Human–Human Handover Tasks and How Distance and Object Mass Matter

Abstract

We investigated the coordination between two individuals during object handovers. Ten participants (eight males, two females; 26.0 ± 5.0 years, 72.7 ± 13.5 kg, 1.73 ± 0.8 m) arranged in pairs (a giver and a receiver), passed an object from the giver to the receiver at a self-selected speed. A motion capture system quantified the giver and the receiver's motion simultaneously. Three interpersonal distances and three object masses were chosen to study the handover. We hypothesized that (a) the handover occurs at half of the interpersonal distance between the giver and receiver and (b) the handover height depends on the objects' mass. Taken together, our results show that the handover strongly depends on the interpersonal distance between the giver and receiver, while object mass related only to handover duration.

The where of handovers by humans: Effect of partner characteristics, distance and visual feedback

“…We observed that the handover positions can be explained surprisingly well by a linear function considering the distance from their partner, and the participant’s, as well as their partner’s, physical and social characteristics (Table 1, Fig 3). While previous studies have proposed models for describing the handover position considering the physical characteristics of the participant [11] as well the inter-personal distance [15], our study is probably the first to show the influence of partner characteristics, especially social dominance, in human handovers (see third bar in Fig 3a and 3b). This result suggests that human participants can immediately estimate the preferred handover positions of partners they have just met.…”

“…The experiment started with the measurement of the arm lengths of the partner and participant, which were used to define the distance AL (as in [15]). A mark on the floor indicated the position where the receiver should stand, while three marks were made for the giver at three inter-personal distances (or IDs) of 0.7AL, AL and 1.3 AL.…”

“…In this study we concentrated on the where of the handovers- we examined how humans determine the position of handovers, and whether and how the handover position depends on who the interacting partner is, and how far he is. These two issues are still not clear from human hand over studies [15]. To address these issue, we looked at the contribution of ‘feedforward’ control in handovers between humans.…”

“…Previous studies have shown that handover positions are modulated by the distance between the partners [15]. Handovers require one individual’s hand to enter the peri-personal space of another individual, which is a space around an individual’s body that they are known to be protective of [22], [23]Ṡtudies of peri-personal space has shown that it is affected by an individual’s reach [24] [25] and hence we hypothesized that an individual’s size and arm length to affect handovers.…”

Estimation of the wrist joint center of rotation

“…The human hand is involved in many daily human activities. The hand is connected to the forearm by the wrist joint which contributes to its special orientation facilitating the manipulation of objects (Hansen et al 2017). However, the wrist joint has a complex organisation of carpal bones.…”