There is insufficient epidemiologic evidence to draw meaningful conclusions about ( i ) the existence of causal associations between specific occupational mechanical exposures and the development of inguinal hernia , and ( ii ) the influence of these exposures on prognosis after inguinal hernia repair with respect to hernia recurrence and persistent pain
OBJECTIVES The aim of this review was to evaluate the epidemiologic evidence for ( i ) a causal effect of occupational mechanical exposures on incidence of inguinal hernia , and ( ii ) a prognostic effect of such exposures on hernia recurrence and persistent pain after inguinal hernia repair .
Intra-abdominal pressure increases during exhausting back extension in humans
Abstract . The aim of this study was to investigate in humans the effect of maintained spinal load on the intra-abdominal pressure ( IAP ) , low back kinematics and trunk muscle activity . This study consisted of two endurance tests for the low back muscles performed 3 weeks apart . Nine healthy subjects participated in the study . In the first test ( upright-test ) , the subject had to pull with the back muscles at a constant force in an upright position , and in the second test ( incline-test ) , the subject had to resist a constant forward pulling force while st and ing with a 45 ° inclination of the back in relation to vertical .  The IAP , rate of perceived exertion and electromyogram ( EMG ) from the erector spinae , iliocostalis lumborum , rectus abdominus and the external and internal oblique muscles were measured using surface electrodes . There was no significant difference in endurance time between the two tests . Both tests showed a significant increase in EMG amplitude with time for all muscles except the erector spinae muscle . A decrease in the median frequency for the erector spinae muscle was found indicating fatigue , and since no increase in EMG amplitude was found a decrease in force output from the muscle must be assumed . The IAP increased significantly during both tests . There was a considerable variation between the subjects in the size of this development , but the pattern was the same for all subjects . In conclusion it was found that trunk extension until exhaustion initiates an increase in the activity of the abdominal muscles and an increase in the IAP as the low back muscles become fatigued
There is insufficient epidemiologic evidence to draw meaningful conclusions about ( i ) the existence of causal associations between specific occupational mechanical exposures and the development of inguinal hernia , and ( ii ) the influence of these exposures on prognosis after inguinal hernia repair with respect to hernia recurrence and persistent pain
OBJECTIVES The aim of this review was to evaluate the epidemiologic evidence for ( i ) a causal effect of occupational mechanical exposures on incidence of inguinal hernia , and ( ii ) a prognostic effect of such exposures on hernia recurrence and persistent pain after inguinal hernia repair .