Fig 1.
CyberGlove sensor placement and corresponding kinematic model of human hand.
(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.
Fig 2.
A Pareto chart for the variance explained by the movement dataset of joint angles.
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.
Fig 3.
Movement-coordinated relationships between joints of the human hand in each type of task.
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.
Fig 4.
Relationship between the mean movement coordination (MMC) and the numbers of task types.
It shows some representative results from several subjects. Abbreviate: SUBJ, Subject.
Fig 5.
Graphic description of coordinated relationships for joint pairs.
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 Fig 1.
Fig 6.
Dendrogram of the clustering of joints.
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.