The electrodiagnostic sensitivity of proximal lower extremity muscles in the diagnosis of L5 radiculopathy

The aim of this study was to assess the electrodiagnostic (EDx) sensitivity of proximal lower extremity muscles, including tensor fascia lata (TFL) and gluteus medius (GMED), in the diagnosis of L5 radiculopathy.Eleven EDx recordings with L5 radiculopathy were collected. The motor unit action potentials were assessed for morphology, stability, and firing characteristics. A descriptive analysis was performed. In proximal L5-supplied muscles, 4 of 11 recordings were abnormal in TFL only, with normal GMED; 4 of 11 recordings had similar findings in both muscles; 2 of 11 had abnormal findings in both muscles, but TFL had more noticeable findings; and 1 had abnormal findings in both muscles, but GMED findings were more noticeable. No patient had abnormalities limited to GMED. TFL was more sensitive than GMED in detecting L5 radiculopathy. Knowing which muscles are more likely to show abnormalities can improve the efficiency of EMG and reduce patient discomfort. Muscle Nerve 45: 891–893, 2012