Spine Loading and Trunk Kinematic Changes during Team Lifting

Abstract

Two-person or team lifting is a popular method for handling materials under certain conditions. While many guidelines and standards address safe lifting limits for individuals, 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 under team conditions compared to one-person lifting. Yet at least one study has reported an increase in team lifting capacity when subjects were height matched. This study explored the spine loading characteristics of one-person and two-person lifting teams when subjects lifted under several sagittally symmetric and asymmetric conditions. Spine compression was lower for two person lifts 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 verse two-person lifting.

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References

Davis

K. G.

Kirking

B.C.

Gaudes

L.L.

Yang

Marras

W.S.

(1997) Influence of lift moment in determining MAWL. Human Factors, (in press).

Fathallah

F.A.

Marras

W.S.

Parnianpour

Granata

K.P.

(1997) A method for measuring external spinal loads during whole-body free-dynamic lifting, Journal of Biomechanics, (in press).

Granata

K.P.

Marras

W.S.

(1993) An EMG-assisted model of loads on the lumbar spine during asymmetric trunk extensions. J. Biomechanics; 26 (12): 1429–1438.

Granata

K.P.

Marras

W.S.

(1995b) An EMG-assisted model of trunk loading during free-dynamic lifting exertions, J. Biomechanics, 28(11), 1309–1317.

Karwowski

Mital

(1986) Isometric and isokinetic testing of lifting strength of males in teamwork. Ergonomics, 29, 869–878.

Karwowski

Pongpatanasuegsa

(1986) Testing of isometric and isokinetic lifting strengths of untrained females in teamwork. Ergonomics, 29, 869–878.

Karwowski

(1988) Maximum load lifting capacity of males and females in teamwork. Proceedings of the Human Factors Society 32nd Annual Meeting. Santa Monica, CA, Human Factors Society, 680–682.

Johnson

Lewis

(1989) A psychophysical study of two-person manual materials handling tasks. Proceedings of the Human Factors Society 33rd Annual Meeting. Santa Monica, CA, Human Factors Society, 651–653.

Marras

W.S.

Granata

K.P.

(1995) A Biomechanical Assessment and Model of Axial Twisting in the Thoraco-Lumbar Spine. Spine, 20 (13), 1440–1451.

10.

Marras

W.S.

Granata

K.P.

(1997) Spine loading during trunk lateral bending motions. Journal of Biomechanics, 28, (in press).

11.

Marras

W. S.

Reilly

C.H.

(1988) Networks of internal trunk loading activities under controlled trunk motion conditions, Spine, 13(6), 661–667.

12.

Marras

W.S.

Sommerich

C.M.

(1991a) A three-dimensional motion model of loads on the Lumbar spine: I Model Structure. Human Factors, 33 (2), 123–137.

13.

Marras

W.S.

Sommerich

C.M.

(1991b), A three dimensional motion model of loads on the lumbar spine, Part II: Model validation, Human Factors, 33(2), 139–149.

14.

Rice

Sharp

Nindl

Bills

(1995) Predictions of two-person team lifting capacity. Proceedings of the Human Factors and Ergonomics 39th Annual Meeting. Santa Monica, CA, Human Factors Society, 645–649.

15.

Sharp

Rice

Nindl

B.C.

Mello

(1995) Maximum acceptable load for lifting and carrying in two-person teams. Proceedings of the Human Factors and Ergonomics 39th Annual Meeting. Santa Monica, CA, Human Factors Society, 640–644.