Musculoskeletal System

1. Introduction to the Musculoskeletal System

The musculoskeletal system provides the framework for the human body, allowing movement, protection of vital organs, and physiological homeostasis. It consists of:

• Bones → Structural support, hematopoiesis, mineral storage.
• Muscles → Movement, posture, heat production.
• Joints → Articulations allowing mobility and stability.
• Tendons & Ligaments → Connective tissue structures providing support and transmitting force.
• Nerve Interactions → Motor control, reflexes, proprioception.

Clinical Importance

• Understanding this system is crucial for diagnosing fractures, arthritis, muscle disorders, and neuromuscular diseases.
• The interplay of structure and function determines mobility and posture, with abnormalities leading to deformities and disabilities.

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2. Anatomy of the Musculoskeletal System

2.1. Bones and Skeletal System

The human skeleton consists of 206 bones, classified based on structure and function.

2.1.1. Functions of Bones

• Structural Support → Provides rigidity and framework.
• Movement → Serves as a lever system for muscle action.
• Protection → Skull (brain), rib cage (heart, lungs).
• Mineral Storage → Calcium, phosphate regulation.
• Hematopoiesis → Blood cell production in bone marrow.
• Endocrine Regulation → Osteocalcin secretion affects glucose metabolism.

2.1.2. Types of Bones

• Long Bones (Femur, Humerus) → Strength & movement.
• Short Bones (Carpals, Tarsals) → Stability & support.
• Flat Bones (Sternum, Skull) → Protection & muscle attachment.
• Irregular Bones (Vertebrae) → Complex functions.
• Sesamoid Bones (Patella) → Reduce friction & enhance movement.

2.1.3. Macroscopic Structure of Bone

• Compact Bone (Cortical Bone) → Dense outer layer, provides mechanical strength.
• Spongy Bone (Cancellous Bone) → Porous, contains trabeculae, supports hematopoiesis.
• Periosteum → Outer fibrous covering, vascularized, allows bone growth & healing.
• Endosteum → Inner lining, contains osteogenic cells.
• Medullary Cavity → Contains yellow marrow (fat storage) or red marrow (hematopoiesis).

2.1.4. Microscopic Structure of Bone

• Osteons (Haversian System) → Functional unit of compact bone.
• Lamellae → Concentric layers of bone matrix.
• Lacunae → Spaces containing osteocytes.
• Canaliculi → Small channels allowing nutrient exchange.

2.1.5. Bone Cells & Their Functions

• Osteoblasts → Bone-forming cells, secrete osteoid.
• Osteocytes → Mature bone cells maintaining structure.
• Osteoclasts → Bone-resorbing cells, maintain remodeling.

2.1.6. Bone Formation

1. Intramembranous Ossification → Direct bone formation from mesenchyme (Skull, Clavicle).
2. Endochondral Ossification → Bone replaces cartilage template (Long bones).

2.1.7. Bone Remodeling & Healing

• Bone is constantly remodeled → Balance between resorption (osteoclasts) and deposition (osteoblasts).
• Fracture Healing Stages
  • Inflammatory Phase (Hematoma formation).
  • Reparative Phase (Fibrocartilaginous & bony callus formation).
  • Remodeling Phase (Trabecular bone replaces woven bone).

2.1.8. Pathology of Bone

• Osteoporosis → Decreased bone mass, increased fracture risk.
• Osteomalacia & Rickets → Vitamin D deficiency, defective mineralization.
• Paget’s Disease → Disorganized bone remodeling.
• Osteomyelitis → Bone infection, usually Staphylococcus aureus.
• Bone Tumors
  • Benign → Osteochondroma, Osteoid Osteoma.
  • Malignant → Osteosarcoma, Ewing’s Sarcoma.

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2.2. Joints and Their Functions

2.2.1. Classification of Joints

1. Fibrous Joints → No movement (Sutures, Syndesmosis).
2. Cartilaginous Joints → Limited movement (Symphysis, Synchondrosis).
3. Synovial Joints → Freely movable, classified as:
   • Hinge (Elbow, Knee).
   • Ball and Socket (Shoulder, Hip).
   • Pivot (Atlantoaxial Joint).
   • Gliding (Intercarpal joints).
   • Saddle (Thumb).
   • Condyloid (Wrist).

