Anatomic considerations in headaches associated with cervical sagittal imbalance: A cadaveric biomechanical study

An anatomical investigation of the suboccipital- and inferior suboccipital triangles

“…One obvious reason for the difference between the results recorded by this study, and those recorded by Kalmanson et al [16] is the difference in the methodologies of data collection. Instead of measuring the lengths of the physical muscles as this study did, Kalmanson et al [16] dissected away the muscles and used CT scans to generate 3D models of each specimen, and then superimposed the muscles forming the ST onto the computer-generated model. This was achieved by estimating each muscle to be a straight line extending from the muscles' origin to insertion as defined in anatomic literature [16].…”

“…A study conducted by Kalmanson et al [ 16 ], measured the borders and area of the ST while the cervical spine was in a neutral position, and then again when the head was in a forward position. The length of the RCPM was published to be 48±8 mm, the length of OCS was published to be 52±5 mm, the length of OCI was published to be 49±4 mm, with the overall area of the ST being 1,040±190 mm 2 [ 16 ].…”

“…A study conducted by Kalmanson et al [ 16 ], measured the borders and area of the ST while the cervical spine was in a neutral position, and then again when the head was in a forward position. The length of the RCPM was published to be 48±8 mm, the length of OCS was published to be 52±5 mm, the length of OCI was published to be 49±4 mm, with the overall area of the ST being 1,040±190 mm 2 [ 16 ]. The measurements obtained by the current study found the average length of the RCPM and OCS muscles, as well as the area of the ST overall to be less than the values obtained by Kalmanson et al [ 16 ], and the average length of the OCI to be longer.…”

Suboccipital Muscles, Forward Head Posture, and Cervicogenic Dizziness

“…Continuous loading on the cervical spine, e.g., with extended smartphone or computer use, results in excessive thoracic kyphosis, degenerative disc disease, and FHP [58][59][60]. It is one of the commonly recognized types of poor head postures in the sagittal plane and involves changes in the surrounding soft tissues and cervical instability [21,[61][62][63]. Various measurement tools are used for FHP: the craniovertebral angle, cervical inclination angle, and head tilt angle [61].…”

“…The occipital extensors (longissimus capits, semispinalis capitis, sternocleidomastoid, upper trapezius, and most of the suboccipital muscles), except the splenius capitis, are shortened. The suboccipital muscles, except the obliquus capitis inferior, which acts in head rotation, undergo the greatest shortening [33,62,72]. Changes in muscle length caused by postural changes affect the binding between actin and myosin filaments, resulting in changes in muscle strength (i.e., force-generating capacity) and endurance (i.e., fatigue-resistant capacity) [73].…”