Liu et al. Electronic Supplementary Information from Assessing the manipulative potentials of monkeys, apes and humans from hand proportions: implications for hand evolution

Supplementary figures, tables and note

Biomechanical Characteristics of Hand Coordination in Grasping Activities of Daily Living

<div><p>Hand coordination can allow humans to have dexterous control with many degrees of freedom to perform various tasks in daily living. An important contributing factor to this important ability is the complex biomechanical architecture of the human hand. However, drawing a clear functional link between biomechanical architecture and hand coordination is challenging. It is not understood which biomechanical characteristics are responsible for hand coordination and what specific effect each biomechanical characteristic has. To explore this link, we first inspected the characteristics of hand coordination during daily tasks through a statistical analysis of the kinematic data, which were collected from thirty right-handed subjects during a multitude of grasping tasks. Then, the functional link between biomechanical architecture and hand coordination was drawn by establishing the clear corresponding causality between the tendinous connective characteristics of the human hand and the coordinated characteristics during daily grasping activities. The explicit functional link indicates that the biomechanical characteristic of tendinous connective architecture between muscles and articulations is the proper design by the Creator to perform a multitude of daily tasks in a comfortable way. The clear link between the structure and the function of the human hand also suggests that the design of a multifunctional robotic hand should be able to better imitate such basic architecture.</p></div

Graphic description of coordinated relationships for joint pairs.

<p>The value of coordination was averaged across subjects and is denoted by the grayscale with pink in each square. The pink color indicates the higher coordination for the corresponding joint pair. The diagram is axisymmetric. Dashed and solid lines passing through squares are used to describe different areas for joint pairs. The joints and abbreviated names are shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0146193#pone.0146193.g001" target="_blank">Fig 1</a>.</p

Relationship between the mean movement coordination (MMC) and the numbers of task types.

<p>It shows some representative results from several subjects. Abbreviate: SUBJ, Subject.</p

CyberGlove sensor placement and corresponding kinematic model of human hand.

<p>(A) Placement of 16 sensors used in the CyberGlove (the image is adapted from Ingram 2008, with kind permission from Springer Science + Business Media). (B) Joints and the kinematic model of the human hand. Abbreviations: MCP, metacarpal-phalangeal; PIP, proximal inter-phalangeal; DIP, distal inter-phalangeal; CMC, carpometacarpal; IP, inter-phalangeal; ABD, abduction; T, thumb; I, Index; M, Middle; R, Ring; L, Little; fe, flexion-extension; aa, abduction-adduction.</p

Dendrogram of the clustering of joints.

<p>This graphically shows the network of movement-coordinated relationships among the joints of the human hand. The lower branch nodes of the tree indicate better-coordinated relationships between the joints under the two branches. The significances of clustering are marked with * (p<0.05), ** (p<0.01) and *** (p<0.001) under the nodes.</p

Movement-coordinated relationships between joints of the human hand in each type of task.

<p>There are 16×(16–1)/2 = 120 variables of movement-coordinated relationships between every two of the 16 joints recorded in the movement dataset, and they are distributed along the ring circle in the radar chart. Area 1 represents the coordinated relationships regarding the joints of thumb and contains the internal relationships between the joints of the thumb and the external relationships between the joints of thumb and the other four fingers. Similarly, area 2 represents the coordinated relationships regarding o the joints of the index finger excluding the joints of the thumb, and so on. The coordinated relationships between all joints of the ring and little fingers are represented in area 4 of the chart. The amplitudes of the coordinated relationships are averaged across all subjects. The six tasks are chosen to represent the features of all tasks.</p

A Pareto chart for the variance explained by the movement dataset of joint angles.

<p>The bars illustrate the variance explained by each principal component (PC) from the PCA, and the line illustrates the cumulative variance explained by the retaining PCs. Error bars indicate standard deviations across subjects.</p

Design and implementation of an anthropomorphic hand for replicating human grasping functions

How to design an anthropomorphic hand with a few actuators to replicate the grasping functions of the human hand is still a challenging problem. This paper aims to develop a general theory for designing the anthropomorphic hand and endowing the designed hand with natural grasping functions. A grasping experimental paradigm was set up for analyzing the grasping mechanism of the human hand in daily living. The movement relationship among joints in a digit, among digits in the human hand, and the postural synergic characteristic of the fingers were studied during the grasping. The design principle of the anthropomorphic mechanical digit that can reproduce the digit grasping movement of the human hand was developed. The design theory of the kinematic transmission mechanism that can be embedded into the palm of the anthropomorphic hand to reproduce the postural synergic characteristic of the fingers by using a limited number of actuators is proposed. The design method of the anthropomorphic hand for replicating human grasping functions was formulated. Grasping experiments are given to verify the effectiveness of the proposed design method of the anthropomorphic hand. © 2016 IEEE.</p

Design and implementation of an anthropomorphic hand for replicating human grasping functions

How to design an anthropomorphic hand with a few actuators to replicate the grasping functions of the human hand is still a challenging problem. This paper aims to develop a general theory for designing the anthropomorphic hand and endowing the designed hand with natural grasping functions. A grasping experimental paradigm was set up for analyzing the grasping mechanism of the human hand in daily living. The movement relationship among joints in a digit, among digits in the human hand, and the postural synergic characteristic of the fingers were studied during the grasping. The design principle of the anthropomorphic mechanical digit that can reproduce the digit grasping movement of the human hand was developed. The design theory of the kinematic transmission mechanism that can be embedded into the palm of the anthropomorphic hand to reproduce the postural synergic characteristic of the fingers by using a limited number of actuators is proposed. The design method of the anthropomorphic hand for replicating human grasping functions was formulated. Grasping experiments are given to verify the effectiveness of the proposed design method of the anthropomorphic hand. © 2016 IEEE.</p