The functions of semispinalis capitis and splenius capitis muscles: An electromyographic study

Abstract

The functions of the normal semispinalis capitis and splenius capitis muscles of fifteen subjects were evaluated electromyographically with bipolar fine-wire electrodes. The voltage-output data were integrated and analyzed by computer and showed that the main function of semispinalis capitis is limited to extension of the head. However, splenius capitis both extends the head and rotates it to its own side.The posterior cervical muscles can be divided into four layers. The first layer is formed by the trapezius muscle which is concerned with the movements of the upper limb and the shoulder. The second and the third layers are mainly formed by splenius and semispinalis muscles respectively, and the fourth layer is formed by small muscles which are seen between the occipital bone and the first two cervical vertebrae. Among these muscles the semispinalis capitis and the splenius capitis are considered to have an important role in the movements of the head and neck because of their anatomical situation and their dimensions. But only one early report is available on the role of the muscles studied electromyographically (Tournay and Paillard, '52). Modern fine-wire electrode techniques and computer analysis of the myopotentials permitted us to analyze their exact functions in a series of normal volunteers. MATERIALS AND METHODSUsing bipolar fine-wire electrodes (Basmajian and Stecko, '62) we recorded the electromyographic activity of both right and left semispinalis capitis and splenius capitis muscles simultaneously in fifteen healthy adults (ten males and five females) who have no history of neck injury. Their ages ranged from twenty-one to fifty. We determined the exact ideal location and depth for the electrodes by means of preliminary tests in the dissecting room. Thus the electrodes were inserted into the semispinalis capitis 2 cm below the occipital bone and 2 cm lateral from the midline, and into the splenius capitis about 3 cm below the mastoid process and 3 cm lateral from the mid-line.Action potentials were amplified and recorded on FM magnetic tape and both movements and muscle activity were videotaped simultaneously for later validation of results, The EMG data were analyzed by a PDP-8 Computer programmed to integrate the voltage output and to normalize (or compare it on a percentage basis) with standards of maximum (100% ) activity for the muscles individually over the total time of a movement. The muscles were studied according to a set protocol in the resting position and in a variety of movements of the neck and head, each lasting five seconds.Final grading of the EMG for the purpose of making the numerical data meaningful to readers is on the basis of: 0, inactive (less than 1% ); -, negligible (1-5% ); -t, slight (6-1596 ); 2 +, moderate (16-50% ); 3 +,marked (51-100% ).

A Within Trial Measure of the Stop Signal Reaction Time in a Head-Unrestrained Oculomotor Countermanding Task

“…The absence of such antagonist muscle activity suggests that there is no active braking of the head from this muscle; instead, the end of head motion was associated with a decrease in the activity of the agonist right-SPL muscle with residual activity following the head movement maintaining the head's eccentric position. The absence of antagonist muscle recruitment during regularly paced eye-head gaze shifts is consistent with reports of SPL activity in humans (MayouxBenhamou et al 1997;Takebe et al 1974) and from reports in monkeys that have recorded from SPL and other neck muscles during horizontal head turns (Corneil et al 2001;Lestienne et al 1995). Active braking by antagonist neck muscles (including SPL) is observed during rapid head turns in both humans and monkeys (Corneil et al 2001;Lestienne et al 1995;Zangemeister and Stark 1981).…”

Rehabilitative Ultrasound Imaging of the Posterior Paraspinal Muscles

“…The most superficial layer [ CLINICAL COMMENTARY ] consists of the upper trapezius muscles, the second layer consists of the splenius capitis muscle, 62 the third layer consists of the semispinalis capitis 63 and semispinalis cervicis muscles, 71 while the deepest layer contains the multifidus and rotatores muscles. Some studies place semispinalis cervicis in this deepest layer, 61 while others also include the suboccipital muscles of rectus capitis posterior minor (RCPmin) and major (RCPmaj).…”

“…Some studies place semispinalis cervicis in this deepest layer, 61 while others also include the suboccipital muscles of rectus capitis posterior minor (RCPmin) and major (RCPmaj). 71 We have limited the description of anatomical features of cervical muscles to those described by researchers using RUSI. 37,39,[61][62][63] Cervical Multifidus and Semispinalis Cervicis Winkelstein et al 81 have suggested that the ability of the multifidus muscle to control cervical segmental motion could be compromised by its insertion directly into the capsules of the facet joints (TABLE 1), which have been widely implicated in neck pain and injury.…”

“…62,63 The main function of these muscles is neck extension, 46,71 and they are more active during large, fast movements of the neck 11 than during sustained postural activity.…”

Muscular Patterns and Activation Levels of Auxiliary Breathing Muscles and Thorax Movement in Classical Singing

“…The fi rst layer is formed by TR, the second and the third layers are mainly formed by the splenius capitis (SP) and semispinalis capitis (SSP) muscles, respectively, and the fourth layer is formed by the small muscles located between the occipital bone and the fi rst two cervical vertebrae. Takabe et al [60] reported either inactive or negligible activity in SP and SSP during deep breathing, fl exion of the head, free lateral bending and lateral bending against resistance. SP showed activity in movements with rotation of the head, which was not the case for SSP.…”