Fiber types of the anterior and lateral cervical muscles in elderly males
Cornwall, Jon; Kennedy, Ewan
Purpose: The anterior and lateral cervical muscles (ALCM) are generally considered to be postural, yet few studies have investigated ALCM fiber types to help clarify the function of these muscles. This study aimed to systematically investigate ALCM fiber types in cadavers. Methods: Anterior and lateral cervical muscles (4 scalenus anterior, medius, posterior muscles; 5 longus colli, 5 longus capitis taken bilaterally from one cadaver) were removed from four male embalmed cadavers (mean age 87.25 years). Paraffin embedded specimens were sectioned then stained immunohistochemically to identify type I and II skeletal muscle fibers. Proportional fiber type numbers and cross-sectional area (CSA) occupied by fiber types were determined using stereology (random systematic sampling). Results were analyzed using ANOVA (P<0.05) and descriptive statistics. Results: Scalenus anterior had the greatest average number and CSA of type I fibers (71.9% and 83.7%, respectively); longus capitis had the lowest number (48.5%) and CSA (61.4%). All scalenes muscles had significantly greater type I CSA than longus capitis and longus colli; scalenus anterior and medius had significantly greater type I numbers than longus capitis and longus colli. Some significant differences were observed between individual cadavers in longus colli for CSA, and longus capitis for number. Conclusion: The ALCM do not share a common functional fiber type distribution, although similar fiber type distributions are shared by longus colli and longus capitis, and by the scalene muscles. Contrary to conventional descriptions, longus colli and longus capitis have type I fiber proportions indicative of postural as well as phasic muscle function.
Rights Statement: The final publication is available at Springer via http://dx.doi.org/10.1007/s00586-015-3795-3
Keywords: Fiber type; Fibre type; Clinical anatomy; Cervical muscles; Neck muscles; Anterior cervical muscles; Lateral cervical muscles; Muscle function
Research Type: Journal Article