2.2.2. Synovial Joint Structure

• Articular Cartilage → Shock absorption, friction reduction.
• Synovial Membrane → Produces synovial fluid for lubrication.
• Joint Capsule → Provides stability.

2.2.3. Common Joint Disorders

• Osteoarthritis → Degeneration of cartilage, pain, stiffness.
• Rheumatoid Arthritis → Autoimmune attack on synovium.
• Gout → Uric acid crystal deposition.

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2.3. Muscles and Their Functions

2.3.1. Types of Muscles

1. Skeletal Muscle → Voluntary, striated.
2. Cardiac Muscle → Involuntary, striated.
3. Smooth Muscle → Involuntary, non-striated.

2.3.2. Structure of Skeletal Muscle

• Sarcolemma → Muscle cell membrane.
• Sarcoplasm → Cytoplasm containing myoglobin & mitochondria.
• Myofibrils → Actin & Myosin filaments.

2.3.3. Mechanism of Muscle Contraction

• Sliding Filament Theory → Actin and myosin interaction via ATP hydrolysis.
• Neuromuscular Junction → ACh release stimulates contraction.

2.3.4. Muscle Pathologies

• Myasthenia Gravis → Autoimmune disease affecting NMJ.
• Muscular Dystrophy → Progressive muscle degeneration.

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Clinical Examination of the Musculoskeletal System

The clinical examination of the musculoskeletal system is a systematic approach used to assess bones, joints, muscles, tendons, ligaments, and nerves. It is essential for diagnosing conditions like arthritis, fractures, soft tissue injuries, neuromuscular disorders, and postural abnormalities.

This note covers:

1. General Principles of Examination
2. Inspection (Visual Assessment)
3. Palpation (Touch & Feel)
4. Range of Motion (ROM) Testing
5. Neurological Assessment (Motor, Sensory, Reflexes)
6. Special Tests (Condition-Specific Clinical Tests)
7. Gait Analysis
8. Common Pathological Findings

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1. 

Clinical Examination of the Musculoskeletal System

The clinical examination of the musculoskeletal system is a systematic approach used to assess bones, joints, muscles, tendons, ligaments, and nerves. It is essential for diagnosing conditions like arthritis, fractures, soft tissue injuries, neuromuscular disorders, and postural abnormalities.

This note covers:

1. General Principles of Examination
2. Inspection (Visual Assessment)
3. Palpation (Touch & Feel)
4. Range of Motion (ROM) Testing
5. Neurological Assessment (Motor, Sensory, Reflexes)
6. Special Tests (Condition-Specific Clinical Tests)
7. Gait Analysis
8. Common Pathological Findings

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1. General Principles of Musculoskeletal Examination

• Approach → Start with a systematic head-to-toe assessment.
• Positioning → Examine in standing, sitting, and supine positions for thorough evaluation.
• Compare Both Sides → Always assess bilaterally to detect asymmetry.
• Patient Comfort & Cooperation → Explain procedures, obtain consent.
• Systematic Order → Look (Inspection) → Feel (Palpation) → Move (ROM) → Test (Neurological & Special Tests).

Clinical Relevance → Following this order ensures no critical detail is missed in orthopedic, rheumatologic, or neurological cases.

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2. Inspection (Visual Assessment)

2.1. General Inspection

• Posture → Any spinal curvature (e.g., kyphosis, scoliosis, lordosis).
• Gait → Abnormalities like limping, toe walking, foot drop.
• Muscle Bulk → Look for wasting (atrophy) or hypertrophy.
• Swelling/Edema → Indicates inflammation, infection, or trauma.
• Deformities → Joint dislocations, fractures, congenital anomalies.
• Skin Changes →
  • Redness (Erythema) → Inflammation (e.g., arthritis).
  • Bruising (Ecchymosis) → Trauma, fractures.
  • Scars → Prior surgeries, infections.

Example Clinical Findings

• Wasting of Thenar Muscles → Median nerve palsy (Carpal Tunnel Syndrome).
• Claw Hand → Ulnar nerve palsy.
• Wrist Drop → Radial nerve palsy.

