Bravenboer N, van Rens B T T M, van Essen H W, van Dieën J H, Lips P
Amsterdam Movement Sciences, Department of Clinical Chemistry, VU University Medical Center, PO Box 7057, 1007 MB, Amsterdam, the Netherlands.
Amsterdam Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands.
J Exp Orthop. 2017 Aug 31;4(1):28. doi: 10.1186/s40634-017-0102-8.
Treadmill animal models are commonly used to study effects of exercise on bone. Since mechanical loading induces bone strain, resulting in bone formation, exercise that induces higher strains is likely to cause more bone formation. Our aim was to investigate the effect of slope and additional load on limb bone strain.
Horizontal and vertical ground reaction forces on left fore-limb (FL) and hind-limb (HL) of twenty 23-week old female Wistar rats (weight 279 ± 26 g) were measured for six combinations of SLOPE (-10°, 0°, +10°) and LOAD (0 to 23% of body mass). Peak force (Fmax), rate of force rise (RC), stance time (Tstance) and impulse (Fint) on FLs and HLs were analyzed.
For the FL, peak ground reaction forces and rate of force rise were highest when walking downward -10° with load (Fmax = 2.09±0.05 N, FLRC = 34±2 N/s) For the HL, ground reaction forces and rate of force rise were highest when walking upward +10°, without load (Fmax = 2.20±0.05 N, HLRC = 34±1 N/s). Load increased stance time. Without additional load, estimates for the highest FL loading (slope is -10°) were larger than for the highest HL loading (slope is +10°) relative to level walking.
Thus, walking downward has a higher impact on FL bones, while walking upward is a more optimal HL exercise. Additional load may have a small effect on FL loading.
跑步机动物模型常用于研究运动对骨骼的影响。由于机械负荷会引起骨应变，进而导致骨形成，所以能引起更高应变的运动可能会促使更多的骨形成。我们的目的是研究坡度和额外负荷对四肢骨应变的影响。
对20只23周龄雌性Wistar大鼠（体重279±26克）的左前肢（FL）和后肢（HL）的水平和垂直地面反作用力进行测量，测量坡度（-10°、0°、+10°）和负荷（体重的0%至23%）的六种组合情况。分析FL和HL的峰值力（Fmax）、力上升速率（RC）、站立时间（Tstance）和冲量（Fint）。
对于FL，在负重向下行走-10°时，地面反作用力峰值和力上升速率最高（Fmax = 2.09±0.05 N，FLRC = 34±2 N/s）。对于HL，在无负重向上行走+10°时，地面反作用力和力上升速率最高（Fmax = 2.20±0.05 N，HLRC = 34±1 N/s）。负荷增加了站立时间。在无额外负荷的情况下，相对于水平行走，FL最高负荷（坡度为-10°）的估计值大于HL最高负荷（坡度为+10°）的估计值。
因此，向下行走对FL骨骼的影响更大，而向上行走是更理想的HL运动方式。额外负荷可能对FL负荷有较小影响。
