L5–S1 Disc Prolapsed

A prolapsed (herniated) disc at the L5–S1 level occurs when the soft, gel-like center of the disc between the fifth lumbar vertebra (L5) and the first sacral vertebra (S1) pushes through a tear in its tougher outer ring. This condition—often called an L5–S1 disc herniation or lumbar herniated disc—can compress nearby nerves, leading to back pain, sciatica, and neurological symptoms in the legs. It most commonly affects adults aged 30–50 and is a leading cause of lower back disability worldwide. Early recognition and targeted diagnosis are crucial to prevent chronic pain and disability.

A prolapsed (herniated) disc at the L5–S1 level occurs when the inner gel-like core (nucleus pulposus) of the intervertebral disc between the fifth lumbar vertebra (L5) and the first sacral vertebra (S1) pushes out through a tear in the tougher outer ring (annulus fibrosus). This bulging material can press on nearby spinal nerves, causing pain, numbness, or weakness in the lower back, buttocks, legs, and feet Mayo Clinic.

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Anatomy of the L5–S1 Intervertebral Disc

Structure

The L5–S1 disc is composed of two main parts: the nucleus pulposus (a soft, gelatinous core rich in water and proteoglycans) and the annulus fibrosus (a multilamellar, fibrocartilaginous ring surrounding the nucleus). Under normal load, the annulus evenly distributes pressure across the nucleus, while the nucleus acts like a shock absorber. Over time or under excessive stress, microtears can develop in the annulus, allowing parts of the nucleus to bulge or herniate through these tears.

Location

Situated between the fifth lumbar vertebra (L5) and the first sacral vertebra (S1), this intervertebral disc bridges the spine’s mobile lumbar region and the relatively fixed sacrum. Its unique position bears considerable biomechanical stress during activities like lifting, bending, and twisting, making it particularly susceptible to degeneration and injury.

Origin and Insertion

Unlike muscles or tendons, the intervertebral disc does not “originate” from or “insert” into bones via distinct attachments. Instead, the annulus fibrosus anchors directly to the bony endplates of L5 and S1. These cartilaginous endplates secure the disc, allowing hydration of the nucleus while maintaining structural continuity with adjacent vertebrae.

Blood Supply

In adults, the inner two-thirds of the disc (nucleus and inner annulus) are avascular—relying on diffusion through the endplates for nutrients. The outer third of the annulus receives a delicate network of capillaries branching from nearby segmental arteries (primarily the lumbar arteries). This limited blood flow contributes to slow healing of annular tears.

Nerve Supply

Sensory nerve fibers (primarily sinuvertebral nerves) penetrate only the outer annulus fibrosus. These fibers transmit pain signals when the annulus is overstretched or torn. No nerves reach the nucleus, which explains why early, contained bulges may be asymptomatic until the outer annulus is breached.

Functions ( Key Roles)

1. Load Bearing: The disc transmits axial loads from the torso to the pelvis.

2. Shock Absorption: The hydrated nucleus pulposus cushions compressive forces during activities.

3. Spinal Flexibility: Together with facet joints, the disc allows flexion, extension, lateral bending, and rotation.

4. Intervertebral Space Maintenance: Adequate disc height ensures foraminal opening for nerve roots.

5. Force Distribution: The annulus distributes localized stresses evenly to prevent focal overload.

6. Nutrition and Waste Exchange: Via endplate diffusion, discs exchange metabolic substrates essential for cell viability.

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Types of L5–S1 Disc Prolapse

Intervertebral disc herniations at L5–S1 are classified by the morphology and extent of nucleus displacement:

1. Disc Protrusion: The nucleus pushes into the annulus, causing a broad-based bulge without outer annulus disruption.

2. Disc Extrusion: Nuclear material breaks through the annulus but remains connected to the parent disc.

3. Sequestered Disc (Free Fragment): A fragment of nucleus separates completely and may migrate within the spinal canal.

4. Contained Bulge: Uniform circumferential bulging of the annulus without focal herniation.

5. Migrated Herniation: Extruded material moves either upward (cranial migration) or downward (caudal migration) along the thecal sac.

Each type can exert varying degrees of nerve compression, influencing symptom severity and treatment choice.

