Computer keyboarding biomechanics and acute changes in median nerve indicative of carpal tunnel syndrome.

Background: Carpal tunnel syndrome is a common and costly peripheral neuropathy. Occupations requiring repetitive, forceful motions of the hand and wrist may play a role in the development of carpal tunnel syndrome. Computer keyboarding is one such task, and has been associated with upper-extremity musculoskeletal disorder development.

Effects of computer keyboarding on ultrasonographic measures of the median nerve.

Background: Keyboarding is a highly repetitive daily task and has been linked to musculoskeletal disorders of the upper extremity. However, the effect of keyboarding on median nerve injuries is not well understood. The purpose of this study was to use ultrasonographic measurements to determine whether continuous keyboarding can cause acute changes in the median nerve.

The effects of long-term spinal cord injury on mechanical properties of the rat urinary bladder.

We have demonstrated that bladder wall tissue in spinal cord injury (SCI) rats at 10 days post-injury is more compliant and accompanied by changes in material class from orthotropic to isotropic as compared to normal tissue. The present study examined the long-term effects (3-, 6-, and 10-weeks) post-SCI on the mechanical properties of bladder wall tissues, along with quantitative changes in smooth muscle orientation and collagen and elastin content. Bladder wall compliance (defined as det(F) - 1 under an equi-biaxial stress state of 100 kPa, where F is the deformation gradient tensor) was found to be significantly greater at 3- and 6-weeks (0.

Contribution of the extracellular matrix to the viscoelastic behavior of the urinary bladder wall.

We previously reported that when the stress relaxation response of urinary bladder wall (UBW) tissue was analyzed using a single continuous reduced relaxation function (RRF), we observed non-uniformly distributed, time-dependent residuals (Ann Biomed Eng 32(10):1409-1419, 2004). We concluded that the single relaxation spectrum was inadequate and that a new viscoelastic model for bladder wall was necessary. In the present study, we report a new approach composed of independent RRFs for smooth muscle and the extracellular matrix components (ECM), connected through a stress-dependent recruitment function.