Reflex hyperactivity of paraspinal muscles in etiology of back pain in helicopter pilots (full text in pdf)
Stojan Jovelic1, a
1Institute of Aviation Medicine, VMA, Belgrade, Serbia
Abstract The position of the helicopter pilot can be described as a forced seated posture in relation to the seat and controls. The aim of this study was to detect reflex hyperactivity of the paraspinal muscles in test subjects resulting from prolonged uncomfortable sitting. Electromyographic activity was registered from paraspinal muscles during sustained paraspinal contraction. This activity was recorded by surface electrodes on four levels, from both sides on the erector spinae muscle with an eight-channel oscilloscope using integrated EMG signals. The results indicated a significant rise (p<0.05) in electromyographic activity of the paraspinal muscles for five test subjects on both levels and sides investigated and compared to a raw signal recorded just before being placed in a sitting position. Findings made during this study suggest the possibility of existence of a reflex spasm in the paraspinal muscles, provoked by an awkward, fixed sitting position. This reflex is believed to be a potential generator of low back pain.
Keywords: Electromyography; paraspinal muscles; pilots.