Clinical Management of Spinal Deformities and Orthotic Bracing

Posted on Oct 27, 2025 in Biology

The human spine is a complex structure composed of 33 vertebrae arranged in cervical, thoracic, lumbar, sacral, and coccygeal regions. In the normal anatomical state, the spine demonstrates four physiological curves: cervical lordosis, thoracic kyphosis, lumbar lordosis, and sacral kyphosis. These curvatures maintain balance, absorb shock, and allow flexibility and mobility.

When these curves are exaggerated, diminished, or altered by abnormal lateral deviations or rotational deformities, spinal deformities develop. Such deformities can impair posture, cause pain, reduce lung capacity, compress neural elements, and significantly affect quality of life. The study and management of spinal deformities are therefore essential in orthopedics, physical medicine, and rehabilitation.

This document provides a detailed discussion of the different types of spinal deformities, including scoliosis, kyphosis, lordosis, flat back syndrome, spondylolisthesis, gibbus deformity, torticollis, and kyphoscoliosis. Each deformity is analyzed with respect to definition, etiology, pathophysiology, clinical features, diagnosis, and management approaches.

1. Scoliosis: Three-Dimensional Spinal Deformity

Definition

Scoliosis is a three-dimensional deformity of the spine characterized by lateral curvature in the coronal plane, associated with vertebral rotation and often an element of sagittal imbalance.

Types of Scoliosis

1. Idiopathic scoliosis: Most common (approximately 80% of cases), subdivided into infantile, juvenile, and adolescent scoliosis.
2. Congenital scoliosis: Caused by vertebral malformations such as hemivertebra or block vertebra during embryonic development.
3. Neuromuscular scoliosis: Secondary to muscle imbalance or paralysis, e.g., in cerebral palsy, muscular dystrophy, or poliomyelitis.
4. Degenerative scoliosis: Occurs in adults due to asymmetric degeneration of discs and facet joints.
5. Functional scoliosis: Due to compensatory mechanisms, such as leg length discrepancy or pelvic tilt.

Causes and Risk Factors

• Genetic predisposition (family history).
• Rapid growth spurts in adolescence.
• Neuromuscular disorders.
• Congenital anomalies.

Clinical Features

• Unequal shoulder or hip height.
• Rib hump visible on forward bending (Adam’s test).
• Asymmetrical waistline.
• Pain (especially in adult scoliosis).
• In severe cases: cardiopulmonary restriction due to thoracic deformity.

Diagnosis

• Physical exam: Inspection, Adam’s forward bend test.
• Radiology: X-ray (standing AP and lateral views, Cobb angle measurement). MRI/CT in congenital or neurological cases.

Complications

• Cosmetic deformity.
• Reduced lung function in severe curves (>80°).
• Back pain and degenerative changes.

Management

• Mild (<20° Cobb angle): Observation and physiotherapy.
• Moderate (20°–40° Cobb angle): Orthotic management (Boston brace, Milwaukee brace, Charleston brace).
• Severe (>40°–50° Cobb angle): Surgical correction via spinal fusion with rods and screws.
• Rehabilitation: Core strengthening, breathing exercises, postural correction, psychosocial support.

2. Kyphosis: Abnormal Posterior Convexity

Definition

Kyphosis is an abnormal increase in the posterior convexity of the thoracic spine, resulting in a hunchback posture.

Types of Kyphosis

1. Postural kyphosis: Due to poor posture, common in adolescents, correctable voluntarily.
2. Scheuermann’s kyphosis: Structural deformity in adolescents, with wedge-shaped vertebrae.
3. Congenital kyphosis: Caused by vertebral anomalies present at birth.
4. Pathological kyphosis: Secondary to infections (e.g., tuberculosis, syphilis), trauma, tumors, or metabolic bone diseases.
5. Osteoporotic kyphosis: Due to multiple compression fractures in elderly patients.

Causes

• Poor posture habits.
• Vertebral anomalies.
• Osteoporosis with vertebral collapse.
• Tuberculosis of the spine (Pott’s disease).

