Abstract:
The aim of the study was to investigate the micro-structure and biomechanical properties of femur of rats that treated with weight-bearing treadmill running and climb ladder, and evaluating the meaning of two exercise to the femur. Twenty-eight male Sprague-Dawley rats were randomly divided into 3 groups: weight-bearing treadmill group (WR), weight-bearing climbing ladder group (CL), control group (CON). WR group were trained, running on a motor-driven treadmill at a speed of 15 m/min (0 incline) bearing with 35% their body-weight mass added, two minutes running and two minutes intervals between each 40 minutes cycle, 6 days/week. LC group were trained three cycle (10times/cycle) with the same weight, two minutes intervals. After trained with 8 weeks, all rats were euthanized by pentobarbital sodium and the femur were harvested for Micro-CT and three-point test.The results is revealed by Micro-CT.Comparing with the CON group, the trabecular number (Tb.N) and bone volume over total volume (BV/TV) of the WR group and CL group increased significantly.Meanwhile the trabecular separation (Tb.Sp) and structure model index (SMI) decreased significantly. The three-point test showed that, the Modulus of Elasticity (MOE) of the CL group were significantly higher than the WR group and CON group.The maximum loading (ML) of the WR group and CL group were significantly higher than the CON group.And the stiffness (slope linear) in the WR group increased significantly compared with the CON group. The results suggested that both ways of weight-bearing training can improve the micro-structure and the biomechanical properties in different degrees after the 8 weeks of weight-bearing training, and the weight-bearing climbing training is better than the weight-bearing treadmill training.