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Causes of L5–S1 Disc Prolapse

1. Age-Related Degeneration: Natural loss of water content weakens the nucleus and annulus over decades.

2. Repetitive Heavy Lifting: Chronic mechanical overload causes microtears in the annulus.

3. Sudden Trauma: Falls or automobile collisions can acutely rupture annular fibers.

4. Prolonged Sitting: Sustained flexion increases disc pressure, especially in desk workers or drivers.

5. Smoking: Nicotine impairs disc nutrition and accelerates degeneration.

6. Obesity: Excess body weight amplifies axial loading on lumbar discs.

7. Genetic Predisposition: Variants in genes regulating collagen and proteoglycan synthesis affect disc resilience.

8. Poor Posture: Chronic slouching concentrates stress on anterior annulus fibers.

9. Occupational Vibration: Machinery or vehicle vibrations fatigue disc tissue over time.

10. Prior Spinal Surgery: Altered biomechanics adjacent to a fused segment increase load on L5–S1.

11. High-Impact Sports: Activities like gymnastics or weightlifting can lead to acute herniations.

12. Connective Tissue Disorders: Conditions like Marfan or Ehlers–Danlos syndromes weaken annular integrity.

13. Lumbar Instability: Spondylolisthesis or facet joint degeneration places uneven loads on the disc.

14. Nutritional Deficiencies: Lack of vitamin D or C impairs collagen cross-linking in the annulus.

15. Inflammatory Arthritis: Autoimmune processes (e.g., ankylosing spondylitis) alter disc metabolism.

16. Dehydration: Reduced systemic hydration lowers disc turgor and resilience.

17. Repetitive Twisting: Frequent spinal rotation stresses annular fibers.

18. Sedentary Lifestyle: Weak paraspinal muscles fail to off-load disc stress.

19. Hormonal Imbalances: Estrogen deficiency post-menopause may accelerate disc degeneration.

20. Occupational Overuse: Repeating the same lumbar movements (e.g., warehouse work) causes cumulative annular damage.

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Symptoms of L5–S1 Disc Prolapse

1. Localized Lower Back Pain: Often dull and aching, worsened by bending or lifting.

2. Unilateral Sciatica: Sharp, shooting pain down the buttock and back of the thigh.

3. Radicular Leg Pain: Pain following the S1 dermatome into the calf and lateral foot.

4. Paresthesia: Tingling or “pins and needles” in the posterior leg or sole.

5. Muscle Weakness: Reduced strength in ankle plantarflexion or toe strength.

6. Reflex Changes: Decreased ankle jerk (S1 reflex) on the affected side.

7. Gait Disturbance: Antalgic limp or difficulty pushing off the foot.

8. Worsening with Valsalva: Coughing or sneezing exacerbates symptoms.

9. Nocturnal Pain: Back discomfort interfering with sleep.

10. Muscle Spasm: Paraspinal muscle tightness as a protective response.

11. Limited Flexion/Extension: Stiffness in bending forward or arching back.

12. Lateral Bending Pain: Discomfort when leaning sideways.

13. Radiculopathy: Sensory deficits along the S1 nerve root.

14. Numbness: Decreased sensation in the heel or outer foot.

15. Foot Drop: In severe S1 compression, difficulty pointing the foot downward.

16. Bladder or Bowel Dysfunction: Rare “red flag” indicating cauda equina syndrome.

17. Hypersensitivity: Increased pain response to light touch.

18. Claudication: Neurogenic leg pain with walking, relieved by rest.

19. Postural Shift: Leaning to one side to off-load the irritated nerve root.

20. Psychological Distress: Chronic pain leading to anxiety or depression.

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Diagnostic Tests for L5–S1 Disc Prolapse

