A Comparison of Single Leg Countermovement Jump Techniques on Jump Performance: Considerations for Test...

Area of Science:

• Biomechanics
• Sports Science
• Human Movement Analysis

Background:

• Single leg countermovement jump (SLCMJ) testing is prevalent in sports performance and rehabilitation.
• Inconsistent protocols and techniques exist in SLCMJ literature, hindering standardization.

Purpose of the Study:

• To evaluate four distinct SLCMJ techniques (90° hip/knee flexion, 90° knee bend, straight limb, unrestricted limb).
• To examine the reliability and performance metrics of each technique for improved test standardization.

Main Methods:

• Twenty-four university sports science students participated.
• Three trials of each of the four SLCMJ techniques were performed on both limbs.
• Vertical ground reaction forces and 2D sagittal plane video data were collected.

Main Results:

• Technique B (90° knee bend) exhibited the highest reliability (ICC ≥0.80, CV ≤ 13%) across most metrics.
• Significant differences (p < 0.05) were found across techniques for various variables.
• Technique D (unrestricted limb) yielded greater outcome measures but utilized a different strategy involving angular momentum.

Conclusions:

• Technique B, by limiting free limb contribution, promotes optimal hip, knee, and ankle flexion/extension.
• Technique B is deemed more appropriate for standardized sports performance testing and rehabilitation contexts.