We used self-reported direct finger measurements from 255,116 participants in a BBC Internet survey to investigate the measurement of 2D:4D ratios and their association with sex, ethnicity, and sexual orientation. We found significant sex differences such that males had lower 2D:4D than females and the effect size of the sex differences was greatest for right hand 2D:4D. Mean 2D:4D was lower for right hands than for left hands in men, but lower for left hands compared to right hands in women. The sexual dimorphism in 2D:4D was present across ethnic and country groupings, suggesting that it is universal in humans. However, there was also evidence that mean 2D:4D varied across ethnic groups with higher ratios for Whites, Non-Chinese Asians, and Mid-Easterners and lower ratios in Chinese and Black samples. There were significant differences in 2D:4D across sexual orientation groups but these were confined to men. Male homosexuals and bisexuals had higher mean 2D:4D (suggesting exposure to lower prenatal T) than heterosexuals. The effect was present in Whites, but there was no evidence for the pattern among Black and Chinese participants. In women, there were no significant effects of sexual orientation on 2D:4D. Most studies of sexual orientation effects on 2D:4D have measured finger length from photocopies of the hands. In comparison, our self-reported measures gave higher mean 2D:4D, lower effect sizes, and, in some instances, different patterns of effect size. The implications of our findings for future research into 2D:4D are discussed.

Previous findings on the role of visual contact with the hand in the control of reaching and grasping have been contradictory. Some studies have shown that such contact is largely irrelevant, while more recent ones have emphasised its importance. In contrast, information arising from the surrounding environment has received relatively little attention in the study of prehensile actions. In order to identify the roles of both sources of information, we made kinematic comparisons between three conditions. In the first, reaching was performed in a dimly lit room and compared with a second condition in which reaches in the dark, but with the thumb and first finger illuminated, were made to a luminous object. This contrast allows the effects of environmental context to be identified. A comparison between the second and a third condition, in which both vision of the hand and the environment was removed, but the object was still visually available, enabled the assessment of how and when vision of the hand plays a role. Removing environmental cues had effects both early and late in the reach, while vision of the hand was only crucial in the period after peak deceleration. In addition, removal of both sources of information resulted in larger grip apertures. Differences and similarities between our findings and those of other studies are discussed, as is the ongoing debate about the relative importance of visual feedback of the hand in the control and co-ordination of prehensile actions. We conclude with suggestions for further research based on the set-up used in the present study.

Background-Freezing of gait (FOG) remains one of the most common debilitating aspects of Parkinson's disease and has been linked to injuries, falls and reduced quality of life. Although commercially available portable cueing devices exist claiming to assist with overcoming freezing; their immediate effectiveness in overcoming gait initiation failure currently unknown. This study investigated the effects of three different types of cueing device in people with Parkinson's disease who experience freezing.

Three experiments were performed on reach and grasp in 9- to 10-year-old children (8 controls and 8 with developmental coordination disorder [DCD]). In normal reaching, children in the DCD group were less responsive to the accuracy demands of the task in controlling the transport component of prehension and spent less time in the deceleration phase of hand transport. When vision was removed as movement began, children in the control group spent more time decelerating and reached peak aperture earlier. Children in the DCD group did not do that, although, like the control group, they did increase grip aperture in the dark. When depth cues were reduced and only the target or only the target and hand were visible, children in the control group used target information to maintain the same grip aperture in all conditions, but DCD children behaved as if the target was not visible. Throughout the studies, the control group of 9- to 10-year-olds did not produce adult-like adaptations to reduced vision, suggesting that they had not yet attained adult-like integration of sensory input. Compared with control children, children with DCD did not exhibit increased dependence on vision but showed less recognition of accuracy demands, less adaptation to the removal of vision, and less use of minimal visual information when it was available.

The appropriate comparative baseline for assessing the efficacy of an AFO is subjects walking with existing footwear and not barefoot.