title: Index finger and thumb kinematics and performance measurements for common touchscreen gestures.
abstract: This study aimed to quantify differences in 7 touchscreen gestures. Eighteen participants performed index finger tapping, sliding in 4 orthogonal directions, and index finger and thumb pinch and stretch gestures on a touchscreen tablet computer. We hypothesized that two finger gestures would require longer task completion time and greater finger joint excursions than sliding gestures using only the index finger. We measured task completion times and finger joint kinematics. Tapping showed the fastest average (±SD) task completion time, 567(190) ms, of all gestures (p < 0.001). Pinch had faster task completion time, 765(277) ms, than all single-finger sliding gestures (p < 0.001). Stretch was faster to complete at 843(317) ms (p < 0.001) than all sliding gestures except slide right. Stretch demonstrated greater mean index finger metacarpophalangeal flexion/extension joint excursions, 63(16)°, compared to sliding gestures, 34(10)°, and tapping, 27(13)° (p < 0.01). Overall, two-finger gestures were faster to complete and showed greater joint excursions than single-finger sliding gestures.
authors.affiliation: Department of Kinesiology, California State University San Marcos, 333. S. Twin Oaks Valley Rd., San Marcos, CA, USA.
authors.forename: Deanna S
authors.initials: DS
authors.lastname: Asakawa
authors.affiliation: Department of Physical Therapy, Movement, and Rehabilitation Sciences, Bouvé College of Health Sciences, Northeastern University, 360 Huntington Avenue, Boston, USA.
authors.forename: Jack T
authors.initials: JT
authors.lastname: Dennerlein
authors.affiliation: Department of Kinesiology, California State University San Marcos, 333. S. Twin Oaks Valley Rd., San Marcos, CA, USA. Electronic address: djindrich@csusm.edu.
authors.forename: Devin L
authors.initials: DL
authors.lastname: Jindrich
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D034201:Computers, Handheld; D005260:Female; D005385:Fingers / Q000502:physiology*; D005868:Gestures; D006801:Humans; D008297:Male; D013933:Thumb / Q000502:physiology; D013997:Time Factors; D013996:Time and Motion Studies; D014110:Touch; D055815:Young Adult
keywords: Mobile technology; Pinch; Thumb