Spine loading and trunk kinematics during team lifting.

Two-person or team lifting is a popular method for handling materials under awkward or heavy lifting conditions. While many guidelines and standards address safe lifting limits for individual lifting, there are no such limits for team lifting, and these lifts are poorly understood. The literature associated with team lifting offers some interesting paradoxes. Many studies have indicated that people lift less per individual under team conditions compared with one-person lifting. Yet, at least one study has reported an increase in team-lifting capacity when subjects were height-matched. The current study explored the spine loading characteristics of one- and two-person lifting teams when subjects lifted under several sagittally symmetric and asymmetric conditions. Spine compression was lower for two person lifts for a given weight, while lifting in sagittally symmetric conditions whereas lateral shear became much greater for two-person lifts under asymmetric lifting conditions. This study has linked these changes to differences in trunk kinematic patterns adopted during one- versus two-person lifting.

[1]  W. Marras,et al.  A comprehensive analysis of low-back disorder risk and spinal loading during the transferring and repositioning of patients using different techniques. , 1999, Ergonomics.

[2]  Waldemar Karwowski,et al.  Maximum Load Lifting Capacity of Males and Females in Teamwork , 1988 .

[3]  W. Marras,et al.  Spine loading during trunk lateral bending motions. , 1997, Journal of biomechanics.

[4]  W S Marras,et al.  A Three-Dimensional Motion Model of Loads on the Lumbar Spine: I. Model Structure , 1991, Human factors.

[5]  D. Anton.  Occupational biomechanics , 1986 .

[6]  T. Waters,et al.  Evaluation of spinal loading during lowering and lifting. , 1998, Clinical biomechanics.

[7]  D. Chaffin,et al.  A proposed standard procedure for static muscle strength testing. , 1974, American Industrial Hygiene Association journal.

[8]  W S Marras,et al.  Networks of internal trunk-loading activities under controlled trunk-motion conditions. , 1988, Spine.

[9]  W Karwowski,et al.  Testing of isometric and isokinetic lifting strengths of untrained females in teamwork. , 1988, Ergonomics.

[10]  Gary A. Mirka,et al.  Accuracy of a three-dimensional lumbar motion monitor for recording dynamic trunk motion characteristics , 1992 .

[11]  W. Marras,et al.  A Three-Dimensional Motion Model of Loads on the Lumbar Spine: II. Model Validation , 1991, Human factors.

[12]  W S Marras,et al.  A stochastic model of trunk muscle coactivation during trunk bending. , 1993, Spine.

[13]  Marilyn A. Sharp,et al.  Maximum Acceptable Load for Lifting and Carrying in Two-Person Teams , 1995 .

[14]  W S Marras,et al.  Spine loading during asymmetric lifting using one versus two hands. , 1998, Ergonomics.

[15]  W. Marras,et al.  An EMG-assisted model of trunk loading during free-dynamic lifting. , 1995, Journal of biomechanics.

[16]  W S Marras,et al.  Biomechanical risk factors for occupationally related low back disorders. , 1995, Ergonomics.

[17]  A Shirazi-Adl,et al.  Mechanical Response of a Lumbar Motion Segment in Axial Torque Alone and Combined with Compression , 1986, Spine.

[18]  W. Marras,et al.  An EMG-assisted model of loads on the lumbar spine during asymmetric trunk extensions. , 1993, Journal of biomechanics.

[19]  C G Drury,et al.  Accurate movement of two-probe components. , 1995, Ergonomics.

[20]  Steven L. Johnson,et al.  A Psychophysical Study of Two-Person Manual Material Handling Tasks , 1989 .

[21]  W Karwowski,et al.  Isometric and isokinetic testing of lifting strength of males in teamwork. , 1986, Ergonomics.

[22]  K P Granata,et al.  A method for measuring external spinal loads during unconstrained free-dynamic lifting. , 1997, Journal of biomechanics.

[23]  Avis,et al.  A comprehensive analysis of low-back disorder risk and spinal loading during the transferring and repositioning of patients using diŒerent techniques , 2001 .

[24]  W. G. Allread,et al.  The Role of Dynamic Three-Dimensional Trunk Motion in Occupationally-Related Low Back Disorders: The Effects of Workplace Factors, Trunk Position, and Trunk Motion Characteristics on Risk of Injury , 1993, Spine.

[25]  Marilyn A. Sharp,et al.  Prediction of Two-Person Team Lifting Capacity , 1995 .

[26]  W. Marras,et al.  A Biomechanical Assessment and Model of Axial Twisting in the Thoracolumbar Spine , 1995, Spine.