1 / 16

Chord Keyboard

Chord Keyboard. Richard Wells. Complaints. user-keyboard interface postures movements of the fingers, wrists, shoulders forces necessary to activate keys.

odele
Download Presentation

Chord Keyboard

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chord Keyboard Richard Wells

  2. Complaints • user-keyboard interface • postures • movements of the fingers, wrists, shoulders • forces necessary to activate keys. R.P. Wells, P.J. Keir, A.E. Moore & D.A. Ranney, Muscle Activity in the Hand and Forearm using a Traditional and a Chording Keyboard, Marconi Keyboard Conference, 1996.

  3. Ergonomic Issues Wrist Posture • Ulnar deviation • Extension • Finger Range of Motion Repetitiveness • muscle activity - frequency • joint motion/tendon travel Force • static load - wrist extensors • key actuation force R.P. Wells, P.J. Keir, A.E. Moore & D.A. Ranney, Muscle Activity in the Hand and Forearm using a Traditional and a Chording Keyboard, Marconi Keyboard Conference, 1996.

  4. Solutions? • Modifications • remapping the key configuration to reduce finger motion,( Dvorak) • physical layout of the keys have been altered (eg. Kinesis, Apple Split, Microsoft Natural) • Alternatives • “chording” keyboards • 8-10 key • simultaneous key combinations (“chords”) • requires learning of “new” system R.P. Wells, P.J. Keir, A.E. Moore & D.A. Ranney, Muscle Activity in the Hand and Forearm using a Traditional and a Chording Keyboard, Marconi Keyboard Conference, 1996.

  5. Purpose • The purpose of this phenomenological study is to quantify the activity of some of the major muscles responsible for keying in computer input tasks and the influence of a chord keyboard R.P. Wells, P.J. Keir, A.E. Moore & D.A. Ranney, Muscle Activity in the Hand and Forearm using a Traditional and a Chording Keyboard, Marconi Keyboard Conference, 1996.

  6. Chord Keyboard Accukey • 8 ternary keys • simultaneous key combinations (“chords”)

  7. Methods • EMG • surface (5 sites) • fine wire (3 sites) • wrist goniometry (not reported here) • 2 keyboards • generic 101- key • Ternary Chord keyboard (“Accukey”) • n = 8 males R.P. Wells, P.J. Keir, A.E. Moore & D.A. Ranney, Muscle Activity in the Hand and Forearm using a Traditional and a Chording Keyboard, Marconi Keyboard Conference, 1996.

  8. Electromyography • 5 surface sites • first dorsal interosseous (FDI) • extensor carpi ulnaris (ECU) • common extensor site • pronator teres (PT) • forearm flexor • 3 bipolar fine wire sites (index finger) • lumbrical (LUM) • palmar interosseus (PI) • flexor digitorum profundus (FDP) R.P. Wells, P.J. Keir, A.E. Moore & D.A. Ranney, Muscle Activity in the Hand and Forearm using a Traditional and a Chording Keyboard, Marconi Keyboard Conference, 1996.

  9. EMG Processing and Analysis • Linear envelope processing • Normalization to MVC • Amplitude Probability Distribution Function (APDF) • “Static” - 10th percentile • “Dynamic” - 50th percentile • “Peak” - 90th percentile • ANOVA (SPSS) R.P. Wells, P.J. Keir, A.E. Moore & D.A. Ranney, Muscle Activity in the Hand and Forearm using a Traditional and a Chording Keyboard, Marconi Keyboard Conference, 1996.

  10. Chord Standard Lumbrical Activity:Chord vs Standard *p<0.1, **p<0.05, ***p<0.01 R.P. Wells, P.J. Keir, A.E. Moore & D.A. Ranney, Muscle Activity in the Hand and Forearm using a Traditional and a Chording Keyboard, Marconi Keyboard Conference, 1996.

  11. Chord vs. StandardPalmar Interosseous Activity Chord Standard *p<0.1, **p<0.05, ***p<0.01 R.P. Wells, P.J. Keir, A.E. Moore & D.A. Ranney, Muscle Activity in the Hand and Forearm using a Traditional and a Chording Keyboard, Marconi Keyboard Conference, 1996.

  12. Chord vs. StandardExtensor Activity Chord Standard *p<0.1, **p<0.05, ***p<0.01 R.P. Wells, P.J. Keir, A.E. Moore & D.A. Ranney, Muscle Activity in the Hand and Forearm using a Traditional and a Chording Keyboard, Marconi Keyboard Conference, 1996.

  13. Chord vs. StandardExtensor Carpi Ulnaris Activity Chord Standard *p<0.1, **p<0.05, ***p<0.01 R.P. Wells, P.J. Keir, A.E. Moore & D.A. Ranney, Muscle Activity in the Hand and Forearm using a Traditional and a Chording Keyboard, Marconi Keyboard Conference, 1996.

  14. Chord vs. Standard Flexor Digitorum Profundus Activity Chord Standard *p<0.1, **p<0.05, ***p<0.01 R.P. Wells, P.J. Keir, A.E. Moore & D.A. Ranney, Muscle Activity in the Hand and Forearm using a Traditional and a Chording Keyboard, Marconi Keyboard Conference, 1996.

  15. Summary • Trend to lower activation on the chord keyboard • Extensors/ulnar deviators lower • Intrinsic muscles lower or similar activation • Flexor muscles similar or higher R.P. Wells, P.J. Keir, A.E. Moore & D.A. Ranney, Muscle Activity in the Hand and Forearm using a Traditional and a Chording Keyboard, Marconi Keyboard Conference, 1996.

  16. Conclusions The ternary chord keyboard, under the conditions tested, appears to promote lower activations in many of the muscles of the forearm and hand BUT The results of this phenomenological study may not be representative of typical use by trained “chord” typists under field conditions R.P. Wells, P.J. Keir, A.E. Moore & D.A. Ranney, Muscle Activity in the Hand and Forearm using a Traditional and a Chording Keyboard, Marconi Keyboard Conference, 1996.

More Related