Upper limb joint forces and moments during underwater cyclical movements

Area of Science:

• Biomechanics
• Fluid Dynamics
• Sports Science

Background:

• Measuring hydrodynamic forces in dynamic aquatic conditions is challenging, limiting sound inverse dynamics modeling in locomotion research.
• Existing methods struggle to accurately quantify joint forces and moments during complex movements in water.

Purpose of the Study:

• To develop and validate an innovative methodology for quantifying upper limb joint forces and moments in aquatic locomotion.
• To overcome the limitations of current techniques in measuring hydrodynamic forces during dynamic conditions.

Main Methods:

• Combined computational fluid dynamics and inverse dynamics techniques.
• Utilized underwater motion capture for upper limb kinematics of swimmers.
• Employed a dynamic mesh algorithm for hydrodynamic resistance computation and inverse dynamics modeling for joint kinetics.

Main Results:

• Successfully implemented and validated a novel methodology for quantifying upper limb joint forces and moments during aquatic movement.
• Simulation results showed a small discrepancy (1.2±3.5%) between calculated and theoretical impulse, validating the model.
• Upper limb joint loads were found to be within 5% of body weight, suggesting potential for low-load aquatic exercises.

Conclusions:

• The developed methodology provides a significant advancement for studying aquatic movement mechanics.
• Findings support the use of low-load aquatic exercises for reducing joint stress in rehabilitation and fitness.
• This approach is expected to enhance understanding of swimming performance and inform practice guidelines.