A. Physical Examination

1. Inspection: Observe posture, spinal curvature, and muscle wasting.

2. Palpation: Tenderness over the lumbar paraspinals suggests local inflammation.

3. Range of Motion: Assess lumbar flexion, extension, and lateral bending for pain triggers.

4. Gait Analysis: Note antalgic limp or heel-toe sequence abnormalities.

5. Straight-Leg Raise (SLR): Passive elevation of the leg; pain below 60° suggests nerve root irritation.

6. Crossed SLR: Raising the opposite leg reproduces pain on the symptomatic side—highly specific for herniation.

B. Manual (Orthopedic) Tests

1. Slump Test: Seated flexion of the neck and back with knee extension—reproduces radicular pain if positive.

2. Femoral Nerve Stretch: Prone hip extension to test upper lumbar nerve roots.

3. Valsalva Maneuver: Bearing down increases intrathecal pressure—elicits pain if a disc is herniated.

4. Bonnet’s Sign: Internal rotation of the hip with SLR—pain indicates piriformis involvement vs. disc.

5. Kemp’s Test: Lumbar extension and rotation towards the affected side—reproduces lateralized pain.

6. Trendelenburg Sign: Pelvic drop on the contralateral side—suggests gluteal weakness from S1 involvement.

C. Laboratory & Pathological Tests

1. Complete Blood Count (CBC): Rules out infection or systemic inflammation.

2. Erythrocyte Sedimentation Rate (ESR): Elevated in inflammatory or infectious etiologies.

3. C-Reactive Protein (CRP): Acute-phase marker to exclude spinal infection.

4. HLA-B27 Testing: Positive in ankylosing spondylitis, a differential diagnosis.

5. Rheumatoid Factor (RF) & ANA: Screen for autoimmune spine involvement.

6. Serum Electrolytes & Calcium: Rule out metabolic bone disease.

D. Electrodiagnostic Studies

1. Nerve Conduction Velocity (NCV): Measures conduction speed; slowed in nerve root compression.

2. Electromyography (EMG): Detects denervation potentials in muscles supplied by S1.

3. Somatosensory Evoked Potentials (SSEPs): Assesses sensory pathways integrity.

4. F-Wave Studies: Prolonged F-waves indicate proximal nerve root dysfunction.

5. H-Reflex Testing: Similar to ankle reflex; latency increase suggests S1 root pathology.

6. EMG Paraspinal Mapping: Localizes level of denervation in lumbar spine.

E. Imaging Studies

1. Plain Radiography (X-Ray): Assesses alignment, bony abnormalities, and disc space narrowing.

2. Magnetic Resonance Imaging (MRI): Gold standard for visualizing disc morphology and nerve compression.

3. Computed Tomography (CT) Scan: Detailed bony anatomy; useful when MRI contraindicated.

4. CT Myelography: Intrathecal contrast highlights nerve root impingement.

5. Ultrasound: Emerging tool for dynamic evaluation of paraspinal soft tissues.

6. Discography: Contrast injection into the disc reproduces pain but carries risk of degeneration acceleration.

Non-Pharmacological Treatments

(Preferred first-line options to reduce pain and improve function PubMedMDPI)

1. Physical Therapy Exercises
   Description: Tailored stretches and strengthening routines prescribed by a physical therapist.
   Purpose: Improve flexibility, core stability, and reduce nerve compression.
   Mechanism: Strengthened core muscles off-load stress on the disc and take pressure off nerves.

2. McKenzie Extension Exercises
   Description: Repeated back extensions performed while lying face down or standing.
   Purpose: Centralize disc material back toward the centre.
   Mechanism: Creates a posterior force on the disc, reducing protrusion.

3. Lumbar Flexion Exercises
   Description: Gentle forward bends under supervision.
   Purpose: Increase disc space opening in the back.
   Mechanism: Promotes nutrient exchange and reduces pressure on posterior annulus.

4. Core Stabilization Training
   Description: Isometric holds (e.g., planks).
   Purpose: Enhance deep abdominal and back muscle support.
   Mechanism: Creates a natural “corset” around the spine, improving load distribution.

5. Manual Therapy (Mobilization)
   Description: Hands-on joint glides and soft tissue techniques.
   Purpose: Reduce stiffness and improve spinal segment mobility.
   Mechanism: Gentle mobilization stretches the annulus and adjacent soft tissues.

6. Spinal Manipulation
   Description: High-velocity, low-amplitude thrust by a chiropractor or osteopath.
   Purpose: Temporarily increase disc height and relieve nerve pressure.
   Mechanism: Quick joint gapping may reduce disc bulge and improve nerve blood flow.

7. Traction Therapy
   Description: Mechanical or manual pulling to stretch the spine.
   Purpose: Decompress intervertebral spaces.
   Mechanism: Increases foraminal area to ease nerve root compression Verywell Health.

8. Acupuncture
   Description: Insertion of fine needles at specific body points.
   Purpose: Alleviate pain and promote healing.
   Mechanism: Stimulates endorphin release and modulates pain pathways.

