Osteopathic Journals and Research by Darren Chandler

 

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  1. Anatomy of the hamstrings, gluteus maximus and sacrotuberous ligament

    Hamstrings

    Perez-Bellmunt et al (2015) found the proximal attachment of the hamstrings to be anchored in place (along with the sacrotuberous ligament) by a retinaculum attached to each side of the ischial tuberosity. This retinaculum is formed by the epimysium from the anterior aspect of the gluteus maximus and the biceps femoris epitenon (refer 'Fascia of the gluteus maximus').

    Biceps femoris

    Origin: (long head) ischial tuberosity (shared tendon with the semitendinosus*) & sacrotuberous ligament; (short head) lateral lip of linea aspera --> lateral intermuscular septum and supracondylar line. 

    Insertion: fibula head; fibula collateral ligament and lateral condyle of tibia.

    Semitendinosus

    Origin: ischial tuberosity (shared tendon with long head of biceps femoris*) and the aponeurosis it shares with the long head of biceps femoris.

    Insertion: upper surface of the medial aspect of the tibia (pes anserine). With the gracilis it gives off a prolongation to the deep fascia of the leg and medial gastrocnemius.

    May attach to the biceps femoris at the mid-point of the muscle.

    *: Farfan et al (2020) found the joint biceps femoris-semitendinosus proximal tendon has a posteromedial insertion on the ischial tuberosity. Whilst there is a direct connection between the tendon of the long head of biceps femoris and the sacrotuberous ligament this is not the case for the semitendinosus.

    Semimembranosus

    Origin: ischial tuberosity (anterolateral insertion, Farfan et al 2020); receives two fibrous expansions from the ischial tuberosity and ramus that flanks the adductor magnus; can attach on to the sacrotuberous ligament (Solonen 1957).

    Insertion: medial tibial condyle; medial margin of the tibia; fascia over the popliteus; femoral intercondylar line; lateral femoral condyle; forms the oblique popliteal ligament of the knee.

    Interdigitates to some extent with the biceps femoris and semitendinosus.

    Gluteus Maximus 

    Origin: ilium (posterior gluteal line and iliac crest); aponeurosis of erector spinae; sacrum; coccyx; sacrotuberous ligament; fascia (gluteal aponeurosis) of the gluteus medius.

    Insertion: iliotibial band and gluteal tuberosity of the femur.

    Sacrotuberous ligament

    Runs from the PSIS, posterior sacroiliac ligaments (with which it is partly blended), lateral sacral crest and upper coccyx --> ischial tuberosity and ramus.

    Wingerden et al (1993) found the fibers of the sacrotuberous ligament were not parallel but coiled in a spiral fashion. The medial fibers of the ligament cross to the cephalic side of the sacrum and the lateral fibers from the ischial tuberosity attach to the caudal part of the sacrum.

    The sacrotuberous ligament's soft tissue attachments are:

    • Blends with the fascial sheet of the internal pudendal vessels and pudendal nerve.
    • Piriformis (Solonen 1957).
    • Lowest fibers of the Gluteus Maximus.
    • Blends partially with the sacrospinous ligament.
    • Biceps Femoris and semimembranosis (Solonen 1957).
    • Thoracolumbar fascia: between the outer thoracolumbar fascia and inner sacrotuberous ligament a tunnel is formed that nerves from the sacral rami run through (Willard et al 1998).
    • Deep pelvic fascia (Poilliot et al 2019).
    • Obturator fascia: blends with the sacrotuberous ligament at the ischial ramus.

    Nerves that pierce this ligament are:

    • Nerves from the coccygeal plexus.
    • Perforating cutaneous nerve (S1-3 nerve roots --> lower medial buttocks).

    Common tendon of the biceps femoris and semitendinosus

    Farfan et al (2020) found the joint biceps femoris-semitendinosus tendon has a posteromedial insertion on to the ischial tuberosity. Whilst there is a direct connection between the tendon of the long head of biceps femoris and the sacrotuberous ligament this was not observed for the semitendinosus.

    The common tendon is oval shape and is located 4cm lateral to the vertex of the ischial tuberosity with a surface area of approximately 10cm2.

