Arterial compression during overhead throwing: a risk for arterial injury?

Case studies reporting aneurysm formation in the axillary artery have been described in overhead throwing athletes, possibly due to repetitive arterial compression by the humeral head that has been transiently observed during sonographic diagnostic arm manoeuvres. Whether compression negatively alters arterial health has not been investigated and was the focus of this study. The throwing arm of elite overhead athletes was screened for inducible axillary artery compression. Compressors (COMP, n = 11, mean age: 20 (SD: 2) year, 7 male, 4 female) were age and sex matched with noncompressing (NONCOMP) athlete controls. Four indices of arterial health (flow mediated dilation [FMD], conduit artery vasodilatory capacity [CADC], glyceryl-trinitrate [GTN]-induced vasodilation and intima-media thickness [IMT]) were assessed with high-resolution ultrasound at the brachial and the axillary, artery. No significant between-group differences were observed at the brachial, or axillary, artery for FMD (brachial: COMP: mean (SD) 6.2 (3.1)%, NONCOMP: 6.1 (3.5)%, p = 0.967, axillary: COMP: 8.0 (5.5)%, NONCOMP: 9.0 (3.6)%, p = 0.602), CADC (brachial: COMP: 10.4 (3.4)%, NONCOMP: 10.4 (5.4)%, p = 0.999, axillary: COMP: 9.6 (4.2)%, NONCOMP: 8.5 (3.2)%, p = 0.492), GTN-induced vasodilation (brachial: COMP: 17.9 (5.1)%, NONCOMP:14.1 (7.2)%, p = 0.173, axillary: COMP: 9.5 (4.3)%, NONCOMP: 7.7 (3.1)%, p = 0.302) or IMT (brachial: p = 0.084, axillary: p = 0.581). These results suggest that transient arterial compression, observed during diagnostic arm manoeuvres in overhead throwing athletes, is not associated with abnormal indices of artery function or structure and that other mechanisms must be responsible for the published cases of aneurysm formation in elite athletes performing overhead throwing actions.

Anterior translation at the glenohumeral joint: a cause of axillary artery compression?

BACKGROUND: Lesions to the axillary artery are reported in overhead athletes. One speculated cause is repeated transient compression by the humeral head due to excessive laxity at the glenohumeral joint. HYPOTHESES: (1) Anterior translation of the glenohumeral joint alters axillary artery diameter and blood flow characteristics, and (2) individuals demonstrating inducible axillary artery compression with the arm in an overhead position (as indicated by diameter and blood flow characteristics) will demonstrate greater magnitudes of anterior translation. STUDY DESIGN: Descriptive laboratory study. METHODS: After receiving ethical approval and screening for problematic conditions/injuries, 26 subjects were tested (10 men and 16 women; mean age [standard deviation], 25 years [4]). Axillary artery diameter and peak systolic velocity were measured with B-mode and Doppler ultrasound before, during, and after glenohumeral anterior translation at 90 degrees of abduction, 60 degrees of external rotation, and 30 degrees of horizontal flexion, and at baseline and a simulated overhead throwing position (120 degrees of abduction, 90 degrees of external rotation, and 30 degrees of horizontal extension). The magnitude of anterior translation was captured with B-mode ultrasound using a posterior transverse approach. RESULTS: Application of the glide resulted in a significant (F(2,21) = 9.965, P = .001) reduction in axillary artery diameter and a significant increase in peak systolic velocity (F(2,21) = 5.286, P = .014). Subjects demonstrating clinically significant levels of axillary artery compression ( > 50% reduction in vessel diameter with the arm in the overhead throwing position) exhibited significantly (t = -2.260, P = .040) greater ranges of anterior translation at the glenohumeral joint than the 9 subjects who exhibited < 10% reduction in arterial diameter. CONCLUSIONS: This investigation provides the first empirical support for the clinical opinion that glenohumeral anterior translation could be a mechanism for inducible axillary artery compression. CLINICAL RELEVANCE: The response of axillary artery hemodynamics in normal, healthy individuals is the first step in the process of determining whether the finding of inducible axillary artery compression in overhead athletes with arterial pathology is related to glenohumeral translation.