Napier set out to classify the grasping movements of the whole hand on an anatomical and functional basis rather than by the shape of the object held.
Methods
Design
Descriptive anatomical study
Basis
Anatomy and function of the whole hand
Intended activity rather than object form
Key Findings
Two basic patterns, power grip and precision grip, appeared to account for all prehensile activity of the hand.
The intended activity, not the object's form, ultimately determined which grip pattern was used.
Object shape and size could still affect the type of prehension under certain conditions.
The hook grip was rarely used in the normal hand but became virtually the only prehension possible with intrinsic muscle paralysis.
Board pearl
The thumb separates the two grips: it opposes the fingers in precision grip, while in power grip it lies roughly in the plane of the palm and applies counter pressure.
Authors' conclusion
These two patterns appear to cover the whole range of prehensile activity of the human hand.
Napier set out to classify the grasping movements of the whole hand on an anatomical and functional basis rather than by the shape of the object held.
Methods
Design
Descriptive anatomical study
Basis
Anatomy and function of the whole hand
Intended activity rather than object form
Key Findings
Two basic patterns, power grip and precision grip, appeared to account for all prehensile activity of the hand.
The intended activity, not the object's form, ultimately determined which grip pattern was used.
Object shape and size could still affect the type of prehension under certain conditions.
The hook grip was rarely used in the normal hand but became virtually the only prehension possible with intrinsic muscle paralysis.
Board pearl
The thumb separates the two grips: it opposes the fingers in precision grip, while in power grip it lies roughly in the plane of the palm and applies counter pressure.
Authors' conclusion
These two patterns appear to cover the whole range of prehensile activity of the human hand.