View source for Muscle:Thoracolumbar Paraspinal/Superficial

The '''superficial thoracolumbar paraspinal muscles''' — the '''Iliocostalis Thoracis''', '''Iliocostalis Lumborum''', and '''Longissimus Thoracis''' — form the erector spinae group and are the most clinically important sources of myofascial back pain. Trigger points (TrPs) in these muscles are one of the most common causes of enigmatic back pain, accounting for tender/trigger points in 96% of patients referred for chronic intractable benign lumbar pain. Patients typically call this pain "lumbago." Pain from these muscles is consistently mistaken for visceral, cardiac, or radicular disease. Together with the [[Muscle:Thoracolumbar_Paraspinal/Deep|deep paraspinal muscles]], they form the erector spinae complex whose TrP management and corrective action programme is described in [[Concept:Paraspinal_Corrective_Actions|Paraspinal Corrective Actions]].

== Contents ==
* [[#Anatomy|Anatomy]]
* [[#Referred_Pain_Patterns|Referred Pain Patterns]]
** [[#Iliocostalis_Thoracis_Pain|Iliocostalis Thoracis]]
** [[#Iliocostalis_Lumborum_Pain|Iliocostalis Lumborum]]
** [[#Longissimus_Thoracis_Pain|Longissimus Thoracis]]
* [[#Activation_and_Perpetuating_Factors|Activation and Perpetuating Factors]]
* [[#Clinical_Examination|Clinical Examination]]
** [[#Postural_Assessment|Postural and Structural Assessment]]
** [[#Range_of_Motion|Range of Motion]]
** [[#Trigger_Point_Examination|Trigger Point Examination]]
** [[#Entrapment|Nerve Entrapment Signs]]
** [[#Skin_Signs|Skin Signs]]
* [[#Differential_Diagnosis|Differential Diagnosis]]
* [[#Treatment|Treatment]]
* [[#Patient_Education|Patient Education]]
* [[#Satellite_Trigger_Points|Satellite Trigger Points]]
* [[#Related_Pages|Related Pages]]
* [[#References|References]]

== Anatomy ==

All paraspinal muscles are innervated by branches of the '''dorsal primary divisions''' of the spinal nerves — this distinguishes them from the [[Muscle:Serratus_Posterior|serratus posterior inferior]], which is innervated by anterior primary divisions.

=== Iliocostalis Thoracis ===

* '''Attachments:''' Above — transverse process of C7 and angles of the upper six ribs; Below — angles of the lower six ribs
* '''Position:''' Lateral column of the erector spinae
* '''Continuation:''' Superiorly continues as iliocostalis cervicis

=== Iliocostalis Lumborum ===

* '''Attachments:''' Above — angles of the lowest six ribs; Below — sacrum
* '''Position:''' Lateral column; caudal continuation of iliocostalis thoracis
* '''Note:''' Overlaps with the lower iliocostalis thoracis at the thoracolumbar transition — TrPs in the transition zone may belong to either muscle

=== Longissimus Thoracis ===

* '''Attachments:''' Above — transverse processes of all thoracic vertebrae and adjacent ribs 1–9 or 10; Below — lumbar transverse processes and anterior layer of the lumbocostal aponeurosis; caudally blends with iliocostalis and spinalis
* '''Position:''' Medial column of the erector spinae; has the '''longest fibres''' of the paraspinal muscles
* '''Continuation:''' Extends into the lumbar region as a variable longissimus lumborum

=== General layering and function ===

Acting unilaterally, the iliocostalis and longissimus produce lateral flexion and rotation to the same side; acting bilaterally, they extend the spine. Their primary functional role is eccentric "paying out" during forward flexion — they resist gravity as the spine bends forward, up to approximately 45° of flexion; beyond that, ligamentous tension unloads them. They contract vigorously during coughing and straining.

The erector spinae can achieve complete electrical silence when standing fully erect, when fully forward flexed, and when side-bending without any component of flexion or extension — these are the positions of true relaxation.

