Biomechanical Analysis of Force Distribution in Human Finger Extensor Mechanisms

Table 1

The measured pressing load, the phalanx angles, the calculated extensor muscle forces (normalised by pressing load), and the bone-bone contact forces (normalised by pressing load) under maximum isometric finger pressing at three different postures.

Phalanx angle (degree)

Press load 𝑃 (N)

Extensor muscle force

Bone-to-bone contact force

𝜃1

𝜃2

𝜃3

𝜃4

𝑃𝑥

𝑃𝑦

𝑃𝑧

𝐹RI

𝐹LU

𝐹LE

𝐹UI

𝐹DIP

𝐹PIP

𝐹MCP

77

44

4

−15

−0.95

25.48

0.90

0.1𝑃

3.1𝑃

2.8𝑃

3.9𝑃

9.7𝑃

14.6𝑃

13.8𝑃

51

39

18

−10

2.05

25.20

1.18

0.4𝑃

0.7𝑃

1.3𝑃

2.2𝑃

8.0𝑃

10.4𝑃

10.2𝑃

45

44

40

30

6.16

25.29

1.02

0.1𝑃

0.8𝑃

1.1𝑃

1.9𝑃

8.3𝑃

10.3𝑃

9.1𝑃