Related Experiment Video
Updated: May 20, 2026
A Tactile Automated Passive-Finger Stimulator (TAPS)
Published on: June 3, 2009
Packaging--a problem for patients with hand disorders? A cross-sectional study on the forces applied to packaging
Miriam Marks1, Carina Muoth, Jörg Goldhahn
1Department of Research and Development, Schulthess Klinik, Zurich, Switzerland. Miriam.Marks@kws.ch
Introduction:
Patients with hand disorders frequently experience difficulties opening peelable packaging.
Purpose:
To investigate the forces patients can apply to tear tabs and to compare the results with normative data to make recommendations for the industry and clinical practice.
Study Design:
Descriptive, cross-sectional.
Methods:
One hundred patients with hand disorders were studied. The pinch pull force (PPF) applied to tear tabs of different lengths and materials (aluminum, plastic) was measured with a specially designed device. Key pinch was measured with a pinch gauge. Normative data were taken from another study on 402 healthy adults.
Results:
Patients were able to apply most force to the longest aluminum tab, using the key grip, but this was only 53% of the force exerted by healthy people. Key pinch determines PPF (R(2)=0.548, p≤0.001).
Conclusions:
Manufacturers should provide long aluminum tear tabs. Health professionals are encouraged to measure key pinch to detect difficulties in opening packages.
Level Of Evidence:
Level IV.
