EUROPEAN SPACE AGECNY HAND POSTURE ANALYZER (ESA HPA)
Research Area: Bone and Muscle Physiology
Expedition(s): 7, 8, 11
Principal Investigator(s): ● Valfredo Zolesi, PhD, Kayser Italia, Livorno, Italy
● Aleandro Norfini, Kayser Italia, Livorno, Italy
RESEARCH OBJECTIVES
Upper limbs are the principal means of locomotion for astronauts and fatigue can have a
significant effect on the hand during ordinary work, or in particular for extravehicular activities.
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.
RESULTS
The experiment was undertaken with 2 long-duration astronauts during Expeditions 7 and 8
aboard the International Space Station (ISS) and 1 astronaut during a short-duration Soyuz
mission. The HPA hardware consisted of 2 dynamometers (Handgrip and Pinch Force
Dynamometers - HGD/PFD) for measuring handgrip and pinch forces, together with an
instrumented glove device.
With respect to power
performance parameters,
the Maximum Voluntary
Contraction (greatest
amount of tension a muscle
can generate and hold)
decreased by up to 45% in
weightlessness for the
handgrip measurements
whereas the Static Effort
(which investigates the
subject’s muscle fatigue,
measuring force/effort
applied for a period of time)
globally increased for both
hand grip tests and pinch
force tests. Muscular
microfilaments performance
could be reduced by the reduction of the concentration of the calcium ion Ca2+ or by other
physiological factors correlated with the Ca2+ concentration. This process is without adaptation
in long-term space missions as confirmed by Maximum Voluntary Contraction and Static Effort
parameters.
ISS008E21614 – International Space Station Science Officer Mike Foale
performs the Hand Poster Analyzer investigation during Expedition 8, using
the hand grip dynamometer to test the muscle fatigue of the forearm.