Large index-fingertip forces are produced by subject-independent patterns of muscle excitation
Large index-fingertip forces are produced by subject-independent patterns of muscle excitation
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DOI：
10.1016/s0021-9290(98)00082-7
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发表时间：
1998-08-01
影响因子：
2.4
通讯作者：
Burgar, CG
中科院分区：
文献类型：
--
作者：
Valero-Cuevas, FJ;Zajac, FE;Burgar, CG
指尖力是由受试者独立的肌肉兴奋模式产生的吗？如果是这样的话，了解这些肌肉协调策略的力学基础将大大有助于外科医生评估恢复抓握的选择。手指处于中立外展状态，在MCP和PIP处弯曲45度，在DIP关节处弯曲10度，八名受试者尝试在垂直于远端指骨的四个正交方向（掌侧、背侧、外侧和内侧）上产生最大的随意力。）和与其共线的一个方向（远端）。力的方向在4.7 ± 2.2度（平均值± S.D.）内目标和它们的大小聚类成三个不同的水平（p < 0.05;事后成对RMANOVA）。手掌（27.9 +/- 4.1 N）、远端（24.3 +/- 8.3 N）和内侧（22.9 +/- 7.8 N）的力最高，外侧（14.7 +/- 4.8 N）居中，背侧（7.5 +/- 1.5 N）最低。来自所有七块肌肉的标准化细钢丝EMG揭示了手掌、背侧和远端力的不同肌肉兴奋组（p < 0.05;事后成对RMANOVA）。掌侧力使用屈肌、伸肌和背侧骨间肌;背侧力使用所有肌肉;远端力使用除伸肌外的所有肌肉;内侧和外侧力使用所有肌肉，包括骨间显著的共同兴奋。通过三维计算机模型预测达到最大力的激励策略（四针关节，不可伸展肌腱，伸肌机制和等长力模型的所有七块肌肉）再现了观察到的使用伸肌和缺乏掌侧骨间肌产生掌力（调节净关节屈曲扭矩），没有用于远端力的伸肌，以及使用用于背侧力的固有肌（强MCP屈肌）。该模型不能预测骨间共同激励的内侧和外侧的力量，这可能是一种策略，以防止MCP关节损伤。该模型预测远端力是最敏感的背侧骨间强度，手掌和远端力是非常敏感的MCP和PIP屈肌力臂，背侧力是敏感的力臂和张力分配到PIP伸肌肌腱的伸肌机制。(C)1998爱思唯尔科技有限公司版权所有。
Are fingertip forces produced by subject-independent patterns of muscle excitation? If so, understanding the mechanical basis underlying these muscle coordination strategies would greatly assist surgeons in evaluating options for restoring grasping. With the finger in neutral ad- abduction and flexed 45 degrees at the MCP and PIP, and 10 degrees at DIP joints, eight subjects attempted to produce maximal voluntary forces in four orthogonal directions perpendicular to the distal phalanx (palmar, dorsal, lateral and medial) and in one direction collinear with it (distal). Forces were directed within 4.7 +/- 2.2 degrees (mean +/- S.D.) of target and their magnitudes clustered into three distinct levels (p < 0.05; post hoc pairwise RMANOVA). Palmar (27.9 +/- 4.1 N), distal (24.3 +/- 8.3 N) and medial (22.9 +/- 7.8 N) forces were highest, lateral (14.7 +/- 4.8 N) was intermediate, and dorsal (7.5 +/- 1.5 N) was lowest. Normalized fine-wire EMGs from all seven muscles revealed distinct muscle excitation groups for palmar, dorsal and distal forces (p < 0.05; post hoc pairwise RMANOVA). Palmar force used flexors, extensors and dorsal interosseous; dorsal force used all muscles; distal force used all muscles except for extensors; medial and lateral forces used all muscles including significant co-excitation of interossei. The excitation strategies predicted to achieve maximal force by a 3-D computer model (four pin joints, inextensible tendons, extensor mechanism and isometric force models for all seven muscles) reproduced the observed use of extensors and absence of palmar interosseous to produce palmar force (to regulate net joint flexion torques), the absence of extensors for distal force, and the use of intrinsics (strong MCP flexors) for dorsal force. The model could not predict the interossei co-excitation seen for medial and lateral forces, which may be a strategy to prevent MCP joint damage. The model predicts distal force to be most sensitive to dorsal interosseous strength, and palmar and distal forces to be very sensitive to MCP and PIP flexor moment arms, and dorsal force to be sensitive to the moment arm of and the tension allocation to the PIP extensor tendon of the extensor mechanism. (C) 1998 Elsevier Science Ltd. All rights reserved.