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Knowledge of anatomical variations can be of use to clinicians and surgeons when, for example, viewing images of a patient or performing operations. Such knowledge can minimize the risk of iatrogenic complications. Herein, we present a case of a variant atlantomastoid muscle. The muscle was identified on the left side in an adult cadaver. The muscle's measurements and anatomical relationships are presented as well as a review of salient literature. We hope that increased knowledge of anatomical variants in the suboccipital region can improve patient care.

Introduction Manual therapy has been shown to reduce self-reported symptoms in patients with chronic tension-type headache (CTTH). However, simultaneous application of suboccipital muscle inhibition and interferential current has not previously been investigated. This study evaluates the effectiveness of combined treatment with suboccipital muscle inhibition and interferential current compared to standard treatment for pain, disability, and headache impact in patients with CTTH. Methods Patients were randomly allocated to receive either standard treatment (n = 13) or the experimental treatment (n = 12), consisting of 20 minutes of suboccipital muscle inhibition plus interferential current twice weekly for 4 weeks. The primary outcome was improvement in pain, and secondary outcomes included improvement in headache-related disability and reduction in headache impact, which were assessed at baseline and at 4 weeks by a blinded rater. Results Statistical analysis showed improvements in the experimental treatment group at 4 weeks for headache-related disability (Neck Disability Index: Hedges' g = 1.01, P = .001; and Headache Disability Inventory: Hedges' g = 0.48, P = .022) and headache impact (6-item Headache Impact Test: Hedges' g = 0.15, P = .037) but not for self-reported pain (numerical rating scale: Hedges' g = 1.13, P = .18). Conclusions Combined treatment with suboccipital muscle inhibition and interferential current in patients with CTTH did not significantly improve self-reported pain but did reduce disability and the impact of headache on daily life at 4 weeks. These improvements exceed the minimum clinically important difference, demonstrating the clinical relevance of our findings.

Background Atlantoaxial instability (AAI) is primarily a congenital neurological disorder affecting young toy-breed dogs. So far, most studies have focused on bones and ligaments related to AAI, and there are no studies on the suboccipital muscles (SOMs) that occupy a large area from the occipital bone to C2 in dogs. This study evaluated the cross-sectional area (CSA) and fat infiltration of the SOMs using magnetic resonance imaging (MRI), specifically, T1-weighted images, in normal dogs (≤ 5 kg) and AAI dogs. The relationship between the severity of the neurological symptoms of AAI (group A and group B) and the values from MRI was also assessed. Results AAI dogs had significantly smaller CSA (P = 0.029) and greater fat infiltration (P = 0.044) of the SOMs compared to normal dogs. AAI dogs with mild neurological symptoms for a long period (group A) had greater fat infiltration than AAI dogs with severe neurological symptoms (group B) (P = 0.035). Conclusions The muscle changes are most likely due to spinal cord compression resulting from instability; however, the possibility that chronic changes of the muscle may play an additional role in maintaining stability in this region cannot be excluded. This study provides fundamental quantitative information of the SOMs in normal and AAI dogs.

Background Occipital artery–posterior inferior cerebellar artery (OA–PICA) bypass is a challenging procedure and not frequently performed due to difficulties in occipital artery (OA) harvest. To facilitate the harvest, the intersection between the sternocleidomastoid and splenius capitis (known as the “OA triangle”) is used as the anatomical landmark to identify the OA segment that carry the highest risk of damage. This clinical study aimed to demonstrate the efficacy and safety of OA harvest using this landmark. Methods Eighteen patients who underwent the OA harvest using the OA triangle as a landmark for treatment of vertebral artery and PICA aneurysms were retrospectively evaluated for the safety and patency of OA after the harvest and OA–PICA bypass. Results Eighteen patients experienced ruptured and unruptured vertebral artery and PICA aneurysms. Thirteen patients (72.2%) underwent OA–PICA bypass and 5 patients (27.8%) did not undergo bypass. The OA was completely harvested without damage in all patients. After the harvest, the OA was patent in 17 patients (94.4%) and was occluded in one patient due to vasospasm, who then underwent recanalization resulting in good patency of the OA–PICA bypass thereafter. The patency rate of the OA–PICA bypass was 100%. Conclusions The OA triangle, which is the anatomical landmark of the proximal end of the transitional segment of OA, facilitated the OA harvest using the distal-to-proximal harvest technique with safety and good patency. To the best of our knowledge, this is the first study of OA harvest in the clinical cases.

Background and objectives: Shortening of hamstring has a negative impact on the posture of the pelvic region. The increase in stiffness of the hamstring may serve as a cause of low back pain and is also thought to predispose athletes to injury. The objective of this study was to compare the immediate effect of neural mobilization and myofascial release of suboccipital muscle on hamstring length in younger adults. Methodology: This was a Comparative study conducted in a tertiary care hospital. A total 40 individuals between age group of 18-25 years having reduced hamstring length were included in this study. They were randomly divided into two groups by lottery method. Group 1 received neural mobilization and group 2 received myofascial release of suboccipital muscle. Ranges were recorded post treatment. Straight Leg Raise (SLR), Sit and Reach Test (SR) and Finger to Foot Test (FFT) were used to record pre treatment ranges Results: The result revealed that hamstring length significantly improved in both the groups further between the groups comparison demonstrated that non-significant difference existed in improvement scores of SLR, where as statistically not significant but clinically significant difference was existed in improvement of FFT. Furthermore between groups comparison demonstrated that statically and clinically significant difference existed in improvement scores of sit and reach, indicating that neural mobilization was more effective in improving hamstring length then myofascial release of suboccipital muscle in improving hamstring length. Conclusion: This study concluded that both neural mobilization and myofascial release of suboccipital muscle is effective in increasing length of hamstring muscle, where as neural mobilization was better when assessed with sit and reach test. Keywords: Hamstring length, neural mobilization, myofascial release, suboccipital muscle, sit and reach test, Straight leg raise, finger to foot test.

