ABSTRACT
AIM: Based on cadaveric, neurosurgical and medico-diagnostic evidence the axillary arch of Langer (AA) is assumed to create symptoms similar to those of entrapment or obstruction type syndromes, e.g. Thoracic Outlet Syndrome. Although the incidence of a AA varies between studies and races, there are many assumptions that its frequency and its axillary location influences the motor control of the shoulder girdle. In addition to the existing anatomical evidence and based on functional reasoning it can be predicted that the AA influences the shoulder girdle kinesiology in vivo also. However no study is known that verifies these functional assumptions in vivo. METHODS: In order to complete our knowledge of the AA we evaluated strength, endurance, motor control, precision and proprioception in vivo, e.g. hand held dynamometry, abduction and adduction shoulder strength and endurance, functional exercise assessment, throwing impact force on a (precision) target and shoulder joint position sense were measured in two groups of athletes and physical education students, one with an AA (N.=22) and a control group without AA (N.=22). RESULTS: The results indicate a significant (p<0.05) influence of the presence of an AA on strength, endurance and motor control increase in women associated with an increase of paraesthetics. For all these parameters no significant difference occurred in men. The throwing and proprioceptive joint position sense data however indicate a clear (P<0.05) increase of impact forces suggesting a possible shoulder stabilisation and an improvement of proprioception both in men and most in women. CONCLUSION: These finding have both a functional and clinical relevance and do not fully confirm the anatomical predictions from the cadaveric evidence nor support the (surgical) diagnoses of excision of the AA of Langer in throwing in athletes.
