The Effect of Isolated Finger Stiffness on Adjacent Digit Function.

Area of Science:

• Orthopedics
• Hand Surgery
• Biomechanics

Background:

• Isolated finger stiffness can compromise overall hand function due to the quadriga phenomenon.
• This study quantifies the impact of individual stiff fingers on adjacent digits.

Purpose of the Study:

• To objectively measure the dysfunctional effects of isolated finger stiffness on the motion of adjacent digits.
• To determine which finger, when stiff, has the greatest impact on overall hand function.

Main Methods:

• Twenty-five healthy participants had individual fingers immobilized using volar splints.
• Total active range of motion (TAM) and fingertip-to-distal palmar crease (DPC) distance of non-splinted digits were measured.
• One-way analysis of variance (ANOVA) compared motion before and after splinting.

Main Results:

• Splinting any finger significantly reduced TAM in adjacent fingers (P < .001).
• Adjacent digits were more affected than non-adjacent ones.
• Ring finger stiffness caused the most significant reduction in TAM (26-47%) and increased DPC distance; index finger caused the least disturbance.

Conclusions:

• Isolated finger stiffness leads to variable dysfunction in adjacent digits.
• A proactive approach to restore full active motion after finger injuries is essential.
• Early intervention can prevent persistent hand functional deficits.