9. Electroacupuncture
   Description: Low-frequency electrical stimulation through acupuncture needles.
   Purpose: Enhance analgesic effects.
   Mechanism: Increases local blood flow and inhibits pain signals.

10. Transcutaneous Electrical Nerve Stimulation (TENS)
    Description: Electrodes deliver gentle pulses to the skin.
    Purpose: Block pain transmission.
    Mechanism: Activates gate control mechanisms in the spinal cord.

11. Heat Therapy
    Description: Application of warm packs or pads.
    Purpose: Relax tight muscles, improve circulation.
    Mechanism: Heat dilates vessels, reducing spasms around the disc.

12. Cold Therapy
    Description: Ice packs applied intermittently.
    Purpose: Reduce inflammation and numb pain.
    Mechanism: Vasoconstriction limits inflammatory mediator spread.

13. Ultrasound Therapy
    Description: High-frequency sound waves via a probe.
    Purpose: Deep tissue heating.
    Mechanism: Promotes collagen extensibility and local blood flow.

14. Low-Level Laser Therapy
    Description: Light energy directed at soft tissue.
    Purpose: Stimulate cellular repair.
    Mechanism: Increases ATP production in mitochondria to enhance healing.

15. Massage Therapy
    Description: Hands-on kneading and stroking of soft tissue.
    Purpose: Ease muscle tension and improve circulation.
    Mechanism: Mechanically breaks adhesions and promotes lymphatic drainage.

16. Myofascial Release
    Description: Sustained pressure on fascial restrictions.
    Purpose: Improve tissue mobility.
    Mechanism: Deforms fascia, relieving mechanical stress on the disc.

17. Yoga
    Description: Guided stretching, breathing, and posture exercises.
    Purpose: Increase flexibility and core strength.
    Mechanism: Combines muscle conditioning with spinal decompression.

18. Pilates
    Description: Controlled movements focusing on core stability.
    Purpose: Strengthen deep spinal stabilizers.
    Mechanism: Enhances neuromuscular control, reducing aberrant movements.

19. Hydrotherapy
    Description: Exercise in a warm pool.
    Purpose: Minimize weight-bearing stress.
    Mechanism: Buoyancy reduces axial load, allowing safe movement.

20. Kinesio Taping
    Description: Elastic tape applied to skin over muscles and joints.
    Purpose: Support soft tissues and improve proprioception.
    Mechanism: Lifts skin slightly to reduce pressure and stimulate receptors.

21. Ergonomic Adjustment
    Description: Modifying workstations (chair height, lumbar support).
    Purpose: Prevent harmful postures.
    Mechanism: Maintains neutral spine alignment, reducing repetitive stress.

22. Postural Education
    Description: Training in proper standing, sitting, and lifting techniques.
    Purpose: Avoid positions that exacerbate disc bulge.
    Mechanism: Promotes spinal curves that minimize annulus strain.

23. Weight Management Programs
    Description: Diet and exercise guidance for healthy weight.
    Purpose: Reduce mechanical load on the lumbar spine.
    Mechanism: Less body weight decreases compressive forces on the disc.

24. Cognitive Behavioral Therapy (CBT)
    Description: Psychological techniques to manage pain perception.
    Purpose: Reduce fear-avoidance and improve activity levels.
    Mechanism: Alters pain processing in the brain.

25. Mindfulness Meditation
    Description: Focused breathing and awareness practices.
    Purpose: Lower stress and perceived pain intensity.
    Mechanism: Modulates limbic system activity to reduce pain signals.

26. Biofeedback
    Description: Real-time monitoring of muscle activity.
    Purpose: Teach relaxation of lumbar muscles.
    Mechanism: Visual/auditory feedback helps patients reduce muscle tension.

27. Spinal Decompression Table
    Description: Motorized table that gently stretches the spine.
    Purpose: Create negative pressure in discs.
    Mechanism: “Sucks” herniated material back toward center, easing nerve pressure.

28. Bracing
    Description: Use of a lumbar support belt.
    Purpose: Limit painful movements.
    Mechanism: Provides external support to off-load the spine during flares.

29. Activity Modification
    Description: Temporary avoidance of aggravating movements (heavy lifting).
    Purpose: Prevent worsening of the herniation.
    Mechanism: Reduces repeated stress that can enlarge the tear.

