Validation of cognitive and neuromuscular latencies using an iPad-based tool to quantify simple reaction times in asymptomatic subjects.

Context: Simple reaction times (SRTs), measured in milliseconds (msec), are equal to the sum of subject-dependent latencies that occur during cognitive processing and neuromuscular responses to a preprogrammed stimulus presented to a subject. SRTs have the advantage of being a relatively pure, neurologically driven motor/sensory task that provides a clinician with a generalized assessment of functional deficits. SRTs are easily obtained, and studies have reported that the average number of finger-taps during a 10-s interval can be utilized to distinguish between patients with mild traumatic brain injury (TBI) and healthy controls.

Assessment of potential strain injury to rectus capitis posterior minor muscles during whiplash type distortions of the cervical spine.

Context: Whiplash type injuries resulting from a rear end motor vehicle accident (REMVA) are thought to be caused by excessive loading and displacement of structural components of the cervical spine. On impact, the seat propels the driver's torso forward relative to the head, resulting in forced flexion of the occipitoatlantal (OA) joint, accompanied by forced stretching of the rectus capitis posterior minor (RCPm) muscles. Flexion of the OA joint and stretching of the RCPm muscles continues to increase until the vehicle's headrest strikes the back of the driver's head.

Implied Evidence of the Functional Role of the Rectus Capitis Posterior Muscles.

Context: Osteopathic physicians often target the rectus capitis posterior minor (RCPm) and rectus capitis posterior major (RCPM) muscles when using muscle energy or soft tissue cervical techniques to treat patients with head and neck pain. The RCPm and RCPM muscles are located deep within the posterior occipitoatlantal and atlantoaxial interspaces, respectively.

Objective: To characterize the functional role of RCPm and RCPM muscles by comparing electromyographic (EMG) activation patterns of these muscles with EMG activation patterns of specific flexor and extensor muscles of the head and neck, the sternocleidomastoid (SCM), and the splenius capitis (SC) muscles, respectively.

Magnetic Resonance Imaging Parameters Selected for Optimal Visualization of the Occipitoatlantal Interspace.

Context: Disorders of the rectus capitis posterior minor (RCPm) muscles have been associated with chronic headache. Magnetic resonance (MR) imaging protocols currently used in clinical settings do not result in image sets that can be used to adequately visualize the integrity of occipitoatlantal structures or to definitively quantify time-dependent functional morphologic changes.

Objective: To develop an MR imaging protocol that provides the superior image quality needed to visualize occipitoatlantal soft tissue structures and quantify time-dependent pathologic changes.

Forward Head Posture and Activation of Rectus Capitis Posterior Muscles.

Context: Rectus capitis posterior (RCP) muscles have physical attachments to the pain-sensitive spinal dura. Atrophy of these muscles is associated with chronic headache in some patients. The authors suspect that the significance of atrophy in the RCP muscles has been undervalued because the functional role of these muscles is not well defined.

Injury Threshold of Rectus Capitis Muscles at the Atlanto-occipital Joint.

Objective: The objective of this study was to collect muscle stiffness data from the 4 rectus capitis (RC) muscles to better understand their role in stabilizing the atlanto-occipital joint. The passive load displacement properties of these muscles have not been previously reported.

Methods: Rectus capitis muscles were removed from 3 unembalmed head and neck specimens.

Activation of rectus capitis posterior major muscles during voluntary retraction of the head in asymptomatic subjects.

Objective: The purpose of this study was to assess levels of electromyographic activity measured from rectus capitis posterior major (RCPM) muscles of asymptomatic subjects as their heads moved from a self-defined neutral position to a retracted position.

Methods: A 2 × 2 within-subjects factorial research design was used. Disposable, intramuscular electrodes were used to collect electromyographic data from asymptomatic subjects between the ages of 20 and 40 years old.

Modeling length-tension properties of RCPm muscles during voluntary retraction of the head.

Head retraction exercises are one of several commonly used clinical tools that are used to assess and treat patients with head and neck pain and to aid in restoration of a normal neutral head posture. Retraction of the head results in flexion of the occipitoatlantal (OA) joint and stretching of rectus capitis posterior minor (RCPm) muscles. The role that retraction of the head might have in treating head and neck pain patients is currently unknown.

Electromyographic activity of rectus capitis posterior minor muscles associated with voluntary retraction of the head.

Background Context: The functional role of rectus capitis posterior minor (RCPm) muscles is not well defined. To the best of our knowledge, electromyographic (EMG) data from RCPm muscles in humans have never been collected and analyzed.

Purpose: To test the null hypothesis that there will be no difference in normalized levels of EMG activity measured from RCPm muscles with the head in a neutral position and with the head in a retracted position.

In vitro characterization of the anterior to posterior curvature of the superior articular facets of the atlas as a function of age.

Background Context: Reference is made in the literature to the inherent instability of the atlantooccipital joint in infants and young children because of pliant ligaments, undeveloped musculature, smaller condyles, and the relative lack of anteroposterior curvature of the superior articular facet surfaces of the atlas. The combination of these morphologic factors is purported to make this population particularly vulnerable to whiplash-type injuries. Although a significant difference in the magnitude of the anteroposterior curvature of the superior articular facet surfaces of the atlas between young children and adults has been observed, quantitative analysis of the curvature of these surfaces has not been documented.

Undershooting of a neutral reference position by asymptomatic subjects after cervical motion in the sagittal plane.

Objective: The objective of this study was to determine if blindfolded, asymptomatic subjects undershoot or overshoot a self-selected neutral reference position (NRP) when performing a full-cycle, head repositioning accuracy test in the sagittal plane.

Methods: An asymptomatic group of subjects, consisting of 7 men and 5 women with no history of head and neck pain, were recruited for the study. Subjects, performing a full-cycle series of head/neck movements in the sagittal plane, attempted to return to a self-selected NRP, defined at the beginning of the movement sequence, without benefit of visual clues.

A standardized protocol for needle placement in suboccipital muscles.

The objective of this study was to assess the safety and accuracy of using common anatomic landmarks to guide the placement of needle electrodes into suboccipital muscles. Atrophic changes in suboccipital muscles have been reported in some patients who have tension-type headaches, and in some patients who have headaches resulting from whiplash-type injuries. These atrophic changes most likely result from disuse or denervation.

The prevalence of fibromyalgia in collegiate athletes.

Background: : The prevalence of fibromyalgia in the general population is reported in numbers that range between 0.5% and 10%, with considerable variability in the populations studied and criteria for diagnosis used. The prevalence in competitive young adult athletes is unknown, but we expect it to be less than the general population.

Chronic headache relief after section of suboccipital muscle dural connections: a case report.

The presence of a connective tissue bridge, attaching suboccipital muscles to the dura mater, is now recognized as a feature of normal human anatomy. The role that this myodural bridge may play in headache production is uncertain; however, a new conceptual model is emerging. Postsurgical myodural adhesions have been reported as a complication resulting from excision of acoustic tumors.

An interactive, web-based tool for learning anatomic landmarks.

Purpose: To evaluate the effectiveness of a Web-based interactive teaching tool that uses self-assessment exercises with real-time feedback to aid students' learning in a gross anatomy class.

Method: A total of 107 of 124 first-year medical students at one school were enrolled in the study. Students were divided into three groups: Group 1 (n = 63) received introductory material and activated their Web-based accounts; Group 2 (n = 44) received introductory material but did not activate their Web-based accounts; and Group 3 (n = 17) were not enrolled in the study and received no introductory material.