Search results

Search:
in the keywords: grip force

Sort By:

Limit search:

Maximal Grip Force During Holding A Cylindrical Handle with Different Diameters

100%

Mastalerz A., Nowak E., Palczewska I., Kalka E.

Human Movement

2009

vol. 10

issue 1

26-30

Purpose. The purpose of the study was to estimate the effects of cylindrical handle diameter and handle position on maximal grip force in young males and females. Basic procedures. The maximal voluntary grip force perpendicular to the surface of the handle was estimated using a glove with 320 sensors (Tekscan, USA - GripTM System). Individual digit and palm forces were studied. Different handle diameters (20, 30, 40 and 50 mm) and handle positions (vertical, natural - vertical handle with 12 deg of ulnar deviation of the hand, and horizontal) were applied during measurement. Main findings. Using handles and hand tools frequently leads to the feeling of discomfort in daily life. In a longer term, using improper handles and hand tools may also cause musculoskeletal disorders. Poor wrist positioning and handle diameter can diminish grip strength. The ideal diameter and wrist position during holding a tool handle was determined for males and females using maximal grip strength measurements. The obtained results showed that a tool handle diameter of 20 to 30 mm is optimal for the general population. Further research should be carried out to estimate the impact of wrist positioning in the elderly. Conclusions. The handle positioning is not a significant factor influencing hand grip force capabilities for young men and women. The grip force of three digits did not significantly vary for different handle positions used in the study. The optimal handle diameter for maximal grip force was estimated to be between 20 and 30 mm, and the diameter was larger for men. On the basis of results for individual digits the 30 mm diameter was chosen as optimal for both sexes.

Assessment of Hand Function Through the Coordination of Contact Forces in Manipulation Tasks

88%

Jaric S., Uygur M.

Journal of Human Kinetics

2013

vol. 36

issue 1

5-160

Exploration of force coordination has been one of the most often used approaches in studies of hand function. When holding and manipulating a hand-held object healthy individuals are typically able to highly coordinate the perpendicular (grip force; GF) with the tangential component of the contact force (load force; LF). The purpose of this review is to present the findings of our recent studies of GF-LF coordination. Regarding the mechanical factors affecting GF-LF coordination, our data suggest that both different hand segments and their particular skin areas could have markedly different friction properties. It also appears that the absolute, rather than relative safety margin (i.e., how much the actual GF exceeds the minimum value that prevents slipping) should be a variable of choice when assessing the applied magnitude of GF. The safety margin could also be lower in static than in free holding tasks. Regarding the involved neural factors, the data suggest that the increased frequency, rather than an increased range of a cyclic LF could have a prominent detrimental effect on the GF-LF coordination. Finally, it appears that the given instructions (e.g., 'to hold' vs. 'to pull') can prominently alter GF-LF coordination in otherwise identical manipulation tasks. Conversely, the effects of handedness could be relatively week showing only slight lagging of GF in the non-dominant, but not in the dominant hand. The presented findings reveal important aspects of hand function as seen through GF-LF coordination. Specifically, the use of specific hand areas for grasping, calculation of particular safety margins, the role of LF frequency (but not of LF range) and the effects of given instructions should be all taken into account when conducting future studies of manipulation tasks, standardizing their procedures and designing routine clinical tests of hand function.

Refine search results

1 Human Movement

1 Journal of Human Kinetics

1 2013

1 2009

1 Jaric S.

1 Kalka E.

1 Mastalerz A.

1 Nowak E.

1 Palczewska I.

1 Uygur M.

Search results

Maximal Grip Force During Holding A Cylindrical Handle with Different Diameters

Assessment of Hand Function Through the Coordination of Contact Forces in Manipulation Tasks