30. Education & Self-Management
    Description: Understanding condition, risk factors, and home exercises.
    Purpose: Empower patients to take control of their recovery.
    Mechanism: Adherence to safe movement patterns and exercises speeds healing.

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Pharmacological Treatments

(Used when non-pharmacologic measures alone are insufficient)

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Dietary Molecular Supplements

(May support disc health and reduce inflammation)

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 Advanced Drug & Biologic Therapies

(Emerging options targeting disc regeneration)

1. Alendronate (Bisphosphonate)

   • Dosage: 70 mg once weekly

   • Function: Inhibits bone resorption to maintain vertebral endplate integrity.

   • Mechanism: Binds hydroxyapatite, blocking osteoclast activity.

2. Pamidronate (Bisphosphonate)

   • Dosage: 30–90 mg IV every 3–4 weeks

   • Function: Reduces local bone turnover to stabilize disc environment.

   • Mechanism: Induces osteoclast apoptosis.

3. Zoledronic Acid (Bisphosphonate)

   • Dosage: 5 mg IV once yearly

   • Function & Mechanism: Similar to other bisphosphonates, with potent, long-lasting effect.

4. Platelet-Rich Plasma (PRP) Injection

   • Dosage: 3–5 mL into epidural or disc space

   • Function: Delivers growth factors to injured disc.

   • Mechanism: Releases PDGF, TGF-β to stimulate matrix repair.

5. Bone Morphogenetic Protein-7 (BMP-7)

   • Dosage: 0.5–1 mg per injection site

   • Function: Promotes disc cell proliferation.

   • Mechanism: Activates SMAD signaling for extracellular matrix synthesis.

6. Hyaluronic Acid (Viscosupplement)

   • Dosage: 1–2 mL per intervertebral injection

   • Function: Improves hydration and viscoelasticity of the disc.

   • Mechanism: Attracts and retains water molecules in nucleus pulposus.

7. Cross-Linked Hyaluronic Acid

   • Dosage & Function: Similar to native HA but longer-lasting.

   • Mechanism: Resists enzymatic degradation, sustaining disc lubrication.

8. Mesenchymal Stem Cells (Autologous)

   • Dosage: 1–2 × 10⁶ cells per disc injection

   • Function: Differentiate into disc-like cells.

   • Mechanism: Paracrine release of trophic factors to regenerate matrix.

9. Adipose-Derived Stem Cells

   • Dosage: 5–10 × 10⁶ cells

   • Function: Support nucleus pulposus repair.

   • Mechanism: Secrete anti-inflammatory cytokines and growth factors.

10. Exosome Therapy

    • Dosage: Variable (research stage)

    • Function: Deliver regenerative microRNAs and proteins.

    • Mechanism: Modulate local cellular activity to enhance repair.

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Surgical Options

(Reserved for persistent, severe cases Mayo Clinic)

1. Microdiscectomy

   • Procedure: Removal of herniated disc portion via a small incision under a microscope.

   • Benefits: Rapid pain relief, minimally invasive, shorter recovery.

2. Open Discectomy

   • Procedure: Traditional open removal of extruded disc.

   • Benefits: Direct visualization; useful for large herniations.

3. Endoscopic Discectomy

   • Procedure: Uses an endoscope and small instruments through a tiny incision.

   • Benefits: Less tissue damage, faster return to activities.

4. Laminectomy (Decompression Surgery)

   • Procedure: Removal of part of the vertebral arch (lamina) to enlarge spinal canal.

   • Benefits: Reduces nerve compression from bony overgrowth.

5. Foraminotomy

   • Procedure: Widening of the foraminal canal where nerves exit.

   • Benefits: Eases nerve root pressure without disc removal.

6. Spinal Fusion

   • Procedure: Joins two or more vertebrae with bone graft and hardware.

   • Benefits: Stabilizes unstable segments; reduces abnormal motion.

7. Artificial Disc Replacement

   • Procedure: Removes damaged disc and inserts a prosthetic one.

   • Benefits: Maintains motion, avoids fusion-related degeneration.

8. Chemonucleolysis

   • Procedure: Injection of an enzyme (chymopapain) to dissolve disc nucleus.

   • Benefits: Minimally invasive chemical shrinkage of disc.