Introduction: Parkinson's disease (PD) causes impairments in postural control and mobility that affect the individual´s independence. Manual therapy has been used in the treatment of these disorders and can change mobility and postural control. Objective: to assess the immediate effects of an approach in high cervical and occipitomastoid on postural control and mobility of individuals with PD. Methods: three individuals with PD, females, aged 52 to 73 years, participated in this case series. Participants were assessed immediately before and after therapeutic intervention through releases of suboccipital muscles and occipitomastoid sutures. Trunk mobility, functional mobility and postural control (center of pressure parameters - COP) were evaluated. Results: all participants demonstrated improvements in trunk mobility. Participants 1 and 2 slightly improved functional mobility. Participants 1 and 2 showed a decrease in the medial-lateral displacement of the COP. All participants showed increases in at least one direction to the limits of stability. Conclusions: the results showed that the intervention appears more effective on trunk mobility. Variables related to postural control changed with no consistent pattern. Further studies could investigate the association of other manual therapy techniques and their effects on mobility and postural control in individuals with PD.

The INYBI is an instrument used to release the suboccipital myofascial area. There is scarce evidence of its efficacy. A randomized controlled, double-blinded, longitudinal and prospective trial was performed. Ninety-six subjects (aged 29.47 ± 5.16 years) (70 women) with chronic neck pain were randomly assigned to the manual suboccipital inhibition technique (MSIT), instrumental suboccipital inhibition (INYBI) or the INYBI plus upper cervical manipulation technique (INYBI + UCMT) groups and received two sessions with a week interval between them. The Neck Disability Index was used before the first intervention and two weeks after the second intervention. Pre- and post-measurements were taken on both intervention days for pressure pain threshold of the upper trapezius and suboccipital muscles, self-perceived pain and cervical range of motion. In spite of a significant general improvement in time that was found for the three groups for all of the outcome measurements (p &lt, 0.05 in all cases), no between-groups differences were found (p &gt, 0.05 in all cases), with the exception of self-perceived pain for left rotation (p = 0.024), with the MSIT group showing the lower improvement. However, the higher degree of within-group improvements was found for the INYBI + UCMT group. It was concluded that the myofascial release therapy in the suboccipital area is effective in patients with chronic neck pain, either through a manual application or by means of the INYBI tool. Moreover, the addition of craniocervical manipulation achieved the higher within-group improvements, but with no statistical significance.

Craniovertebral junction surgery usually requires the exposure of the third segment of the vertebral artery (V3). However, the complexity of musculature, a relatively high incidence of anomalies in the course of the vertebral artery (VA), and the presence of a rich venous plexus in this region make the V3 exposure challenging with a high risk of serious complications while taking down the suboccipital muscles in a single layer. A muscle dissection in interfascial layers, however, overcomes the drawbacks inherent in a blind dissection of the V3 as each of the muscles represents substantial landmark aiding subsequent step of the procedure and thus helping identify underlying anatomical structure early and safely. Moreover, along with a bloodless VA dissection off its surrounding venous plexus, it permits a safe and comfortable V3 exposure during the surgically demanding procedures.

Background: Cervicogenic Headache (CGH) represents a major health problem, aggravating Quality of Life (QOL) and work productivity. The Suboccipital Muscles (SOM) have been identified as playing a role in cervical pain, and are therefore a target for rehabilitation.Aim of the Study: To asses the effect of CGH on myoe-lectrical activities of suboccipital muscles, functional activities and ROM of neck.Subjects and Methods: Thirty patients with CGH of both genders participated in this study. They were recruited from the out patient clinic of Kasr El-Ainy and thirty normal subjects, their ages ranged from 18-55 years old. They were randomly assigned into 2 experimental groups: Group A (18- 35 years)-group B (36-55 years) & 2 control groups: Group C (18-35 years)-group D (36-55 years). Myoelectrical activities was measured by Natus nicolet vikingquest to analyze the motor unit potentials by quantitative measures & neck range of motion was measured by Cervical Range of Motion (CROM) device and functional activities of the neck was measured by Neck Disability Index (NDI).Results: There was non significance increase in myoelec-trical activities of the suboccipital muscles in cervicogenic patients than normal subjects with (p-value=0.147). And there was statistical significant decrease in all ROM values and functional activities in cervicogenic patients than normal subjects in cervicogenic patients than normal subjects with (p-value

BACKGROUND: Compared with healthy people, patients with chronic tension-type headache (CTTH) are likely to have forward head postures (FHP) and a higher number of active trigger points (aTrP) on the suboccipital muscle. OBJECTIVE: This study aims to verify how the suboccipital muscle inhibition (SMI) on aTrPs and the FHP correction exercise can effectively reduce symptoms of the CTTH patients. METHOD: The subjects of this study were 45 individuals with CTTH, divided into three groups of 15 patients each: a) the SMI group using the myofascial release technique; b) the SMIEx group subject to both the SMI therapy and FHP correction exercises; and c) the control group. Group A and B were given the relevant interventions twice a week for four consecutive weeks, and went through the headache impact test (HIT-6) and examinations on the pressure pain threshold (PPT) of the headache areas, the type and number of myofascial trigger points (TrP), the soft tissue PPT, and the posture before and after the intervention. RESULTS: There was a significant improvement in the HIT-6, the headache PPT, the soft tissue PPT, the TrP, and the posture in Group A and B patients to whom the SMI technique and SMIEx interventions were applied. The biggest reduction and increase in the HIT-6 and the headache PPT respectively were seen in the SMIEx group. CONCLUSION: According to this study, the SMIEx can be an effective intervention for patients with CTTH.

Recent studies have evidenced that the anatomical structure now known as the myodural bridge (MDB) connects the suboccipital musculature to the cervical spinal dura mater (SDM). In humans, the MDB passes through both the posterior atlanto-occipital and the posterior atlanto-axial interspaces. The present authors suggest that the MDB has important physiological functions in humans. The existence of the MDB in various mammals, including flying birds (Rock pigeons and Gallus domesticus) has been previously validated. Gentoo penguins are marine birds, able to make 450 dives per day, reaching depths of up to 660 feet. Gentoo penguins are also the world’s fastest diving birds. The present study was therefore carried out to investigate the existence and characteristics of the MDB in Gentoo penguin (Pygoscelis papua), a non-flying, marine bird that can dive. While foraging, this penguin is able to reach speeds of up to 22 miles per hour. For this study, six Gentoo penguin specimens were dissected to observe the existence and composition of their MDB. Histological staining was also performed to analyze the anatomic relationships and characteristic of the MDB in the Gentoo penguin. In this study, it was found that the suboccipital musculature in the Gentoo penguin consists of the rectus capitis dorsalis minor (RCDmi) muscle and rectus capitis dorsalis major (RCDma) muscle. Dense connective tissue fibers were observed connecting these two suboccipital muscles to the spinal dura mater (SDM). This dense connective tissue bridge consists of primarily type I collagen fibers. Thus, this penguin’s MDB appears to be analogous to the MDB previously observed in humans. The present study evidences that the MDB not only exists in penguins but it also has unique features that distinguishes it from that of flying birds. Thus, this study advances the understanding of the morphological characteristics of the MDB in flightless, marine birds.

