Comparison of knee motion on Earth and in space: an observational study

Abstract

Background: Spaceflight has been shown to cause atrophy, reduced functional capacity, and increased fatigue in lower-limb skeletal muscles. The mechanisms of these losses are not fully understood but are thought to result, in part, from alteration in muscle usage.

Space Flight Calcium: Implications for Astronaut Health, Spacecraft Operations, and Earth

“…One of the novel aspects of the ISS was the inclusion of resistance exercise equipment. Details of these efforts will be described below, but although initial evaluations were disappointing [24], possibly because of altered kinematics [25], recent evidence illustrates the potential of proper nutrition and exercise regimens to prevent whole-body and regional loss of bone mineral density [26] during extended space flight. …”

20-Hz whole body vibration training fails to counteract the decrease in leg muscle volume caused by 14 days of 6° head down tilt bed rest

“…Exercise countermeasures onboard the former Russian space station Mir and the current International Space Station ISS include treadmill running, cycling, and resistive exercise training (iRED) and are scheduled for 2 h per day. In part due to an insufficient performance of the recommended program (Pierre et al 2006), these countermeasures insufficiently prevent the negative effects of unloading on leg muscle (Antonutto et al 1999;LeBlanc et al 2000LeBlanc et al , 2007Zange et al 1997). Therefore, future long term missions to space require more time efficient and reliable training countermeasures.…”