Distribution of grip force in three different functional prehension patterns.

Area of Science:

• Biomechanics
• Human Factors Engineering
• Ergonomics

Background:

• Limited normative data exists for grip force distribution during functional tasks.
• Accurate measurement of dynamic handgrip forces requires specialized small force sensors.
• Understanding grip force is crucial for hand function evaluation and design.

Purpose of the Study:

• To measure and analyze the distribution of handgrip forces during various functional prehension patterns.
• To provide normative data for grip force distribution in healthy individuals.
• To identify factors influencing grip force, such as task type and individual characteristics.

Main Methods:

• Utilized small, custom-designed force sensors attached to the palmar surface of the hand.
• Recruited seventeen healthy participants to perform three distinct functional tasks.
• Recorded dynamic grip force distribution during cylindrical and spherical grasps, and a tip pinch task.

Main Results:

• Highest grip forces were observed at the fingertips and thumb during cylindrical object manipulation.
• Thumb, ring, and little fingers contributed over 71% of total grip force in a spherical grasp.
• Peak local force of 9.9 N was recorded during a tip pinch task (zip closure).
• Individual finger forces varied significantly by gender, but not by hand dimensions or age.

Conclusions:

• The study provides valuable normative data on handgrip force distribution for functional tasks.
• Results inform biomechanical modeling of the hand and the design of ergonomic tool grips.
• Findings contribute to a better understanding and evaluation of hand function, with implications for gender-specific considerations.