Study design A scanning electron microscopic study performed on three cadaveric specimens focused on the human suboccipital region, specifically, myodural bridge (MDB). Objective This study showed the connection form of the MDB among the suboccipital muscles, the posterior atlanto-occipital membrane (PAOM) and the spinal dura mater (SDM), and provided an ultrastructural morphological basis for the functional studies of the MDB. Summary of background data Since the myodural bridge was first discovered by Hack, researches on its morphology and functions had been progressing continuously. However, at present, research results about MDB were still limited to the gross anatomical and histological level. There was no research report showing the MDB's ultrastructural morphology and its ultrastructural connection forms between PAOM and SDM. Methods A scanning electron microscope (SEM) was used to observe the connection of myodural bridge fibers with PAOM and SDM in atlanto-occipital and atlanto-axial interspaces, and the connection forms were analyzed. Results Under the SEM, it was observed that there were clear direct connections between the suboccipital muscles and the PAOM and SDM in the atlanto-occipital and atlanto-axial spaces. These connections were myodural bridge. The fibers of the myodural bridge merged into the spinal dura mater and gradually became a superficial layer of the spinal dura mater. Conclusion MDB fibers merged into the SDM and became part of the SDM in the atlanto-occipital and atlanto-axial space. MDB could transfer tension and pulling force to the SDM effectively, during the contraction or relaxation of the suboccipital muscles. Level of evidence N/A.

INTRODUCTION: Hamstring is one of the commonest muscles that often get tight. The suboccipital muscle inhibition (SMI) technique is a manual technique that aims to relax the tension in the suboccipital muscles by decreasing the myofascial restriction in the suboccipital region. Muscle energy technique (MET) is a procedure that involves voluntary contraction of a patient’s muscle in a precisely controlled direction, at varying levels of intensity and against a distinctly executed therapist applied counterforce. AIM: Aim of the study is to compare immediate effect of suboccipital muscle inhibition technique and muscle energy technique on hamstring flexibility in healthy collegiate subjects. METHOD: Total 40 subjects with hamstring tightness (both male and female) (age:18-26 years) were selected for study. Group A: Suboccipital muscle inhibition(SMI) technique. Group B: Muscle energy technique(MET) OUTCOME MEASURE: Active knee extension test(AKET). RESULTS: Results have shown significant difference between pre & post measurements in both the groups and no significant difference was found between the groups. CONCLUSION: Suboccipital muscle inhibition technique (SMI) and Muscle Energy Technique (MET) are equally effective in improving hamstring flexibility in healthy collegiate subjects.

Background: The occipital artery (OA) is an important donor artery for posterior fossa revascularization. Harvesting the OA is difficult in comparison to the superficial temporal artery because the OA runs between suboccipital muscles. Anatomical knowledge of the suboccipital muscles and OA is essential for harvesting the OA during elevation of the splenius capitis muscle (SPL) for reconstruction of the posterior inferior cerebellar artery. We analyzed the running pattern of the OA and its anatomic variations using preoperative and intraoperative findings. Methods: From April 2012 to March 2018, we surgically treated 162 patients with suboccipital muscle dissection by OA dissection using the lateral suboccipital approach. The running pattern and relationship between the suboccipital muscles and OA were retrospectively analyzed using the operation video and preoperative enhanced computed tomography (CT) images. The anatomic variation in the running pattern of the OA was classified into two types: lateral type, running lateral to the muscle and medial type, running medial to the longissimus capitis muscle (LNG). Results: The medial pattern was observed in 107 (66%) patients and the lateral pattern in 54 (33.3%); 1 (0.6%) patient had the OA running between the LNGs. Conclusion: Preoperative CT is effective in determining the running course of the OA, which is important for safely harvesting the OA during SPL elevation. There is a risk of causing OA injury in patients with the lateral pattern. This is the first report showing that the OA rarely runs in between the LNGs.

This study aimed to investigate the effects of suboccipital muscle inhibition technique (SMIT) on active range of motion (AROM) of the ankle joint, lunge angle (LA), and balance in healthy adults, according to the duration of its application. A total of 80 participants were randomly allocated to the 4-min suboccipital muscle inhibition (SMI) group (SMI_4M, n = 20), 8-min SMI group (n = 20), 4-min sham-SMI (SSMI) group (n = 20), and 8-min SSMI group (n = 20). Accordingly, the SMIT and sham SMIT were applied for 4 min or 8 min in the respective groups. AROM of dorsiflexion and LA were assessed, and a single leg balance test (SLBT) was performed before and after the intervention. AROM (4 min, p &lt, 0.001, 8 min, p &lt, 0.001), LA (4 min, p &lt, 0.001), and SLBT (4 min, p &lt, 0.001) significantly improved after SMI application. Compared with the SSMI group, the SMI group showed a significant increase in AROM (p &lt, 0.001), LA (p &lt, 0.001), and SLBT (p &lt, 0.001). Except for SLBT (p = 0.016), there were no significant interactions between intervention and application duration. The results suggest that the SMIT, at durations of both 4 and 8 min, could be effective tools for improving AROM, LA, and balance.

Variations of the suboccipital nerve are infrequently reported. This nerve derived from the C1 spinal nerve is usually a small branch that primarily innervates the short suboccipital muscles. During the routine dissection of the occipital region in an adult cadaver, a vastly enlarged left-sided suboccipital nerve was identified. The nerve innervated the short suboccipital muscles and overlying semispinalis capitis in normal fashion. However, it continued cranially to end in the overlying skin of the occiput. Although not normally thought to have a cutaneous branch, recalcitrant occipital neuralgia might be due to such a variant branch. Future studies are necessary to further elucidate this proposed pathomechanism.