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3. Palpation (Touch & Feel Assessment)

3.1. Temperature & Tenderness

• Increased warmth → Suggests inflammation (arthritis, osteomyelitis).
• Tenderness → Indicates injury, fracture, or infection.

3.2. Swelling Assessment

• Hard & Fixed Swelling → Bone tumors, chronic inflammation.
• Soft & Fluctuant → Fluid accumulation (joint effusion, synovitis).

3.3. Muscle Tone & Strength

• Spasticity → Upper motor neuron lesions (e.g., stroke, cerebral palsy).
• Flaccidity → Lower motor neuron lesions (e.g., polio, peripheral neuropathy).
• Grading of Muscle Strength (MRC Scale) →
  • 0 → No contraction
  • 1 → Flicker of movement
  • 2 → Movement without gravity
  • 3 → Movement against gravity
  • 4 → Movement against some resistance
  • 5 → Normal strength

4. Range of Motion (ROM) Testing

4.1. Types of Movement Testing

• Active Range of Motion (AROM) → The patient moves the joint voluntarily.
• Passive Range of Motion (PROM) → The examiner moves the joint without patient effort.
• Resisted Range of Motion → Movement against resistance to assess muscle strength.

4.2. Normal & Abnormal Findings

• Full AROM & PROM → Normal joint function.
• Restricted AROM but normal PROM → Muscle or tendon injury (e.g., rotator cuff tear).
• Restricted AROM & PROM → Joint pathology (e.g., arthritis, adhesive capsulitis).

4.3. Specific Joint Movements

1. Shoulder → Flexion, extension, abduction, adduction, internal & external rotation.
2. Elbow → Flexion, extension, supination, pronation.
3. Wrist → Flexion, extension, radial & ulnar deviation.
4. Fingers → Flexion, extension, abduction, adduction.
5. Hip → Flexion, extension, abduction, adduction, rotation.
6. Knee → Flexion, extension.
7. Ankle → Dorsiflexion, plantarflexion, inversion, eversion.
8. Spine → Flexion, extension, lateral bending, rotation.

4.4. Clinical Relevance

• Pain with AROM but not PROM → Suggests muscle or tendon pathology.
• Pain with PROM → Suggests joint involvement (capsulitis, arthritis).
• Limited ROM with crepitus → Osteoarthritis.
• Hypermobile Joints → Ehlers-Danlos Syndrome.

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5. Neurological Examination of the Musculoskeletal System

5.1. Motor Function Assessment

• Muscle bulk, tone, and power (graded 0-5 using MRC scale).
• Coordination tests → Finger-nose test, heel-to-shin test.
• Gait abnormalities → Suggest spinal cord or peripheral nerve pathology.

5.2. Reflex Testing

• Biceps Reflex (C5-C6) → Absent in brachial plexus injury.
• Triceps Reflex (C7-C8) → Absent in radial nerve palsy.
• Patellar Reflex (L3-L4) → Weak in peripheral neuropathy.
• Achilles Reflex (S1-S2) → Absent in S1 radiculopathy.
• Babinski’s Sign

5.2. Reflex Testing (Continued)

Reflexes help assess upper motor neuron (UMN) and lower motor neuron (LMN) lesions.

• Hyperreflexia → UMN lesion (e.g., stroke, multiple sclerosis).
• Hyporeflexia or absent reflexes → LMN lesion (e.g., peripheral neuropathy, radiculopathy).

5.3. Sensory Examination

• Light Touch & Pinprick Sensation → Assesses peripheral nerve function.
• Vibration & Proprioception (Joint Position Sense) → Tests posterior column function (lost in B12 deficiency, diabetic neuropathy).
• Dermatomal Testing → Helps in radiculopathy diagnosis.

Clinical Relevance:

• Stocking-glove sensory loss → Diabetic neuropathy.
• Unilateral sensory loss → Stroke or nerve injury.
• Bilateral loss with proprioceptive deficit → Tabes dorsalis, B12 deficiency.

