Ely’s Test

Ely’s Test is used to evaluate the flexibility and range of motion (ROM) of the rectus femoris muscle. It is particularly useful for identifying tightness or spasticity in the rectus femoris, especially in patients with cerebral palsy (CP) and those presenting with stiff-knee gait【1】.

In clinical practice, Ely’s Test is commonly applied to assess muscle balance in the lower extremities and for preoperative evaluation of rectus femoris spasticity【2】【3】.

Test Procedure

Patient Position

• Patient lies prone (face down) in a relaxed position.

Examiner Position

• Examiner stands beside the tested leg.

• One hand is placed on the patient’s lower back to monitor hip movement.

• The other hand holds the patient’s heel.

Execution

• The examiner rapidly flexes the knee, bringing the heel toward the buttocks.

• The test is performed on both sides for comparison.

Interpretation

• Positive test:

  • Heel cannot touch the buttocks

  • Hip rises from the table (compensatory movement)

  • Pain or paresthesia in lumbar spine or lower extremities

• Negative test:

  • Heel touches buttocks without compensatory motion or pain

Diagnostic Validity and Reliability

Sensitivity and Specificity

• Sensitivity: 56–59%

• Specificity: 64–85%【1】【4】

This suggests moderate diagnostic value. High specificity means Ely’s Test is more reliable for confirming muscle tightness, but its relatively low sensitivity means that a negative test does not rule out spasticity.

Reliability

• Intra-rater reliability: ICC = 0.819 at higher testing speeds → highlights the importance of standardized test speed【2】.

• Inter-rater reliability: Moderate to low if test speed varies.

• Using a goniometer or standardized tools improves reliability (ICC = 0.90)【1】.

Comparison with Other Methods

• Compared to 3D gait analysis (3DGA), Ely’s Test showed moderate sensitivity (66.7%) and high specificity (100%) for reduced knee motion【2】.

• However, in stroke patients, studies found no significant correlation between Ely’s Test and EMG activity in rectus femoris, suggesting limited diagnostic value in this population【5】.

Clinical Significance

Implications of Rectus Femoris Spasticity

• Leads to knee extension during swing phase, impairing gait mechanics.

• May cause hip elevation during the test, revealing compensatory strategies important for rehabilitation planning.

• Chronic tightness may result in:

  • Lumbar hyperlordosis during walking

  • Reduced knee mobility → compensatory gait dysfunction

  • Functional limitations in daily activities

Critical Considerations

• Not fully specific for rectus femoris → EMG studies show iliacus muscle activation may also influence test outcomes【6】.

• Test results are highly dependent on speed – faster flexion improves reliability but may increase patient discomfort【3】.

• Individual differences (training history, pain, neurological condition) may impact outcomes【1】.

Conclusion

Ely’s Test is a quick and clinically useful method for assessing rectus femoris flexibility and spasticity, especially in patients with cerebral palsy or stiff-knee gait. Its high specificity makes it effective for confirming tightness, but its low sensitivity limits its ability to rule out pathology.

Due to variable reliability, Ely’s Test should be combined with other clinical assessments and functional analyses for a more accurate evaluation of lower extremity muscle status.

Sources

1. Olivencia O, Godinez GM, Dages J, Duda C, Kaplan K, Kolber MJ. The reliability and minimal detectable change of the ely and active knee extension tests. International journal of sports physical therapy. 2020 Oct;15(5):776.

2. Lee SY, Sung KH, Chung CY, Lee KM, Kwon SS, Kim TG, Lee SH, Lee IH, Park MS. Reliability and validity of the Duncan‐Ely test for assessing rectus femoris spasticity in patients with cerebral palsy. Developmental Medicine & Child Neurology. 2015 Oct;57(10):963-8.

3. Stott S. The Duncan-Ely test: time for standardization. Developmental Medicine & Child Neurology. 2015 Oct 1;57(10).

4. Peeler J, Anderson JE. Reliability of the Ely's test for assessing rectus femoris muscle flexibility and joint range of motion. Journal of Orthopaedic Research. 2008 Jun;26(6):793-9.

5. Tenniglo MJ, Nederhand MJ, Fleuren JF, Rietman JS, Buurke JH, Prinsen EC. Does the Duncan-Ely test predict abnormal activity of the rectus femoris in stroke survivors with a stiff knee gait?. Journal of rehabilitation medicine. 2021 Nov 1;54:637.

6. Perry J, Hoffer MM, Antonelli D, et al. Electromyography before and after surgery for hip deformity in children with cerebral palsy. A comparison of clinical and electromyographic findings. J Bone Joint Surg [Am]. 1976;58:201–208.

7. Chambers H, Lauer A, Kaufman K, et al. Prediction of outcome after rectus femoris surgery in cerebral palsy: the role of cocontraction of thefckLRrectus femoris and vastus lateralis. J Pediatr Orthop. 1998;18:703–711.