An Investigation Into the Relationship Between Maximum Isometric Strength and Vertical Jump Performance

Area of Science:

• Sports Science
• Biomechanics
• Human Performance

Background:

• Dynamic strength is linked to vertical jump (VJ) performance.
• The relationship between isometric strength and VJ performance is less understood.

Purpose of the Study:

• To investigate the correlation between isometric strength and performance in squat jump (SJ) and countermovement jump (CMJ).

Main Methods:

• Twenty-two male collegiate athletes performed isometric midthigh pulls (IMTPs) to measure isometric peak force (IPF), maximum rate of force development, and impulse (IMP).
• VJ force-time data were analyzed for peak velocity, peak force (PF), peak power (PP), and jump height.

Main Results:

• Absolute IMTP impulse measures showed the strongest correlations with VJ PF (r = 0.43-0.64) and VJ PP (r = 0.38-0.60).
• No significant differences in SJ or CMJ height were found between stronger and weaker athletes.
• Absolute isometric peak force and impulse relate to VJ peak force and power, but not jump height.

Conclusions:

• Isometric strength measures, particularly impulse, are associated with aspects of vertical jump force and power.
• Stronger athletes did not demonstrate higher vertical jump heights than weaker athletes.
• Dynamic strength assessments may be more practical for evaluating the relationship between relative strength and dynamic performance in collegiate athletes.