ASSESSMENT OF HUMERAL TORSION BY PALPATION IN BASEBALL PITCHERS: A VALIDATION STUDY

Area of Science:

• Orthopedic biomechanics
• Sports medicine
• Diagnostic methods

Background:

• Greater humeral retroversion (HT) is linked to shoulder and elbow injuries in athletes.
• Imaging techniques like CT and sonography for HT measurement can be costly or inaccessible.
• A non-invasive palpation method is explored as a potentially reliable alternative.

Purpose of the Study:

• To validate the construct of a palpation technique for measuring humeral torsion (HT).
• To determine if a side-to-side difference in HT could be detected in baseball pitchers using palpation.
• To compare palpation-derived HT measurements with ultrasound (US) measurements.

Main Methods:

• Twenty collegiate and high school pitchers were evaluated.
• Bilateral passive range of motion (external and internal rotation) was measured.
• Humeral torsion was assessed using both sonographic and palpatory methods.
• Statistical analyses included paired t-tests and Pearson's correlation coefficients.

Main Results:

• Both palpation and US revealed significantly greater HT in dominant arms.
• A positive correlation was found between palpation and US measurements of HT (r=0.522, p=0.018).
• Palpation underestimated HT magnitude compared to US (difference 4°±9, p=0.048).
• Range of motion differences correlated with HT measurements from both methods.

Conclusions:

• Palpation effectively detects greater HT in the dominant shoulder of pitchers.
• Palpation-based HT assessment correlates with US measurements, confirming its validity.
• While not interchangeable with US, palpation offers a reliable and practical method for assessing HT.