BACKGROUND: Lower back pain or lower limb paresthesia is a symptom commonly encountered in otherwise healthy adults. The dilemma often faced by the clinician is to determine whether the symptom is a result of neurological compromise due to pathological changes in the spinal anatomy. METHODS: Electromyography (EMG) is widely used for diagnosing and localizing the level of radiculopathy. Single radiculopathy were considered to be true positive when electrophysiologic study diagnosed single root lesion. A series of 211 cases with lower back pain or paresthesia in the lower limb was studied. They were composed of 79 patients with single lumbar radiculopathy and 132 patients with normal EMG. RESULTS: The frequency of neurologic deficit was 63.3% in patients with radiculopathy and 44.7% in patients with normal EMG. The sensitivity of neurologic examination was 63.3% and the specificity, 78.6%. Nonsegmental neurologic deficit was more frequent and the rate of diagnosis of radiculopathy was less higher in the patients who needed a repayment. There was no significant effect of the time after onset on clinical features. CONCLUSIONS: This study confirmed that physical examination was not enough to detect radiculopathy and electrophysiological study would be required for accurate diagnosis. In addition, nonorganic factor should be considered in evaluation of the patients concerning for repayment.