Milgrom C, Finestone A, Sharkey N, Hamel A, Mandes V, Burr D, Arndt A, Ekenman I
Dept. of Orthopaedics, Hadassah Univesity Hospital, Ein Kerem, Jerusalem, Israel.
Foot Ankle Int. 2002 Mar;23(3):230-5. doi: 10.1177/107110070202300307.
Human in vivo tibial strains during vigorous walking have not been found to exceed 1200 microstrains. These values are below those found in ex vivo studies (>3000 microstrains) to cause cortical bone fatigue failure, suggesting that an intermediate bone remodeling response may be associated with tibial stress fractures. Metatarsal stress fractures, however, often develop before there is time for such a response to occur. Simultaneous in vivo axial strains were measured at the mid diaphysis of the second metatarsal and the tibia in two subjects. Peak axial metatarsal compression strains and strain rates were significantly higher than those of the tibia during treadmill walking and jogging both barefoot and with running shoes and during simple calisthenics. During barefoot treadmill walking metatarsal compression strains were greater than 2500 microstrains. During one- and two-leg vertical jumps and broad jumping, both metatarsal compression and tension strains were >3000 microstrains. Compression and tension strains in the metatarsus unlike those of the tibia may be sufficiently high even during moderate exertional activities to cause fatigue failure of bone secondary to the number of loading cycles without an intermediate bone remodeling response.
在剧烈行走过程中，尚未发现人体胫骨的体内应变超过1200微应变。这些数值低于体外研究中发现的导致皮质骨疲劳失效的数值（>3000微应变），这表明中间的骨重塑反应可能与胫骨应力性骨折有关。然而，跖骨应力性骨折往往在有时间发生这种反应之前就已经出现。在两名受试者中，同时测量了第二跖骨和胫骨骨干中部的体内轴向应变。在跑步机上行走、慢跑时，无论是赤脚还是穿着跑鞋，以及在简单的健身操过程中，跖骨的峰值轴向压缩应变和应变率均显著高于胫骨。在赤脚跑步机行走过程中，跖骨压缩应变大于2500微应变。在单腿和双腿垂直跳跃以及跳远过程中，跖骨的压缩和拉伸应变均>3000微应变。与胫骨不同，即使在适度的体力活动期间，跖骨的压缩和拉伸应变也可能足够高，以至于在没有中间骨重塑反应的情况下，由于加载循环次数而导致骨疲劳失效。
