Purpose:
The unstable environment and the swaying, rolling, and pitching motions experienced when offshore sailing may disturb motor function and negatively affect personal safety. The aim of the study was to investigate changes in lower limb kinaesthetic sense in sailors after spending time onboard a seagoing vessel.

Methods:
The study involved 39 subjects, of which 13 were professional sailors (PS) (age = 22.56 ± 0.83 years), 13 were recreational sailors (RS) (age = 31.50 ± 7.35 years), and 13 served as a non-sailor group (NS) (age = 21.02 ± 0.82 years) with no sailing experience. PS attended a 1-month on-sea training course, RS attended a 1-month seagoing cruise, and NS did not sail or participate in any congruent activity during the study duration. Kinaesthetic sense was quantified before and after the interventions by a force-matching task in which the force production accuracy (FPA) was measured on a custom-designed kinesthesiometer. The participants performed 5 right and left single-leg extensions at a force perceived to be equal to 10 kg (98 N).

Results:
Right and left limb FPA increased in PS by 0.70% and 79.12% and in RS by 18.97% and 20.26%, respectively. In NS, right and left FPA decreased by 6.97% and 1.42%, respectively. Only the difference for left limb FPA in the PS group achieved statistical significance (p = 0.0006).

Conclusions:
A 1-month sailing intervention reduced lower limb kinaesthesia as measured by the accuracy of reproducing a pre-specified force magnitude.