Video coming soon
Gait Assessment
Rule in:VHStroke, HFalls, HVascular Parkinsonism +24 more
Rule out:SHDementia, SHVascular Parkinsonism, MHFalls +24 more

Related Systems / Regions

KneeLower ExtremitiesMusculoskeletal

Related Diagnoses

Extensor Mechanism DisruptionFemoral NeuropathyFunctional Neurologic DiseaseLumbosacral RadiculopathySciatic Neuropathy

Related Chief Complaints

Anterior Thigh PainBack PainCannot Extend the KneeDifficulty Climbing StairsFront of Thigh PainGroin Pain Radiating to the ThighKnee BucklingKnee Gave Way After a FallLeg Gives WayLeg NumbnessLeg PainLeg WeaknessNumbness Over the Front of the ThighSciaticaShooting Leg PainTingling in the LegUnable to Straighten the KneeWeak Knee ExtensionWeak Quadriceps

References

Research in progress on one or more findings above; ratings may change.

  • Bertilson BC, Brosjö E, Billing H, Strender LE. Assessment of nerve involvement in the lumbar spine: agreement between magnetic resonance imaging, physical examination and pain drawing findings. BMC Musculoskelet Disord. 2010;11:202. doi:10.1186/1471-2474-11-202. PMID: 20831785.
  • Al Nezari NH, Schneiders AG, Hendrick PA. Neurological examination of the peripheral nervous system to diagnose lumbar spinal disc herniation with suspected radiculopathy: a systematic review and meta-analysis. Spine J. 2013 Jun;13(6):657-674. doi:10.1016/j.spinee.2013.02.007. PMID 23499340.
  • Rahman A, Ashour A, Hamed A, Nikolaides AP, Boutefnouchet T. The Fixed Patella Test: a reliable and accurate test for detecting quadriceps tendon rupture. Cureus. 2025;17(10):e93717. doi:10.7759/cureus.93717. PMID: 41181756. (Closest candidate; studied a different sign.)
  • Daum C, Hubschmid M, Aybek S. The value of 'positive' clinical signs for weakness, sensory and gait disorders in conversion disorder: a systematic and narrative review. J Neurol Neurosurg Psychiatry. 2014 Feb;85(2):180-190. doi:10.1136/jnnp-2012-304607. PMID 23467417.
  • Bickley LS, Szilagyi PG, Hoffman RM, Soriano RP. Bates' Guide to Physical Examination and History Taking. 13th ed. Philadelphia, PA: Wolters Kluwer; 2021.
  • Swartz MH. Textbook of Physical Diagnosis: History and Examination. 9th ed. Philadelphia, PA: Elsevier; 2025.

Research last updated September 10, 2026.