A cross-sectional study to evaluate the manual wheelchair-related factors associated with median nerve compression by ultrasonography

Abstract

OBJECTIVES: The objective is to know the prevalence of median nerve compression and determine the relationship of median nerve compression with wheelchair (WC)-associated parameters. MATERIALS AND METHODS: A cross-sectional study was carried out from December 2016 to September 2018, where a total of 50 patients of either sex, aged 20–70 years, with spinal cord injury (D2 or below) who were independent manual WC ambulators (for >6 months) were included. The detailed demography, clinical details, and the wheel ergonomics (height of the shoulder from the axle of WC, weight of the WC) were noted. Ultrasonography of the bilateral median nerve was done at three levels to determine the median nerve thickness. The data were entered into the MS EXCEL spreadsheet, and analysis was performed using the Statistical Package for the Social Sciences (SPSS) version 21.0. A value of P RESULTS: Median nerve compression was present in 12 (24%) patients who had significantly more weight of WC (kg) (19.42 ± 2.02 vs. 18.74 ± 7.38, P = 0.023); comparable mean duration of WC use (months) (31 ± 21.78 vs. 20.9 ± 20.02, P = 0.114); and comparable height between shoulder and axle of WC (inches) (28.17 ± 2.86 vs. 27.16 ± 2.32, P = 0.188). A significant positive correlation was seen between height from the shoulder to axle of WC (inches) and cross-sectional area (CS) of median nerve at carpal tunnel inlet (r = 0.517, P = 0.0001). CONCLUSION: The height of the axle with respect to the shoulder is important to limit the stress on the wrist to the minimum, thus preventing the median nerve compression.