    Farfan et al (2020) identified the common tendon of the long head of biceps femoris and semitendinosus as a delicate structure being the most common site of muscle injury in the lower limb. Perez-Bellmunt et al (2015) found the biceps femoris the most consistently injured of the three hamstrings due to its myofascial attachments.

    The unique myofascial relationship of the biceps femoris making it more prone to injury is it being (i) directly attached to the sacrotuberous ligament and (ii) directly attached to a retinaculum that anchors the hamstring muscles and sacrotuberous ligament (refer 'fascia of the gluteus maximus') (Perez-Bellmunt et al 2015).

    Farfan et al (2020) found transverse connective tissue fibers extending from the fascia of the biceps femoris across the sciatic nerve. Could the mechanical weakness associated with the biceps femoris myofascial attachments also render it prone to causing sciatica?

    Fascia of the gluteus maximus (Perez-Bellmunt et al 2015)

    As well as running continuous with the fascia lata of the thigh the gluteus maximus also has its own fascia, an epimysium.

    The epimysium of the gluteus maximus is a continuation of the connective tissue that is embedded in the different muscle fascicles (the perimysium and endomysium) and emerges on the anterior aspect of the gluteus maximus.

    At this point the epimysium of the gluteus maximus is continuous with:

    • Perineal fascia.
    • Proximal attachments of the hamstring: where the gluteus maximus muscle covers the ischial tuberosity a fascial expansion extends from its anterior aspect to anchor to the lateral and medial aspects of the ischial tuberosity forming a retinaculum. It receives contributions from the biceps femoris epitenon. This retinaculum covers the insertion of the sacrotuberous ligament and hamstrings. It anchors the sacrotuberous ligament and hamstring muscles (< long head of biceps femoris) playing a direct role in force transmission during muscle contraction. This establishes a synergy between the gluteus maximus muscle and the long head of biceps femoris.
    • Sciatic and posterior femoral coutaneous nerve: laterally the fascial expansions from the anterior aspect of the epimysium of the gluteus maximus splits to form a canal that surrounds the sciatic and posterior femoral cutaneous nerve.

    Sciatica

    Epimysium of the gluteus maximus

    Fibrotic bands of connective tissue around the sciatic nerve at the level of the proximal hamstring complex may compress the nerve. The location of the fibrotic bands is consistent with the location of the epimysial expansions from the gluteus maximus to the sciatic nerve and posterior femoral cutaneous nerve. The epimysial expansions form a tunnel around these nerves.

    Fascia of the long head of biceps femoris

    Farfan et al (2020) found the sciatic nerve was located laterally to the common tendon of the biceps femoris and semitendinosus. The nerve is covered by transversally arranged connective tissue that comes from the fascia of the long head of biceps femoris. These authors differentiated between this tissue and that coming from the gluteus maximus. This connection caused displacement of the nerve when the common tendon of the biceps femoris and semitendinosus is pulled.

    Sacrotuberous ligament

    Sato et al (2012) reviewed the evolutionary development of the sacrotuberous ligament. These authors reviewed the literature finding different authors attributed the sacrotuberous ligament as an evolutionary derivative of:

    • Caudal portion of the long head of biceps femoris.
    • Extension of the origin of the gluteus maximus muscle to the ischial tuberosity.
    • Posterior part of the aponeurosis of the superficial gluteal muscle.
    • Degeneration of the gluteus maximus muscle, shortening of the tail length, and transformation of the caudal part of the gluteus maximus muscle into the sacrotuberous ligament.

    Saito et al (2012) however emphasised the strong connection of the tendon of the long head of biceps femoris.

    Whilst traditionally seen as resisting nutation of the sacrum the evolution and functional relationship of the sacrotuberous ligament means it can transfer tension in-between various soft tissues. 

    This relationship was illustrated by Wingerden (1993) who found force applied to the biceps femoris is transmitted to the sacrotuberous ligament.

    Willard et al (2012) researched the effects of traction on the biceps femoris tendon in a medial and lateral direction. Traction applied in a lateral direction, via the sacrotuberous ligament, resulted in displacement of the deep lamina of thoracolumbar fascia up to the level L5–S1. Traction to the biceps femoris applied in a medial direction, via the sacrotuberous ligament, displaced the deep lamina of the thoracolumbar fascia up to the median sacral crest.

