Skeletal Muscle Groups
The human body has more than 600 muscles which account for more than 40% of a person’s weight. Most of the skeletal muscles are assigned names that describes some characteristics of the muscle. Basically, associating a muscles characteristic with its name aid in learning and remembering of the muscle. Generally, the size, shape, direction of fiber, location, number of origin and the origin of insertion are some common terms that relates to the criteria of muscle nomenclature. Muscles are arranged in groups and according to their location and function.
The skeletal muscle of the head and the neck are the muscles in the face that permit a large variety of facial expressions. On one side of the cheeks Masseter and Buccinator muscles are located. The Trapezius lies on the lower part of the neck. On the upper part of the forehead we have the Frontalis muscle. Orbicularis oculi is responsible for eye opening and closure. At the center of the orbicularis oculi and the orbicularis oris the Zygomaticus is located. Sternocleidomastoid separates the neck and the chin.
Four pairs of muscles are responsible for chewing movements. The chewing muscles connect to the mandible which are the strongest muscles in the body. Also, some other and numerous muscles linked to the neck exist. Generally, all the muscles of the head are used to show the various facial expressions like fear, anger, etc. and giving the face its proper shape.
The Muscles of the Trunk on the other hand involves those that move the vertebral column, the thorax and the abdominal walls. From the skull to the scrum we have the vertebral column compact with erector spinae group. These muscles enable the vertebral column to maintain an erect posture. To maintain the Transverse process of the back the deep back muscles connect the spine and the adjacent vertebral. This facilitate the upper part of the body to move freely and maneuver appropriately.
Additionally, the body has the Muscles of the upper Extremity. These include those that connect the thorax. The arm is connected to the scapular through the humerous. Muscles that moves to the shoulder include the trapezius and the serratus anterior. The humerous is associated to Triceps, Brachii, Biceps the Brachioradialis muscles. According to Kim et al., (2018) the upper extremity muscles are responsible for arm elevation and they have a physical demand of task performance.
References
Kim, S., Nussbaum, M. A., Esfahani, M. I. M., Alemi, M. M., Alabdulkarim, S., & Rashedi, E. (2018). Assessing the influence of a passive, upper extremity exoskeletal vest for tasks requiring arm elevation: Part I–”Expected” effects on discomfort, shoulder muscle activity, and work task performance. Applied ergonomics, 70, 315-322.