Reliability and Validity of Visual Estimation in Determining Thorax Rotation Mobility using the Quadruped Lumbar-Locked Position.

Background: Thoracic rotation mobility is crucial for athletes in rotational sports such as baseball, golf, and swimming to maintain the proper biomechanics associated with the sport. Accurate differentiation between normal mobility and active and passive physiological deficits in the thoracic region is critical for identifying the need for intervention to the thorax.

Purpose: To establish the reliability and discriminant validity of visual estimation of thorax rotation range of motion across clinicians of differing experience levels in determining normal mobility and active or passive physiological deficits when utilizing the quadruped lumbar-locked position.

Study design: Cross-sectional.

Methods: Thirty-eight subjects (21 female, 17 male) with a mean age of 27 years ± 6.67 were assessed with the quadruped lumbar-locked thorax rotation test by three examiners with various clinical experience in real-time and again one week later. Bilateral active and passive lumbar-locked thorax rotation mobility was assessed by all raters and categorized as "Unrestricted" (≥50°) or "Restricted" (<50°) while a research assistant simultaneously measured the motion with a digital inclinometer. All raters were blinded to the results. All results were analyzed for intra-rater reliability and agreement.

Results: Test-retest intra-rater reliability ranged from 0.55-0.72 and percent absolute agreement ranged from 0.82-0.89. Inter-rater reliability ranged from 0.45-0.59 while percent absolute agreement between raters ranged from 0.74-0.84. There was a significant difference in range of motion between "Unrestricted" and "Restricted" categories for both active (Unrestricted=54.6-58.9; Restricted=40.4-44.4; p<0.001) and passive motion (Unrestricted=61.3-63.5; Restricted=39.2-39.7; p<0.001). The only interaction effect was for passive left rotation [Rater A Restricted x ® =34.3(30.4-38.2); Rater C Restricted (x ) ®=43.8(41.3-46.4); p=.000].

Conclusion: The quadruped lumbar-locked thorax rotation test demonstrates moderate to substantial test-retest intra-rater and inter-rater reliability regardless of clinical experience. The quadruped lumbar-locked thorax rotation test can accurately discriminate between individuals with active and passive physiological deficits regardless of rater experience using visual estimation.

Level of evidence: 3b.