    This effect of lateral and medial traction producing distorsions on the deep lamina of the thoracolumbar fascia at different levels could be from the soft tissue architecture of the sacrotuberous ligament. Wingerden et al (1993) found the fibers of the sacrotuberous ligament were not parallel but were coiled in a spiral fashion. The medial fibers of the ligament cross higher up to the cephalic side of the sacrum and the lateral fibers from the ischial tuberosity attach lower down to the caudal part of the sacrum. Could medial and lateral traction of the biceps femoris pull on these different fibers of the sacrotuberous ligament? 

    References

    An anatomical and histological study of the structures surrounding the proximal attachment of the hamstring muscles (2015). Albert Perez-Bellmunt, Maribel Miguel-Perez, Marc Blasi Brugue, Juan Blasi Cabús, Martí Casals, Carlo Martinoli, Raija Kuisma

    Common Origin Tendon of the Biceps Femoris and Semitendinosus Muscles, Functional and Clinical Relevance (2020). Emilio Farfán C, Marcia Gaete C, Ramón Olivé V & Alfonso Rodríguez-Baeza

    Anatomical study of the proximal origin of hamstring muscles (2012). Kengo SatoAkimoto NimuraKumiko YamaguchiKeiichi Akita

    The sacroiliac joint in the light of anatomical roentgenological clinical studies (1957). Kauko A Solonen

    A Systematic Review of the Normal Sacroiliac Joint Anatomy and Adjacent Tissues for Pain Physicians (2019) Amelie J. Poilliot, Johann Zwirner, Terence Doyle and Niels Hammer

    The long posterior interosseous ligament and the sacrococcygeal plexus (1998). Third Interdisciplinary world congress on low back and pelvic pain. Willard F, Carreiro J, Manko W

    A functional-anatomical approach to the spine-pelvis mechanism: Interaction between the biceps femoris muscle and the sacrotuberous ligament (1993). Jan-Paul van Wingerden

    The thoracolumbar fascia: anatomy, function and clinical considerations (2012). F H WillardA VleemingM D SchuenkeL Danneels, and R Schleip

  2. Anatomy

    Spinal cord --> dorsal root (sensory) & ventral root (motor) --> spinal nerve (mixed sensory & motor) --> ventral rami (motor > sensory) & dorsal rami (sensory > motor). Dorsal rami --> medial branch of dorsal rami & lateral branch of dorsal rami.

    Saito et al (2013) described the L2 spinal nerve and ventral rami as a 'continuous stem' . This is opposed to the dorsal rami that was described as a 'branch of the spinal nerve'. These authors did not specify if this was unique to L2.

    There are numerous anastomoses between adjacent dorsal rami, medial branches and lateral branches. Shuang et al (2015) confirmed the existence of the middle [intermediate] branch of the dorsal rami which connects the lateral branch to the communicating plexus. These authors acknowledge some might recognize the middle [intermediate] branch as a muscular sub-branch of the lateral branch, and generally, it is acceptable to divide the dorsal rami into the medial and the lateral branches. 

    The dorsal rami enters the back through a foramen bounded by the superior border of the transverse process, the anterior aspect of the superior articular facet joint and the intertransverse ligament (Zhou et al 2012).

    It runs posteriorly on the medial aspect of the intertransversarri muscles (Shuang et al 2015).

    The dorsal ramus then divides into the into medial and lateral branches at the junction of the facet joint and the proximal superior border of the transverse process (Zhou et al 2012). Bogduk and Long (1979) and Masini et al (2005) found the L1-L4 dorsal rami to divide into the medial and lateral branches within the intertransverse ligament.

    Bogduk et al (1982) found different branching patterns for not just the medial and lateral branches of the dorsal rami but also the intermediate branches. The branching patterns varied depending on the spinal levels:

    • L1 & L2 dorsal rami: commonly double branching occurs. This includes a medial branch and a short common stem for the lateral and intermediate branches.
    • L4>L3 dorsal rami: commonly triple branching occurs. This includes the medial, intermediate and lateral branches.
    • L5 dorsal rami: gives rise to the medial and intermediate branches as it runs in the groove formed by the S1 superior articular process and the sacral ala. The L5 dorsal rami lacks a lateral branch as there is no attachment of the iliocostalis lumborum to L5 as it is replaced by the iliolumbar ligament.