Clinical Features

• Rounded upper back (hump).
• Forward stooping.
• Back pain (may be absent in postural cases).
• Neurological symptoms if spinal cord compression occurs (especially in congenital or TB cases).

Diagnosis

• Clinical: Inspection of spinal profile.
• Imaging: X-ray (Cobb angle >50° indicates pathological kyphosis). MRI/CT to assess spinal cord compression.

Complications

• Respiratory restriction in severe cases.
• Cosmetic concerns.
• Neurological deficits in advanced stages.

Management

• Postural kyphosis: Corrective exercises, posture training.
• Scheuermann’s disease: Bracing (Milwaukee, TLSO), physiotherapy, extension exercises.
• Severe (>70°) or neurological cases: Spinal fusion or osteotomy.
• Tuberculosis kyphosis: Anti-tubercular therapy, bracing, surgical decompression if cord compression.

3. Lordosis: Excessive Anterior Concavity

Definition

Lordosis is an excessive anterior concavity of the lumbar or cervical spine, producing a swayback posture.

Types of Lordosis

1. Postural lordosis: Due to obesity, pregnancy, or weak abdominal muscles.
2. Congenital lordosis: Rare, due to structural malformations.
3. Secondary lordosis: Compensation for hip joint deformities or spondylolisthesis.

Causes

• Obesity (protruding abdomen).
• Pregnancy.
• Hip contractures or deformities.
• Neuromuscular weakness.
• Spinal instability.

Clinical Features

• Protruding abdomen.
• Prominent buttocks.
• Back pain and fatigue.
• Altered gait in severe cases.

Diagnosis

• Clinical: Observation of posture, pelvic tilt measurement.
• X-ray: Shows increased lumbar or cervical angle.

Complications

• Back pain and muscle fatigue.
• Increased risk of disc degeneration.

Management

Conservative Treatment

• Weight loss, posture correction.
• Physiotherapy (abdominal strengthening, hip flexor stretching).
• Orthotic: Lumbar corsets for support.

Surgical Treatment

Rare, reserved for structural congenital lordosis.

4. Flat Back Syndrome: Loss of Lumbar Lordosis

Definition

Flat back syndrome is characterized by a loss of lumbar lordosis, resulting in difficulty maintaining an upright posture.

Causes

• Post-surgical (after spinal fusion or Harrington rod placement).
• Degenerative disc disease.
• Ankylosing spondylitis.

Clinical Features

• Stooped posture.
• Difficulty standing erect.
• Low back pain and fatigue.

Diagnosis

• Clinical inspection.
• X-ray showing absent or reduced lumbar curve.

Management

• Physiotherapy: Core strengthening, posture training.
• Orthotic support in early stages.
• Surgery: Spinal osteotomy or revision surgery in severe cases.

5. Spondylolisthesis: Vertebral Slippage

Definition

Spondylolisthesis is the forward slipping of one vertebra over the vertebra below, usually in the lumbar spine.

Types of Spondylolisthesis

1. Congenital (dysplastic): Vertebral malformations.
2. Isthmic: Defect in the pars interarticularis (stress fracture).
3. Degenerative: Due to arthritis and disc degeneration in adults.
4. Traumatic: Secondary to fractures.

Clinical Features

• Low back pain.
• Step deformity on palpation.
• Hamstring tightness.
• Neurological symptoms (sciatica) if nerves are compressed.

Diagnosis

• X-ray (lateral view shows slip).
• MRI/CT for neural involvement.
• Grading: Meyerding classification (I–IV based on percentage slip).

Management

• Mild (Grade I): Physiotherapy, activity modification, lumbosacral corset.
• Moderate/Severe (Grade II–IV): Surgical fusion, decompression if neurological involvement.

6. Gibbus Deformity: Sharp Angular Kyphosis

Definition

Gibbus deformity is a sharp angular kyphosis caused by the collapse of one or more vertebrae.

Causes

• Spinal tuberculosis (Pott’s disease).
• Osteoporosis.
• Congenital anomalies.
• Trauma.

