Bassey E J, Ramsdale S J
Department of Physiology and Pharmacology, Medical School, Queen's Medical Centre, Nottingham, United Kingdom.
Bone. 1995 Apr;16(4):469-76. doi: 10.1016/8756-3282(95)90193-0.
The effects of brief daily exercise on bone mineral density (BMD) were assessed in a randomized controlled trial in 44 healthy postmenopausal women using weight-bearing exercise in a regimen adapted from osteogenic protocols reported in animal studies. BMD was assessed masked using dual energy X-ray absorptiometry at 0, 6, and 12 months. The sites assessed were the proximal femur (neck, Ward's triangle, and trochanter) and the lateral spine (L2-3) to assess the effects of the exercise, and the radius (ultradistal and 33% distal) as a marker for systemic effects. The test group was required to perform 50 "heel drops" daily at home (raising the body weight onto the toes and then letting it drop to the floor keeping the knees and hips extended) and to attend a weekly class of mixed exercises, which included some high-impact activity. The control group also attended a weekly exercise class run by the same teacher, which included only low-impact activity, and did flexibility exercises at home daily. The ground reaction forces (as a ratio of body weight) during heel drops were 2.5 to 3.0 N/N, with a rate of rise of 50-100 kN/sec. A patient with an instrumented femoral implant allowed comparison of compressive axial forces in the shaft of the proximal femur with the ground reaction forces, and these appeared to be transmitted undamped to the shaft of the femur. Initial analysis of BMD in the women showed no significant increases after 12 months of exercise at any site in either group, and the groups did not differ significantly from each other in this respect. Proximity to menopause was not associated with rapid bone loss, and in those who were more than 6 years postmenopausal, there was evidence for a maintenance effect of the exercise in the test group. Compliance (83%) and increases in leg extensor power (15%) were similar in both groups, and when they were combined, BMD was maintained at the trochanter but fell significantly at the radius (p < 0.001).
在一项随机对照试验中，对44名健康的绝经后女性进行了研究，采用了动物研究中报道的成骨方案的改良方案进行负重锻炼，评估每日简短锻炼对骨密度（BMD）的影响。在0、6和12个月时，使用双能X线吸收法对BMD进行盲法评估。评估的部位包括股骨近端（颈部、沃德三角区和大转子）和腰椎外侧（L2 - 3）以评估锻炼效果，以及桡骨（超远端和33%远端）作为全身效应的标志物。试验组被要求每天在家进行50次“足跟下落”（将体重提升到脚尖然后让其落到地面，保持膝盖和臀部伸展），并参加每周一次的混合锻炼课程，其中包括一些高强度活动。对照组也参加由同一位教师授课的每周一次的锻炼课程，课程仅包括低强度活动，并每天在家进行柔韧性锻炼。足跟下落时的地面反作用力（以体重的比例表示）为2.5至3.0 N/N，上升速率为50 - 100 kN/秒。一名植入仪器化股骨假体的患者使得能够比较股骨近端骨干的压缩轴向力与地面反作用力，并且这些力似乎无衰减地传递到股骨干。对这些女性骨密度的初步分析表明，两组在任何部位经过12个月的锻炼后骨密度均无显著增加，并且在这方面两组之间无显著差异。接近绝经与快速骨质流失无关，在绝经超过6年的女性中，有证据表明试验组的锻炼具有维持作用。两组的依从性（83%）和腿部伸肌力量增加（15%）相似，当将两者结合时，大转子处的骨密度得以维持，但桡骨处的骨密度显著下降（p < 0.001）。