    Medial branch of the dorsal rami

    As the medial branch of the dorsal rami passes through a groove formed between the root of the transverse process and root of the superior articular process Bogduk et al (1982) found it was bound to the periosteum by a layer of connective tissue which coated the superior articular process and transverse process.

    The nerve then passes through a fibroosseous canal formed by the junction of the transverse process and the lateral aspect of the superior articular process. The roof of the canal is formed by the mammilloaccessory ligament. 

    *: Mammilloaccessory ligament is a part of the medial side of the intertransverse ligament. It extends from the mammillary process to the accessory process. It gives origin to the intertransversarii, multifidus, longissimus and iliocostalis muscles.

    The medial branch of the dorsal rami then penetrates the deep fascia near the median line to enter the subcutaneous tissue.

    The medial branch of the dorsal rami innervates:

    • Facet joints: innervates the two to three adjacent facet joints e.g. the L4 facet joint is innervated by the L3 and L4 medial branches. To innervate the facet joint the proximal nerve runs between the intertransversarii and the most lateral fibres of multifidus; the distal nerve runs deep to the multifidus (Bogduk et al 1982).
    • Multifidus: Shuang et al (2015) found this innervation to be highly specific. They found each medial branch ran on the deep aspect of the multifidus and was solely innervated by this one branch without any communicating branches. This finding was disputed by Wu et al (1997) who found the multifidus to be polysegmentally innervated.
    • Interspinous ligament and muscle: the nerve weaves medially between the fascicles of the multifidus to reach the interspinous space (Bogduk et al 1982).
    • Supraspinous ligament.

    Saito et al (2013) believed the intermediate branches are more widespread but have been regarded simply as muscular branches of the lateral branches. These authors described the anatomy of the dorsal rami as:

    • Medial branch: arises from the mammillary processes to enter the multifidus muscle.
    • Intermediate branch: arises from the accessory processes and enters the longissimus muscle.
    • Lateral branch: arises from the transverse processes and enters the iliocostalis.

    Lateral branch of the dorsal rami

    The lateral branch of dorsal rami lies in an osseous groove on the superior transverse process. It then sends branches to the iliocostalis and longissimus muscles.

    After passing the iliocostalis muscle, the main lateral branch descends approximately two vertebral segments before it pierces the dorsal layer of the thoracolumbar fascia into the subcutaneous region and supplies the skin.

    Distal anastomoses of the lateral branches have been noted < T11 and T12, T12 and L1, and L2 and L3.

    The lateral branch innervates the tissues lateral to the facet joint line e.g:

    • Iliocostalis and Longissimus muscles. 
    • Cutaneous innervation of the back and pelvis.

    Several authors regard the intermediate branch as a muscular branch of the lateral branch (Saito et al 2013). Those that classify the intermediate branch as a distinct branch of the dorsal rami found it to innervate the Longissimus (refer 'intermediate branch of the dorsal rami').

    Bogduk et al (1982) found:

    • L1 and L2 lateral branches: cross the iliac crest in the subcutaneous tissue in parallel with the T12 cutaneous branch. T12 and L1 innervate the dermatome just below the lateral iliac crest and posterior to the ASIS.
    • L1-3 lateral branches: emerge from the posterolateral surface of the iliocostalis lumborum, pierce the posterior layer of the thoracolumbar fascia and become cutaneous. L3 is bound down to the iliac crest by a bridge of connective tissue just lateral to the origin of iliocostalis lumborum. L2 and L3 lateral branches innervate the skin over the buttocks.
    • L4-L5 lateral branches: there are no cutaneous branches of the L4 and L5 lateral branches. L4 lateral branch remains intramuscular. The L5 lateral branch typically communicates with the S1 dorsal ramus.

    The lateral branch of the L5 dorsal ramus descends and merges into the S1 dorsal ramus (Zhou et al 2012).

    Bogduk et al (1982) described the L5 dorsal ramus as lacking a lateral branch dividing the dorsal ramus at this level into the medial and intermediate branches. This was due to the absence of an attachment of the iliocostalis to L5 which is replaced by the iliolumbar ligament.

