Hand Posture analyzer (HPA): Research on human factors in microgravity is an important activity for science and technology in space. It is known that a long stay in a 0g environment causes alterations in the performances of the muscular system; in particular, it causes impairments in the muscle ability to produce force. The information acquired in these researches can be then exploited for the optimisation of constructive criteria in the design of orbital modules, devices and tools. The way in which the movements are commanded, executed and controlled is an important field of investigation. Experimental activity in microgravity conditions is of high importance in the motion research. All the factors and information depending from gravity are cancelled. Moreover, the fact that the human body is subjected to disabling conditions in weightlessness requires adaptation and re-calibration of most of the motion processes. In this perspective, research in the performances of the upper limb in weightlessness is very interesting, in particular when focusing on grasp force, posture and manipulation strategies.
The HPA facility is a set of instruments to do experimental activities on the human utilisation of the hand in weightlessness.
Fields of investigations interested in the exploitation of such instrumentation are the postural behaviour of palm and fingers during grasping tasks and the muscular fatigue caused by the force of the hand.
Payload description: A complete HPA system is composed of two sets of instruments which can be operated separately or simultaneously to acquire data on the upper limb posture and on the ability to produce grip force. The two subsystems are respectively the HandGrip Dynamometer/Pinch Force Dynamometer (HGD/PFD) for the acquisition of hand and pinch force and the Posture Acquisition Glove (PAG) and Inertial Tracking System (ITS) for the measurement of upper limb kinematics and fingers position. This system is composed of an Interface Box (IBOX) where the HGD and PFD connect directly through dedicated cables. The PAG instead connects first to the Wrist Electronic Box (WEB) which in turn connects to the IBOX. The WEB contains also the ITS. The IBOX is connected to PCMCIA card at a Laptop PC for data acquisition and a dedicated software application manages the execution of experimental protocols.