Most trigger digit (TD) patients complain that they have problems using their hand in daily or occupational tasks due to single or multiple digits being affected. Unfortunately, clinicians do not know much about how this disease affects the subtle force coordination among digits during manipulation. Thus, this study examined the differences in force patterns during cylindrical grasp between TD and healthy subjects. Forty-two TD patients with single digit involvement were included and sorted into four groups based on the involved digits, including thumb, index, middle and ring fingers. Twelve healthy subjects volunteered as healthy controls. Two testing tasks, holding and drinking, were performed by natural grasping with minimal forces. The relations between the force of the thumb and each finger were examined by Pearson correlation coefficients. The force amount and contribution of each digit were compared between healthy controls and each TD group by the independent t test. The results showed all TD groups demonstrated altered correlation patterns of the thumb relative to each finger. Larger forces and higher contributions of the index finger were found during holding by patients with index finger involved, and also during drinking by patients with affected thumb and with affected middle finger. Although no triggering symptom occurred during grasping, the patients showed altered force patterns which may be related to the role of the affected digit in natural grasping function. In conclusion, even if only one digit was affected, the subtle force coordination of all the digits was altered during simple tasks among the TD patients. This study provides the information for the future studies to further comprehend the possible injuries secondary to the altered finger coordination and also to adopt suitable treatment strategies.

No abstract

Background The impaired sensory function of the hand induced by carpal tunnel syndrome (CTS) is known to disturb dexterous manipulations. However, force control during daily grasping configuration among the five digits has not been a prominent focus of study. Because grasping is so important to normal function and use of a hand, it is important to understand how sensory changes in CTS affect the digit force of natural grasp. Questions/purposes We therefore examined the altered patterns of digit forces applied during natural five-digit grasping in patients with CTS and compared them with those seen in control subjects without CTS. We hypothesized that the patients with CTS will grasp by applying larger forces with lowered pair correlations and more force variability of the involved digits than the control subjects. Specifically, we asked: (1) Is there a difference between patients with CTS and control subjects in applied force by digits during lift-hold-lower task? (2) Is there a difference in force correlation coefficient of the digit pairs? (3) Are there force variability differences during the holding phase? Methods We evaluated 15 female patients with CTS and 15 control subjects matched for age, gender, and hand dominance. The applied radial forces (F r ) of the five digits were recorded by respective force transducers on a cylinder simulator during the lift-hold-lower task with natural grasping. The movement phases of the task were determined by a video-based motion capture system. Results The applied forces of the thumb in patients with CTS (7 ± 0.8 N; 95% CI, 7.2-7.4 N) versus control subjects (5 ± 0.8 N; 95% CI, 5.1-5.3 N) and the index finger in patients with CTS (3 ± 0.3 N; 95% CI, 3.2-3.3 N) versus control subjects (2 ± 0.3 N; 95% CI, 2.2-2.3 N) observed throughout most of the task were larger in the CTS group (p ranges 0.035-0.050 for thumb and 0.016-0.050 for index finger). In addition, the applied force of the middle finger in patients with CTS (1 ± 0.1 N; 95% 3-1.4 N) versus the control subjects (2 ± 0.2 N; 95% CI, 1.9-2.0 N) during the lowering phase was larger in CTS group (p ranges 0.039-0.050). The force correlations of the thumb-middle finger observed during the lowering phase in the patients with CTS (0.8 ± 0.2; 95% CI, 0.6-0.9) versus the control subjects (0.9 ± 0.1; 95% CI, 0.8-1.0; p = 0.04) were weaker in the CTS group. The thumb-little finger during holding in the patients with CTS (0.5 ± 0.2; 95% CI, 0.3-0.7) versus the control subjects (0.8 ± 0.2; 95% CI, 0.6-0.9; p = 0.02), and the lowering phase in the patients with CTS (0.6 ± 0.2; 95% CI, 0.3-0.8) versus the control subjects (0.9 ± 0.1; 95% CI, 0.8-1.0; p = 0.01) also were weaker. The force variabilities of patients with CTS were greater in the CTS group than in the control subjects: in the thumb ([0.26 ± 0.11 N, 95% CI, Conclusions Patients with CTS grasped with greater digit force associated with weaker correlation and higher variability on specific digits in different task demands. These altered patterns in daily graspi...

No abstract

A nanocomposite of multiwalled carbon nanotubes (CNTs) and poly(3-hexylthiophene) (P3HT) was prepared by grafting P3HT uniformly on the surface of CNTs (P3HT/P3HT-g-CNT) via a ''grafting from'' method with the coating thicknesses controlled. It was found that as the coating thickness decreased, the crystallinity of the P3HT decreased, along with significant red-shifting of Raman that signified alterations of chain conformation. Furthermore, although the photoluminescence (PL) peak remained unchanged when grafted on CNTs, modifications of P3HT energy gap was observed, indicating variations of vibronic levels arising from the grafting. Moreover, broadening of the PL emission took place that suggested decreasing of lifetimes of the photo-generated species when grafted on CNTs. Bilayer photovoltaic devices with the (6,6)phenyl C61-butyric acid methyl ester as the electron acceptor have shown that the nanocomposite P3HT/P3HT-g-CNT performed much more efficiently as the electron donor, in both photocurrent density and power conversion efficiency, compared with the neat P3HT.