[The load bearing function of patellar tendon bearing brace--on the relation between shaft length and rate of load bearing].

The load bearing function of the PTB brace was studied with emphasis on the relationship between shaft length and rate of load bearing. A PTB brace with a heel was used in this experiment, and a sliding device was attached to the shaft of the brace. Load cells were placed in the brace in the patellar tendon, anterior and posterior of the lower leg and the anterior and posterior sole. To each group of data on pressure on the load cells and vertical component of the ground reaction force, multiple regression analysis was applied to evaluate the load bearing function of the PTB brace. Results showed that 80% of non-loading was obtained at the start point of the shaft in which the load cell on the posterior sole of the brace indicated no-loading, 60% was obtained at a point 4.8 mm below the start point, 40% at 8.6 mm, and 20% at 12.3 mm.