Performance on the Single-Legged Step Down and Running Mechanics.

Area of Science:

• Biomechanics
• Sports Medicine
• Running Analysis

Background:

• The single-legged step down (SLSD) test is a potential tool for assessing running mechanics when advanced gait analysis is unavailable.
• Previous research indicates associations between SLSD kinematics and running mechanics, but the relationship with running kinetics and the influence of sex and muscle strength remain unclear.

Purpose of the Study:

• To determine if SLSD kinematics predict running kinematics and kinetics.
• To investigate if these relationships differ between male and female runners.
• To examine the moderating role of muscle strength in these associations.

Main Methods:

• A cross-sectional study was conducted in a biomechanics research laboratory.
• Fifty highly trained runners (25 men, 25 women) participated.
• Kinematics during the SLSD and running were measured, and muscle strength was assessed to evaluate predictive relationships and moderation effects.

Main Results:

• SLSD kinematics, including hip adduction, internal rotation, knee valgus, and rearfoot eversion, predicted running kinematics in men.
• In women, SLSD hip internal rotation, knee valgus, and rearfoot eversion predicted running kinematics.
• For women, SLSD medial collapse predicted running hip-adductor moment; muscle strength did not moderate any relationships.

Conclusions:

• SLSD kinematics are predictive of running kinematics in both men and women.
• SLSD performance predicts running kinetics only in women.
• Clinicians should independently assess movement quality and muscle strength, as strength does not mediate the SLSD-running mechanics relationship.