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An analytical expression for the D.I.P.–P.I.P. flexion interdependence in human fingers

Van-Zwieten K. J., Schmidt K. P., Bex G. J., Lippens P. L., Duyvendak W.

Acta of Bioengineering and Biomechanics

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2015

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Vol. 17, no. 1

129--135

EN

Empirical evidence shows that a strong correlation exists between the flexion angles of the distal and proximal interphalangeal (D.I.P., P.I.P.) joints of the human finger. Several authors measured this functional dependence, stating that the interdependence of D.I.P. and P.I.P. flexion is different for healthy individuals and patients displaying pathologies. The purpose of our study is to find an analytical expression for this correlation. Methods: Following closely the anatomical in situ relations, we developed a two-dimensional kinematical model which expresses analytically the D.I.P.–P.I.P. angle correlation. Numerical values for the model were extracted from one healthy and one pathological case data set. Results: The analytical form of the model allows for any P.I.P. angle not only to calculate the corresponding D.I.P. angle, but after first order differentiation with respect to the P.I.P. angle, it also shows the rate of change of the D.I.P. flexion. The model reproduces well the differences in the angular correlation of D.I.P. flexion of the two healthy-pathological data sets. Displaying the rate of change of D.I.P. flexion versus P.I.P. flexion provides an additional, clear-cut discriminatory tool between normal and pathological states. Conclusions: Information on differences between normal and pathological flexion of fingers is more pronounced and easier accessible from the derivatives of the D.I.P.–P.I.P. flexion behaviour than from direct angular correlation data. The analytical form of our model allows one to establish the rate of change of the D.I.P. angles, resulting in a better analysis of the situations at hand.

2

Flexion and Extension Angles of Resting Fingers and Wrist

Lee K.-S., Jung M.- C.

International Journal of Occupational Safety and Ergonomics

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2014

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Vol. 20, No. 1

91--101

EN

This study determined flexion and extension angles of resting fingers and wrist in terms of forearm posture (neutral, pronation and supination) and shoulder flexion (0°, 45°, 90° and 135°). The participants participated in 12 angle measurements for 16 finger joints and wrist. The finger joints flexed more in supination than in neutral posture and pronation and the thumb flexed more than the other fingers because of the gravity and skin tension. This phenomenon became more apparent as the shoulder flexed. The carpometacarpal joint had the largest flexion angle in the thumb joints, whereas the proximal interphalangeal joints had the largest flexion angles in the other finger joints. The resting posture of the wrist extended of ~16° in any forearm postures when the shoulder was at 0°. The results of this study could be useful for rehabilitation tool and product designs.

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Kinematic analysis of the finger exoskeleton using MATLAB/Simulink

Nasiłowski K., Awrejcewicz J., Lewandowski D.

Acta of Bioengineering and Biomechanics

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2014

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Vol. 16, no. 3

129--134

EN

A paralyzed and not fully functional part of human body can be supported by the properly designed exoskeleton system with motoric abilities. It can help in rehabilitation, or movement of a disabled/paralyzed limb. Both suitably selected geometry and specialized software are studied applying the MATLAB environment. A finger exoskeleton was the base for MATLAB/Simulink model. Specialized software, such as MATLAB/Simulink give us an opportunity to optimize calculation reaching precise results, which help in next steps of design process. The calculations carried out yield information regarding movement relation between three functionally connected actuators and showed distance and velocity changes during the whole simulation time.

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Gdy bogiem było Słońce - starożytne jednostki miar (cz. I)

Wollek A.

Pomiary Automatyka Kontrola

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2009

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R. 55, nr 9

787-789

PL

W artykule autor zabiera czytelnika w wędrówkę po świecie antyku przedstawiając wybrane jednostki miar używanych przez największe cywilizacje świata starożytnego: Sumer, Egipt, Grecję i Rzym. Artykuł podzielono na dwie części. W pierwszej opisano prawdopodobnie pierwszy przykład wykorzystania do pomiarów skali naturalnej, którym były tokeny. Kolejne rozdziały zawierają opisy jednostek miar długości, odległości i pola powierzchni. W drugiej części artykułu autor przedstawił jednostki miar masy, objętości oraz związane z nimi aspekty prawne i religijne.

EN

In his paper the Author is taking readers to the journey through the ancient world. He describes old units of measure used by the most famous ancient civilizations of the world such as: Sumer, Egypt, Greece and Rome. The paper is divided into two parts. The first one contains 7 chapters (including references), the second one 6. The first part includes information about tokens, the length, the distance and the area measure units. Tokens are small forms made from the clay. They were used for counting from about 8,000 B.C. to 1500 B.C in Mesopotamia. This is the first known usage of the natural scale to the measure. The length units were the first defined units of the measure (approximately 3,000 B.C.). In Sumer and Egypt the basic unit of the length was a cubit, in Greece and Rome it was a foot. The Sumerian cubit was divided into the 30 fingers, the Egyptian into the 28 (the royal cubit) or into the 24 (the small cubit). The foot was divided to the 16 fingers. The area measure were an agricultural or a life frequently dependent. The information about weight and volume units are in the second part of the paper including. The Sumerian weight measure units were taken by another civilizations like: Acadians, Babylonians, Assyrians and Greeks. The most kinds have the volume units. Another one was for liquids and another one for dry measure. The one of the lasts chapters describes the law conditions refer to the measure units. Some samples, including Urnammu legal code and the Bible, are available.