Background Context Studies over the past 20 years have revealed that there are fibrous connective tissues between the suboccipital muscles, nuchal ligament, and cervical spinal dura mater (SDM). This fibrous connection with the SDM is through the posterior atlanto-occipital or atlantoaxial interspaces and is called the myodural bridge (MDB). Researchers have inferred that the MDB might have important functions. It was speculated that the function of MDB might be related to proprioception transmission, keeping the subarachnoid space and the cerebellomedullary cistern unobstructed, and affecting the dynamic circulation of the cerebrospinal fluid. In addition, clinicians have found that the pathologic change of the MDB might cause cervicogenic or chronic tension-type headache. Previous gross anatomical and histologic studies only confirmed the existence of the MDB but did not reveal the fiber properties of the MDB. This is important to further mechanical and functional research on the MDB. Purpose Multiple histologic staining methods were used in the present study to reveal the various origin and fiber properties of the MDB. Muscles and ligaments participating in forming the MDB at the posterior atlanto-occipital or atlantoaxial interspaces were observed, and the fiber properties of the MDB were confirmed. The present study provides a basis for speculating the tensile force values of the MDB on the SDM and a morphologic foundational work for exploring the physiological functions and clinical significances of the MDB. Study Design Anatomical and histologic analyses of suboccipital structures that communicate with the SDM at the posterior atlanto-occipital or atlantoaxial interspaces were carried out. Methods Multiple histologic staining methods were used to evaluate the histologic properties and composition of the MDB at the posterior atlanto-occipital or atlantoaxial interspaces in five formalin-fixed head-neck human specimens. Results The results show that the MDB traversing the atlanto-occipital interspace originated from the rectus capitis posterior minor (RCPmi). The MDB traversing the atlantoaxial interspace originated mainly from the RCPmi, rectus capitis posterior major, and obliquus capitis inferior. These fibers form the vertebral dural ligament in the atlantoaxial interspace and connect with SDM. The MDB is mainly formed by parallel running type I collagen fibers; thus, suboccipital muscle could pull SDM strongly through the effective force propagated by the MDB during head movement. Conclusions Myodural bridge is mainly formed by parallel running type I collagen fibers; thus, it can transmit the strong pull from the diverse suboccipital muscles or ligaments during head movement. The results of the present study will serve as a basis for further biomechanical and functional MDB research.

Objective: The purpose of this study is to research the effects of the Neurodynamics sliding (NDS) and sub-occipital muscle inhibition technique (SMI) on flexibility of hamstring in asymptomatic subjects with hamstring syndrome. Method: According to finger floor test and SLR test thirty male subjects were selected subjects were randomly allocated to Neurodynamics sliding group and sub-occipital muscle inhibition group of 15 each. Neurodynamic sliding and Sub occipital inhibition technique were applied to the groups. For analysis straight leg raise (SLR) finger floor test (FFT) and range of motion (ROM) of knee joint were used. Outcome measures were assessed before and after intervention at end of two weeks. Result:There is a significant change in SLR, FFT and ROM measures in both SMI and NDS groups. When compared the Neurodynamics sliding group measures show significant changes than the sub-occipital muscle inhibition group. Conclusion: Application of NDS& SMI to persons with short hamstring syndrome resulted in increases in flexibility of the hamstring. However the NDS technique was more effective.

[Resumen] Introducción. El término trastornos temporomandibulares (TTM) hace referencia a los problemas clínicos que implican el sistema masticatorio. Los TTM están asociados con alteraciones que afectan a los músculos, a la articulación o a ambas. El síntoma principal que presentan es el dolor durante el movimiento de la boca y “chasquidos” de las articulaciones. Además del dolor, cursa con signos y síntomas diversos, como fuerzas de la mordedura reducidas, disminución del rango de apertura de la boca, dolores de cabeza, bloqueo de las articulaciones, y dolor referido a la cara y cuero cabelludo. Múltiples factores están asociados con las causas de los TTM, incluyendo estrés u otros trastornos emocionales, hábitos orales parafuncionales, bruxismo del sueño, posturas crónicas de cabeza anteriorizada o sensibilización del sistema nervioso central. Objetivo. Realizar un proyecto de investigación para comparar la efectividad de dos técnicas de tratamiento de la musculatura suboccipital, la manual y la instrumental, en pacientes con trastornos temporomandibulares. Material y método. El presente trabajo de investigación consiste en un estudio clínico aleatorizado (ECA), con enmascaramiento a simple ciego y controlado. La población diana son sujetos diagnosticados de trastornos temporomandibulares, repartidos en dos grupos. Un grupo de participantes recibirá un tratamiento basado en la técnica manual de inhibición de la musculatura suboccipital; y el otro grupo, la técnica instrumental. Las variables medidas serán el nivel de disfunción temporomandibular, el dolor y la amplitud de movimiento. Con el fin de localizar publicaciones actuales se realizaron búsquedas bibliográficas en diferentes bases de datos: Pubmed, Pedro y Scopus. Resultados. Se han seleccionado un total de 8 artículos de estudios científicos que coinciden con la temática de estudio y cumplen con los requisitos establecidos para poder conseguir el objetivo. En ellos, la técnica manual de inhibición de la musculatura suboccipital se emplea como medida de tratamiento, en diversas patologías. Conclusiones. Los resultados de los estudios analizados demuestran que la técnica manual de inhibición de la musculatura suboccipital tiene efectos favorables en la sintomatología de sujetos con patologías como Fibromialgia, Whiplash, Síndrome de la corva corta o Cefalea. Por otra parte, sobre la técnica instrumental de inhibición de la musculatura suboccipital no existen referencias científicas ningunas. [Abstract] Background. The term temporomandibular refers to some clinical problems that involve masticatory system. TTM are asociated with alterations that affect muscles, joints, or even both. The main symptom they present is pain during mouth movements and clicks of the joints. In addition, the pain goes also with different signs and symptons, such as reduced bite forces, decrease of the mouth's opening range, headaches, joints blockages, and face and scalp pains. There are multiple factors associated with TTM causes, including stress or other emotional disorders, oral parafunctional habits, dream's bruxism, cronic head postures or Central Nervous System's sensibilization. Objective. To carry out a research project in order to compare the efectivness of two different techniques used for the suboccipital musculature treatment, the manual and the instrumental ones, in patients with temporomandibular disorders. Material and method. This research project consists on a randomized controlled clinical study with simple blind masking. Focused on patients diagnosed with temporomandibular disorders. One group will receive a treatment based on manual technique of suboccipital musculature's inhibition and the other group the instrumental ones. The variables measured will be the level of temporomandibular dysfunction, pain and range of motion. Some different databases such as PubMed, Pedro and Scopus have been used in order to find current publications. Results. Eight scientific articles have been selected according to the estudy topic and the stablished requirements. The technique used on this studies is the manual inhibition of the suboccipital musculature on different patologies. Conclusions. The analyzed results show that manual technique of suboccipital musculature 's inhibition has possitive effects on patients with different pathologies such as Fibromialgia, Whiplash, Headaches or Short hamstring syndrome. On the other hand, about instrumental technique there are not scientific references at all. [Resumo] Introdución. O termo trastornos temporomandibulares (TTM) fai referencia aos problemas clínicos que implican o sistema masticatorio. Os TTM están asociados con alteracións que afectan os músculos, á articulación ou a ambas. O síntoma principal que presentan é a dor durante o movemento da boca e “chasquidos” das articulacións. Ademais da dor, cursa con signos e síntomas diversos, como forzas da mordedura reducidas, diminución do rango de apertura da boca, dores de cabeza, bloqueo das articulacións, e dor referida á cara e coiro cabeludo. Múltiples factores están asociados coas causas dos TTM, incluíndo tensións ou outros trastornos emocionais, hábitos orais parafuncionales, bruxismo do soño, posturas crónicas de cabeza anteriorizada ou sensibilización do sistema nervioso central. Obxectivo. Realizar un proxecto de investigación para comparar a efectividade de dúas técnicas de tratamento da musculatura suboccipital, a manual e a instrumental, en pacientes con trastornos temporomandibulares. Material e método. O presente traballo de investigación consiste nun estudo clínico aleatorizado (ECA), con enmascaramiento a simple cego e controlado. A poboación diana son suxeitos diagnosticados de trastornos temporomandibulares, repartidos en dous grupos. Un grupo de participantes recibirá un tratamento baseado na técnica manual de inhibición da musculatura suboccipital; e o outro grupo, a técnica instrumental. As variables medidas serán o nivel de disfunción temporomandibular, a dor e a amplitude de movemento. Co fin de localizar publicacións actuais realizáronse procuras bibliográficas en diferentes bases de datos: Pubmed, Pedro e Scopus. Resultados. Seleccionáronse un total de 8 artigos de estudos científicos que coinciden coa temática de estudo e cumpren cos requisitos establecidos para poder conseguir o obxectivo. Neles, a técnica manual de inhibición da musculatura suboccipital emprégase como medida de tratamento en diversas patoloxías. Conclusións. Os resultados dos estudos analizados demostran que a técnica manual de inhibición da musculatura suboccipital ten efectos favorables na sintomatología de suxeitos con patoloxías como fibromialxia, Whiplash, síndrome da curva curta ou cefalea. Por outra banda, sobre a técnica instrumental de inhibición da musculatura suboccipital non existen referencias científicas ningunhas. Traballo fin de grao (UDC.FCS). Fisioterapia. Curso 2016/2017