Clinical Features

• Sharp, angular hump (usually thoracic region).
• Pain, stiffness.
• Neurological deficits in severe cases.

Diagnosis

• X-ray: Angular kyphosis.
• MRI: Spinal cord compression assessment.

Management

• Anti-tubercular therapy (if TB is the cause).
• Orthotic: TLSO or custom brace.
• Surgery: Decompression and fusion in neurological cases.

7. Torticollis (Wry Neck)

Definition

Torticollis is a deformity of the cervical spine and neck muscles, leading to head tilt and restricted neck movement.

Types of Torticollis

• Congenital: Sternocleidomastoid muscle fibrosis or contracture.
• Acquired: Trauma, infection, tumors, poor posture.

Clinical Features

• Head tilt toward the affected side.
• Chin rotated to the opposite side.
• Facial asymmetry in long-standing cases.

Diagnosis

• Clinical examination.
• Imaging (X-ray, USG, MRI if needed).

Management

• Stretching exercises.
• Physiotherapy (heat, massage).
• Orthotic: Cervical collar or head halter traction.
• Surgical release of the Sternocleidomastoid (SCM) muscle in severe congenital cases.

8. Kyphoscoliosis: Combined Deformity

Definition

Kyphoscoliosis is a combination of kyphosis and scoliosis, producing a three-dimensional deformity with both lateral and posterior deviation.

Causes

• Congenital anomalies.
• Neuromuscular disorders.
• Spinal infections (e.g., TB).
• Degenerative changes.

Clinical Features

• Rib hump combined with a rounded back.
• Severe deformity leading to respiratory compromise.
• Neurological involvement in advanced cases.

Diagnosis

• Clinical observation.
• X-ray (AP and lateral views).
• Pulmonary function tests (to assess lung restriction).

Management

• Orthotic: Modified TLSO or Milwaukee brace.
• Physiotherapy: Breathing exercises, mobility training.
• Surgical: Spinal fusion and correction in severe or progressive deformities.

Orthotic Management of Spinal Deformities

Boston Brace Fabrication Process (TLSO)

Introduction

The Boston Brace is a type of thoraco-lumbo-sacral orthosis (TLSO) developed in the early 1970s at the Boston Children’s Hospital. It is widely used for the conservative management of idiopathic scoliosis, particularly in adolescents. The brace is based on the principle of three-point pressure correction, with pads placed on the convex side of spinal curves and relief areas opposite them to encourage realignment.

Unlike older braces such as the Milwaukee brace, the Boston Brace is low-profile, lightweight, and worn under clothing, significantly improving patient compliance. Its fabrication requires both biomechanical knowledge and technical skill to ensure the orthosis corrects spinal curvature while maintaining patient comfort.

This section describes the fabrication process of the Boston Brace in detail, including the stages of assessment, model preparation, material processing, assembly, and fitting.

1. Patient Assessment and Preparation

The first step is a comprehensive evaluation of the patient:

Medical and Radiological Examination

• The orthotist reviews the patient’s medical history and recent spinal X-rays (antero-posterior and lateral views).
• Cobb angle measurement is crucial to determine the severity and flexibility of the curve.
• Curve type (thoracic, lumbar, double major, or thoracolumbar) influences pad placement.

Physical Assessment

• The patient’s body shape, posture, and growth potential are noted.
• Clinical signs such as shoulder asymmetry, rib hump, and waistline deviation are documented.

Measurements

• Chest, waist, and hip circumferences.
• Vertical distances between anatomical landmarks (axilla, iliac crest, greater trochanter).
• These measurements guide brace sizing and trimline design.

Casting or Digital Scanning

• Traditionally, a plaster wrap cast is made around the torso while the patient lies supine with corrective pressure applied.
• Modern clinics often use CAD-CAM 3D scanning, which captures the torso digitally and allows software-based modifications.

2. Positive Model Preparation

Once the patient’s shape is captured, a positive model is created:

• Plaster Cast Method: The negative plaster mold is filled with liquid plaster of Paris. After hardening, the mold is broken away, leaving a positive replica of the patient’s torso.
• CAD-CAM Method: The digital scan is modified virtually to apply corrections (e.g., increasing pressure zones, adjusting spinal alignment). A CNC milling machine then carves the modified model from polyurethane foam.

