Force-velocity profile: imbalance determination and effect on lower limb ballistic performance

Area of Science:

• Biomechanics
• Sports Science
• Human Movement

Background:

• Theoretical models suggest a link between an athlete's force-velocity (F-v) mechanical profile and jumping performance.
• Maximal power output (P max) is a known determinant of performance, but its independent contribution relative to the F-v profile requires further investigation.

Purpose of the Study:

• To experimentally investigate the influence of the F-v mechanical profile on jumping performance, independent of P max.
• To quantify the relationship between F-v imbalance and jumping ability in high-level athletes.

Main Methods:

• 48 high-level athletes performed maximal squat jumps with varying loads (0-100% body mass).
• Mean force, velocity, and power were calculated from flight time to determine individual linear F-v relationships and P max.
• F-v imbalance was quantified by comparing actual and optimal F-v profiles.

Main Results:

• Multiple regression analysis revealed significant contributions of P max, F-v imbalance, and lower limb extension range (h PO) to jumping performance (r²=0.931).
• Positive correlations were found for P max and h PO, while F-v imbalance showed a negative correlation with performance.
• A lower F-v imbalance was associated with higher jumping performance.

Conclusions:

• Experimental evidence supports that ballistic performance is influenced by the F-v profile of the lower limbs, in addition to P max.
• An individual optimal F-v profile exists that maximizes jumping performance, and deviations (imbalance) lead to reduced performance.
• Findings have significant implications for strength and conditioning programs aimed at optimizing athletic performance.