Diagnostic accuracy of the compression overload test versus straight leg raise test in detecting lumbar disc herniation: an MRI-validated cross-sectional study

Key Points

1. The Compression Overload Test (COLT) demonstrated 92% sensitivity for detecting lumbar disc herniation, significantly outperforming the Straight Leg Raise Test (SLRT).
2. The study was not able to provide evidence that COLT was specific in detecting herniation, because there were only three people in the study sample without disc herniation.

BACKGROUND AND OBJECTIVE

The Straight Leg Raise Test (SLRT) is widely used to diagnose lumbar disc herniation but has limited sensitivity in non-radicular cases. The Compression Overload Test (COLT) seeks to identify disc herniations by creating axial compression.

This study compared the diagnostic accuracy of COLT and SLRT against MRI findings in patients with acute low back pain associated with intervertebral disc herniation (IVDH).

The Straight Leg Raise Test is widely used to diagnose lumbar disc herniation but has limited sensitivity in non-radicular cases.

The Compression Overload Test is more sensitive than the Straight Leg Raise Test for detecting disc pathology.

METHODS

• 53 participants with acute low back pain who recently underwent an MRI were recruited. COLT and SLRT tests were performed on each participant (see Video 1).

• The COLT test was positive if the patient felt pain under the following condition: the patient is in supine with hips/knees flexed to 90°, and the examiner creates axial compression through the femur in a cephalad direction.

• The SLRT test was positive if the pain is felt between 30 and 70 degrees of passive hip flexion with extended knee in supine.

• Diagnostic performance was evaluated using sensitivity, specificity, positive/negative predictive values, and ROC curve analysis with MRI as the reference standard.

VIDEO 1 – COLT AND SLRT

RESULTS

• 50 of 53 participants (94.3%) had MRI-confirmed lumbar IVDH.

• COLT was positive in 47 participants (88.7%) with 92% sensitivity and 66.7% specificity. SLRT was positive in only 15 participants (28.3%) with 28% sensitivity and 66.7% specificity.

• COLT demonstrated diagnostic accuracy of 90.6% compared to 30.2% for SLRT.

• COLT showed moderate correlation with MRI (Φ=0.428, p=0.002) and fair-to-good discriminative capacity (AUC=0.793). SLRT showed no correlation with MRI (Φ=-0.027) and poor discriminative ability (AUC=0.473).

• Vertebral endplate changes (Schmorl's nodes and Modic changes) were observed in 20 participants, predominantly at L1, L3, and L5 levels.

LIMITATIONS

The sample included only three participants with negative MRIs, which means the specificity estimate is not statistically meaningful. Nor is the diagnostic accuracy statistic. To illustrate, any test that provoked back pain would also have received 95% diagnostic accuracy, because 95% of the people had herniated discs.

CLINICAL IMPLICATIONS

Low back pain affects millions worldwide, with lumbar disc herniation being the most prevalent anatomical cause (1). SLRT has been the traditional screening test for disc herniation, but its sensitivity drops significantly in non-radicular cases and older adults (2). COLT is designed to assess the lumbar spine’s capacity to withstand axial compression (3). It is based on the theory that vertebral endplate abnormalities may play a key role in causing IVDH (4).

This study provides evidence that COLT is more sensitive than SLRT (i.e. it avoids false negatives) for detecting disc pathology - it was positive in 88% of participants with lumbar disc herniation compared to only 28% for SLRT.

However, the study does not provide good evidence that COLT is specific, (i.e. it avoids false positives) given that there were only three individuals without disc herniations. Of these, the COLT correctly assessed that two of the three (66.7%) did not have a disc herniation. But the sample is too small to assume this percentage is an accurate estimate of specificity.

Clinicians should consider using COLT to identify cases of disc herniations, but keep in mind that further research is necessary to determine whether it is likely to create false positives.

+STUDY REFERENCE

Madhesh M, Eapen C, Kumaraswamy P, Palaniswamy V (2025) Diagnostic accuracy of the compression overload test versus straight leg raise test in detecting lumbar disc herniation: an MRI-Validated Cross-Sectional study. Eur Spine J, Published online first.

SUPPORTING REFERENCE

1. Shetty GM, Jain S, Thakur H, Khanna K. Prevalence of low back pain in India: A systematic review and meta-analysis. Work. 2022;73(2):429-452.
2. Al-Sharaa M, Salo SA, Kareem AF, Al-Edanni MS. Slump test versus straight leg raise test in the diagnosing of lumbar disc herniation: A prospective comparative study. Al-Kindy Coll Med J. 2021;17(1):41-44.
3. Pouriesa M, Fouladi RF, Mesbahi S. Disproportion of end plates and the lumbar intervertebral disc herniation. Spine J. 2013;13(4):402–407.
4. Van Dieën JH, Weinans H, Toussaint H. Fractures of the lumbar vertebral endplate in the etiology of low back pain: a hypothesis on the causative role of spinal compression in a specific low back pain. Med Hypotheses. 1999;53(3):246-252.