This model serves as the base over which the brace will be molded.

3. Model Modification

The positive model is strategically altered to introduce corrective principles:

• Pressure Areas: Build-ups are added at convex regions of the curve to push the spine toward the midline.
• Relief Areas: Hollow spaces are carved opposite the convexity to allow the spine to shift.
• Balance Adjustments: The sagittal contour (lordosis and kyphosis) is preserved to maintain natural posture.
• Growth Considerations: Extra space is left for anticipated growth in adolescent patients.

This careful modification transforms the neutral torso model into one that actively corrects scoliosis.

4. Thermoplastic Sheet Preparation

The Boston Brace is fabricated using low-density polyethylene (LDPE), which is durable, lightweight, and moldable when heated.

• A sheet of LDPE, usually 3–5 mm thick, is cut to size.
• The sheet is heated in an oven until soft and pliable.
• While hot, it is draped over the modified positive model.
• A vacuum-forming machine applies uniform suction, pulling the sheet tightly over the contours.

The plastic is allowed to cool until rigid, capturing the shape of the modified model.

5. Trimming and Rough Cutting

Once the plastic shell is removed from the model, trimming is performed:

• Anterior Trimlines: Below the sternum but above the pubis to allow sitting comfort.
• Posterior Trimlines: Extending from the inferior angle of the scapula down to the sacrum.
• Lateral Trimlines: Just beneath the axilla to avoid arm restriction.

Rough edges are cut away, and excess plastic is removed for improved fit and comfort.

6. Addition of Pads and Liners

The Boston Brace works by combining pressure pads with relief areas:

• Pressure Pads: Made of firm polyethylene foam, they are positioned at the convexity of spinal curves. The pads apply localized corrective forces to push the spine toward alignment.
• Relief Zones: Corresponding concave areas are left unpadded to encourage movement into the corrected position.
• Liner: A soft ethylene-vinyl acetate (EVA) foam liner is added to the inner surface for cushioning, skin protection, and comfort.

7. Closure and Strapping System

To secure the brace:

• Velcro Straps are attached posteriorly or laterally.
• Multiple straps allow adjustable tightening, which is crucial as patients grow or as curve correction progresses.

The closure is designed for ease of donning and doffing, especially since adolescents must wear the brace for 18–23 hours daily.

8. Finishing and Edge Smoothing

All edges of the plastic shell are:

• Rounded and flared outward to prevent skin irritation.
• Polished smooth to eliminate sharp corners.
• Modified cosmetically if desired, since aesthetics influence compliance in adolescents.

9. Fitting and Alignment Check

Once the brace is fabricated, it undergoes a fitting session:

• The patient wears the brace while standing and sitting.
• Pressure distribution and comfort are checked.
• Adjustments are made by repositioning pads or trimming plastic.
• In-brace X-rays are taken to verify correction. A successful brace should reduce the Cobb angle by at least 50%.

10. Patient Training and Follow-Up

Training

• The orthotist teaches the patient and caregivers how to wear, remove, and maintain the brace.
• Instructions on skin care, posture, and clothing adjustments are given.

Wearing Schedule

• Patients are typically instructed to wear the brace 18–23 hours per day.
• Time out of the brace is usually allowed only for sports or bathing.

Follow-Up

• Regular reviews every 3–6 months.
• Adjustments made for growth or curve progression.
• Repeat X-rays to assess effectiveness.

Key Principles Behind Fabrication

1. Three-Point Pressure System: Corrective pads press on the convex side, counterbalanced by relief zones.
2. Low Profile: Unlike older braces, the Boston Brace is designed to be discreet under clothing.
3. Custom Fit: Every brace is fabricated to match individual patient anatomy and curve type.
4. Growth Accommodation: Frequent modifications are made for adolescent patients.