Objectives The frequency of suboccipital injections to treat headaches has increased. The third segment of the vertebral artery is located in the suboccipital triangle and its main muscular branch, the suboccipital artery of Salmon (SAS), supplies blood to the suboccipital muscles. The purpose of this study was to radiographically investigate the morphology and territory of distribution of SAS. Patients and methods Computed tomography angiographs of brains of 50 subjects (25 female, 25 men, mean age 70.2 years) were analyzed. Results SAS was present in 48% of subjects. The vessel was present bilaterally in 37.1%, and had a mean (SD) luminal diameter of 1.71 (0.34) mm and mean (SD) length of 36.42 (17.1) mm. SAS was found to have two morphologic patterns: (1) a single main trunk with collateral branches (52.6%) and (2) a short common trunk that divided into two branches (48.4%). The SAS supplied the obliquus capitis inferior, semispinalis capitis, and splenius capitis muscles. When the SAS was absent, the suboccipital muscles were supplied by a branch of the occipital artery. No anastomoses were found between the SAS and occipital artery. Conclusion The suboccipital muscles are vascularized by the SAS and occipital artery. The detailed course of the SAS is important for clinicians and surgeons who perform procedures in the suboccipital region.

Changes in the suboccipital muscles and the hamstrings may interfere with head posture and the biomechanics of the temporomandibular joint, both of which contribute to the severity of temporomandibular disorders (TMD). The objective of this investigation was to evaluate the effects of a global postural exercise program (GPEP) on pain intensity and mouth-opening range of motion (ROM) in women with TMD. The participants were comprised of 30 women with TMD who were divided into two groups: an experimental group (EG) and a control group (CG). A pressure algometer was used for pain assessment and a paquimeter was used to measure ROM. The duration of the GPEP was six weeks. In the EG, there was a reduction in pain intensity and an increase in mouth-opening ROM compared to the CG. Therefore, we concluded that the GPEP was effective in relieving pain in all of the evaluated muscles and regions, and in increasing mouth-opening ROM in women with TMD.

[Purpose] The purpose of this study was to research the effect of performing the suboccipital muscle inhibition (SMI) and self-myofascial release (SMFR) techniques in the suboccipital area on the flexibility of the hamstring. [Subjects] Fifty persons with short hamstrings participated in this research. According to the results of the finger-floor distance (FFD) test, the subjects were allocated to SMI and SMFR groups of 25 subjects each. [Methods] The SMI and SMFR techniques were applied to the groups. For the analysis, we used the FFD test and the straight leg raise (SLR) test for the flexibility of hamstring. The evaluator was blindfolded. [Results] In the SMI group, FFD, SLR, and PA were significantly changed after the intervention, and in the SMFR group, there was a significant change in SLR after the intervention. In a comparison between the groups, FED was found to be significantly increased in the SMI group. [Conclusion] Application of the SMI and SMFR to persons with short hamstrings resulted in immediate increases in flexibility of the hamstring. However, we could see that the SMI technique was more effective.

[Purpose] This study aimed to compare and analyze the mechanical properties of the upper cervical muscles in patients with cervicogenic headache to identify efficient methods of treatment and diagnosis. [Subjects and Methods] A total of 40 subjects including 20 healthy individuals and 20 patients with cervicogenic headache were selected. A MyotonPRO device was used to measure the tone (Hz), stiffness (N/m), and elasticity (log decrement) of the suboccipital muscles and upper trapezius of the subjects. [Results] There was no significant difference between the 2 groups in the elasticity of the suboccipital muscles and upper trapezius. However, there was a statistically significant difference in tone and stiffness. [Conclusion] This study showed that the tone and stiffness of the suboccipital muscles and upper trapezius in patients with cervicogenic headache had increased compared to healthy subjects.

