Ward Samuel R, Loren Gregory J, Lundberg Scott, Lieber Richard L
Department of Radiology, Biomedical Sciences Graduate Group, University of California, San Diego, California 92093, USA.
J Neurophysiol. 2006 Nov;96(5):2815-8. doi: 10.1152/jn.00284.2006. Epub 2006 Jul 26.
The objective of this study was to define the biomechanical properties of the human digital flexor tendons and to compare these biomechanical properties to other muscle-tendon units in the forearm. Mechanical measurements were performed on fresh-frozen tendons under physiological load and temperature conditions. Loads were determined by first measuring the physiological cross-sectional area of each digital belly of the flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) and estimating maximum tension (P(o)) of that specific muscle head. Loading each tendon to the appropriate P(o) resulted in no significant difference in tendon strain among any of the tendons within each muscle (P > 0.05; digits 2-5) or between muscle types (FDP vs. FDS). The one exception to this finding was that a significantly higher strain at Po was observed in the FDP tendon to the small finger (P < 0.05). Average absolute strains observed for the FDP and FDS tendons (1.20 +/- 0.38%, mean +/- SD; n = 39) were significantly lower than those observed previously in a study of the prime movers of the wrist. The measured strain of approximately 1.5% was less than half of that predicted to occur in muscles of this architectural design. Modeling sarcomere shortening magnitudes during FDP or FDS contraction yielded a value of only 0.10 microm, which would have a negligible effect on the force generating capacity of these muscles. Thus the high stiffness of the digital flexor tendons suits them well for fine positional control and would render their muscle spindles quite sensitive to length perturbations at the fingertips.
本研究的目的是确定人类手指屈肌腱的生物力学特性，并将这些生物力学特性与前臂的其他肌肉 - 肌腱单元进行比较。在生理负荷和温度条件下，对新鲜冷冻的肌腱进行力学测量。首先通过测量指浅屈肌（FDS）和指深屈肌（FDP）各指腹的生理横截面积并估计该特定肌头的最大张力（P(o)）来确定负荷。将每条肌腱加载到适当的P(o)后，各肌肉内的任何肌腱之间（P > 0.05；2 - 5指）或不同肌肉类型之间（FDP与FDS）的肌腱应变均无显著差异。这一发现的唯一例外是，观察到小指的FDP肌腱在P(o)时的应变显著更高（P < 0.05）。FDP和FDS肌腱观察到的平均绝对应变（1.20 +/- 0.38%，平均值 +/- 标准差；n = 39）显著低于先前在一项关于腕部主要运动肌的研究中观察到的应变。测量得到的约1.5%的应变不到这种结构设计的肌肉中预测应变的一半。对FDP或FDS收缩过程中肌节缩短幅度进行建模得出的值仅为0.10微米，这对这些肌肉的力产生能力影响可忽略不计。因此，手指屈肌腱的高刚度使其非常适合精细的位置控制，并且会使其肌梭对指尖的长度扰动相当敏感。