    However both these authors also described the intermediate branch (Bogduk et al 1984) and lateral branch (Zhou et al 2012) of the L5 dorsal rami as innervating the longissimus thoracis as it attaches to the medial aspect of the dorsal segment of the iliac crest. Therefore both authors are probably describing the same nerve but under a different name.

    Intermediate brach of the dorsal rami

    The L3 and L4 dorsal rami (and sometimes L1 and L2) give off intermediate branches which supply the lumbar fibers of the longissimus thoracis (Zhou et al 2012) and mutifidus (L2 nerve, Saito et al 2013). 

    This branch passed between the longissimus and iliocostalis muscles and extended to the skin.

    Soft tissue relations to the dorsal rami

    Zhou et al (2012) found the most commonly affected area from dorsal rami pain is around the thoracolumbar region and involving the L1 and L2 dorsal rami (Zhou et al 2012). This was opposed to facet joint pain that most commonly affected the L4-5 and L5-S1 levels.

    Intertransversarii and intertransverse ligament

    The L1-L4 dorsal rami to divide into the medial and lateral branches within the intertransverse ligament (Bogduk and Long 1979 &  Masini et al 2005).

    The intertransverse ligament frequently blends with the intertransversarii muscle and has been described as looking more like a part of the thoracolumbar fascia rather than a true ligament (Hirsch et al 1963).

    The intertransversarii muscle and intertransverse ligament relation to the medial branch of the dorsal rami is:

    • The dorsal rami runs on the medial aspect of the intertransversarii muscle.
    • The medial branch of the dorsal ramus innervates the facet joint. To innervate the facet joint the proximal nerve runs between the intertransversarii and the most lateral fibres of multifidus; the distal nerve runs deep to the multifidus (Bogduk et al 1982).
    • Medial branch of the dorsal rami lies in the fibrosseous canal formed from the mamilloaccessory ligament that is associated with the intertransverse ligament and intertransversarri muscle.

    There are three distinct intertransversarii muscles (Gilchrist et al 2003):

    • Intertransversarii laterales ventrales: traverses proximally and distally between neighbouring transverse processes. Innervated by the ventral ramus.
    • Intertransversarii laterales dorsales: lies medial to the intertransversarii laterales ventrales. Inserts proximally to the accessory process and distally to the medial third of the adjacent transverse process below.
    • Intertransversarii mediales: attaches proximally to the accessory process, mamillary process, and mamillary-accessory ligament. Distally it inserts into the mamillary process of the vertebrae below. Innervated by the medial division of the dorsal rami.

    Due to their small size and medial location, the intertransversarii muscles are weak posterior sagittal rotators and lateral flexors of the lumbar spine. These muscles primary function may more proprioceptive in nature providing positioning feedback to the larger muscles of the spine that react to maintain proper spinal alignment. 

    The middle layer of the thoracolumbar fascia is the strongest layer of the thoracolumbar fascia and attaches to intertransverse ligaments. Hirsch et al (1963) described the intertransverse ligaments as being an extension of the thoracolumbar fascia rather than a ligament in its own right.

    This continuity from the middle layer of the thoracolumbar fascia to the intertransverse ligament allows tension from the transversus abdominis, internal oblique and external oblique to be transmitted via the middle layer of the thoracolumbar fascia to the transverse processes and intertransverse ligaments (Barker et al 2007). Gilchrist et al (2003) also found the iliocostalis lumborum attaches on to the middle layer of the thoracolumbar fascia.

    If the intertransversarii and intertransverse ligaments have a proprioceptive function then could this help explain how the lateral abdominal muscles influence segmental motion (Barker et al 2007)?

    Multifidus

    The multifidus relation to the medial branch of the dorsal rami includes:

    • Mammilloaccessory ligament is a point of attachment for the multifidus. This ligament forms the roof of the fibrosseous tunnel that the medial branch of the dorsal ramus runs through.
    • The medial branch of the dorsal ramus innervates the facet joint. To innervate the facet joint the proximal nerve runs between the intertransversarii and the most lateral fibres of multifidus; the distal nerve runs deep to the multifidus (Bogduk et al 1982).
    • The medial branch of the dorsal ramus weaves medially between the fascicles of the multifidus to reach the interspinous space (Bogduk et al 1982).

