Injury to the inferior longitudinal muscle of the tongue can significantly impair speech, swallowing, and overall tongue mobility. The inferior longitudinal muscle lies entirely within the tongue, running from its root to its apex, and plays a crucial role in shaping and positioning the tongue. When this muscle is damaged—whether by trauma, overuse, or surgical injury—patients may experience pain, altered tongue contour, and functional deficits. This evidence-based guide provides detailed, SEO-optimized information on the anatomy, types of injury, causes, symptoms, diagnostic tests, treatments, medications, surgical interventions, prevention strategies, and frequently asked questions related to inferior longitudinal muscle injuries.
Anatomy of the Inferior Longitudinal Muscle
Structure and Location
The inferior longitudinal muscle is one of the four intrinsic muscles of the tongue. Its fibers lie deep to the mucosa on the ventral (underside) surface of the tongue, just beneath the vertical and transverse intrinsic muscles. These fibers run longitudinally from the root toward the tip of the tongue, confined entirely within the tongue substance Radiopaedia.
Origin
The muscle originates from the root of the tongue, near the lingual septum, where muscle fibers converge at the posterior aspect of the tongue base Kenhub.
Insertion
Distally, its fibers insert into the apex of the tongue, blending with the connective tissue at the tip and lateral margins, allowing it to influence the tongue’s shape Kenhub.
Blood Supply
Arterial supply is primarily via the deep lingual artery, the terminal branch of the lingual artery, which courses between the genioglossus and the inferior longitudinal muscle to supply the ventral tongue surface NCBI.
Nerve Supply
Motor innervation is provided by the hypoglossal nerve (cranial nerve XII), which supplies all intrinsic tongue muscles except the palatoglossus Radiopaedia.
Functions
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Retracts the tongue toward the pharynx.
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Shortens the tongue, facilitating speech and swallowing.
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Depresses the tongue apex, aiding in palate contact.
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Curls the lateral borders downward, shaping the tongue surface.
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Broadens the tongue when acting with other intrinsic muscles.
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Assists in precise articulation by modifying tongue tip position KenhubRadiopaedia.
Types of Injuries
Injuries to the inferior longitudinal muscle can be classified similarly to other skeletal muscle injuries based on mechanism and severity:
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Indirect Functional Injuries (no visible tear on imaging):
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Type 1a: Fatigue-induced overuse
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Type 1b: Delayed-onset muscle soreness
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Indirect Structural Injuries (positive imaging findings):
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Type 3: Partial muscle fiber tear
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Type 4: (Sub)total muscle tear
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Direct Muscle Injuries:
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Contusion from blunt trauma
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Laceration or cut from sharp objects Wikipedia.
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Causes
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Blunt Trauma
A forceful impact to the tongue—such as accidental biting or direct blow—can contuse and damage muscle fibers Wikipedia. -
Sharp Laceration
Injury by dental instruments, broken teeth, or other sharp objects can cause partial or complete fiber laceration Wikipedia. -
Accidental Biting
Unintentional biting during seizures, falls, or while eating can tear muscle fibers Wikipedia. -
Iatrogenic Surgical Injury
Oral or oropharyngeal surgeries (e.g., glossectomy, tumor resection) may inadvertently damage the muscle PMC. -
Radiation Fibrosis
Post-radiation changes in head and neck cancer therapy can induce fibrotic muscle injury over time. -
Repetitive Overuse
Excessive protrusion during speech therapy or singing lessons can strain and fatigue muscle fibers Wikipedia. -
Tongue Stretching Exercises
Aggressive stretching without proper rest can overload intrinsic muscle fibers Wikipedia. -
Denervation Injury
Damage to the hypoglossal nerve causes secondary muscle atrophy and weakness PMC. -
Infection and Abscess
Deep tongue infections can damage muscle by inflammatory erosion. -
Tumor Infiltration
Malignant infiltration can disrupt muscle architecture. -
Chemical Burns
Exposure to caustic substances can chemically injure muscle fibers. -
Thermal Burns
Hot liquids or surgical cautery can cause thermal damage. -
Cryogenic Injury
Accidental freezing from medical cryotherapy can injure muscle tissue. -
Neuromuscular Disorders
Conditions like dystonia lead to chronic hypertensive spasm and microtrauma. -
Muscular Dystrophy
Genetic degeneration causes progressive weakening of intrinsic tongue muscles. -
Metabolic Myopathies
Disorders such as Pompe disease impair muscle energy metabolism, leading to injury. -
Nutritional Deficiencies
Severe deficiencies (e.g., vitamin D, protein) may predispose to muscle damage. -
Excessive Alcohol Use
Alcoholic myopathy can weaken and injure tongue muscles. -
Connective Tissue Diseases
Conditions like scleroderma can involve fibrosis of tongue musculature. -
Systemic Inflammatory Myopathies
Polymyositis and dermatomyositis can inflame and injure the muscle.
