BACK PAIN ON HELICOPER PILOTS USING NIGHT VISION GOGGLES, DIAGNOSTIC PROCEDURES AND OPTIONS FOR TREATMENT

G. Fritsch,Schladming MD, practice for sportsmedicine, Schladming, Austria

Abstract

Introduction

Back pain is a common problem in western societies. Many studies show the prevalence of back problems also in helicopter pilots, especially while using night vision googles (NVG). To have no problem because of backpain, it is necessary, to have enough strength in the trunk muscles. So the flying tasks can be made without impairment of concentration, operational readiness and flying safety. Our aim was to measure the strength of the trunk muscles, and if there is not enough, to develope solutions to avoid flight problems because of back problems.

Methods

In the period of time from 2004 to 2007 we tested helicopter pilots of the Austrian Airforce who joined a training for flying with night vision googles. Everybody of this group ran a checkup of the maximum isometric strength of the upper body. We took measure of 4 directions, bending foreward and backward, sideward left and right. The instrument we used for measurement is the so called Back Check^® System. It is built as a frame, the person is fixed within. The person gives the maximum pressure on special sensors, which show the reached maximum in kilograms on a display. The normative value of 100% is reached from persons, which are free of backpain. Lower values correlate with a high prevalence for back problems. Every person had 3 attempts, the best was taken.

Results

We tested 49 helicopterpilots, mean age 38 yrs (SD +/-11), mean weight 78,8 kg (SD +/-8,7) mean height 180 cm (SD +/-6,4), the mean body mass index 24,3 (SD +/-2,3).

The mean maximum force in extension of the trunk was 137% from normal 100% (SD +/- 32), flexion 129% (SD +/-28). 16% (=8 pilots) of the tested crewmembers had a deficit in the force of the trunk muscles. 33% had a strenght difference between left and right of more than 10%. We saw a relation of maximum force between right and left of 52,2% to 47,2%.This fact depends on being right or left handed or also on the pilot´s position inside the helicopter.

Conclusion

Some of the pilots we testes for maximum isometric force, had a distinct  deficit of the strenght of trunk muscles. To avoid back problems it is necessary to establish diagnostic procedures to recognice defizits of strength in trunk muscles and to train persons with a strenght-level which is lower than 100% on one side and to lower the loading for the back by optimizing the design of helmets.

Keywords