Table 5.

Effect of changing algometer tip diameter on forces required to reach mechanical nociceptive threshold (MNT)

• Pressure = force/area • Relationship of diameter to area is not linear: Area = Πr2 • Relationship between MNT and pressure or force is not linear 22 but, as force increases, pressure also increases
Tip diameter 2.5 mm4 Area: 4.9 mm2 Reported MNT at 4 h: ~10 N, pressure = 20 kgf/cm2
Tip diameter 2.0 mm (current study) Area: 3.1 mm2 At 10 N pressure = 32 kgf/cm2	At 5 N pressure = 16 kgf/cm2 Reported MNT at 4 h ~5 N (see Figure 2), pressure = 16 kgf/cm2