TABLE 3.

Bias ± precision (in degrees) for humeral, scapular, and clavicular bone angular error. IR = internal rotation, ER = external rotation, UR = upward rotation, DR = downward rotation. Positive bias values for the humerus indicates shape-matching overestimated abduction, posterior plane of elevation, and external rotation as compared to marker tracking, or underestimated adduction, anterior plane of elevation, and internal rotation. Positive bias values for the scapula indicates shape-matching overestimated external rotation, upward rotation, and anterior tilt as compared to marker tracking, or underestimated internal rotation, downward rotation, and posterior tilt. Positive bias values for the clavicle indicates shape-matching overestimated retraction, elevation, and anterior axial rotation as compared to marker tracking, or underestimated protraction, depression, and posterior axial rotation

Humerus
	Elevation	Plane	Axial Rotation
Min	0.5 ± 0.7	0.1 ± 0.4	−0.4 ± 1.6
30°	0.8 ± 2.1	−0.2 ± 1.1	−1.4 ± 2.8
60°	1.3 ± 3.4	0.4 ± 0.7	−1.1 ± 3.4
90°	1.5 ± 1.3	0.4 ± 0.7	1.2 ± 5.0
Max	1.4 ± 2.4	0.0 ± 2.5	0.6 ± 3.8
Overall	1.1 ± 2.0	0.1 ± 1.2	−0.2 ± 3.3
Scapula
	IR/ER	UR/DR	Tilt
Min	−0.3 ± 1.9	0.2 ± 0.3	0.5 ± 1.3
30°	−0.5 ± 1.4	−0.1 ± 0.4	0.0 ± 0.3
60°	0.1 ± 1.6	0.2 ± 0.3	0.1 ± 1.0
90°	−0.3 ± 1.7	−0.1 ± 0.3	−0.1 ± 1.1
Max	0.0 ± 2.3	0.6 ± 0.6	0.3 ± 0.3
Overall	−0.2 ± 1.6	0.2 ± 0.4	0.2 ± 0.8
Clavicle
	Retraction	Elevation	Axial Rotation
Min	0.0 ± 0.1	−0.2 ± 1.0	−0.3 ± 3.8
30°	0.3 ± 0.6	−0.2 ± 0.6	−2.2 ± 3.5
60°	0.0 ± 0.2	0.0 ± 0.7	−1.8 ± 3.3
90°	0.4 ± 0.5	0.1 ± 0.5	−0.6 ± 6.0
Max	0.2 ± 0.4	0.2 ± 0.5	−1.0 ± 2.3
Overall	0.2 ± 0.4	0.0 ± 0.6	−1.2 ± 3.6