Thumb Motor Performance is Greater for Two-Handed Grip Compared to Single-Handed Grip on a Mobile Phone

Abstract

The aim of this study was to determine if thumb motor performance varied between singlehanded and two-handed grip for thumb tapping tasks on a mobile phone. A secondary aim was to determine if differences in phone movement variation and thumb flexion could account for variations in motor performance across the two grip configurations. Ten right-handed participants (5 males, 5 females) completed reciprocal thumb tapping tasks on an Apple iPhone 3® in a single-handed and a two-handed grip configuration while an active-marker motion capture system measured 3D kinematics of the thumb and phone. The results show that thumb motor performance was significantly greater for the two-handed grip configuration due to less phone movement variation compared to the single-handed grip configuration. Thumb flexion did not significantly vary across configurations. These data suggest that increasing support for the phone such as by using a two-handed grip could lead to increases in tapping performance. For example, increased performance would be expected when using phones that include a landscape mode and are wide enough to allow a stable two-handed grip.

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References

Douglas

S.A.

Kirkpatrick

A.E.

Mackenzie

I.S.

(1999). Testing Pointing Device Performance and User Assessment with ISO 9241, Part 9 Standard. Proceedings of the ACM Conference in Human Factors in Computing Systems - CHI ’99. 215-222.

Fitts

P.M.

(1992). The information capacity of the human motor system in controlling the amplitude of movement. 1954. Journal of Experimental Psycholog: General. 121, 262-269.

Gustafsson

Johnson

P.W.

Lindegard

Hagberg

(2011). Technique, muscle activity and kinematic differences in young adults texting on mobile phones. Ergonomics. 54, 477-487.

Hogg

N.A.

(2010). Design of Thumb Keyboards: Performance, Effort and Kinematics. Doctoral Thesis, University of Waterloo, Waterloo, Canada. 69 pages.

Karlson

A.K.

Bederson

B.B.

Contreras-Vidal

J.L.

(2008). Understanding one-handed use of mobile devices. In Lumsden

(Ed.), Handbook of Research on User Interface Design and Evaluation for Mobile Technology. Hershey, PA: National Research Council of Canada Institute for Information Technology.

Kuo

L.C.

F.C.

Chiu

H.Y.

C.Y.

(2002). Feasibility of using a video-based motion analysis system for measuring thumb kinematics. Journal of Biomechanics. 35, 1499-1506.

Park

Y.S.

Han

S.H.

(2010a). Touch key design for one-handed thumb interaction with a mobile phone: Effects of touch key size and touch key location. International Journal of Industrial Ergonomics. 40, 68-76.

Park

Y.S.

Han

S.H.

(2010b). One-handed thumb interaction of mobile devices from the input accuracy perspective. International Journal of Industrial Ergonomics. 40, 746-756.

Soukoreff

R.W.

Mackenzie

I.S.

(2004). Towards a standard for pointing device evaluation, perspectives on 27 years of Fitts’ law research in HCI. International Journal of Human-Computer Studies. 61, 751-789.

10.

Trudeau

M.B.

Young

J.G.

Jindrich

D.L.

Dennerlein

J.T.

(2012a). Thumb motor performance varies with thumb and wrist posture during single-handed mobile phone use. Journal of Biomechanics. (in-press).

11.

Trudeau

M.B.

Udtamadilok

Karlson

A.K.

Dennerlein

J.T.

(2012b). Thumb Motor Performance Varies by Movement Orientation, Direction, and Device Size during Single-Handed Mobile Phone Use. Human Factors and Ergonomics. 54, 52-59.

12.

Wobbrock

J.O.

Myers

B.A.

Aung

H.H.

(2008). The performance of hand postures in front- and back-of-device interaction for mobile computing. International Journal of Human-Computer Studies. 66, 857-875.