A tendon skeletal finger model for evaluation of pinching effort

In this paper, we propose a tendon skeletal finger model and discuss which finger postures the human feels easy to pinch based on the tendon forces and the human experimental results. The finger model mimics a human tendon skeletal structure. The tendon forces during the pinching motion were simulated using the finger model. Simulation results show that the tendon forces closely mirror the human muscle activity. Sensory evaluation of subjective pinching effort was conducted with five subjects. The subject pinched five kinds of cylinders, from 20 [mm] to 100 [mm]. The pinching force and the surface EMGs were simultaneously measured in the experiment. Based on the human questionnaire tests, we investigated which finger postures the human feels easy to pinch a cylinder. The results show that the pattern of the EMGs measured by the experiment is very similar to that of the tendon forces calculated by the finger model simulation. This indicates that the tendon force is a useful index of the subjective pinching effort and it can be used for the quantitative evaluation instead of EMGs.

[1]  K. An,et al.  Tendon excursion and moment arm of index finger muscles. , 1983, Journal of biomechanics.

[2]  S. Radhakrishnan,et al.  Analysis of hand forces in health and disease during maximum isometric grasping of cylinders , 1993, Medical and Biological Engineering and Computing.

[3]  Francisco J Valero-Cuevas,et al.  An Integrative Approach to the Biomechanical Function and Neuromuscular Control of the Fingers , 2004 .

[4]  F. Zajac,et al.  Large index-fingertip forces are produced by subject-independent patterns of muscle excitation. , 1998, Journal of biomechanics.

[5]  Joseph D. Towles,et al.  Towards a realistic biomechanical model of the thumb: the choice of kinematic description may be more critical than the solution method or the variability/uncertainty of musculoskeletal parameters. , 2003, Journal of biomechanics.

[6]  Aiguo Ming,et al.  A net-structure tactile sensor covering free-form surface and ensuring high-speed response , 2007, 2007 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[7]  F. Zajac.  Muscle and tendon: properties, models, scaling, and application to biomechanics and motor control. , 1989, Critical reviews in biomedical engineering.

[8]  K. An,et al.  Mechanical advantage of the thumb muscles. , 1998, Journal of biomechanics.

[9]  R. Crowninshield,et al.  A physiologically based criterion of muscle force prediction in locomotion. , 1981, Journal of biomechanics.

[10]  Yong-Ku Kong,et al.  Evaluation of meat-hook handle shapes , 2003 .

[11]  Scott L. Delp,et al.  A Model of the Upper Extremity for Simulating Musculoskeletal Surgery and Analyzing Neuromuscular Control , 2005, Annals of Biomedical Engineering.

[12]  Tsukasa Ogasawara,et al.  Pinching motion evaluation using human like sensing device , 2008 .

[13]  Miles C. Bowman,et al.  Control strategies in object manipulation tasks , 2006, Current Opinion in Neurobiology.

[14]  E. G. Cruz,et al.  Impact of finger posture on mapping from muscle activation to joint torque. , 2006, Clinical biomechanics.

[15]  Y. Matsuoka,et al.  Understanding variable moment arms for the index finger MCP joints through the ACT hand , 2008, 2008 2nd IEEE RAS & EMBS International Conference on Biomedical Robotics and Biomechatronics.

[16]  K N An,et al.  Normative model of human hand for biomechanical analysis. , 1979, Journal of biomechanics.