Maximal Fully Tethered Swim Performance in Para Swimmers With Physical Impairment.

Unlabelled: The assessment of swimming propulsion should be a cornerstone of Paralympic swimming classification. However, current methods do not objectively account for this component.

Purpose: To evaluate the swimming propulsion of swimmers with and without physical impairment using a 30-second maximal fully tethered freestyle swim test.

Methods: Tethered forces were recorded during maximal fully tethered swimming in 80 competitive swimmers with (n = 70) and without (n = 10) physical impairment. The relationships between absolute and normalized tether forces and maximal freestyle swim speed were established using general additive models.

Results: Para swimmers with physical impairment had lower absolute and normalized tether forces than able-bodied swimmers, and there were moderate positive correlations found between tether forces and sport class (τ = .52-.55, P < .001). There was a nonlinear relationship between tether force and maximal freestyle swim speed in the participant cohort (adjusted R2 = .78-.80, P < .001). Para swimmers with limb deficiency showed stronger relationships between tether force and maximal freestyle swim speed (adjusted R2 = .78-.82, P < .001) than did Para swimmers with hypertonia (adjusted R2 = .54-.73, P < .001) and impaired muscle power (adjusted R2 = .61-.70, P < .001).

Conclusions: Physical impairments affect Para swimmers' tether forces during maximal fully tethered freestyle swimming, explaining a significant proportion of their activity limitation. It is recommended that maximal fully tethered swimming be included in Paralympic swimming classification as an objective assessment of swimming propulsion.