The Impact of Handheld Device Use on Hand Biomechanics.

Cell phone use has become ubiquitous in everyday life for many, yet the potential long-term impacts on hand biomechanics remain unknown. A review was performed on the topic of handheld device use and biomechanics of the hand to identify common findings as well as gaps in the literature. A literature search was performed using several databases and a comprehensive search strategy using controlled keywords was designed. A total of 1556 studies were screened, and 28 studies examining handheld device use were included. A total of 2173 individuals participated in the included studies where cell phone (n = 23) and tablet (n = 5) usage were examined, focusing on the kinematics (n = 17), muscles (n = 13), joints (n = 2), nerves (n = 4), and tendons (n = 1) of the hand. Handheld device use placed the thumb carpometacarpal (CMC) and metacarpophalangeal (MCP) joints in extreme positions of abduction, as well as wrist extension and ulnar deviation. Increased muscle activity of the first dorsal interossei, extensor digitorum communis, and abductor pollicis brevis was demonstrated while using a handheld cellular device. Studies also suggested that handheld device use is powered by the thumb CMC and MCP joints, as well as intrinsic musculature. Thus, individuals could consider operating handheld devices with a two-hand grip, minimizing device size/weight, or using the index finger or voice texting to decrease muscular fatigue and offload joints. Further studies should be conducted to evaluate the long-term effects of cell phone use on the hand and wrist.