Phase-Specific Kinematic Differences in Change of Direction Interlimb Performance Asymmetry

Area of Science:

• Sports Science
• Biomechanics
• Motor Control

Background:

• Interlimb asymmetry in change of direction (COD) performance is common in athletes.
• Understanding the kinematic basis of this asymmetry is crucial for developing targeted interventions.
• Previous research has not fully elucidated phase-specific kinematic differences during COD tasks.

Purpose of the Study:

• To investigate phase-specific kinematic differences in 180° COD interlimb performance asymmetry.
• To evaluate associations between linear kinematics and change of direction deficit (CODD) across turning limbs.

Main Methods:

• Forty-eight youth basketball players performed 10-m sprint and 505 COD tests on alternating limbs.
• Analysis focused on 37 players with significant interlimb differences (dominant vs. nondominant).
• Paired t-tests and Spearman correlations were used to analyze kinematic data (trunk angular displacement, angular speed, acceleration) and CODD.

Main Results:

• The nondominant limb showed lower trunk angular displacement and slower angular speed during early deceleration.
• During reacceleration, the nondominant limb exhibited greater early phase trunk rotation but lower late phase acceleration.
• Deceleration variables were moderately associated with CODD, while acceleration variables showed no significant association.

Conclusions:

• Significant phase-specific kinematic differences exist in COD interlimb asymmetry, particularly in trunk rotation during deceleration and reacceleration.
• A self-regulating, potentially defensive, strategy may underlie this execution asymmetry.
• Coaching interventions should address turning technique to improve bilateral symmetry, considering potential defensive mechanisms.