Conclusion on Boston Brace

The fabrication of the Boston Brace is a multi-step process that combines medical evaluation, biomechanical principles, and precise technical craftsmanship. When fabricated and fitted correctly, the Boston Brace can halt or slow scoliosis progression, reduce curve severity, and delay or eliminate the need for surgery. However, its success depends heavily on accurate fabrication, patient compliance, and regular follow-up.

Thus, the Boston Brace remains a cornerstone in the non-surgical management of scoliosis, demonstrating the vital role of orthotic science in spinal deformity correction.

Taylor vs. Knight-Taylor Brace: Design and Biomechanics

Introduction

Both the Taylor brace and the Knight-Taylor brace are spinal orthoses designed to provide support, restrict motion, and relieve pain in patients with thoracic and lumbar spine disorders. They belong to the thoraco-lumbo-sacral orthosis (TLSO) category.

• Taylor Brace: Developed by Dr. Charles Fayette Taylor in the 19th century, primarily for controlling spinal movements and supporting weak spinal muscles.
• Knight-Taylor Brace: A modified version of the Taylor brace, incorporating features of the Knight spinal brace, providing greater restriction of lateral bending and rotation.

Taylor Brace Design and Function

Design

• Two paraspinal uprights extending from the pelvic band (sacrum/iliac crest region) up to the infrascapular level.
• Connected by a thoracic band posteriorly.
• Anteriorly, connected via axillary straps across the shoulders and chest.
• Posterior-only rigid design (no rigid anterior bars).

Functions

• Limits flexion and extension of the thoraco-lumbar spine.
• Provides postural support by encouraging an upright position.
• Allows moderate lateral bending and rotation (not fully restricted).

Knight-Taylor Brace Design and Function

Design

Combines the Taylor brace with features of the Knight brace. Includes:

• Pelvic band
• Two paraspinal uprights
• Thoracic band posteriorly
• Lateral uprights on each side (added compared to Taylor brace)
• Axillary straps anteriorly

Functions

• Restricts flexion, extension, and lateral bending (more control than Taylor).
• Provides partial control of rotation.
• Gives a more rigid three-dimensional stabilization.

Key Differences Between Braces

Biomechanical Principles

Taylor Brace Biomechanics

Works mainly on the three-point pressure system in the sagittal plane:

• Posterior paraspinal uprights push against the spine to prevent flexion.
• Counterforce applied anteriorly via axillary straps across the shoulders.

Limits forward bending (flexion) and supports extension. Does not effectively resist rotation or lateral bending because no lateral uprights are present.

Knight-Taylor Brace Biomechanics

Works on an enhanced three-point pressure system in both sagittal and coronal planes:

• Paraspinal uprights and thoracic band prevent flexion.
• Lateral uprights restrict side bending by applying forces on the rib cage and pelvis.
• Partial rotational control due to the combination of posterior and lateral uprights.

Provides more rigid immobilization of the thoraco-lumbar spine.

Clinical Indications

Taylor Brace Indications

• Postural kyphosis
• Spinal muscle weakness
• Mild thoraco-lumbar injuries
• Non-rigid deformities

Knight-Taylor Brace Indications

• Thoraco-lumbar fractures (stable)
• Post-operative immobilization
• Spinal tuberculosis (Pott’s disease)
• More severe instabilities than those managed by Taylor brace alone

Conclusion

The Taylor brace is a simpler orthosis that mainly controls flexion and extension of the spine, offering postural support. The Knight-Taylor brace is a reinforced version with added lateral uprights, giving it greater ability to restrict lateral bending and rotation, making it more suitable for fractures, post-surgical cases, and rigid stabilization.

Both braces operate on biomechanical principles of three-point pressure, but the Knight-Taylor provides multi-planar control compared to the mostly sagittal-plane control of the Taylor brace.

CTLSO: Fabrication and Indications (Milwaukee Brace)

Introduction

A CTLSO (Cervico-Thoraco-Lumbo-Sacral Orthosis) is a spinal orthosis that provides external support and immobilization to the cervical, thoracic, lumbar, and sacral regions of the spine.