Symptoms
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Tongue Pain
Localized aching at the undersurface of the tongue. -
Swelling
Visible or palpable enlargement of the ventral tongue. -
Bruising (Ecchymosis)
Bluish discoloration due to submucosal bleeding. -
Hematoma Formation
Firm, tender swelling from pooled blood. -
Reduced Tongue Mobility
Difficulty retracting or curling the tongue tip. -
Difficulty Speaking
Slurred or unclear articulation of sounds needing tongue tip. -
Dysphagia
Trouble swallowing liquids or solids. -
Altered Taste
Disrupted taste sensation from local inflammation. -
Numbness or Paresthesia
Tingling or loss of sensation if nerve fibers are involved. -
Muscle Weakness
Inability to oppose resistance at tongue tip. -
Tongue Deviation
Tip deviates toward injured side on protrusion. -
Spasm or Cramping
Involuntary contractions causing pain. -
Stiffness
Reduced flexibility when moving the tongue tip. -
Fatigue with Use
Early tiredness during prolonged speech or swallowing. -
Palpable Gap
A defect in muscle continuity in complete tears. -
Crepitus
Grating sensation if muscle fibers rub. -
Infection Signs
Redness, warmth, fever if secondary infection occurs. -
Drooling
Uncontrolled saliva due to poor tongue seal. -
Speech Articulation Errors
Substitution or omission of sounds like /t/, /d/, /l/. -
Chronic Pain
Persistent discomfort after acute injury has healed Wikipedia.
Diagnostic Tests
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Physical Examination
Inspection and palpation of the tongue under direct vision. -
Range of Motion Assessment
Measuring tongue protrusion and lateral movements. -
Manual Muscle Testing
Grading tongue-tip strength against resistance. -
High-Resolution Ultrasound
Identifies fiber disruption and hematoma in intrinsic muscles Radiopaedia. -
Ultrasound Elastography
Assesses tissue stiffness post-injury. -
Magnetic Resonance Imaging (MRI)
Detailed soft-tissue contrast to visualize partial or complete tears PMC. -
Computed Tomography (CT)
Evaluates associated fractures or foreign bodies. -
Electromyography (EMG)
Assesses electrical activity in denervated or injured fibers. -
Nerve Conduction Studies
Evaluate hypoglossal nerve function if denervation is suspected. -
Fiber-optic Endoscopic Evaluation of Swallowing (FEES)
Visualizes swallowing mechanics. -
Videofluoroscopic Swallow Study
Assesses function during dynamic swallowing. -
Tongue Manometry
Measures intraluminal pressure generated by tongue movements. -
Biopsy
Rarely used to rule out myositis or tumor infiltration. -
Blood Tests (CK Levels)
Elevated creatine kinase suggests muscle injury. -
Inflammatory Markers (ESR, CRP)
Elevated in systemic myopathies. -
Ultrasound-guided Aspiration
Drains hematoma or abscess. -
Sialometry
Evaluates salivary function when drooling is present. -
Taste Testing
Quantifies altered taste sensation. -
3D Motor Unit Number Estimation
Research tool for motor unit integrity. -
MRI Neurography
Specialized for nerve-root level denervation.
Non-Pharmacological Treatments
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Rest
Avoid activities that strain the tongue. -
Ice Application
Cold compresses reduce swelling and pain Wikipedia. -
Heat Therapy
Promotes blood flow during subacute phase. -
Compression
Gentle wrap of tongue against palate to limit swelling Wikipedia. -
Elevation
Head-of-bed elevation to reduce edema. -
R.I.C.E. Protocol
Rest, Ice, Compression, Elevation in acute phase Wikipedia. -
Ultrasound Therapy
Therapeutic ultrasound to promote healing. -
Transcutaneous Electrical Nerve Stimulation (TENS)
Reduces pain via gate-control theory. -
Low-Level Laser Therapy
Photobiomodulation for tissue repair. -
Myofascial Release
Manual release of tension in tongue fascia. -
Massage
Gentle intraoral massage to mobilize tissue. -
Stretching Exercises
Gentle elongation of tongue tip and lateral borders. -
Strengthening Exercises
Pushing tongue against palate with graded resistance. -
Proprioceptive Training
Mirror-guided tongue positioning tasks. -
Speech Therapy
Corrective exercises for articulation deficits. -
Orofacial Myofunctional Therapy
Exercises to normalize tongue posture and function. -
Biofeedback
EMG-based feedback to optimize muscle activation. -
Hydrotherapy
Warm-water oral rinses to relieve soreness. -
Acupuncture
Traditional needle therapy for pain modulation. -
Dry Needling
Trigger-point release within muscle fibers. -
Magnet Therapy
Experimental for enhancing local circulation. -
Shockwave Therapy
High-energy waves to stimulate healing. -
Kinesio Taping
External taping for proprioceptive support. -
Diet Modification
Soft, non-irritating foods to reduce strain. -
Oral Splints
Custom devices to limit tongue motion in severe cases. -
Protective Mouthguards
Prevent biting during sports or seizures. -
Therapeutic Ultrasound-guided Injections
Non-pharmacological approach to break adhesions. -
Yoga Breathing Exercises
Improve oro-pharyngeal coordination. -
Pilates-based Oral Exercises
Emphasize core and tongue stability. -
Progressive Loading Programs
Gradually increasing resistance to rebuild strength.
