From the Guidelines
A herniated intervertebral disc (IVD) typically presents with specific physical examination findings, including a positive straight-leg-raise test, neurologic deficits such as motor weakness and sensory changes, and reflex abnormalities, as outlined in the American College of Physicians and American Pain Society guideline 1. The physical examination findings of a herniated IVD can be summarized as follows:
- A positive straight-leg-raise test, which has a relatively high sensitivity (91% [95% CI, 82% to 94%]) but modest specificity (26% [CI, 16% to 38%]) for diagnosing herniated disc 1
- Neurologic deficits, including:
- Motor weakness in the distribution of the affected nerve root, such as foot drop with L5 compression or weak plantar flexion with S1 involvement
- Sensory deficits following dermatomal patterns corresponding to the compressed nerve root
- Reflex abnormalities, including:
- Diminished or absent ankle reflex with S1 compression
- Diminished or absent knee reflex with L4 involvement
- Other findings, such as:
- Antalgic posture, leaning away from the side of herniation to reduce pressure on the nerve root
- Palpation revealing paraspinal muscle spasm and tenderness over the affected area It is essential to note that the crossed straight-leg-raise test is more specific (88% [CI, 86% to 90%]) but less sensitive (29% [CI, 24% to 34%]) for diagnosing herniated disc 1. Additionally, psychosocial factors and emotional distress should be assessed, as they are stronger predictors of low back pain outcomes than physical examination findings or severity and duration 1.
From the Research
Physical Examination Findings
The physical examination findings of a herniated intervertebral disc (IVD) may include:
- Low-back pain with leg pain (sciatica) 2
- Muscle spasm 3
- Scoliosis 2
- Paresis or muscle weakness 2
- Muscle wasting 2
- Impaired reflexes 2
- Sensory deficits 2
- Positive Straight Leg Raising (SLR) test 2
- Positive crossed SLR test 2
Diagnostic Performance of Physical Tests
The diagnostic performance of physical tests used to identify lumbar disc herniation is generally poor when used in isolation 2. However, some tests such as the SLR test and crossed SLR test may perform slightly better 2. The sensitivity and specificity of these tests can vary widely, and the results may be influenced by the population being studied 2.
Specific Findings in Certain Populations
In surgical populations, the SLR test has been shown to have high sensitivity (pooled estimate 0.92) but variable specificity (0.10 to 1.00) 2. In primary care populations, the diagnostic performance of physical tests may be different, with higher specificity and lower sensitivity 2.
Other Findings
In some cases, a herniated IVD can cause cauda equina syndrome, which may present with symptoms such as urinary and defecation dysfunction [(4,5)]. In these cases, early operative decompression may be necessary to relieve symptoms and prevent severe neurological deficits [(4,5)].