It is commonly prescribed in cases where rigid multi-level spinal control is needed, such as scoliosis management, post-operative stabilization, fractures, and deformity correction. The most common form of CTLSO is the Milwaukee Brace, though modern variations include CAD/CAM-designed custom braces with modular cervical attachments.

Indications of CTLSO

1. Scoliosis Management

   • Idiopathic scoliosis (especially double curves or high thoracic curves).
   • Neuromuscular scoliosis requiring long spinal stabilization.

2. Post-Surgical Support

   • After spinal fusion or laminectomy.
   • To protect surgical corrections (e.g., scoliosis correction, tumor excision).

3. Spinal Trauma

   • Stable fractures of cervical and thoraco-lumbar junction.
   • Multiple-level vertebral fractures where TLSO alone is insufficient.

4. Spinal Deformities

   • High thoracic kyphosis or kyphoscoliosis.
   • Scheuermann’s disease with severe deformity.

5. Other Indications

   • Spinal tuberculosis (Pott’s spine) requiring long immobilization.
   • Congenital spinal deformities (high thoracic).

Fabrication Process of CTLSO

The fabrication process is complex and highly individualized since it must cover the entire trunk plus the cervical region.

Step 1: Patient Evaluation

• Medical Examination: X-rays (AP and lateral), MRI/CT if required.
• Curve Analysis: Cobb angle, apex of curve, curve type.
• Physical Exam: Posture, rib hump, asymmetry, growth potential.
• Measurements: Chest, waist, hip circumference; vertical distances (symphysis pubis to sternal notch, axilla to iliac crest); neck circumference for cervical extension.

Step 2: Casting / Digital Scanning

• Plaster casting: Patient positioned (standing or supine) with corrective forces applied during casting.
• Digital 3D scanning (CAD-CAM method): Increasingly preferred for accuracy and patient comfort.

Step 3: Positive Model Preparation

• Traditional Method: Fill negative plaster cast with plaster of Paris to create a positive torso mold.
• CAD-CAM Method: 3D modifications made virtually and foam model carved with CNC milling.

Step 4: Model Modification

• Build-ups at pressure areas (convex side of spinal curve).
• Reliefs at concave side or bony prominences (sternum, iliac crest, spinous processes).
• Sagittal contour correction maintained (lordosis/kyphosis).
• Cervical extension portion adjusted for alignment.

Step 5: Thermoplastic Molding

• A sheet of low-density polyethylene (LDPE) or polypropylene is heated until pliable.
• Drape-molded or vacuum-formed over the positive model.
• After cooling, the rigid shell is removed.

Step 6: Assembly of Components

• Pelvic Section: Provides base support, encircles pelvis.
• Thoraco-lumbar Shell: Covers trunk, shaped for pressure/relief zones.
• Anterior & Posterior Uprights: Metallic or thermoplastic, attached to pelvic section.
• Thoracic Pads: Provide corrective forces on convex side of curve.
• Cervical Component: Includes neck ring (occipital pad + mandibular pad), connected via anterior and posterior uprights from the thoracic section. Chin and Occiput Support pads are adjusted for comfort and correction.

Step 7: Trimming and Finishing

• Trimlines adjusted (Anterior: Below sternal notch, above pubis; Posterior: Up to scapular spine).
• Edges smoothed and flared outward to prevent skin irritation.
• Straps (Velcro) fixed for donning/doffing.

Step 8: Fitting and Adjustment

• Brace fitted on patient in standing and sitting positions.
• In-brace X-rays taken to check correction (goal: ≥50% Cobb angle reduction).
• Modifications made (pad adjustment, strap tightening).

Step 9: Patient Training & Follow-up

• Patient and caregiver instructed on wearing schedule (18–23 hrs/day for scoliosis), skin care, cleaning, and maintenance.
• Follow-up every 3–6 months for growth adjustments and curve monitoring.

