Finger Kinematics during Human Hand Grip and Release

Area of Science:

• Biomechanics
• Robotics
• Human Motion Analysis

Background:

• Robotic hands aim to mimic human dexterity but face manipulation challenges.
• Understanding human hand kinematics is crucial for advancing robotic hand performance.

Purpose of the Study:

• To investigate normal hand motion patterns during grip and release in healthy individuals.
• To establish a kinematic reference for the design and development of advanced robotic hands.

Main Methods:

• Collected kinematic data from the dominant hands of 22 healthy individuals using a sensory glove.
• Analyzed 14 finger joints, focusing on dynamic range of motion (ROM), peak velocity, and joint/finger sequencing during rapid grip and release.

Main Results:

• The proximal interphalangeal (PIP) joint exhibited a larger dynamic ROM and higher peak velocity (flexion/extension) compared to metacarpophalangeal (MCP) and distal interphalangeal (DIP) joints.
• Flexion sequence: PIP joint moved before DIP/MCP joints. Extension sequence: DIP/MCP joints moved before PIP joint.
• The thumb initiated movement before the four fingers during both grip and release, and completed movement after them.

Conclusions:

• Identified distinct kinematic patterns in human hand grip and release, highlighting the significant role of the PIP joint.
• These findings provide essential kinematic data to inform the design of more human-like and functional robotic hands.
• The study contributes a foundational kinematic reference for future advancements in bionic robotic hand technology.