Extension Mechanism of the Proximal Interphalangeal Joint of the Human Phalanx: A Cadaveric Biomechanical Study

Table 1

Slope of the extension force-PIP joint angle curve with metacarpophalangeal joint flexion of 0 degree.

Fingers	Extrinsic group	Intrinsic group	value
#1	-0.119	-0.077
#2	-0.130	-0.109
#3	-0.143	-0.117
#4	-0.117	-0.074
#5	-0.204	-0.189
#6	-0.201	-0.131
#7	-0.124	-0.122
#8	-0.145	-0.119
#9	-0.151	-0.115
Slope mean	-0.148 (SD, 0.03)	-0.117 (SD, 0.03)	<0.001

PIP: proximal interphalangeal joint; SD: standard deviation.