== Referred Pain Patterns ==

'''Key clinical principle:''' Iliocostalis thoracis refers both cephalad and caudad; iliocostalis lumborum and longissimus thoracis refer primarily caudad. The patient with iliocostalis TrPs typically draws an '''up-and-down''' pattern on the back — this contrasts with the '''crosswise''' pattern drawn by patients with lower rectus abdominis TrPs referring to the same region.

=== Iliocostalis Thoracis Pain ===

'''Midthoracic TrPs (around T6):'''
* '''Essential zone:''' Ipsilateral paravertebral region at the TrP level; strong referral upward toward the posterior shoulder and laterally along the chest wall
* '''Spillover:''' Anteriorly along the chest wall — on the left side, '''easily mistaken for cardiac angina'''; on either side, may mimic pleurisy

'''Low thoracic TrPs (around T11):'''
* '''Essential zone:''' Upward across the scapula, around to the abdomen, and downward over the lumbar area
* '''Spillover:''' Abdominal referral — '''readily mistaken for visceral pain''' (appendicitis, gallbladder, renal colic depending on side and level)
* '''Note:''' TrPs at this level may belong to iliocostalis lumborum, as the two muscles overlap here

=== Iliocostalis Lumborum Pain ===

'''Upper lumbar TrPs (around L1):'''
* '''Essential zone:''' Strong referral downward, concentrating on the '''midbuttock''' — a frequent but easily overlooked source of unilateral posterior hip pain
* '''Spillover:''' Lateral hip region
* '''Visceral mimic:''' Right subcostal iliocostalis lumborum TrPs can refer to the right lower quadrant, right flank, and right subcostal area — mimicking renal, ureteral, or appendiceal disease

'''Associated pelvic finding:''' TrPs in the iliocostalis lumborum are closely associated with pelvic obliquity secondary to tension applied to the muscle's insertional aponeurosis onto the sacral base — this can present as sacroiliac dysfunction, demonstrated by a positive seated-flexion test. The side of the positive seated-flexion test is not the side of the sacroiliac dysfunction.

=== Longissimus Thoracis Pain ===

'''Low thoracic TrPs (around T10–11):'''
* '''Essential zone:''' Strong referral low in the '''buttock''' — a remote source of buttock pain that is easily overlooked when the TrP level is not examined

'''Upper lumbar TrPs (around L1–2):'''
* '''Essential zone:''' Referral several segments caudally, remaining within the lumbar region — a muscular source of "lumbago"
* '''Bilateral involvement at L1:''' Patient has difficulty '''rising from a chair''' and '''climbing stairs''' facing forward — a characteristic functional indicator

== Activation and Perpetuating Factors ==

'''Sudden overload:'''
* Quick awkward movement combining bending and twisting, especially with fatigued muscles
* Lifting with the back twisted and flexed instead of erect
* Whiplash — sudden acceleration or deceleration rapidly stretches protectively stiffened spinal muscles
* Chilling of the iliocostalis during a bending/twisting movement, even without lifting — caused by disproportionate loading from poor coordination

'''Sustained overload:'''
* Prolonged immobility: sitting for hours in an aircraft or automobile with a seatbelt; typists immobile for ≥30 minutes develop paraspinal motor unit activity from initial electrical silence
* Stooped posture — sustained or repeated forward flexion
* Hyperlordotic (fully shortened) position — fully shortened position is equally overloading

'''Structural asymmetry (most important perpetuating factors):'''
* Lower limb length inequality — a difference as small as 0.3 cm (⅛ in) in a short person is clinically significant; up to 1.3 cm may not activate TrPs but powerfully perpetuates them; see [[Concept:Paraspinal_Corrective_Actions|Paraspinal Corrective Actions]] for assessment and correction
* Small hemipelvis — tilts the pelvis when sitting with the same effect as leg length inequality when standing
* Wallet in a back pocket — causes asymmetric pelvic tilt ("back-pocket sciatica")
* Flat feet, equinus valgus — any significant gait deviation can activate TrPs in the iliocostalis
* Scoliosis — paraspinal muscles increase activity on the side of the longer leg and on the side of the concavity

'''Key satellite relationship:''' An iliocostalis thoracis TrP may be a satellite of a key TrP in the [[Muscle:Latissimus_Dorsi|latissimus dorsi]] — the latissimus TrP must be treated first for full recovery of the iliocostalis.

