Effect of One-Handed Pushing and Puling Strength at Different Handle Heights in Vertical Direction

The purpose of this study was to measure the maximal isometric strength and to investigate the effects of different handleheights and elbow angles with respect to Mid. sagittal plane on the pushing and pulling strength in vertical direction. Eight male subjects performed a series of static strength measurement for each subject. The highest isometric strength was found in pulling at shoulder height (S.H.) (Mean = 60.29 lb., SD = 16.78 lb.) and the lowest isometric strength was found also in pulling at elbow height (E.H.) (Mean = 33.06 lb., SD = 6.56 lb.). Although the isometric strengths were higher at S.H than at E.H. for both activities, the maximal isometric strengths were compared statistically. ANOVA was performed. The results of the experiment revealed that there was a significant different between handle heights. However, there were no significant different between angles and activities, also no correlation between grip strength and activities.

Authors:

• Tarik H. Badi
• Amer A. Boushaala

Keywords:

• Pushing and pulling
• one arm
• vertical direction
• isometric strength.

References:

[1] Ayoub, M. M. and McDaniel, J. W. (1974), "Effects of operator stance
on pushing and pulling tasks," AIIE Transactions, Vol. 6, Pp. 185-195.
[2] Baril-Gingras, Genevieve and Lortie, Monique (1995), "The handling of
objects other than boxes: univariate analysis of handling techniques in a
large transport company," Ergonomics, 38(5), pages 905 - 925..
[3] Chaffin, D.B., Andres, R.O., and Garg, A. (1983), "Volitional postures
during maximal push/pull exertions in the sagittal plane," Human
Factors, 25: 541-550.
[4] Fothergill, David M., et al. (1991), "Human strength capabilities during
one-handed maximum voluntary exertions in the fore and aft plane,"
Ergonomics, Vol. 34, No. 5, 563-573.
[5] Garg, A., et al. (1988), "One-handed dynamic pulling strength with
special application to lawn mowers," Ergonomics, Vol. 31, No. 8, pp.
1139-1153.
[6] Granata, Kevin P. and Bennett, Bradford C. (2005), "Low-Back
Biomechanics and Static Stability During Isometric Pushing," Human
Factors, 47(3): 536-549.
[7] Hoozemans, Marco J.M., Van der Beek, Allard J., Frings-Dresen,
Monique H.W., and Ven der Molen, Henk F. (2001), "Evaluation of
methods to assess push/pull forces in a construction task," Applied
Ergonomics, 32: 509-516.
[8] Kingma, Idsart P. et. al. (2003), "Effect of design of two-wheeled
containers on mechanical loading," International Journal of Industrial
Ergonomics, 31: 73-86.
[9] Kumar, S., Narayan, Y. and Bacchus, Chris (1995), "Symmetric and
Asymmetric Two-Hand Pull-Push Strength of Young Adult," Human
Factors, 37(4), 854-865.
[10] NIOSH 1981, Work Practices Guide for Manual Lifting. U.S., D.H.S.S.,
Pub. No. 81-122.