Three-dimensional kinematics of shoulder laxity examination and the relationship to clinical interpretation^*

* The Institutional Review Board of the University of Minnesota approved this study. Study number 9911M24181.

Figures & data

Table 1. Subject inclusion/exclusion criteria.

Inclusion

Exclusion

• 18–60 years of age • Shoulder pain during active shoulder motion • Current localized anterolateral shoulder pain • Pain with resisted internal or external rotation • At least two positive impingement tests: Hawkins-Kennedy, Neer or Jobe. • Visible scapula dyskinesia^a

• Joint disease (osteoarthritis or rheumatoid arthritis) • 25% or greater reduction in glenohumeral internal or external rotation when compared to opposite shoulder • Reproduction of symptoms during cervical spine screening • Positive drop arm or apprehension tests • History of shoulder surgery, known labral tear, or known rotator cuff tear • Previous fracture of clavicle, scapula, humerus • Symptom onset following trauma • History of glenohumeral dislocation

^a Scapular dyskinesia was defined as excessive medial border or inferior border prominence during raising or lowering the arm similarly described by McClure et al. (2009).

Table 2. Subject demographic data.

Age, years	37.8 (14.5)
Gender	6 females/5 males
Height, cm	170.0 (10.3)
Mass, kg	78.7 (10.7)
BMI	27.2 (4.5)
Handedness (right), n	11
Dominant side tested, n	9
Symptom duration, years	9.4 (7.8)
VAS (0–10)	2.5 (1.7)
DASH (0–100)	19.8 (10.8)

Note:

BMI, body mass index; n, number; DASH, Disability of the Arm Shoulder and Hand; VAS, visual analog scale of usual shoulder symptom pain severity.

Mean (SD).

Figure 1. Intracortical pin placement in humerus and scapula in a representative subject.

Table 3. Descriptive values and inter-examiner translation repeatability for shoulder laxity tests.

Test	Anterior drawer		Posterior drawer		Sulcus
Examiner	EX1	EX2	EX1	EX2	EX1	EX2
Mean Translation (mm)	3.1	4.0	−3.9	−1.7	−3.0	−2.9
ICC (CI)	0.87 (0.62–0.96)		na		0.84 (0.51–0.95)
SEM (mm)	1.0		2.6		1.2

Note:

ICC, intraclass correlation coefficient (2,1); CI, 95% confidence interval; na, not applicable (ICC calculation for posterior drawer not valid due to low between-subject variation (Fleiss 1986); SEM, standard error of measurement.

Figure 2. Box plot (median, interquartile range, minimum and maximum) of EX1 translations for each subjective grade during Anterior Drawer testing.

Figure 3. Box plot (median, interquartile range, minimum and maximum) of EX1 translations for each subjective grade during Posterior Drawer testing.

Note: A single line without surrounding box plots indicates only one observation at that grade level.

Figure 4. Box plot (median, interquartile range, minimum and maximum) of EX1 translations for each subjective grade during Sulcus testing.

Note: A single line without surrounding box plots indicates only one observation at that grade level.

Figure 5. Regression of combined Anterior Drawer, Posterior Drawer and Sulcus tests RMS translation with the composite subjective test score.

Note: r² = 0.75, r = 0.86, p < 0.005.

McClure PW, Tate AR, Kareha S, Irwin D, Zlupko E. 2009. A clinical method for identifying scapular dyskinesis, part 1: reliability. J Athl Train. 44(2):160–164.10.4085/1062-6050-44.2.160

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