== Clinical Examination ==

=== Postural and Structural Assessment ===

Structural assessment is the essential starting point for any patient with thoracolumbar or buttock pain, since structural asymmetry is the most common perpetuating factor.

'''Standing assessment — leg length inequality:'''
# Observe the patient from behind with feet together or ≤7.6 cm apart
# Assess: (1) body silhouette asymmetry between ribs and pelvis; (2) lateral tilt of the lumbar spine leaving the sacrum; (3) lateral scoliosis; (4) tilted shoulder-girdle axis (scapular bulge symmetry is more reliable than shoulder line, which trapezius TrPs can distort); (5) low posterior superior iliac spine — one low dimple; (6) low iliac crest on one side
# Place a firm lift (pages of a pad or magazine) under the heel of the low-pelvis side — this should level the pelvis and straighten the spine
# '''Confirmatory test:''' Transfer the lift to the opposite heel — the patient feels uncomfortable and asymmetry worsens, confirming which leg is short

'''Sitting assessment — small hemipelvis:'''
# Patient sits on a flat level wood surface
# Assess pelvic tilt — a soft cushioned surface allows the body to tilt and increases tilt, requiring a thicker correction
# Correct with pages or paper under the ischial tuberosity on the shorter side
# A hard surface requires less correction than a padded seat

'''Shoulder-girdle asymmetry rules:'''
* Leg length discrepancy <1.3 cm: shoulder sags on the side of the '''longer''' leg
* Leg length discrepancy ≥1.3 cm: shoulder sags on the side of the '''shorter''' leg

=== Range of Motion ===

'''Superficial erector spinae:'''
* When standing, patient may be unable to flex the torso more than a few degrees
* Palpation is less reliable with the patient standing — postural tension and protective splinting by normal muscles masks taut bands

'''Deep paraspinal TrPs (see [[Muscle:Thoracolumbar_Paraspinal/Deep]]):'''
* Restrict side-bending, rotation, and hyperextension
* A hollow or flat area spans one to three vertebrae in the smooth spinous process curve during forward flexion — this is the hallmark of deep layer involvement

=== Trigger Point Examination ===

'''Optimal positioning:'''
* Patient side-lying on the uninvolved side in a relaxed position, with a pillow under the side of the abdomen for semiprone support
* '''Full prone position is inferior''' — it over-slackens the muscles and strains the neck
* Bring the patient's knees toward the chest just far enough to take up slack in the long erector spinae — this produces the intermediate stretch needed to distinguish taut bands from normal slackened fibres
* A useful clinical sign: when the seated patient leans forward, dangles the arms between the legs, and relaxes, an involved lumbar longissimus stands out and '''feels like a hard rope'''

'''Palpation technique:'''
* Flat palpation of the muscles in the semiprone position elicits spot tenderness — a palpable nodule in a taut band with patient-recognised referred pain
* '''Distinguishing central from attachment TrPs''' is difficult even in superficial muscles: a tender nodule with a taut band extending in either direction suggests a central TrP; tenderness at the end of a taut band suggests an attachment TrP
* When injecting the midthoracic level: TrPs located more medially in the longissimus thoracis refer '''caudally'''; TrPs located 1–2 cm more laterally in the iliocostalis thoracis refer '''upward toward the shoulder''' — this mediolateral distinction is diagnostically useful

'''Mirror-image pattern:''' After releasing the erector spinae on the painful side, mirror-image pain and tension may appear on the opposite side. The two sides frequently function together as a unit. Expect to treat both.

