Relationship between shoulder roll and hand propulsion in the front crawl stroke

Area of Science:

• Sports Science
• Biomechanics
• Swimming Performance

Background:

• Understanding hand propulsion (HP) is crucial for optimizing swimming technique.
• The front crawl stroke involves distinct pull and push phases, each contributing differently to propulsion.
• The role of shoulder roll (SR) in generating hand propulsive lift (HP_L) requires further investigation.

Purpose of the Study:

• To re-evaluate the magnitude of hand propulsion (HP) in the pull and push phases of the front crawl stroke.
• To investigate the association between the angular velocity of shoulder roll (ωSR) and hand propulsive lift (HP_L).

Main Methods:

• 16 skilled swimmers performed the front crawl stroke at maximal sprinting pace.
• Hand propulsion (HP), hand propulsive drag (HP_D), and hand propulsive lift (HP_L) were determined using a dynamic pressure approach.
• Angular velocity of shoulder roll (ωSR) was computed in the plane normal to the forward direction.

Main Results:

• HP and HP_D were significantly greater in the pull phase compared to the push phase (P < 0.05).
• HP_L was similar between the pull and push phases.
• A significant positive correlation between ωSR and HP_L in the push phase was found in 11 out of 16 swimmers (P < 0.05).

Conclusions:

• Swimmers should utilize more drag for HP in the pull phase.
• Propulsion from drag and lift should be balanced in the push phase.
• Increasing ωSR during the push phase may enhance HP_L, suggesting potential technique modifications.