Double crush syndrome in lower extremities.

Retrospective analysis of results of electromyography and nerve conduction velocity was performed in 169 patients with lower back pain, mostly caused by trauma. A total 289 peroneal, 280 posterior tibial and 301 sural nerves were included in statistical analysis. Peripheral entrapment of nerves (tarsal tunnel syndrome and anterior tarsal tunnel syndrome) were found in 5.3% of patients, signs of acute or chronic partial muscle denervation of corresponding muscles of lower extremities in 21.8% of patients, and abnormally prolonged F-wave latency in 12.5% of patients. Combined partial denervation and abnormally prolonged F-wave latency were found in 6.2% of patients, combined partial denervation and peripheral entrapment of nerves in 4.4% of patients, combined abnormally prolonged F-wave latency and peripheral entrapment of nerves in 2.4% of patients and combined partial denervation, abnormally prolonged F-wave latency and peripheral entrapment of nerves in 3.5% of patients. Statistical analysis of these data showed significantly higher than random overlap of peripheral entrapment syndromes and signs of proximal nerve damage of the corresponding nerves (partial muscle denervation or abnormalities of F-wave). This higher than random coincidence of the two conditions strongly suggests cause-and-effect relationship of damage of the proximal stretch of motor nerve fibers and development of peripheral entrapment syndromes in the same nerves rather than a random coincidence of two independent pathologies. Appreciation of this causal relationship is important in the development of comprehensive approach to treatment of peripheral entrapment syndromes. In appropriate cases, simultaneous treatment of the lower back problem should be considered as well.