=== Nerve Entrapment Signs ===

The dorsal primary rami pass through the paraspinal muscles to reach the skin. Active TrPs with tense bands can entrap these rami, producing skin symptoms:

* '''Above T8:''' Medial branches of the dorsal rami — pass through semispinalis thoracis and longissimus thoracis; entrapment produces hyperesthesia, dysesthesia, or hypoesthesia of the skin over the upper and midthoracic back
* '''Below T8 including lumbar:''' Lateral branches — pass through the iliocostalis; high lumbar symptoms of skin-referred pain are usually due to compression of low thoracic dorsal rami by bands of tense fibres in the iliocostalis lumborum

'''Skin rolling test (panniculosis):''' The skin overlying involved lumbar paraspinal muscles often shows superficial tenderness and resistance to skin rolling (panniculosis) or trophedema. These signs disappear after therapeutic skin rolling and inactivation of the underlying TrPs. When marked panniculosis is present, identifying and treating both the skin and muscle components together may be critical to recovery.

=== Skin Signs ===

Local areas of reduced skin resistance to direct current are characteristic of the musculoskeletal and myofascial symptoms of backache with limitation of spinal motion. Focal reduction of skin resistance over the tender spots demonstrates an autonomic effect of the TrPs.

== Differential Diagnosis ==

{| class="wikitable"
|-
! Condition !! Must-have distinguishing features !! Paraspinal TrP features
|-
| '''Radiculopathy''' || Objective neurological deficits: decreased tendon reflexes, impaired cutaneous sensation, motor weakness with atrophy; pain radiates into the lower extremity || Paraspinal TrPs alone do not cause pain radiating to the lower extremity; no primary neurological deficit; TrP tenderness, palpable bands, and referred pain on pressure are absent in true radiculopathy
|-
| '''Visceral disease''' (cardiac angina, pleurisy, appendicitis, renal/ureteral colic, gallstones) || Positive visceral investigations; symptom provocation by visceral-specific tests; systemic features || Pain from iliocostalis thoracis TrPs at midthoracic level mimics cardiac angina and pleurisy; low thoracic/lumborum TrPs refer to the abdomen — all must be ruled out before attributing pain to muscle
|-
| '''Lumbar facet (zygapophysial) joint pain''' || Overlapping referred pain pattern with multifidus (see Volume 2); distinguishes by articular provocation tests and diagnostic blocks || Multifidus TrPs mimic lumbar facet pain; the two may coexist — see [[Muscle:Thoracolumbar_Paraspinal/Deep]]
|-
| '''Intervertebral disc herniation''' || Neurological deficit; imaging correlation; provocation by axial loading and straight-leg raise || Disc herniation, ligamentous strain, and paraspinal muscular overload are all likely caused by similar lifting strains; both may coexist. TrPs may persist long after disc pathology is resolved — this is the mechanism of '''failed-back syndrome''' and post-laminectomy pain.
|-
| '''Sacroiliac dysfunction''' || Positive seated-flexion test; pain behaviour on sacroiliac provocation || Iliocostalis lumborum TrPs cause pelvic obliquity from aponeurotic tension and can present as sacroiliac dysfunction — positive seated-flexion test; be aware the positive side is not the side of the dysfunction
|-
| '''Fibromyalgia''' || Widespread bilateral pain above and below the waist; tender points at ≥11/18 standard sites; specific diagnostic criteria (see [[Concept:Trigger_Point|Trigger Point]] for distinction from fibromyalgia) || Patients with fibromyalgia frequently also have myofascial TrPs; both diagnoses may coexist; each requires its own therapeutic approach
|-
| '''Osteoarthritis''' || Radiographic signs of degenerative joint disease — but these correlate poorly with the occurrence of pain; over one-third of asymptomatic controls have degenerative changes || Many patients with spinal degenerative changes are completely relieved of pain when responsible TrPs are inactivated; do not assume degenerative changes cause the pain
|-
| '''Subcutaneous fat lobule herniation''' || Palpable fibrolipomatous nodule in the lumbosacral region with attachment TrP characteristics; temporarily relieved by procaine injection; permanently by surgical excision || Subcutaneous nodules occur in 25% of white adults and are rarely a cause of back pain; the palpable nodule of a fat lobule is in the subcutaneous layer, not in muscle; biopsy is seldom required
|}

