Palpation of the lateral bands of the extensor apparatus of the fingers. Anatomy of a neglected clinical finding

Palpation and Ultrasonography Reveal an Ignored Function of the Inferior Belly of Omohyoid: A Case Series and a Proof-of-Concept Study

BACKGROUND

Palpation, a traditional haptic ability, is used daily by practitioners of all medical and surgical specialties to assess patients. In the current study, one of the authors, in a routine clinical setting, was able to deduce the dynamic features of the putative inferior belly of omohyoid. This led to a proof-of-concept study that yielded results consistent with the clinical findings.

METHODS

The first part of the study involved a survey of 300 rheumatic disease patients in whom the greater supraclavicular fossa was explored by palpation. While the patient kept the head straight, the clinician placed his middle three fingers 2.5-3 cm dorsal to the clavicle in the window between the sternocleidomastoid and trapezius clavicular insertions, explored the supraclavicular fossa, and palpated the paired contractile inferior belly of the assumed omohyoid during flexion in the three orthogonal planes. In the second part of the study, five normal subjects were examined in a similar manner by the same clinician and had independent ultrasonography performed on the dominant side. Descriptive statistics were used, and Yates' corrected chi-squared test was applied to certain nominal variables. Additionally, a comparative anterolateral bilateral neck dissection was performed in a cadaveric specimen.

RESULTS

Both studies showed that the contractile structure was the inferior belly of omohyoid and that its contraction occurred during anterior neck flexion and was opposite to the side of neck rotation, resembling the sternocleidomastoid.

CONCLUSIONS

Palpation uncovered a previously unknown function of the inferior belly of omohyoid, suggesting that physical examination of the musculoskeletal system based on palpation may lead to hypotheses worthy of exploration.

Ultrasonography, Microcomputed Tomography, and Macroscopic Preparation in an Anatomical Study of the Thoracic Limb of the Golden-Headed Lion Tamarin (Leontopithecus chrysomelas)

The aim of this study was to evaluate the normal anatomy of the forearm of the golden-headed lion tamarin (Leontopithecus chrysomelas) using microcomputed tomography (micro-CT) and ultrasonography (US) and then compare the results with the results of a gross anatomy dissection of the forearm. The results of the US examination of the musculoskeletal system of the tamarin forearm were not satisfactory. US imaging enabled observation of the shape of the soft tissue and the size of muscle groups; however, we distinguished more muscles by traditional methods. In addition, in the dissection study, the assessment of the muscles was easier. Examination of the forearm bones using micro-CT provided a complete picture of the bones in this part of the body and was less time-consuming than traditional methods. Imaging allows the anatomy to be represented as a 3D image. However, some methods are not accurate; as in our study, US did not allow a complete assessment of the forearm musculature.