Reliability of and the relationship between ultrasound measurement and three clinical assessments of humeral torsion.

PURPOSE/

backgroundDifferences in humeral torsion have been observed between overhead athletes and non-athletes. Although humeral torsion may be an adaptive process for athletic performance, it may be associated with injury. Methods for measuring humeral torsion have consisted of radiography, computer tomography, and ultrasound imaging. However, diagnostic imaging may be costly and not available to all clinicians. The implementation of clinical assessments may be an alternative way to measure humeral torsion. Before clinical measures can be recommended, these assessments need to be evaluated for validity and reliability of each test. The purpose of this study was to assess the intratester and intertester reliability of three clinical tests, intratester reliability of ultrasound measures, and the validity of each clinical test to ultrasound measures.

methodsThirty participants (male: 12, female: 18; age: 20±2 years; height: 174.24±9.35 cm; mass: 70.53±11.06 kg; body mass index: 23.13±2.47 kg/m(2); years in sport: 9±4 years) with experience in overhead sports were assessed for humeral torsion, bilaterally. Humeral torsion was assessed using musculoskeletal ultrasound by a single assessor, and using three separate clinical assessments by two independent assessors. Clinical assessments included the angle of rotation during both the bicipital tuberosity palpation with the shoulder abducted at 90 degrees (Palp90) or 45 degrees (Palp45), and the angle of external rotation during horizontal adduction (HADD).

resultsIntratester reliability for the ultrasound measure was good (ICC=0.907), along with intratester reliability for both assessors across each clinical assessment (ICC's > 0.769). Poor to moderate reliability was observed between assessors for each clinical assessment (ICC=0.256 Palp90, ICC=0.419 Palp45, ICC=0.243 HADD. Only the Palp90 measure had a fair but significant (r=0.326, p=0.011) relationship with ultrasound measures.

conclusionIndividual assessors can achieve reliable ultrasound, bicipital tuberosity palpation and HADD values across multiple trials; however, these measures are not consistent between assessors. Additionally, only one clinical test had a fair but significant relationship with ultrasound measures. Improved testing procedures may be needed to increase between assessor reliability and strength of relationships to ultrasound measures. Current application of clinical assessments to measure humeral torsion is limited. LEVEL OF EVIDENCE: 3b; Grade of Recommendation C.