15.9
머리를 움직이는 근육
머리를 움직이는 근육은 회전, 굴곡, 확장 및 측면 굽힘을 포함한 광범위한 머리 움직임을 촉진하기 위해 함께 작동하는 역동적이고 복잡한 구조 그룹입니다.
양측 흉쇄유돌근(SCM), 설골상근 및 설골하근은 중요한 머리 굴근입니다. SCM 근육은 흉골과 쇄골에서 시작하여…
여러 개의 목 근육은 머리의 균형을 잡고 대서양-후두 관절에서 머리의 움직임을 촉진하는 데 도움이 됩니다.
예를 들어, 양측 흉쇄유돌근(SCM)은 상상근(suprahyoid muscle) 및 인프라히오이드(infrahyoid) 근육과 함께 주요 머리 굴곡근(head flexor)입니다.
배는 흉골과 쇄골에서 시작하여 측두골의 유양돌기로 삽입됩니다.
SCM이 양측으로 수축할 때 머리를 앞으로 구부리는 데 도움이 됩니다. 대조적으로, 편측성 수축은 같은 쪽의 측면 굴곡 또는 반대쪽으로의 머리 회전을 용이하게 합니다.
측면 목 근육(anterior, middle, posterior scalenes)은 척추를 따라 대각선으로 뻗어 있습니다.
그들은 경추를 위쪽 두 갈비뼈에 연결하고 측면 굴곡을 촉진합니다.
목의 뒤쪽 근육인 전형비장염(splenius capitis)은 목덜미 인대(nuchal ligament)와 C7에서 T3까지의 가시돌기(spinous process)에서 시작하여 후두골과 측두골에 삽입됩니다.
양측으로 수축하면 머리 신전을 돕고, 편측 수축은 측면 굴곡과 같은 쪽으로의 회전을 돕습니다.
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Q1: What is the sternocleidomastoid muscle and what movements does it control?
The sternocleidomastoid (SCM) is a major head flexor originating at the sternum and clavicle and inserting into the mastoid process of the temporal bone. Bilateral contraction bends the head forward, while unilateral contraction causes lateral flexion on the same side or head rotation to the opposite side.
Q2: How do the scalene muscles contribute to head and neck movement?
The anterior, middle, and posterior scalenes run diagonally along the vertebral column, connecting cervical vertebrae to the upper two ribs. These lateral neck muscles facilitate lateral flexion and work with other structures to support diverse head movements, stabilization, and coordinated neck function.
Q3: What is the role of the splenius capitis in head movement?
The splenius capitis originates from the nuchal ligament and C7 to T3 spinous processes, inserting onto the occipital and temporal bones. Bilateral contraction aids head extension, whereas unilateral contraction assists lateral flexion and rotation to the same side, enabling diverse directional movements.
Q4: What are the three layers of posterior neck muscles and their functions?
The superficial layer includes the trapezius and splenius muscles, controlling shoulder and head extension. The middle layer contains cervical transversospinalis muscles like semispinalis capitis, extending and rotating the head. The deepest layer includes suboccipital muscles providing fine motor control and proprioception for precise head positioning.
Q5: How do suboccipital muscles differ from other neck muscles in function?
Suboccipital muscles, located just below the occipital bone, are crucial for fine motor control and proprioception—the sense of self-movement and body position. Unlike larger neck muscles that produce major movements, suboccipitals make minor adjustments to head position and coordinate spatial awareness during complex head movements.
Q6: What is the relationship between the suprahyoid and infrahyoid muscles and head movement?
The suprahyoid and infrahyoid muscles are significant head flexors that work alongside the sternocleidomastoid to facilitate forward head bending. These muscles support muscle coordination and action by stabilizing the hyoid bone and enabling smooth, controlled flexion movements of the head.
Q7: How do bilateral versus unilateral muscle contractions produce different head movements?
Bilateral contraction of muscles like the SCM or splenius capitis produces forward extension or head bending. Unilateral contraction of the same muscles causes lateral flexion toward the contracting side or rotation to the opposite side, allowing precise directional control of head position.