The Effects of Chronic Weightlessness on Limited of Stability and Dynamic Balance in ‎Breath-hold and SCUBA Divers

Water immersion built a new environment in which weightlessness puts unknown demand on somatosensory system such as altered sensory integration due to the improper proprioception afferent. This condition can lead to an imprecise function of human postural balance system. But studies focused on the short-term effects of water immersion instead of truly long-term adaptations. So, the aim of this study was to investigate if chronic exposure to microgravity environment can lead to balance deficits and furthermore, to assess potential differences between two types of diving which is breath-hold and SCUBA.

11 breath-hold divers (BHD), 13 scuba divers (both types of divers must have diving experience for at least 4 years) and 22 non-divers (ND), without any history of recent injuries or history that affects balance control, recent were undergone Functional reach test (FRT) as well as Y balance test (YBT).

There were no meaningful differences among experimental groups in limited of stability (p=0.860) and all groups were highly stable in FRT. But in other research criteria, BHD group were significantly had a better ability to maintain their balance during YBT task (p=0.004), while that SCUBA group found to have a poor ability in this matter versus BHD (p=0.001) and ND (p=0.001) groups.

Our findings suggest that BHD and SCUBA divers have a normal ability in order to do functional reach tasks, but by increasing movement demands, SCUBA divers have been faced with balance difficulty more than BHD divers. Hence, according to the obvious difference between BHD and SCUBA divers, along with showing a meaningful difference by ND group, it seems that adding balance training to the routine BHD and SCUBA divers’ program, should be beneficial in order to improve their balance ability.