Biomechanical Principles of CTLSO

• Three-Point Pressure System: Corrective pads push at curve apex with counterforces above and below.
• Elongation Principle: Neck ring provides vertical traction via occipital and mandibular pads.
• Derotation Forces: Pads and reliefs help reduce vertebral rotation.
• Sagittal Alignment Support: Maintains physiological lordosis and kyphosis.

Advantages and Limitations of CTLSO

Advantages

• Controls motion in cervical, thoracic, and lumbar spine.
• Effective in high thoracic scoliosis where TLSO is insufficient.
• Provides strong immobilization after surgery or trauma.

Limitations

• Bulky and less cosmetic (harder for adolescents to accept).
• Skin problems if poorly fitted.
• Psychological & compliance issues (especially in teenagers).
• Restricts normal activities (sports, bending).

Conclusion on CTLSO

The CTLSO (e.g., Milwaukee brace) is a powerful orthosis providing multi-level spinal immobilization and deformity correction. Biomechanically, it relies on three-point pressure, traction, and derotation forces. While less cosmetically appealing compared to TLSOs like the Boston brace, CTLSO remains the gold standard for high thoracic and cervico-thoracic scoliosis management.

SOMI: Sterno-Occipital-Mandibular Immobilizer

Introduction

The Sterno-Occipital-Mandibular Immobilizer (SOMI) is a type of cervical orthosis that provides immobilization of the cervical spine in cases of trauma, instability, or post-operative management. It is classified as a three-poster cervical orthosis (anterior-based).

SOMI provides moderate to strong restriction of cervical spine movement, especially flexion. It is generally more comfortable and less bulky compared to a halo vest, but offers less rigidity.

Design of SOMI

The brace is composed of:

• Sternal plate (anterior chest support): A broad padded plate that rests on the upper sternum and chest, providing the anterior anchor point.
• Occipital support: A posterior pad that cradles the occiput (back of the head), attached to uprights extending from the chest plate.
• Mandibular support (chin support): An anterior pad under the mandible, connected to the sternal plate via uprights.
• Straps and uprights: Adjustable Velcro straps allow tightening and stability.

Biomechanics of SOMI

SOMI works mainly by the three-point pressure system:

1. Mandibular support prevents forward flexion.
2. Sternal plate acts as a counterforce anteriorly.
3. Occipital support prevents excessive extension.

It restricts flexion most effectively, while also limiting some extension and lateral bending, but provides minimal control of rotation. Thus, it is best suited for flexion control of the cervical spine.

Uses and Indications of SOMI

SOMI is used in conditions requiring immobilization and stabilization of the cervical spine, including:

• Trauma & Fractures

  • Stable cervical spine fractures (C1–C5 region).
  • Odontoid fractures (type I & III; type II if stable).
  • Cervical sprains and soft tissue injuries.

• Post-Surgical Support

  • After cervical laminectomy, fusion, or discectomy.
  • To protect surgical corrections and allow healing.

• Pathological Conditions

  • Cervical spondylosis with instability.
  • Metastatic disease involving cervical vertebrae.
  • Infections like tuberculosis of the cervical spine.

• General Stabilization

  • For patients needing cervical support during rehabilitation.
  • As an alternative to the Halo vest when less rigid immobilization is sufficient.

Advantages and Limitations of SOMI

Advantages

• Provides excellent flexion control (better than many other cervical collars).
• Lightweight and relatively comfortable compared to the halo vest.
• Easy to apply and remove — useful for bedridden patients.
• Non-invasive (unlike halo orthosis).

Limitations

• Less effective in controlling rotation and lateral bending.
• Provides weaker extension control compared to flexion control.
• Not suitable for unstable or high cervical spine fractures (C1-C2, especially unstable Type II odontoid fracture).
• Long-term use may cause skin irritation at chin and chest pads.

Conclusion on SOMI

The Sterno-Occipital-Mandibular Immobilizer (SOMI) is a semi-rigid cervical orthosis designed to immobilize the cervical spine, particularly in the flexion-extension plane. It is best used for stable fractures, post-operative cases, and conditions requiring moderate immobilization. While not as rigid as a halo vest, SOMI is widely used because of its comfort, ease of application, and effectiveness in flexion control.