Analyzing the Active and Functional Grasping Force/Contact Area in Healthy Adults During Activity

• Published in: Hand (New York, N.Y.) N.Y.), 2016-09, Vol.11 (1_suppl), p.12S-12S
• Main Authors: Ergen, Halil Ibrahim, Oksuz, Cigdem
• Format: Article
• Language: English
• ISSN: 1558-9447; 1558-9455
• DOI: 10.1177/1558944716660555v

Objective/Hypothesis: The primary goal of this study was to analyze 4 different active and functional grip patterns (standard, pinch, lateral, and tripod), which are commonly used in daily life activities on 4 different objects. The size of contact area and the amount of force applied to the objects were evaluated and compared in 4 different active (process of grasping the sample object) and functional (process of using the object functionally) grip patterns. Materials and Methods: Study includes right-handed healthy 80 participants (43 female, 37 male) between the ages of 18 and 65 years. Participants wearing sensors located special gloves (Tekscan Grip System) were firstly asked to grip and release 4 different objects (active grip), and then they were asked to use the objects functionally (functional grip), like holding/leaving the key (active grip) and locking/unlocking the door by the key. The glove has 17 sensorial areas (14 in the fingers, 3 in palm) on the palmar surface of hand. Different objects were used for measurements; the plastic bottle for standard grip, the screw for pinch grip, the key and the lock for lateral grip, 750-g metal object for tripod grip. The location of maximum force and contact area between the object and hand were determined. Results: There was a significant difference between active and functional grips (P < .05). Functional grip elevated the force amount and the contact area size compared with active grip. The maximum force occurred in the pulp of the middle finger for both active and functional tripod grip. The biggest force amount was observed on the radial sides of hand during standard grip. Although the required active grip force for holding the 500-g plastic bottle was 3 fold higher than the bottle weight, required functional grip force was 7 fold higher. Different grip forces were seen for grasping the 750-g metal object actively and functionally. Active force necessitated 2 fold of object weight, whereas the functional grip necessitated 3 fold of object weight. Conclusions: These results of our study showed that grasping analysis, which is important part of the hand assessment, should be evaluated not only actively but also functionally. We believe that our study will bring a new perspective to the grip analysis. Our data could be beneficial in hand surgery, process of hand therapy, and also robotic and electronic hand prosthesis.