'''Key rule for radiculopathy:''' When active TrPs in back muscles induce satellite TrPs in gluteal muscles, the gluteal TrPs often refer myofascial pain down the lateral or posterior thigh or leg, sometimes to the foot — this can be mistaken for radiculopathy. Radiculopathy is characterised by objective neurological deficits. When radiculopathy activates TrPs, those TrPs may persist long after nerve root compression has been relieved, producing the post-laminectomy pain syndrome (failed-back syndrome).

'''Articular dysfunction and TrP depth:'''
* Rotatores TrPs → single-level articular dysfunction
* Multifidi TrPs → two to three adjacent levels
* Semispinalis TrPs → four to six segmental levels; apex segment exquisitely tender
* Iliocostalis and longissimus TrPs → group dysfunctions; compensatory S-curve misinterpreted as primary scoliosis

== Treatment ==

=== Trigger Point Release ===

'''Spray and stretch — erector spinae (superficial group):'''

''Less strenuous (thoracic emphasis):''
# Patient seated in a chair, feet flat on the floor, legs apart
# Patient leans forward, head hangs, arms drop between the knees
# Operator applies downward parallel sweeps of vapocoolant bilaterally over the paraspinal muscles
# Patient is instructed to take a deep breath, exhale fully, and '''hump the back''' (correct cue — ''not'' "arch your back," which causes extension)
# Operator gradually increases pressure on the upper back to guide movement
# Vapocooling is followed immediately by moist heat to rewarm, then active range of motion

''More strenuous (lumbar and gluteal emphasis):''
# Patient in long-sitting position on a flat surface with hips flexed and knees straight
# Paraspinal and gluteal muscles sprayed in parallel downward sweeps continuing over the buttocks
# This position places strong stretch on gluteus maximus and hamstrings — if tight, release these first by stretch and spray during straight-leg raising before attempting full hip flexion
# Operator guides but does not force flexion

'''TrP pressure release:''' Most helpful for the most superficial erector spinae layers; patient can self-apply using a tennis ball supine — see [[Concept:Paraspinal_Corrective_Actions|Paraspinal Corrective Actions]].

'''Iliocostalis thoracis satellite rule:''' A TrP in the iliocostalis thoracis that is refractory to treatment may be a satellite TrP induced by a key TrP in the [[Muscle:Latissimus_Dorsi|latissimus dorsi]]. The latissimus dorsi TrP must be inactivated first for full recovery.

=== Trigger Point Injection ===

See [[Concept:Trigger_Point_Injection]].

* Longissimus and iliocostalis TrPs are clearly palpable and readily located in all but very obese patients
* When injecting the iliocostalis thoracis, the '''needle must be directed tangent to, and not between, the ribs''' — pneumothorax risk
* TrP injection is followed immediately by repetition of stretch and spray, then moist heat and active range of motion
* When multiple TrPs are spread throughout the paraspinal musculature: start with stretch and spray; reserve injection for the few refractory or deep TrPs that remain

== Patient Education ==

The full corrective action programme — structural asymmetry correction, chair and seating modification, lifting mechanics, sleep posture, and exercises — is presented at [[Concept:Paraspinal_Corrective_Actions|Paraspinal Corrective Actions]].