    The multifidus arises from the spinous process of L5 to as low as the fourth sacral foramen, PSIS and dorsal sacroiliac ligament. The longest fibers of the multifidus run from the spinous processes of L1 and L2 to the dorsal segment of the iliac crest.

    The multifidus is tightly adhered to the erector spinae aponeurosis at the lumbar (close to the midline) and sacral levels (Creze et al 2018). Johnson and Zang (2002) found the multifidus, longissimus thoracis and thoracolumbar fascia to be contributers to the supraspinous and interspinous ligaments. 

    Paralleling the mutlifidus relation with the medial branch of the dorsal rami the sacral attachment of the multifidus is also tightly adhered to the medial branches of the sacral dorsal rami. To illustrate how tight this adherence is when the multifidus was removed piecemeal many of these nerves were removed along side with it (Cox & Fortin 2014).

    Masaki et al (2019) paralled the work of Macintosh & Bogduk (1986) and found the lumbar multifidus is stretched effectively in trunk flexion. The addition of lateral flexion or ipsilateral rotation to flexion did not alter the effectiveness of the stretch. Flexion will also stretch the interspinous space.

    References

    The Anatomy of Dorsal Ramus Nerves and Its Implications in Lower Back Pain (2012) Linqiu Zhou, Carson D. Schneck, Zhenhai Shao.

    Clinical Anatomy and Measurement of the Medial Branch of the Spinal Dorsal Ramus (2015). Feng Shuang, Shu-Xun HouJia-Liang Zhu, Yan LiuYing Zhou, Chun-Li Zhang, Jia-Guang Tang.

    Muscular Control of the Lumbar Spine (2003). Russell V. Gilchrist, Michael E. Frey and Scott F. Nadler

    An electrophysiological demonstration of polysegmental innervation in the lumbar medial paraspinal muscles (1997). P B WuW S KingeryM L FrazierE S Date

    Analysis of the Posterior Ramus of the Lumbar Spinal Nerve: The Structure of the Posterior Ramus of the Spinal Nerve 2013). Toshiyuki Saito, Hanno Steinke, Takayoshi Miyaki,Shiro Nawa, Kanae Umemoto, Kunihisa Miyakawa, Norimitsu Wakao, Ken Asamoto, Takashi Nakano.

    The human lumbar dorsal rami (1982)N BogdukA S Wilson, and W Tynan

    The middle layer of lumbar fascia and attachments to lumbar transverse processes: implications for segmental control and fracture (2007). Priscilla J. Barker, Donna M. UrquhartIan H. StoryMarius Fahrer, and Christopher A. Briggs.

    Effects of the trunk position on muscle stiffness that reflects elongation of the lumbar erector spinae and multifidus muscles: an ultrasonic shear wave elastography study (2019). Mitsuhiro MasakiXiang Ji, Taishi YamauchiHiroshige TateuchiNoriaki Ichihashi

    Organization of the fascia and aponeurosis in the lumbar paraspinal compartment (2018). Creze M, Soubeyrand M, Nyangoh Timoh K, Gagey O.

    Regional differences within the human supraspinous and interspinous ligaments: a sheet plastination study (2002). Gillian M Johnson and Ming Zhang

    The anatomy of the lateral branches of the sacral dorsal rami: implications for radiofrequency ablation (2014). Cox R, Fortin  J.

    The biomechanics of the lumbar multifidus (1986). J E MacintoshN Bogduk

    The anatomy of the so-called "articular nerves" and their relationship to facet denervation in the treatment of low-back pain. N BogdukD M Long

    Anatomical description of the facet joint innervation and its implication in the treatment of recurrent back pain (2005). M Masini, W S Paiva, A S Araújo Jr

    THE ANATOMICAL BASIS FOR LOW BACK PAIN Studies on the presence of sensory nerve endings in ligamentous, capsular and intervertebral disc structures in the hurnnn lumbar spine (1963). CARL HIRSCH, Bo-ERIC INGELMARK and MALCOLME MILLER
     
    The anatomy of the so-called “articular nerves” and their relationship to facet denervation in the treatment of low-back pain (1979).Nikolai Bogduk and Don M. Long