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Motor Cortex Control of a Complex Peripheral Apparatus: The Neuromuscular Evolution of Individuated Finger Movements
Published in Alexa Riehle, Eilon Vaadia, Motor Cortex in Voluntary Movements, 2004
Marc H. Schieber, Karen T. Reilly, Catherine E. Lang
Of the macaque multitendoned finger muscles, FDP most clearly shows compartmentalization.20 Four distinct neuromuscular compartments of the macaque FDP each receive their own primary nerve branch, stimulation of which produces a different distribution of tension across the five tendons. Voluntary activation during finger movements has been studied in the large radial and ulnar compartments (FDPr and FDPu) but not in the two smaller compartments. FDPr is activated during flexion of the index or middle finger but not during flexion of the ring or little finger, whereas FDPu is activated during flexion of the little or ring finger, but not during flexion of the index finger.27 Largely because of the interconnected tendon structure described above, however, none of the four compartments exerts tension on just one digit.
Designing for Hand and Wrist Anatomy
Published in Karen L. LaBat, Karen S. Ryan, Human Body, 2019
Injury to the median nerve is not completely debilitating because the ulnar nerve provides motor control to some of the smaller thenar muscles as well as the many remaining intrinsic hand muscles. The ulnar nerve supplies sensation to the palmar and dorsal hand near the little finger, on to the little finger and the adjacent half of the ring finger. The ulnar nerve is susceptible to compression at the elbow (sometimes referred to as hitting the “crazy bone”) and in the hypothenar palm. Press firmly, beyond the wrist creases and distal to the prominent pisiform (the most proximal carpal bone on the little finger side of the hand). You have found the ulnar nerve in that area when you sense a deep, aching pain.
Multi-Finger-Based Arbitrary Region-of-Interest Selection in Virtual Reality
Published in International Journal of Human–Computer Interaction, 2022
Qimeng Zhang, Chang-Hun Kim, Hae Won Byun
Our method consists of two levels. The first level is based on the first cutting plane to conduct a basic selection (Figure 5(a)), and the second stage is based on the obtained first level results and the remaining cutting planes, according to the “pasting/cutting” algorithm to select ROI (Figure 5(b)). The proposed algorithm is based on the information (position and order) of the cutting planes and fingers to decide the operation of “pasting” or “cutting.” To index the order of the fingers, we ordered the thumb and little finger as start and end, respectively. Correspondingly, the plane generated between the thumb and index finger is the first cutting plane (as shown in Figure 4(a)), and the plane between the ring finger and the little finger is the last. After the operation is performed on all fingers, convex or concave shape selection is completed.
Development and performance assessment of electrically heated gloves with smart temperature control function
Published in International Journal of Occupational Safety and Ergonomics, 2020
Nini Ma, Yehu Lu, Fanfei Xu, Hongqin Dai
Figure 3(a)–(f) shows the evolution of the LST at five fingers and the opisthenar at an air velocity of 0.17 m/s, respectively. All observed curves of the control group (i.e., no heating) exhibited a declination trend throughout the whole 60 min, whereas the LSTs in the scenario of heating decreased at the initial stage and gradually exhibited a relatively stable state. The temperature was significantly higher in the heating scenario, compared with the control group (p < 0.01). Particularly, the LST at the thumb exhibited a significant difference after the 30th min between the two scenarios. For the index finger, middle finger, ring finger and little finger, significant statistical difference in LST was observed during 10–60 min. The LST at the opisthenar showed significant statistical difference after the 20th min. In the control scenario, these tested parts displayed different changes of temperature, e.g, the temperature at parts of the hands (i.e., thumb, index finger, middle finger, ring finger, little finger and opisthenar) declined from about 31.3 ± 0.3 °C and reached a final temperature of 14.4, 13.9, 13.8, 13.9, 14.1 and 19.1 °C, respectively. In contrast, the temperature at all fingers and the opisthenar in the heating scenario decreased from about 31.6 ± 0.6 °C and the final temperatures reached 21.9, 24.1, 24.1, 23.5, 23.1 and 26.9 °C, respectively. Obviously, in the control scenario, LST at the middle finger had a maximum declination (i.e., 17.8 °C) and that at the opisthenar displayed a minimum decrease (i.e., 11.9 °C). Further, except for the opisthenar, the final LSTs of all five fingers were below 15 °C. In the heating scenario, LST at the thumb presented a maximum drop (i.e., 9.5 °C) and that at the opisthenar declined the least (i.e., 5.7 °C). The LSTs at all five fingers and the opisthenar exceeded 21.9 °C. The LST at the opisthenar in both scenarios had the highest final temperature.
Effects of flow and heat transfer around a hand-shaped former
Published in Engineering Applications of Computational Fluid Mechanics, 2022
Kittipos Loksupapaiboon, Chakrit Suvanjumrat
The wrist was not obstructed by other parts of the hand-shaped former, and the angle of attack had little effect on the Nusselt number. The difference in Nusselt number was only in a narrow range from 6.16 to 8.83% for CVs from 0.026 to 0.034, respectively. the directions and speeds of the airflow also affected the Nusselt numbers of the other sections. Any former surface that was directly affected by airflow would have higher Nusselt number values. For example, at an angle of attack of 0°, the dorsal surface was parallel to the airflow direction. It was then perpendicular to the airflow and shielded by the palm surface at an airflow angle of 90°. Therefore, the difference in Nusselt number values was reduced to 27.37%. In addition, the angle of attack was more effective, and the difference in the Nusselt number was more than 10% on the five fingers, palm, and dorsal surface at a Reynolds number of 15,837. These values were between 10.93% and 42.01%. The angle of attack did not affect heat transfer at Reynolds numbers between 31,675 and 63,351. The effect of the airflow attack angle on the Nusselt number of the index finger, middle finger, ring finger, little finger, and palm parts was eliminated because the CV was only between 0.56% and 8.64%. The angle of attack affected the Nusselt number on the thumb and dorsal parts more than on other parts. Considering that airflow impinged on the thumb part at 45°, the Nusselt number of the thumb was maximum and decreased when the attack angles increased. The difference decreased from 42.01% to 15.62% when the Reynolds number increased from 15,837 to 63,351. However, the Nusselt numbers at attack angles of 0° and 45° were approximately the same. The average difference in the Nusselt number for all Reynolds numbers was less than 0.83%. The dorsal part exhibited the highest Nusselt number at an angle of attack of 180°. This caused the dorsal side to be parallel to the airflow and not shielded by other parts. The Nusselt number at 0° was slightly less than that at 180°. It decreased by approximately 5.63%. At angles of attack of 45°, 90°, and 135°, the dorsal part was in a leeward position and did not perform well in heat transfer. The difference between the highest and lowest Nusselt number was approximately 38.87 to 11.58% as the Reynolds number increased.