Purpose:

To bring the PIP into extension with spring force while maintaining the possibility for active flexion.

Adjusting:

Strength of the spring should be fine for a normal index finger to resist. The degree of resistance is adjustable, for example:

• In case of weakened muscle strength, or a little finger, less resistance may be required.
• In case of a strong male hand or increased muscle tension, more resistance may be required. 

Additions:

Not applicable