Effects of the Weight Configuration of Hand Load on Trunk Musculature During Static Weight Holding

Overview

Journal Ergonomics

Publisher Informa Healthcare

Specialty Psychology

Date 2017 Oct 3

PMID 28965479

Citations 4

Authors

Saman Madinei

Xiaopeng Ning

Affiliations

Soon will be listed here.

Abstract

The performance of manual material handling tasks is one major cause of lower back injuries. In the current study, we investigated the influence of the weight configuration of hand loads on trunk muscle activities and the associated spinal stability. Thirteen volunteers each performed static weight-holding tasks using two different 9 kg weight bars (with medial and lateral weight configurations) at two levels of height (low and high) and one fixed horizontal distance (which resulted in constant spinal joint moment across conditions). Results of the current study demonstrated that holding the laterally distributed load significantly reduced activation levels of lumbar and abdominal muscles by 9-13% as compared with holding the medially distributed load. We believe such an effect is due to an elevated rotational moment of inertia when the weight of the load is laterally distributed. These findings suggest that during the design and assessment of manual material handling tasks, such as lifting and carrying, the weight configuration of the hand load should be considered. Practitioner summary: Elevated trunk muscle activities were found when holding a medially distributed load vs. a laterally distributed load (with an equivalent external moment to the spine), indicating a reduced spinal stability due to the reduced rotational moment of inertia. The configuration of the hand load should be considered when evaluating manual material handling tasks.

Citing Articles

Effect of different postures and loads on joint motion and muscle activity in older adults during overhead retrieval.

Zhou C, Xu X, Huang T, Kaner J Front Physiol. 2024; 14:1303577.

PMID: 38304288 PMC: 10830688. DOI: 10.3389/fphys.2023.1303577.

Effects of Vertical Lifting Distance on Upper-Body Muscle Fatigue.

Fang N, Zhang C, Lv J Int J Environ Res Public Health. 2021; 18(10).

PMID: 34065333 PMC: 8160884. DOI: 10.3390/ijerph18105468.

Measuring Effects of Two-Handed Side and Anterior Load Carriage on Thoracic-Pelvic Coordination Using Wearable Gyroscopes.

Lim S, DSouza C Sensors (Basel). 2020; 20(18).

PMID: 32932627 PMC: 7571224. DOI: 10.3390/s20185206.

Statistical prediction of load carriage mode and magnitude from inertial sensor derived gait kinematics.

Lim S, DSouza C Appl Ergon. 2019; 76:1-11.

PMID: 30642513 PMC: 7079201. DOI: 10.1016/j.apergo.2018.11.007.

References

Stokes I, Gardner-Morse M, Henry S . Abdominal muscle activation increases lumbar spinal stability: analysis of contributions of different muscle groups. Clin Biomech (Bristol). 2011; 26(8):797-803. PMC: 3157598. DOI: 10.1016/j.clinbiomech.2011.04.006. View

Cholewicki J, Simons A, Radebold A . Effects of external trunk loads on lumbar spine stability. J Biomech. 2000; 33(11):1377-85. DOI: 10.1016/s0021-9290(00)00118-4. View

Granata K, Marras W . Cost-benefit of muscle cocontraction in protecting against spinal instability. Spine (Phila Pa 1976). 2000; 25(11):1398-404. DOI: 10.1097/00007632-200006010-00012. View

Hu B, Ning X, Nimbarte A . The changes of lumbar muscle flexion-relaxation response due to laterally slanted ground surfaces. Ergonomics. 2013; 56(8):1295-303. DOI: 10.1080/00140139.2013.803161. View

Marras W, Lavender S, Leurgans S, Rajulu S, Allread W, Fathallah F . 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. Spine (Phila Pa 1976). 1993; 18(5):617-28. DOI: 10.1097/00007632-199304000-00015. View

Arjmand N, Shirazi-Adl A . Biomechanics of changes in lumbar posture in static lifting. Spine (Phila Pa 1976). 2005; 30(23):2637-48. DOI: 10.1097/01.brs.0000187907.02910.4f. View

Norman R, Wells R, Neumann P, Frank J, Shannon H, Kerr M . A comparison of peak vs cumulative physical work exposure risk factors for the reporting of low back pain in the automotive industry. Clin Biomech (Bristol). 2001; 13(8):561-573. DOI: 10.1016/s0268-0033(98)00020-5. View

Granata K, Gottipati P . Fatigue influences the dynamic stability of the torso. Ergonomics. 2008; 51(8):1258-71. DOI: 10.1080/00140130802030722. View

Marras W, Davis K . A non-MVC EMG normalization technique for the trunk musculature: Part 1. Method development. J Electromyogr Kinesiol. 2001; 11(1):1-9. DOI: 10.1016/s1050-6411(00)00039-0. View

10.

Ning X, Zhou J, Dai B, Jaridi M . The assessment of material handling strategies in dealing with sudden loading: the effects of load handling position on trunk biomechanics. Appl Ergon. 2014; 45(6):1399-405. DOI: 10.1016/j.apergo.2014.03.008. View

11.

Kerr M, Frank J, Shannon H, Norman R, Wells R, Neumann W . Biomechanical and psychosocial risk factors for low back pain at work. Am J Public Health. 2001; 91(7):1069-75. PMC: 1446725. DOI: 10.2105/ajph.91.7.1069. View

12.

Bakker E, Verhagen A, Lucas C, Koning H, de Haan R, Koes B . Daily spinal mechanical loading as a risk factor for acute non-specific low back pain: a case-control study using the 24-Hour Schedule. Eur Spine J. 2006; 16(1):107-13. PMC: 2198897. DOI: 10.1007/s00586-006-0111-2. View

13.

Bergmark A . Stability of the lumbar spine. A study in mechanical engineering. Acta Orthop Scand Suppl. 1989; 230:1-54. DOI: 10.3109/17453678909154177. View

14.

Bazrgari B, Shirazi-Adl A, Arjmand N . Analysis of squat and stoop dynamic liftings: muscle forces and internal spinal loads. Eur Spine J. 2006; 16(5):687-99. PMC: 2213554. DOI: 10.1007/s00586-006-0240-7. View

15.

Reeves N, Narendra K, Cholewicki J . Spine stability: the six blind men and the elephant. Clin Biomech (Bristol). 2007; 22(3):266-74. PMC: 1865578. DOI: 10.1016/j.clinbiomech.2006.11.011. View

16.

Caldwell L, Chaffin D, DUKES-DOBOS F, Kroemer K, Laubach L, Snook S . A proposed standard procedure for static muscle strength testing. Am Ind Hyg Assoc J. 1974; 35(4):201-6. DOI: 10.1080/0002889748507023. View

17.

Marras W, Mirka G . Electromyographic studies of the lumbar trunk musculature during the generation of low-level trunk acceleration. J Orthop Res. 1993; 11(6):811-7. DOI: 10.1002/jor.1100110606. View

18.

Granata K, Orishimo K . Response of trunk muscle coactivation to changes in spinal stability. J Biomech. 2001; 34(9):1117-23. DOI: 10.1016/s0021-9290(01)00081-1. View

19.

Granata K, Slota G, Wilson S . Influence of fatigue in neuromuscular control of spinal stability. Hum Factors. 2004; 46(1):81-91. PMC: 1633714. DOI: 10.1518/hfes.46.1.81.30391. View

20.

Marras W, Mirka G . Muscle activities during asymmetric trunk angular accelerations. J Orthop Res. 1990; 8(6):824-32. DOI: 10.1002/jor.1100080607. View