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6. Special Tests (Condition-Specific Clinical Tests)

6.1. Shoulder Examination

• Neer’s Test → Pain suggests shoulder impingement syndrome.
• Hawkins-Kennedy Test → Identifies subacromial impingement.
• Drop Arm Test → Indicates rotator cuff tear.

6.2. Elbow Examination

• Cozen’s Test → Positive in lateral epicondylitis (tennis elbow).
• Golfer’s Elbow Test → Positive in medial epicondylitis.

6.3. Wrist & Hand Examination

• Tinel’s Sign → Tapping over median nerve causes tingling in carpal tunnel syndrome.
• Phalen’s Test → Wrist flexion for 60 seconds reproduces symptoms in carpal tunnel syndrome.

• Finkelstein’s Test → Pain along the radial wrist indicates De Quervain’s tenosynovitis.

6.4. Hip Examination

• Trendelenburg Test → Positive if hip drops on the opposite side, indicating gluteus medius weakness.
• FABER Test (Flexion, Abduction, External Rotation) → Pain suggests hip joint pathology or sacroiliac dysfunction.
• Thomas Test → Tests for hip flexor tightness.

6.5. Knee Examination

• Lachman’s Test → Gold standard for detecting ACL injuries.
• Anterior Drawer Test → Also assesses ACL injury.
• Posterior Drawer Test → Identifies PCL injury.
• McMurray’s Test → Pain or clicking suggests meniscal tear.

6.6. Ankle Examination

• Thompson’s Test → Absence of plantarflexion indicates Achilles tendon rupture.
• Anterior Drawer Test (Ankle) → Assesses ankle ligament instability.

6.7. Spine Examination

• Schober’s Test → Measures lumbar flexion, reduced in ankylosing spondylitis.
• Straight Leg Raise (SLR) Test → Pain between 30°–70° indicates sciatic nerve compression (herniated disc, radiculopathy).
• Lhermitte’s Sign → Electric shock sensation down the spine on neck flexion, seen in multiple sclerosis, cervical myelopathy.

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7. Gait Analysis

Gait analysis is a crucial component of the musculoskeletal and neurological examination. It helps evaluate coordination, balance, strength, and neuromuscular function. Abnormalities in gait can indicate musculoskeletal deformities, neurological disorders, or systemic diseases.

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7.1. Phases of Normal Gait Cycle

A complete gait cycle consists of two main phases:

1. Stance Phase (60%) – The foot is in contact with the ground.

   • Heel Strike (Initial Contact) → First contact of the foot with the ground.
   • Foot Flat (Loading Response) → Weight transfer occurs.
   • Midstance → The body is directly over the foot.
   • Heel Off (Terminal Stance) → The heel lifts off.
   • Toe Off (Pre-Swing) → The foot leaves the ground.

2. Swing Phase (40%) – The foot moves forward.

   • Initial Swing (Acceleration) → The limb starts moving forward.
   • Mid-Swing → The limb reaches the highest point.
   • Terminal Swing (Deceleration) → The limb prepares for the next step.

Each phase is controlled by muscle activation, joint motion, and proprioception.

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7.2. Types of Abnormal Gaits & Their Clinical Correlations

1. Antalgic Gait (Painful Gait)

• Description: Shortened stance phase on the affected side to minimize weight-bearing.
• Cause: Arthritis, fractures, soft tissue injuries, joint inflammation.

2. Trendelenburg Gait

• Description: Drooping of the pelvis on the opposite side during stance.
• Cause: Weakness of gluteus medius/minimus (superior gluteal nerve injury, hip arthritis, congenital hip dislocation).

3. Steppage Gait (High Stepping Gait)

• Description: Excessive hip and knee flexion due to foot drop.
• Cause: Peroneal nerve palsy, L5 radiculopathy, Charcot-Marie-Tooth disease.

4. Spastic Gait

• Description: Stiff, scissoring walk with legs crossing over each other.
• Cause: Cerebral palsy, stroke, multiple sclerosis, spinal cord injury.

5. Ataxic Gait

• Description: Wide-based, unsteady gait with difficulty maintaining balance.
• Cause: Cerebellar ataxia (stroke, alcohol intoxication, multiple sclerosis, Friedrich’s ataxia).

