Upper Quadrant Field Tests and Isokinetic Upper Limb Strength in Overhead Athletes

Area of Science:

• Sports Medicine
• Biomechanics
• Exercise Physiology

Background:

• Isokinetic testing is the standard for assessing upper extremity strength in overhead athletes but requires a laboratory setting.
• Field tests like the Seated Medicine Ball Throw (SMBT) and Upper Quarter Y-Balance Test (YBT-UQ) were developed as accessible alternatives.
• The relationship between these field tests and objective isokinetic strength measures has not been previously established.

Purpose of the Study:

• To examine the correlation between isokinetic strength of the shoulder and elbow and performance on the SMBT and YBT-UQ in overhead athletes.
• To determine the validity of field-based tests for assessing upper limb strength.

Main Methods:

• A cross-sectional study was conducted in an institutional laboratory setting.
• Twenty-nine healthy overhead athletes (14 male, 15 female) participated.
• Isokinetic strength of shoulder and elbow muscles was measured using a Biodex dynamometer, alongside SMBT distance and YBT-UQ performance.

Main Results:

• Moderate to strong correlations (r = 0.595–0.855) were found between SMBT performance and isokinetic shoulder and elbow strength.
• The SMBT explained a significant portion of the variance in shoulder (35.4%–64.5%) and elbow (58.5%–73.1%) strength.
• No significant correlations were observed between YBT-UQ performance and isokinetic strength variables.

Conclusions:

• The SMBT is a reliable, cost-effective, and time-efficient alternative for assessing upper extremity strength in clinical settings.
• The YBT-UQ is not a valid measure for upper limb strength in this population.
• The YBT-UQ may be suitable for assessing other aspects of athletic performance.