Responses of intra-abdominal pressure and abdominal muscle activity during dynamic trunk loading in man

SummaryThe purpose of this study was to determine and compare interactions between the abdominal musculature and intea-abdominal pressure (IAP) during controlled dynamic and static trunk muscle loading. Myoelectric activity was recorded in six subjects from the rectus abdominis, obliquus externus, obliquus internus, transversus abdominis and erector spinae muscles using surface and intea-muscular fine-wire electrodes. The IAP was recorded intea-gastrically. Trunk flexions and extensions were performed lying on one side on a swivel table. An adjustable brake provided different friction loading conditions, while adding weights to an unbraked swivel table afforded various levels of inertial loading. During trunk extensions at all friction loads, IAP was elevated (1.8–7.2 kPa) with concomitant activity in transversus abdominis and obliquus internus muscles — little or no activity was seen from rectus abdomin is and obliquus externus muscles. For inertia loading during trunk extension, IAP levels were somewhat lower (1.8–5.6 kPa) and displayed a second peak when abdominal muscle activity occurred in the course of decelerating the movement. For single trunk flexions with friction loading, IAP was higher than that seen in extension conditions and increased with added resistance. For inertial loading during trunk flexion, IAP showed two peaks, the larger first peak matched peak forward acceleration and general abdominal muscle activation, while the second corresponded to peak deceleration and was accompanied by activity in transversus abdominis and erector spinae muscles. It was apparent that different loading strategies produced markedly different patterns of response in both trunk musculature and intea-abdominal pressure.

[1]  I A Kuorinka,et al.  A Comparison of Intraabdominal Pressure Increases, Hip Torque, and Lumbar Vertebral Compression in Different Lifting Techniques , 1983, Human factors.

[2]  K D Thomson.  On the bending moment capability of the pressurized abdominal cavity during human lifting activity. , 1988, Ergonomics.

[3]  U. Moritz,et al.  Intra-abdominal pressure and trunk muscle activity during lifting. II. Chronic low-back patients. , 1985, Scandinavian journal of rehabilitation medicine.

[4]  A. Thorstensson,et al.  The role of the abdominal musculature in the elevation of the intra-abdominal pressure during specified tasks. , 1989, Ergonomics.

[5]  A Thorstensson,et al.  Observations on intra-abdominal pressure and patterns of abdominal intra-muscular activity in man. , 1992, Acta physiologica Scandinavica.

[6]  J. Silver,et al.  An electromyographic study of the abdominal muscles during postural and respiratory manoeuvres. , 1987, Journal of neurology, neurosurgery, and psychiatry.

[7]  D B Chaffin,et al.  A Study of Lumbosacral Orientation under Varied Static Loads , 1986, Spine.

[8]  S Kumar,et al.  Physiological responses to weight lifting in different planes. , 1980, Ergonomics.

[9]  V. Ninane,et al.  Transversus abdominis muscle function in humans. , 1990, Journal of applied physiology.

[10]  A. Schultz,et al.  Valsalva Maneuver Biomechanics: Effects on Lumbar Trunk Loads of Elevated Intraabdominal Pressures , 1986, Spine.

[11]  A. Thorstensson,et al.  Trunk muscle strength during constant velocity movements. , 1982, Scandinavian journal of rehabilitation medicine.

[12]  D. Bartelink.  The role of abdominal pressure on the lumbar intervertebral disk , 1957 .

[13]  A Thorstensson,et al.  Intra-abdominal pressure changes during natural movements in man. , 1978, Acta physiologica Scandinavica.

[14]  S. McGill,et al.  Relationship between intra-abdominal pressure and trunk EMG. , 1990, Clinical biomechanics.

[15]  A. Schultz,et al.  The Activity of Individual Trunk Muscles During Heavy Physical Loading , 1987, Spine.

[16]  K. Strohl,et al.  Regional differences in abdominal muscle activity during various maneuvers in humans. , 1981, Journal of applied physiology: respiratory, environmental and exercise physiology.

[17]  U. Moritz,et al.  Intraabdominal pressure and trunk muscle activity during lifting--effect of abdominal muscle training in healthy subjects. , 1983, Scandinavian journal of rehabilitation medicine.

[18]  E. Knutsson,et al.  The effect of voluntary diaphragmatic activation on back lifting. , 1988, Scandinavian journal of rehabilitation medicine.