Few studies have been performed regarding the reduction of pain in the upper trapezius (UT) muscle by applying interventions to the sternocleidomastoid (SCM) muscle, which is innervated by the same nerves.The purpose of this study was to investigate the effects of soft tissue release intervention on the SCM and suboccipital muscles with regard to muscle hardness and pressure pain threshold (PPT) of the SCM and UT muscles in smartphone users with latent myofascial trigger points (MTrPs) in the UT muscle.Seventeen smartphone users (5 men and 12 women) with latent MTrPs in the UT muscle participated in the study. This study used a single blinding, cross-over design, wherein sternocleidomastoid soft tissue release (SSTR) and suboccipital release (SR) were applied on the subjects in random order one week apart. Muscle hardness and the PPT of the SCM and UT muscles were assessed before and after the intervention.After SSTR was applied, the SCM and UT muscles showed a significant decrease in muscle hardness and a significant increase in PPT. After SR was applied, the UT muscle showed a significant decrease in muscle hardness and a significant increase in PPT. When comparing the amount of change between the SSTR and SR interventions, significant differences were found for SCM muscle hardness and PPT of the UT muscle in the SSTR intervention, compared with the SR intervention.Therefore, we suggest that, to reduce pain in the UT muscle, it may be useful to apply intervention directly to the UT muscle, as well as to the SCM muscle, which is innervated by the same nerve.

Recent studies have identified that the myodural bridge (MDB) is located between the suboccipital muscles and cervical dura mater in the posterior atlanto-occipital interspace within humans. The myodural bridge has been considered to have a significant role in physiological functions. However, there is little information about the myodural bridge in marine mammals; we conducted this study to investigate and examine the morphology of the myodural bridge in a sperm whale. We also aim to discuss the physiological functions of the myodural bridge. In this study, a 15.1-meter long sperm whale carcass was examined. Multiple methods were conducted to examine the bridges of the sperm whale which included dissection, P45 plastination and histological analysis. This study confirmed the existence of the myodural bridge in the sperm whale and shows there are two types of the bridge in the sperm whale: one type was the occipital-dural bridge (ODB), the other type was the MDB. A large venous plexus was found within the epidural space and this venous plexus is thought to contain a great amount of blood when in deep water and thus the movements of suboccipital muscles could be a unique power source that drives cerebrospinal fluid circulation.

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. Needle electromyography is a definitive technique for determining the cause of muscle atrophy, but requires that needle electrodes be inserted into the muscle. Suboccipital muscles present a challenge to the electromyographer in that they are physically small and are located in close proximity to one another. Atrophied muscles with fatty replacement and the presence of critical structures such as the vertebral artery further complicate the procedure. Using a standardized protocol, three investigators attempted blind needle insertions into each of the suboccipital muscles of eight embalmed cadavers. A dissector then assessed targeted muscle penetrations, final resting positions of the wires, and their proximity to critical structures. Eighty-one percent of 181 attempted insertions penetrated the targeted muscles: 83% for the rectus capitis posterior minor, 83% for the rectus capitis posterior major, 94% for the obliquus capitis superior, and 63% for the obliquus capitis inferior muscles, respectively. It was concluded that readily palpable external landmarks can be used to safely and reliably guide the insertion of needle electrodes into three of the four pairs of suboccipital muscles.

This paper describes the differences in the presence of myofascial trigger points (TrPs) in the upper trapezius, sternocleidomastoid, temporalis and suboccipital muscles between unilateral migraine subjects and healthy controls, and the differences in the presence of TrPs between the symptomatic side and the nonsymptomatic side in migraine subjects. In addition, we assess the differences in the presence of both forward head posture (FHP) and active neck mobility between migraine subjects and healthy controls and the relationship between FHP and neck mobility. Twenty subjects with unilateral migraine without side-shift and 20 matched controls participated. TrPs were identified when there was a hypersensible tender spot in a palpable taut band, local twitch response elicited by the snapping palpation of the taut band and reproduction of the referred pain typical of each TrP. Side-view pictures were taken in both sitting and standing positions to measure the cranio-vertebral angle. A cervical goniometer was employed to measure neck mobility. Migraine subjects showed a significantly greater number of active TrPs ( P < 0.001), but not latent TrPs, than healthy controls. Active TrPs were mostly located ipsilateral to migraine headaches ( P < 0.01). Migraine subjects showed a smaller cranio-vertebral angle than controls ( P < 0.001), thus presenting a greater FHP. Neck mobility in migraine subjects was less than in controls only for extension ( P = 0.02) and the total range of motion in flexion/extension ( P = 0.01). However, there was a positive correlation between the cranio-vertebral angle and neck mobility. Nociceptive inputs from TrPs in head and neck muscles may produce continuous afferent bombardment of the trigeminal nerve nucleus caudalis and, thence, activation of the trigeminovascular system. Active TrPs located ipsilateral to migraine headaches might be a contributing factor in the initiation or perpetuation of migraine.

Objective.—To assess the presence of trigger points (TrPs) in the suboccipital muscles and forward head posture (FHP) in subjects with chronic tension-type headache (CTTH) and in healthy subjects, and to evaluate the relationship of TrPs and FHP with headache intensity, duration, and frequency. Background.—Tension-type headache (TTH) is a prototypical headache in which myofascial TrPs in the cervical and pericranial musculature can play an important role. Design.—A blinded, controlled pilot study. Methods.—Twenty CTTH subjects and 20 matched controls without headache participated. TrPs were identified by eliciting referred pain with palpation, and increased referred pain with muscle contraction. Side-view pictures of each subject were taken in sitting and standing positions, in order to assess FHP by measuring the craniovertebral angle. Both measures were taken by a blinded assessor. A headache diary was kept for 4 weeks in order to assess headache intensity, frequency, and duration. Results.—Sixty-five percent (13/20) CTTH subjects showed active TrPs and 35% (7/20) had latent TrPs in the suboccipital muscles. Six (30%) controls also had latent TrPs. Differences in the presence of suboccipital muscle TrPs between both the groups were significant for active TrPs (P .5). CTTH subjects with active TrPs reported a greater headache intensity and frequency than those with latent TrPs (P < .05). The degree of FHP was greater in CTTH subjects than in controls in both sitting and standing positions (P < .01). Within the CTTH group, there was a negative correlation between the craniovertebral angle and the frequency of headache (rs=−0.6, P < .01, in sitting position; rs=−0.5, P < .05, in standing position). CTTH subjects with active TrPs had a greater FHP than those with latent TrPs, though this difference was not significant. Conclusions.—Suboccipital active TrPs and FHP were associated with CTTH. CCTH subjects with active TrPs reported a greater headache intensity and frequency than those with latent TrPs. The degree of FHP correlated positively with headache duration, headache frequency, and the presence of suboccipital active TrPs.

