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Optimal location of the tablet for typing while listening to a song
Author(s) -
Yoon Jangwhon,
Lee Jihyun
Publication year - 2018
Publication title -
human factors and ergonomics in manufacturing and service industries
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.408
H-Index - 39
eISSN - 1520-6564
pISSN - 1090-8471
DOI - 10.1002/hfm.20744
Subject(s) - shoulders , medicine , elbow , scapula , elbow flexion , sitting , physical therapy , physical medicine and rehabilitation , biceps , anatomy , surgery , pathology
Tablets are much heavier than smartphones and able to bring more musculoskeletal disorders in the upper extremities. The aim of this study was to understand the effects of tablet location on the recruitment of muscles in the neck and upper extremities. Fifteen healthy volunteers typed the lyrics while listening to a song at three tablet locations for 5 min. An iPad 2 was randomly located at one of the levels with 70, 90, and 130 degrees of elbow flexion in sitting. Typing duration, frequency of typing error, perceived levels of fatigue, and subjective position preferences were recorded and recruitment of muscles in the neck and upper extremities was measured. Muscle recruitment of three parts of the trapezius and biceps brachii decreased and use of the levator scapula increased as the vertical level of the tablet heightened. Self‐reported discomfort increased significantly in the neck, upper back, shoulders, elbows, and wrists over time regardless of the tablet location. The table location affected the self‐reported discomfort only at the elbow joints. Subjective preference was highest at the lowest tablet location with the 130‐degree elbow flexion. The vertical levels of the tablet and typing duration independently affected the muscle recruitment and self‐reported discomfort. Findings of this study can be helpful for tablet users in preventing musculoskeletal disorders in the upper extremities.