9. Laser Discectomy

   • Procedure: Laser vaporizes a small portion of disc to reduce pressure.

   • Benefits: Precise ablation, minimal bleeding.

10. Dynamic Stabilization

    • Procedure: Implantation of flexible devices to support spine motion.

    • Benefits: Stabilizes without fully eliminating movement.

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Prevention Strategies

1. Practice Proper Lifting Techniques – Bend at hips and knees, keep back straight.

2. Maintain a Healthy Weight – Reduces spinal load and disc stress.

3. Strengthen Core Muscles – Regular core workouts support the lumbar spine.

4. Use Ergonomic Furniture – Chairs with lumbar support maintain natural curve.

5. Stay Active – Low-impact aerobic exercise (walking, swimming) boosts disc nutrition.

6. Avoid Prolonged Sitting – Take frequent breaks to stand and stretch.

7. Quit Smoking – Nicotine impairs disc blood flow and healing.

8. Stay Hydrated – Adequate water intake helps maintain disc hydration.

9. Perform Back-Strengthening Exercises – Yoga, Pilates, and targeted PT routines.

10. Learn Stress-Reduction Techniques – Chronic stress can increase muscle tension.

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When to See a Doctor

• Severe or Worsening Pain: Not relieved by rest or home care.

• Progressive Weakness or Numbness: Particularly in legs or feet.

• Bowel or Bladder Dysfunction: Incontinence or retention.

• Sudden Onset of Foot Drop: Inability to lift the front part of the foot.

• Fever with Back Pain: Possible infection.

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Frequently Asked Questions

1. What causes L5–S1 disc prolapse?
   Age-related wear (degeneration), repetitive heavy lifting, sudden trauma, genetic factors, smoking, and obesity all contribute to annulus weakening and nucleus protrusion.

2. What are common symptoms?
   Shooting pain down the leg (sciatica), numbness, tingling, muscle weakness, and localized back stiffness.

3. How is it diagnosed?
   Clinical exam (straight leg raise, neurological testing) plus imaging (MRI is gold standard; CT or X-ray in some cases).

4. Can it heal on its own?
   Many prolapsed discs regress over weeks to months with conservative care (PT, medications) as the body reabsorbs disc material.

5. How long does recovery take?
   With proper treatment, most patients improve significantly within 6–12 weeks, though full healing may take longer.

6. Is surgery always required?
   No. Only about 10–20% of cases with red-flag signs or severe, persistent pain need surgery.

7. What risks come with surgery?
   Infection, nerve damage, blood loss, failed back surgery syndrome, and adjacent segment degeneration.

8. How can I manage pain at home?
   Heat/cold packs, gentle stretching, over-the-counter NSAIDs, and activity modification.

9. Are opioids recommended?
   Generally avoided due to addiction risk; reserved for short-term, severe pain under close supervision.

10. Do injections help?
    Epidural steroid injections can provide temporary relief by reducing inflammation around nerve roots.

11. Can exercise worsen it?
    Improper techniques or excessive loading can aggravate symptoms; always follow a guided PT program.

12. Will it affect my daily life forever?
    With proper management, many return to normal activities; some may have occasional flare-ups.

13. Is massage safe?
    Yes, when performed by a qualified therapist; it can relieve muscle spasm but should be gentle.

14. What is the role of diet?
    An anti-inflammatory diet rich in omega-3s, antioxidants, and lean proteins supports healing.

15. How can I prevent recurrence?
    Maintain core strength, healthy weight, proper ergonomics, and avoid high-risk activities.

Disclaimer: Each person’s journey is unique, treatment plan, life style, food habit, hormonal condition, immune system, chronic disease condition, geological location, weather and previous medical  history is also unique. So always seek the best advice from a qualified medical professional or health care provider before trying any treatments to ensure to find out the best plan for you. This guide is for general information and educational purposes only. Regular check-ups and awareness can help to manage and prevent complications associated with these diseases conditions. If you or someone are suffering from this disease condition bookmark this website or share with someone who might find it useful! Boost your knowledge and stay ahead in your health journey. We always try to ensure that the content is regularly updated to reflect the latest medical research and treatment options. Thank you for giving your valuable time to read the article.

The article is written by Team Rxharun and reviewed by the Rx Editorial Board Members

Last Updated: May 12, 2025.