Effect of Ramp on Joint Moment of Attendants during Manual Control of Wheelchairs

Objective@#This study aimed to predict the injury risk to attendants by simulating and analyzing the joint moment that occurs during wheelchair transportation for five different ramp ratios and five different velocities. Method: Three-dimensional musculoskeletal models and rigid structure of a standard wheelchair were developed using the AnyBody Modeling System. The ramp ratio was set to 1：6 (the steepest), 1：8, 1：10, 1：12, and 1：14 (the gentlest). The wheelchair speeds were set to 0.4, 0.5, 0.6, 0.7, and 0.8 m/s. Both the uphill and downhill movement conditions were investigated. @*Results@#Most of the joint moments that occur in the wrist joint, elbow and shoulder while driving uphill increased or decreased proportionally to the slope and speed of the ramp. However, the external moment of the wrist occurring downhill was largely influenced by the slope, and the joint moment of the shoulder showed a dynamic pattern of change in the middle of the ramp in spite of constant driving speed. @*Conclusion@#The influence that occurs during deceleration while wheelchair driving on a ramp is primarily on the proximal shoulder joint, and the influence of the release control in the middle of driving primarily causes loads on the distal wrist and forearm. A high risk of damage exists because the moment change value of the load on the shoulder joint is relatively large and increases with inclination. The increase in wrist abduction moment for deceleration while driving downhill also suggests the possibility of damage.

Provocative Discography Following Focal Selective Coagulation in a Patient with Chronic Lumbar Discogenic Pain

This is a case report of the provocative discographic findings before and after focal selective coagulation of the major annular fissure using intradiscal navigable catheter. A 46-year-old woman had a 30-month history of axial low back pain and magnetic resonance imaging findings suspicious for painful L4/5 disc. The provocative discography confirmed painful disc before coagulation. The final electrode tip position in the coagulation procedure was at the largest fissure within the outer annular margin identified through the discography. Six months after the successful coagulation therapy, inadvertently performed discography resulted in decreased pressure rise over time. Neither evoked pain nor change in the integrity of outer annulus as compared with the previous results was reported. Such an interventional method has not been reported previously, and the analytic results suggest that it may be possible to relocate the pressure of the entire nucleus pulposus only by focal selective coagulation of the fissure.