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Understanding the musculoskeletal anatomy of soft tissues of the head and neck is important for surgical applications, biomechanical modelling and management of injuries, such as whiplash. Additionally, analysing sex and population differences in cervical anatomy can inform how biological sex and population variation may impact these anatomical applications. Although some muscles of the head and neck are well‐studied, there is limited architectural information that also analyses sex and population variation, for many small cervical soft tissues (muscles and ligaments) and associated entheses (soft tissue attachment sites). Therefore, the aim of this study was to present architectural data (e.g., proximal and distal attachment sites, muscle physiological cross‐sectional area, ligament mass, enthesis area) and analyse sex and population differences in soft tissues and entheses associated with sexually dimorphic landmarks on the cranium (nuchal crest and mastoid process) and clavicle (rhomboid fossa). Through the dissection and three‐dimensional analysis of 20 donated cadavers from New Zealand (five males, five females; mean age 83 ± 8 years; range 67–93 years) and Thailand (five males, five females; 69 ± 13 years; range 44–87 years), the following soft tissues and their associated entheses were analysed: upper trapezius, semispinalis capitis and the nuchal ligament (nuchal crest); sternocleidomastoid, splenius capitis and longissimus capitis (mastoid process); the clavicular head of pectoralis major, subclavius, sternohyoid and the costoclavicular (rhomboid) ligament (rhomboid fossa). Findings indicate that although muscle, ligament and enthesis sizes were generally similar to previously published data, muscle size was smaller for six of the eight muscles in this study, with only the upper trapezius and subclavius demonstrating similar values to previous studies. Proximal and distal attachment sites were largely consistent with the current research. However, some individuals (six of 20) had proximal upper trapezius attachments on the cranium, with most attaching solely to the nuchal ligament, contrasting with existing literature, which often describes attachment to the occipital bone. With respect to sexual dimorphism, the Thai sample exhibited more sex differences in muscle size than the New Zealand sample, but for enthesis size (area), both samples had the same amount of statistically significant sex differences (5 of 10). Additionally, some significant population differences were found when comparing muscle and enthesis size data between the New Zealand and Thai samples. Despite these findings, no sex or population differences were found for ligament size (mass) in either group. This paper presents new architectural data for several understudied areas of the head and neck, as well as providing analyses on sex and population differences, two areas that have limited representation in anatomy. [ABSTRACT FROM AUTHOR]

Backgroud: The intramuscular nerve distribution of mammalian skeletal muscle may be of importance for understanding of muscle-nerve relationship. The purpose of this study was to examine the intramuscular nerve distribution patterns of various skeletal muscles in rabbits. Methods: The relationships among pectoralis major muscle, plantaris, extensor digitorum longus with various architecture and their intramuscular nerve distribution patterns were examined in twenty New Zealand rabbits using the modified Sihler's stain method. Results: The pectoralis major muscle, plantaris, extensor digitorum longus contain separate nerve compartments. Neural anastomoses were observed in three shape skeletal muscles, including the U-like, Y-like, L-like appearance. Conclusion: Intramuscular nerves running in parallel or perpendicular with the muscle fibers. The spatial arrangement of the muscle fibers was related to the intramuscular nerve distribution patterns. Giriş: Kas-sinir ilişkisini anlamada memeli iskelet kasının intramusküler sinir dağılımını bilmenin önemi olabilir. Bu çalışmanın amacı tavşanda değişik iskelet kaslarının intramusküler sinir dağılımlarını incelemektir. Yöntem: Modifiye edilmiş Sihler boyası yöntemi kullanılarak yirmi Yeni Zelanda tavşanında büyük pektoral, plantaris, ekstensör digitorum longus ile intramusküler sinir dağılım patternleri ve değişik mimari yapı arasındaki ilişki incelendi. Sonuç: Pectoralis major, plantaris, ekstensör digitorum longus kasları ayrı sinir kompartmanlarına sahiptir. İskelet kaslarında U-benzeri, Y-benzeri ve L-benzeri olmak üzere üç tip nöral anastomoz görünümü gözlendi. Yargı: İntramusküler sinirler kas lifleriyle paralel ya da dik olarak seyrederler. Kas liflerinin uzaysal düzenlenmeleri intramusküler sinir dağılım patternleri ile ilişkilidir. [ABSTRACT FROM AUTHOR]