A comparison of wrist posture and forearm muscle activities while using an alternative keyboard and a standard keyboard

The wrist posture associated with the use of the conventional "QWERTY" keyboard is a risk factor for work-related musculoskeletal disorders in the upper limbs. Newly designed keyboards have been produced with the aim to reduce the strain in the wrist and forearm region. The present study compared the effects of using a standard keyboard and a split/angled keyboard on the forearm muscle activities and wrist joint angles. Ten subjects (6 males and 4 females) performed a standard keyboard task for 30 min, using each of the two keyboards while wrist joint angles and electromyography (EMG) were recorded. Wrist extension and ulnar deviation angles were both significantly reduced with the split/angled keyboard (p = .030 and .010), and lower EMG activities were recorded in the extensor carpi radialis and ulnaris muscles. The present results implied that the split/angled keyboard may be a better instrument for prolonged keyboard operation, resulting in reduced strain in the wrist and forearm region.