Identification of three movement phases of the hand during lateral and pulp pinches using video motion capture

Effect of pinch types on pinch force sense in healthy adults

Pinch force sense plays an important role in the performance of daily finger movements, including tip, key, palmar pinch. The present study investigated the roles of pinch type in the sensation of pinch force among healthy participants in the ipsilateral force reproduction trial. This study instructed forty healthy adult subjects (20 women and 20 men) in producing reference forces at different levels [10, 30, 50% maximal voluntary isometric contraction (MVIC)] by adopting 3 pinch types (tip, key, and palmar pinches) and in reproducing the above force levels with the identical hand. Our study revealed that subjects are significantly more sensitive detecting alterations of pinching forces with tip pinch but not key or palmar pinch under high forces (30 and 50% MVIC) but not at lower force levels (10% MVIC).

Development and Usability Testing of a Finger Grip Enhancer for the Elderly

As people age, their finger function deteriorates due to muscle, nerve, and brain degeneration. While exercises might delay this deterioration, an invention that enhances elderly people’s pinching abilities is essential. This study aims to design and develop a finger grip enhancer that facilitates the day-to-day pinching activities of elderly people. This research is an extension of a previous study that conceptualised a finger grip enhancer. The device facilitates finger flexion on the thumb and index finger, and weighs 520 g, allowing for improved portability and sufficient force exertion (13.9 N) for day-to-day pinching. To test for usability, eleven subjects aged 65 years and above performed a pinch-lift-hold test on various household objects. The pinch force before and after utilising the device was measured. Using Minitab 18, the statistical significance of using this device was analysed with a paired-samples t-test. With this device, the elderly people’s pinching abilities significantly improved in both pinch force and pinch force steadiness (p < 0.05). The proposed device has the potential to enhance elderly people’s quality of life by supporting a firm pinch in the handling of everyday objects. This research has applicational value in developing exoskeleton devices for patients who require rehabilitation.

Influence of aging, disease, exercise, and injury on human hand movements: A systematic review

The human hand is a versatile organ that performs a variety of activities in daily life. The coordination of digits allows them to deal with objects of various sizes and shapes with an appropriate range of motions (ROM). A systematic literature review was performed to identify the clinical and non-clinical factors which affected the normal ROM, grip strength (GS), and dexterity of hand. The overall outcomes of the systematic review showed that: the performance of the individual declined as the age progressed; the performance of the dominant hand (DH) of an individual was better compared to his/her non-dominant hand (NDH); the tasks performed by a healthy hand was more efficient compared to a diseased one; appropriate rehabilitation programs/exercise techniques after a disease or injury improved the ROM, GS, and dexterity of hand post-surgery on par to a healthy hand.

Chrome nitride coating reduces wear of small, spherical CrCoMo metal-on-metal articulations in a joint simulator

Metal-on-metal articulations have fallen out of favour in larger joint replacements, but are still used in smaller joints. Coating the articulation has been suggested as one way of reducing wear. We compared a standard 6 mm CrCoMo articulation designed for the carpometacarpal joint of the thumb with a chromium nitride-coated version after 512,000 cycles in a joint simulator. A total of 6 articulations in each group were tested with a unidirectional load of 5 kg in Ringer's solution. We found a statistically significant reduction in weight loss, amount of metallic wear produced and volumetric wear for the chromium nitride-coated articulation. Our findings support the use of chromium nitride coating in order to minimize the amount of metallic wear produced.