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. Extensive research now exists implicating these myodural adhesions as a possible source of postoperative headache. Integrating these 2 types of myodural unions (anatomic and pathologic) into a unified theory of headache production, we report a single patient who experienced relief from chronic headache after surgical separation of the myodural bridge from the suboccipital musculature.

In the last two decades, many studies have focused on the muscles and dense connective tissues located in the suboccipital region. Our study investigated the existence of the second terminations originating from the suboccipital muscles, and the relationship between the variable types of the To Be Named Ligament (TBNL). Anatomical dissection was performed on 35 head-neck specimens. The existence of the second terminations of the suboccipital muscles was confirmed and various types of the TBNL were observed in this study. The second terminations originated from multiple suboccipital muscles including the rectus capitis posterior minor (RCPmi), rectus capitis posterior major (RCPma) and obliquus capitis inferior (OCI) muscles, merged and terminated at the TBNL. The overall incidence of the second terminations of the suboccipital muscles was 34.29% and it varied among the various suboccipital muscle origins. 28.57% of the second terminations originated from the RCPma; 11.43% was from the RCPmi and 8.57% was from the OCI. Furthermore, there was a significant relationship between the existence of second terminations and the particular type of the TBNL. 95% of the arcuate type of the TBNL was accompanied with the second terminations which attached to their turning part, whereas only 10% of all the radiate type of the TBNL was accompanied with the second terminations. This study for the first time described the second terminations originating from multiple suboccipital muscles and demonstrated the relationship with the various types of the TBNL. We speculated that the second terminations maintain the arcuate TBNL and transfer tensile forces to the Myodural Bridge (MDB), thereby modulating the physiological functions of the MDB.

In an attempt to clarify the function of the suboccipital muscles, we performed morphological observation of the suboccipital muscles for variations in the muscle belly and compared the morphology of their muscle fibers in terms of cross-sectional area by immunostaining with anti-myosin heavy chain antibodies. The cadavers of 25 Japanese individuals were used: 22 for morphological examinations and three for histological examinations. Among samples of the rectus capitis posterior major muscle (RCPma) and rectus capitis posterior minor muscle (RCPmi), 86.4% had a typical muscle appearance with a single belly, and 13.6% had an anomalous morphology. None of the samples of the obliquus capitis superior (OCS) or obliquus capitis inferior (OCI) muscles had an anomalous appearance. Measurement of cross-sectional area revealed that fast-twitch muscle fibers in the RCPma and OCI had a significantly greater cross-sectional area than those of the RCPmi and OCS. The cross-sectional area of intermediate muscle fibers was also significantly greater in the OCS than in the RCPma, RCPmi, and OCI. The cross-sectional area of slow-twitch muscle fibers was significantly greater in the OCS than in the RCPma, RCPmi, and OCI, and the RCPmi showed a significantly greater cross-sectional area for slow-twitch muscle fibers than did the RCPma, and OCI. Our findings indicate that the RCPmi and OCS exert a greater force than the RCPma and OCI, and act as anti-gravity agonist muscles of the head. Prolonged head extension in individuals with anomalous suboccipital muscle groups could result in dysfunction due to undue stress.

Morphometric methods were used to describe the musculotendinous lengths, fascicle lengths, pennation angles, and cross-sectional areas of neck muscles in adult Macaca mulatta monkeys. Additionally, muscles were frozen, sectioned, and stained for ATPase activity to determine fiber-type composition. Individual rhesus muscles were found to vary widely in their degree of similarity to feline and human muscles studied previously. Suboccipital muscles and muscles supplied by the spinal accessory nerve were most similar to human homologs, whereas most other muscles exhibited architectural specializations. Many neck muscles were architecturally complex, with multiple attachments and internal aponeuroses or tendinous inscriptions that affected the determination of their cross-sectional areas. All muscles were composed of a mixture of type I, IIa, and IIb fiber types the relative proportions of which varied. Typically, head-turning muscles had lower proportions of type II (fast) fibers than homologous feline muscles, whereas extensor muscles contained higher proportions of type II fibers. The physical and histochemical specializations described here are known to have a direct bearing on functional properties, such as force-developing capacity and fatigue-resistance. These specializations must be recognized if muscles are to be modeled accurately or studied electrophysiologically.

Obliquus capitis inferior (OCI) is a monoarticular suboccipital muscle linking the transverse process of the atlas (C1) to the spinous process of the axis (C2). Histochemical analysis of fiber-type composition showed that the muscle has a marked gradient of fiber-type distribution in which type I fibers comprise 95-100% of fibers in the deepest region but less than 10% of fibers in the superficial layer. Step-like changes in fiber-type proportions occurred between groups of fascicles. In most instances the boundaries between these fascicles did not exhibit different perimysial features from those fascicles with similar fiber-type proportions. OCI contained large numbers of muscle spindles, which were concentrated in deep regions rich in type I fibers. The degree of nonuniformity in fiber-type distribution seen in OCI is unusually large when compared with patterns described in other primate muscles, and has implications for the way that the muscle is studied anatomically and physiologically.

The frequency of suboccipital injections to treat cluster and chronic migraine headaches has increased in the last decade. The third segment of the vertebral artery is located in the suboccipital triangle and its main muscular branch, the suboccipital artery of Salmon (SAS), supplies blood to the suboccipital muscles and related tissues. The purpose of this study was to radiographically investigate the morphology of the SAS and its branches, and to document which muscles are supplied by this clinically-relevant blood vessel. Computed tomography angiographs of the brains of 50 subjects (25 female, 25 men) with a mean age of 70.2 years were analysed. The SAS was present in 48% of subjects. The vessel was present bilaterally in 37.1% of subjects, and had a mean (SD) luminal diameter of 1.71 (0.34) mm and mean (SD) length of 36.42 (17.1) mm. The SAS was found to have two morphologic patterns: 1) a single main trunk with collateral branches (52.6%) and 2) a short common trunk that divided into two branches (48.4%). The SAS supplied the obliquus capitis inferior, semispinalis capitis, and splenius capitis muscles. When the SAS was absent, the suboccipital muscles were supplied by a branch of the occipital artery. No anastomoses were found between the SAS and occipital artery. The suboccipital muscles are vascularised by the SAS and occipital artery. The detailed course of the SAS is important for clinicians and surgeons who perform procedures in the suboccipital region., Italian Journal of Anatomy and Embryology, Vol 118, No 2 (Supplement) 2013

