Intra-abdominal pressure and trunk muscle activity during lifting. III. Effect of abdominal muscle training in chronic low-back patients.
Isometric training of the abdominal muscles is often recommended in programs of primary or secondary prevention for low-back pain. In this study 20 male workers with 2-18 years' history (average 5 1/2 years) of low-back pain without sciatica went through intense isometric abdominal muscle training for 5 weeks. Before and after training the subjects had trunk flexion and extension strength tests and a series of standardized lifts. The intraabdominal pressure (IAP) and the EMG activity of the oblique abdominal muscles, and of the erector spinae muscle were recorded. It was found that: the strength of the abdominal muscles increased; the increased strength was correlated to an improved recruitment of motor units in the oblique abdominal muscles; the EMG activity of the oblique abdominal muscles when lifting decreased after training, i.e. the acquired ability to recruit more motor units was not made use of; the IAP at lifting was generally not affected. A better knowledge of the mechanisms responsible for the IAP in different situations is needed to support advice on training or other prevention.
Hemborg
B
B
Moritz
U
U
Hamberg
J
J
Holmström
E
E
Löwing
H
H
Akesson
I
I
D000005:Abdomen; D000009:Abdominal Muscles / Q000503:physiopathology*; D000328:Adult; D001416:Back Pain / Q000503:physiopathology / Q000517:prevention & control / Q000628:therapy*; D004576:Electromyography; D006801:Humans; D007537:Isometric Contraction; D008297:Male; D009119:Muscle Contraction; D010806:Physical Education and Training / Q000379:methods; D005082:Physical Exertion; D011312:Pressure