Developmental biomechanics of neck musculature

Abstract

Neck mechanics is central to head injury prevention since it is the musculoskeletal neck, which dictates the position and movement of the head. In the US, traumatic injury is the leading cause of death for children; however prevention is hampered by the lack of data concerning the mechanics of the immature head-and-neck. Thus, the objective of this study was to quantify neck muscle strength and endurance across the maturation spectrum and correlate these with head-and-neck anthropometry. A factorial study was performed on 91 human subjects measuring head-and-neck anthropometry and neck strength and endurance in three bending directions (flexion, extension, and lateral) as a function of age (6–23 years). Using a custom device, neck maximum voluntary contraction (MVC) force was measured in triplicate. Next, neck muscle endurance (sustained effort) was measured as the subjects’ ability to maintain 70% of peak force over 30 s. Linear regression of peak force and endurance as a function of age revealed each direction to significantly (p<0.0001) increase with age. The MVC force, averaged across all directions and normalized to the adult values, exhibits the following maturation curve: %MVC Force= −0.0879(age)2+6.018(age)+8.120. Neck muscle strength, similar between young males and females, becomes disparate in adolescence and adulthood with males exhibiting greater strength. Bending direction differences were also found with extension strength being the greatest regardless of age and sex. Furthermore, neck circumference appears predictive of neck strength and endurance in children. Together, these relationships may facilitate improved design of injury prevention interventions.

Collegiate and High School Athlete Neck Strength in Neutral and Rotated Postures

“…This study found that flexion, extension, and lateral flexion neck strength increased with age according to a second-order polynomial relationship (31). Further, sex differences in neck strength were not seen in children ages 6-11 years, but significant differences begin to develop in the age group 12-17 and are much stronger in those aged 18-23 years (18).…”

“…To our knowledge, only 1 research group has examined neck strength in children and adolescents (18,31). This study found that flexion, extension, and lateral flexion neck strength increased with age according to a second-order polynomial relationship (31).…”

Development and Tensile Investigation of a 3-year-old Cervical Spine Finite Element Model

“…In this study, the C2-C7 cervical segmental response was first validated under the dynamic tensile response and the dynamic extension-flexion response were then compared with both segmental and global experimental data. However, the muscles were not included in this model because accurate muscle force is dependent on the physiological cross-section area (PCSA), the muscle activation level and muscle fiber length [39], which were unavailable in the 3-year-old pediatric cervical spine [40]. (b) The simulated ultimate failure displacement and ultimate failure force of the C0-C7 FE model for the 3-year-old pediatric cervical spine compared with the tensile experiment data reported by Ouyang et al [38].…”

Pediatric Biomechanics

“…Similarly, muscles active during extension are termed extensors (e.g., splenius capitis, trapezius). During the developmental process, crosssectional area of the flexors and extensor muscles increase [111][112][113]. However, the difference between pediatric and adult muscle crosssectional area varies by muscle type (Fig.…”

“…22.15) [111]. Additional studies have quantified that neck muscle maximum voluntary contraction as measured by peak force and muscle endurance as measured by the ability to sustain that force increases with age [112]. Differences between the genders do not appear until adolescence.…”