Drugs
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Acetaminophen
Analgesic for mild to moderate pain. -
Ibuprofen
NSAID reducing pain and inflammation. -
Naproxen
Longer-acting NSAID for sustained relief. -
Diclofenac
Topical or oral NSAID option. -
Ketorolac
Short-term, potent NSAID. -
Aspirin
Analgesic and anti-platelet. -
Celecoxib
Cox-2 selective NSAID with fewer GI side effects. -
Meloxicam
Once-daily NSAID for pain and inflammation. -
Indomethacin
Potent NSAID used in acute injury. -
Piroxicam
Long-acting NSAID for musculoskeletal pain. -
Prednisone
Oral corticosteroid for severe inflammation. -
Methylprednisolone
Tapered systemic steroid regimen. -
Triamcinolone
Intralesional steroid injection for focal fibrosis. -
Diazepam
Muscle relaxant to reduce spasm. -
Baclofen
Central muscle relaxant. -
Tizanidine
Alpha-2 agonist muscle relaxant. -
Cyclobenzaprine
Short-term relief of muscle spasm. -
Methocarbamol
Centrally acting muscle relaxant. -
Gabapentin
Adjunct for neuropathic pain. -
Lidocaine Gel
Topical anesthetic for localized pain relief Wikipedia.
Surgeries
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Primary Suture Repair
Direct repair of a muscle laceration under magnification. -
Muscle Flap Reconstruction
Local flap to restore tongue bulk. -
Free Flap Reconstruction
Radial forearm flap for large defects. -
Pedicled Flap Reconstruction
Pectoralis major or platysma flap transposition. -
Z-Plasty Release
Scar contracture correction to improve mobility. -
Partial Glossectomy
Resection of irreversibly damaged segment. -
Frenotomy/Frenectomy
Release of restrictive fibrotic bands. -
Scar Revision Surgery
Excision of scar and repositioning of muscle. -
Myomectomy
Removal of fibrotic or ossified tissue. -
Microsurgical Nerve Grafting
Hypoglossal nerve repair in denervation cases.
Prevention Strategies
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Use Mouthguards
Protect tongue during contact sports. -
Proper Dental Care
Repair sharp edges on teeth to prevent lacerations. -
Safe Surgical Technique
Gentle handling of tongue during oral procedures. -
Gradual Exercise Progression
Avoid sudden increases in tongue exercises. -
Adequate Warm-Up
Gentle range-of-motion movements before intense speech or singing. -
Maintain Hydration
Well-hydrated muscle fibers are more resilient. -
Balanced Nutrition
Sufficient protein and micronutrients support muscle health. -
Manage Inflammation
Early icing and NSAIDs for minor strains. -
Ergonomic Oral Posture
Avoid prolonged protrusion or unusual tongue positions. -
Regular Check-Ups
Routine dental and ENT evaluations can catch early issues.
When to See a Doctor
Consult a healthcare professional if you experience persistent tongue pain beyond 72 hours, significant swelling, bleeding, inability to move the tongue tip, signs of infection (fever, redness), or any difficulty breathing, swallowing, or speaking that does not improve with self-care measures Wikipedia.
Frequently Asked Questions
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What is an inferior longitudinal muscle injury?
It’s damage to the muscle fibers located on the underside of the tongue, affecting shape and movement. -
How common are these injuries?
They are relatively rare, often associated with trauma or oral surgery. -
Can the muscle heal on its own?
Mild strains (Grade I) often recover with rest and conservative care. -
What is the typical recovery time?
Recovery ranges from days (mild strain) to months (complete tears). -
Do I need imaging to diagnose it?
MRI or ultrasound is helpful for moderate to severe injuries. -
Are tongue exercises safe after injury?
Yes—when guided by a professional, gentle exercises aid healing. -
Is surgery always required?
No—only for complete tears, significant scarring, or persistent dysfunction. -
Can I speak normally after injury?
Most patients regain normal speech with therapy and time. -
Will there be long-term effects?
Untreated severe injuries may lead to chronic weakness or altered taste. -
How can I prevent re-injury?
Use protective mouthguards, avoid sudden tongue over-protrusion, and progress exercises gradually. -
Are there risks with NSAIDs?
Short-term use is safe, but prolonged use can cause gastrointestinal or renal issues. -
What alternative treatments exist?
Acupuncture, low-level laser, and myofascial release may help reduce pain. -
Can nerve injury mimic muscle injury?
Yes—hypoglossal nerve damage can cause similar weakness and atrophy. -
Is swallowing always affected?
Moderate to severe injuries can impair swallowing mechanics temporarily. -
When should I see a speech therapist?
If speech remains unclear after one week of conservative treatment.
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Last Updated: April 23, 2025.