Key points for patient instruction:

'''Lifting:'''
* Hold the object close to the body with the pelvis tucked in — centre of gravity close to the hip joints
* Bend knees, keep back upright — load the hip and knee extensors, not the paraspinal muscles
* The 90°-forward-bent standing position places maximum strain on the lumbosacral joints — avoid
* '''Most dangerous movement:''' twisting turn while lifting or pulling — whenever possible, rotate the entire body to face the load squarely

'''Sit-to-stand technique:''' Move hips to the front of the chair seat; turn the body slightly to the side; place one foot under the front edge of the chair; hold the torso erect while straightening the knees and hips. This transfers load from the paraspinal muscles to the hip extensors.

'''Stair climbing:''' Patient with myofascial back pain who leans forward on stairs can avoid pain by turning the body to face approximately 45° to one side — this automatically straightens posture and lightens the paraspinal load.

'''Chair and bed:''' See [[Concept:Paraspinal_Corrective_Actions|Paraspinal Corrective Actions]] for full protocol.

== Satellite Trigger Points ==

'''Latissimus dorsi → Iliocostalis thoracis (key satellite):'''
* [[Muscle:Latissimus_Dorsi|Latissimus dorsi]] is the primary key TrP driver for iliocostalis thoracis; treat it first
* The same initiating event that activates the superficial paraspinals often simultaneously activates latissimus dorsi and [[Muscle:Quadratus_Lumborum|quadratus lumborum]]

'''Gluteal TrPs as satellites of paraspinal TrPs:'''
* When active back muscle TrPs induce satellite TrPs in the gluteal muscles, the gluteal TrPs refer pain down the lateral or posterior thigh and leg — potentially to the foot
* This satellite pattern is the mechanism of the '''pseudo-radicular''' presentation of lumbar paraspinal TrP syndrome

'''Thoracolumbar junction group (mutual interdependence):'''
* Articular dysfunction at the thoracolumbar junction is associated with active TrPs in the erector spinae, [[Muscle:Psoas|psoas]], and [[Muscle:Quadratus_Lumborum|quadratus lumborum]]
* Treating any one of the three (the thoracolumbar junction dysfunction, or TrPs in either of the other two muscles) often relieves TrPs in the other two

'''Also examine:'''
* [[Muscle:Serratus_Posterior|Serratus posterior inferior and superior]] — associated TrPs develop with paraspinal TrP activity
* [[Muscle:Thoracolumbar_Paraspinal/Deep|Deep paraspinal muscles]] — the two groups frequently develop TrPs together; superficial group more likely to accumulate associated TrPs in functionally related muscles (including the contralateral side); deep group more likely to show isolated muscle involvement

== Related Pages ==

* [[Muscle:Thoracolumbar_Paraspinal/Deep]] — Semispinalis thoracis, multifidi, rotatores; deep layer pain patterns and examination
* [[Concept:Paraspinal_Corrective_Actions]] — Canonical corrective actions programme: structural correction, chair design, lifting mechanics, exercises
* [[Muscle:Latissimus_Dorsi]] — Key TrP driver for iliocostalis thoracis satellite
* [[Muscle:Quadratus_Lumborum]] — Commonly co-active at the thoracolumbar junction
* [[Muscle:Psoas]] — Thoracolumbar junction triad
* [[Muscle:Serratus_Posterior]] — Associated TrPs in both serratus posterior muscles
* [[Muscle:Gluteus_Medius]] — Primary satellite target for lumborum and longissimus TrPs; source of pseudo-radicular thigh and leg pain
* [[Concept:Trigger_Point_Injection]] — Injection technique; pneumothorax precautions for iliocostalis thoracis
* [[Concept:Perpetuating_Factors]] — Structural asymmetry, leg length, hemipelvis

== References ==

* Travell JG, Simons DG. ''Myofascial Pain and Dysfunction: The Trigger Point Manual, Volume 1: The Upper Half of Body''. 2nd ed. Baltimore: Williams & Wilkins; 1999. Chapter 48.

[[Category:Muscle]]
[[Category:Vol1 Ch48]]
[[Category:Torso]]