[Electromyographic Analysis of Neck Muscles at a Simulated Rear-end Impact in Healthy Subjects]. / Elektromyografische Analyse der Halsmuskulatur bei simulierter Heckkollision an gesunden Probanden.

ABSTRACT

BACKGROUND: Despite the introduction of safety belts and head restraints, severe neck injuries still occur in traffic accidents. Whether there are anthropometric factors or muscular properties, that affect the reflex times during a rear-end collision, and if they have predictive value for the expected trauma, should be reviewed in this investigation. METHODS: In 32 male volunteers anthropometric data and the maximal strength of their cervical musculature were measured. Thereafter, the volunteers were subjected to a simulated rear-end collision with a speed of 2 km/h. The impending crash was not announced to the subjects during the first test run. The situation was repeated several times to test the effect of warning. During the investigation, the muscle activity of neck and shoulder muscles was derived with surface electromyography (EMG). RESULTS: There was a strong correlation between the reflex time of the anterior neck muscles and the strength of that muscle group (r=-0.75; r²=0.57). In addition, the neck length correlated to the reflex time (r=-0.67; r²=0.45). The warning provided for the volunteers influences the EMG as well. The reflex times of the subjects were shorter (p Alle statistischen Berechnungen wurden mit IBM SPSS Statistics (Version 18; IBM Inc., Armonk, USA), sowie dem Programm Excel, (Microsoft, Redmond, USA) vorgenommen. Die Reflexzeiten wurden den anthropometrischen Daten, sowie der Muskelkraft gegenübergestellt und nach Pearson korreliert. Als eine angemessene Korrelation wurde das Quadrat des Korrelationskoeffizienten bei Werten r²>0,4 festgelegt. Außerdem wurden die Mediane der Reflexzeiten, der verschiedenen Kollisionssituationen miteinander verglichen. Das Signifikanz-Niveau wurde auf p<0,05 festgelegt. 0.05), when they knew about the impending collision. CONCLUSION: A high force capacity of anterior neck muscles has preventive value to reduce the consequences of whiplash accidents. The use and development of early warning systems in cars should be supported.