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

Table 2

Slope of the extension force-PIP joint angle curve with metacarpophalangeal joint flexion of 60 degrees.

Fingers	Extrinsic group	Intrinsic group	value
#1	-0.095	-0.078
#2	-0.091	-0.079
#3	-0.150	-0.068
#4	-0.108	-0.071
#5	-0.252	-0.158
#6	-0.185	-0.145
#7	-0.146	-0.131
#8	-0.145	-0.102
#9	-0.149	-0.106
Slope mean	-0.147 (SD, 0.05)	-0.104 (SD, 0.03)	0.002

PIP: proximal interphalangeal joint; SD: standard deviation.