HAND POSTURE ANALYZER (HPA)
Research Area: Bone and Muscle Physiology
Expeditions: 7, 8, 11, 16
Principal Investigator(s): ● Valfredo Zolesi, PhD, Kayser Italia Srl, Livorno, Italy
RESEARCH OBJECTIVES
Hand Posture Analyzer (HPA) examines the way hand and arm muscles are used differently
during grasping and reaching tasks in weightlessness. Measurements are compared to those
taken before and after flight to improve understanding of the effects of long-duration
spaceflight on muscle fatigue.
EARTH BENEFITS
Data from the investigation contribute to the development of new methods, protocols, and
instruments for the study and treatment of upper limb problems on Earth.
SPACE BENEFITS
This investigation provides information on
performance modification of the muscular
system during long stays in microgravity
and the characterization of motion
strategies and postural behavior of the
human body in weightlessness. Results
may lead to the optimization of
constructive criteria in the design of orbital
modules, devices, and tools for use in
space.RESULTS
The absence of gravity causes many
inconveniences, generically referred to as
“space motion sickness,” but collected data
have shown crew members normally adapt to microgravity in about a week. The HPA was used
extensively on the ISS during 2003 and 2004. The main objective of HPA is the assessment of
upper limbs performance, specifically the holding or grasping movements, and muscular
function since the upper limbs are the principal means of work and locomotion onboard the
space station. Daily tasks and movements, as well as physically demanding extra-vehicular
activities, can have a significant effect on the hand causing muscle fatigue. This degradation of
muscular-skeletal performance can be easily recognized on the upper limb. Another aspect is
the adjustment of the brain and motor control system to microgravity on the upper limb,
affecting not only bio-mechanics but in general the psycho-physical conditions. Overall, tests
show prompt recovery after short-term flight and loss of force up to 40% after 6 months in
space. These results provide a quantitative evaluation of the performance of the upper limb
and provide the base to develop countermeasures (eg, tools to facilitate adaptation and make
working in space easier) against the impairments due to change in gravity. Also, the experience
ISS008E21614 – ISS science officer Mike Foale is
performing the HPA investigation during Expedition 8,
using the hand grip dynamometer to test the muscle
fatigue of the forearm.