Year, Volume, Issue, Page(s):15, 30, , 546-550
Study investigated whether continuous keyboarding can cause acute changes in the median nerve at the inlet of the carpal tunnel and whether these changes correlate with wrist biomechanics during keyboarding. Thirty-seven healthy individuals performed a 60-minute typing task. Ultrasound images were collected at baseline, after 30 and 60 minutes of typing, then after 30 minutes of rest. Kinematic data were collected during the typing task. Variables of interest were median nerve cross-sectional area, flattening ratio, and swelling ratio at the pisiform; subject characteristics (age, gender, body mass index, wrist circumference, typing speed); and wrist joint angles. Results showed increased cross-sectional area and swelling ratio after 30 and 60 minutes of typing, and then decreased to baseline after 30 minutes of rest. Peak ulnar deviation contributed to changes in cross-sectional area after 30 minutes of typing. The results from this study confirmed a typing task causes changes in the median nerve, and changes are influenced by level of ulnar deviation. Furthermore, changes in the median nerve are present until cessation of the activity. While it is unclear if these changes lead to long-term symptoms or nerve injury, their existence adds to the evidence of a possible link between carpal tunnel syndrome and keyboarding.