A combination of retrograde tracers was used to compare the relative distributions of motoneurons supplying the ventral and lateral suboccipital muscles, rectus capitis anterior (RCA), and rectus capitis lateralis (RCL), with those supplying dorsal muscles, including rectus capitis posterior muscles (RCP), complexus (CM), and the medial head of obliquus capitis superior (OCS). Three of the tracers, horseradish peroxidase, fluororuby, and fluorescein-conjugated dextran, were applied to cut nerve ends. Fast blue was applied by intramuscular injection, and fluorogold was delivered both by injection and by cut nerve exposure. Motoneurons supplying RCA and RCL were clustered on the medial wall of the ventral horn in a restricted region defined previously as the commissural nucleus. Labelled cells supplying RCL were confined to the C1 segment, but those supplying RCA were distributed from C1 to rostral C4. Motoneurons supplying RCA tended to lie more dorsomedially than those supplying RCL, but there was substantial overlap between the two populations. Motoneurons supplying dorsal muscles had a separate, more ventral distribution. RCP motoneurons were located primarily in the ventromedial nucleus, but a small proportion of cells was found in the white matter of the ventral funiculus or the gray matter surrounding the central canal. Motoneurons supplying CM and OCS were located dorsomedially to the RCP cell population. These results suggest that neck motoneurons are arranged according to a "musculotopic" pattern in which dorsal muscles have the most ventral locations, and progressively more lateral and then ventral muscles are layered dorsomedially along the medial wall of the ventral horn.

The purpose of this study was to measure the immediate differences in craniocervical posture and pressure pain threshold of the greater occipital (GO) nerve in asymptomatic subjects with a history of having used orthodontics, after intervention by a suboccipital muscle inhibition (SMI) technique.This was a randomized, single-blind, clinical study with a sample of 24 subjects (21±1.78 years) that were divided into an experimental group (n=12) who underwent the SMI technique and a sham group (n=12) who underwent a sham (placebo) intervention. The sitting and standing craniovertebral angle and the pressure pain threshold of the GO nerve in both hemispheres were measured.The between-group comparison of the sample indicated that individuals subjected to the SMI technique showed a statistically significant increase in the craniovertebral angle in both the sitting (P.001, F1,22=102.09, R2=0.82) and the standing (P.001, F1,22=21.42, R2=0.56) positions and in the GO nerve pressure pain threshold in the nondominant hemisphere (P=.014, F1,22=7.06, R2=0.24). There were no statistically significant differences observed for the GO nerve mechanosensitivity in the dominant side (P=.202).Suboccipital muscle inhibition technique immediately improved the position of the head with the subject seated and standing, the clinical effect size being large in the former case. It also immediately decreased the mechanosensitivity of the GO nerve in the nondominant hemisphere, although the effect size was small.

AIM: The purpose of this study was to assess in a sample of female community cases the relationship between the increase of percentage of cervical signs and symptoms and the severity of temporomandibular disorders (TMD) and vice-versa. MATERIAL AND METHODS: One hundred women (aged 18-26 years) clinically diagnosed with TMD signs and symptoms and cervical spine disorders were randomly selected from a sample of college students. RESULTS: 43% of the volunteers demonstrated the same severity for TMD and cervical spine disorders (CSD). The increase in TMD signs and symptoms was accompanied by increase in CSD severity, except for pain during palpation of posterior temporal muscle, more frequently observed in the severe CSD group. However, increase in pain during cervical extension, sounds during cervical lateral flexion, and tenderness to palpation of upper fibers of trapezius and suboccipital muscles were observed in association with the progression of TMD severity. CONCLUSION: The increase in cervical symptomatology seems to accompany TMD severity; nonetheless, the inverse was not verified. Such results suggest that cervical spine signs and symptoms could be better recognized as perpetuating rather than predisposing factors for TMD.

Referred pain evoked by suboccipital muscle trigger points (TrPs) spreads to the side of the head over the occipital and temporal bones and is usually perceived as bilateral headache. This paper describes the presence of referred pain from suboccipital muscle TrPs in subjects with episodic tension-type headache (ETTH) and in healthy controls. Ten patients presenting with ETTH and 10 matched controls without headache were examined by a blinded assessor for the presence of suboccipital muscle TrPs. Diagnostic criteria described by Simons and Gerwin were adapted to diagnose TrPs, i.e. presence of tenderness in the suboccipital region, referred pain evoked by maintained pressure for 10 s, and increased referred pain on muscle contraction. Six ETTH patients (60%) had active TrPs and 4 had latent TrPs (40%). On the other hand, 2 control subjects also had latent TrPs. Differences in the presence of suboccipital muscle TrPs between both groups were significant for active TrPs (P

This investigation determined the variation, prevalence, tissue-type, and sex bias in the soft-tissue bridge between rectus capitis posterior minor (RCPMi) and the posterior atlanto-occipital membrane (PAO). Seventy-five cadavers (27 females and 48 males) were surveyed. When RCPMi was revealed, its superior attachment was detached and the muscle was reflected inferiorly to determine if it was attached to the underlying PAO. If a soft-tissue bridge was identified, the fibers found within the bridge were classified by visual inspection into three categories: tendon-like, muscle-like, and fascia-like. A fourth category of no attachment was also noted. These results show that RCPMi was present bilaterally in 93% of all cadavers surveyed (89% of the female cadavers and 96% of the male cadavers). On the right side, a soft-tissue bridge was present in 67% of males and 78% of females. On the left side, the soft-tissue bridge was present in 69% of males and 82% of females. The number of male cadavers possessing tendon fibers in a soft-tissue bridge was 56% on the right side and 55% on the left side. In females, the number of cadavers possessing tendon fibers in a soft-tissue bridge was 44% on the right side and 64% on the left side. In males, muscle fibers were present in the soft-tissue bridge, 34% on the right side and 36% on the left. In females, muscle fibers were found in the soft-tissue bridge, 43% on the right side and 36% on the left. There were no significant associations of sex and the presence of the soft-tissue bridge and a fiber-type within a soft-tissue bridge.