Beevor’s sign is an upward movement of the umbilicus in a supine patient attempting either to flex the head onto the chest against resistance (e.g., the examiner’s hand) or performing a sit-up. It indicates a lesion causing rectus abdominis muscle weakness below the umbilicus. This may occur with a spinal lesion (e.g., tumor, syringomyelia) between T10 and T12 causing isolated weakness of the lower part of the muscle, or myopathies affecting abdominal muscles, particularly facioscapulohumeral muscular dystrophy. Lower cutaneous abdominal reflexes are also absent, having the same localizing value.
Downward movement of the umbilicus ("inverted Beevor’s sign") due to weakness of the upper part of rectus abdominis is less often seen.
Hilton-Jones D. Beevor’s sign. Practical Neurology 2004; 4: 176-177 Tashiro K. Charles Edward Beevor (1854-1908) and Beevor’s sign. In: Rose FC (ed.). A short history of neurology: the British contribution 1660-1910. Oxford: Butterworth Heinemann, 1999: 222-225