Effects of muscle training on improving neck/lumbar functions

Objective To provide measure for preventing and rehabilitating neck and lumbar injury in fighter pilots by 6-wk program of neck and psoas muscle isometric training cooperated with healing setting-up exercises. Methods Six male healthy volunteers were trained in isometric contractions twice a week for 6 weeks by using self-designed Neck and Psoas Muscle Isometric Training Cooperated Equipment. During training, subjects seated and kept the same posture as in flight. They performed 2 sets of neck and lumbar extension exercises with 60% maximal voluntary contraction (MVC) strength for 10 times. Subjects also completed healing setting-up exercises before equipment training. They were also asked to perform additional healing setting-up exercises by themselves at least twice a week. The setting-up exercises included: relax in prone posture, prone posture stretching, prostrate straight on back, sit-up, and standing stretching. The pre- and post-training tests consisted of the isometric MVC strength in neck extension, neck left lateral flexion (Ltflx) and right lateral flexion (Rtflx), lumbar extension, 10 s maximal strength impulse and 90 s maximal strength total impulse in neck/lumbar extension test, electromyography in impulse test, spine active range-of-motion (ROM) in flexion and extension, Ltflx and Rtflx, left and right rotation. The software package SPSS 18.0 was applied for paired t-test. Results Compared with those before training, post-training neck isometric MVC in extension and Ltflx improved significantly (t=4.140, 3.125, P<0.05). Lumbar extension isometric MVC mean value increased 10%. 10 s maximal strength impulse and 90 s maximal strength total impulse in neck and lumbar extension increased significantly (t=2.631-3.202, P<0.05). ROM in neck extension, lumbar flexion and left rotation improved significantly (t=4.011-6.343, P<0.01). In SEMG, median frequency in 90 s neck extension and root-mean-square in 10 s lumbar extension decreased significantly (t=3.402, 2.944, P<0.05). The others did not significantly change. Conclusions Neck and lumbar muscle isometric exercise at the same sitting posture as pilot in flight cooperated with healing setting-up exercises shows a positive trend toward improving pilot extension strength and endurance, enhancing stabilizers of spine and activity functions. Further research should be directed to the effect of training on promoting neck and lumbar healing. Key words: Neck muscles; Psoas muscles; Muscle strength; Exercise; Physical education and training; Methods