Abstract
The contraction of deep abdominal musculature increase the stiffness of lumbar spine via the thoracolumbar fascia, and has also been shown to increase intra-abdominal pressure, which has important roles to provide stability of posture and lumbar spine. We investigated age-related changes of lateral abdominal muscles, and postoperative changes of these during rest position, abdominal drawing-in maneuver (Draw-in) and head-lift exercise by using ultrasound imaging device. Thirty elderly men with spine disorder to undergo surgery (elderly patients: average 67 years old) and 10 healthy young men (young men: average 22 years old) as a control group were participated in this study. The thickness and echo intensity of transversus abdominis (TrA), internal oblique (IO) and external oblique (EO) were observed. The elderly patients were measured at before surgery, at 2 and 7 days after surgery. No age-related change was observed in the TrA muscle thickness at rest position, but the EO muscle thickness in elderly patients reduced 50 % compared with those in young men (p<0.05). In the elderly patients, the amount of adipose tissue and non-contractile tissue was increasing, which was observed at superficial abdominal muscles rather than deep abdominal muscles. Compared with before operation, the TrA muscle at rest position was significantly reduced by 17% at 7 days after surgery (p<0.05). The muscle thickness of the TrA and IO were increased by the Draw-in and head-lift after surgery (p<0.05). Our findings indicate that age-related qualitative and quantitative changes were observed in superficial abdominal muscles compared with deep abdominal muscles, and the Draw-in and head-lift were effective trainings of activation deep abdominal muscles rather than superficial. In addition, our results suggest that the TrA might be atrophy in elderly individuals after lumbar surgery in the early phase because of operative stress or reduced activity by postoperative bed rest.