6. Parkinsonian Gait

• Description: Small, shuffling steps with reduced arm swing, festination (involuntary acceleration).
• Cause: Parkinson’s disease, progressive supranuclear palsy.

7. Hemiplegic Gait

• Description: Affected limb is stiff, with circumduction (outward swinging motion) of the leg.
• Cause: Stroke, cerebral palsy, traumatic brain injury.

8. Waddling Gait

• Description: Bilateral hip weakness causing exaggerated side-to-side movements.
• Cause: Duchenne muscular dystrophy, myopathies, pregnancy-related pelvic instability.

9. Stamping Gait (Sensory Ataxia)

• Description: The patient slams the foot on the ground to increase sensory feedback.
• Cause: Dorsal column lesions (tabes dorsalis, vitamin B12 deficiency, diabetic neuropathy).

10. Choreiform Gait

• Description: Involuntary, irregular, jerky movements during walking.
• Cause: Huntington’s disease, Sydenham’s chorea.

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7.3. Clinical Tests for Gait Abnormalities

1. Romberg’s Test (Sensory Ataxia vs. Cerebellar Ataxia)

• Procedure: The patient stands with feet together, arms by the sides, and eyes open, then closes their eyes.
• Interpretation:
  • Positive Romberg’s sign (Increased sway or fall with eyes closed) → Sensory ataxia (dorsal column disease, vitamin B12 deficiency).
  • Negative Romberg’s sign (Unsteady with eyes open and closed) → Cerebellar ataxia.

2. Heel-to-Toe Walking (Tandem Gait Test)

• Procedure: The patient walks in a straight line, placing the heel of one foot directly in front of the toes of the other foot.
• Abnormality Suggests: Cerebellar dysfunction, vestibular disorders, proprioceptive deficits.

3. Get Up and Go Test

• Procedure: The patient is asked to rise from a chair, walk 3 meters, turn, and return.
• Abnormalities Suggest: Fall risk in elderly, stroke, Parkinson’s disease.

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7.4. Clinical Importance of Gait Examination

✔ Early Diagnosis: Helps detect neurological, musculoskeletal, and systemic diseases.
✔ Fall Risk Assessment: Crucial in elderly, stroke survivors, and Parkinson’s disease patients.
✔ Rehabilitation & Prognosis: Guides physiotherapy, orthotic use, and mobility training.

SPECIFIC JOINT EXAMINATION DETAILED

Clinical Examination of the Shoulder Joint

The shoulder joint is a highly mobile but less stable joint, making it prone to dislocations, rotator cuff injuries, and degenerative changes. Clinical examination of the shoulder assesses pain, instability, range of motion, strength, and neurological involvement.

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1. Introduction to Shoulder Joint Anatomy & Clinical Relevance

✔ Type of Joint: Ball-and-socket synovial joint.
✔ Articulating Surfaces:

• Head of the humerus (large and convex).
• Glenoid cavity of the scapula (shallow and concave).
  ✔ Key Supporting Structures:
• Capsule & Ligaments: Glenohumeral, coracoacromial, coracoclavicular, acromioclavicular, transverse humeral ligament.
• Rotator Cuff Muscles: Supraspinatus, Infraspinatus, Teres Minor, Subscapularis (SITS muscles) – important for stability and movement.
• Bursae: Subacromial, subdeltoid, subcoracoid bursae reduce friction.

✔ Clinical Importance:

• Most commonly dislocated joint (anterior dislocation most frequent).
• Common injuries: Rotator cuff tears, impingement syndrome, frozen shoulder.
• Referred pain: Can originate from cervical spine (C5-C6), heart, lungs, diaphragm.

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2. Steps of Shoulder Joint Examination

✔ Inspection
✔ Palpation
✔ Range of Motion (ROM) Testing
✔ Strength Testing
✔ Special Tests for Shoulder Pathology
✔ Neurological Examination

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3. Inspection

✔ Patient Position: Standing/sitting with arms relaxed at the side.
✔ Look for:

• Postural abnormalities: Rounded shoulders (kyphosis), scoliosis, or shoulder drooping (nerve injury).
• Muscle atrophy: Wasting of deltoid (axillary nerve injury), supraspinatus & infraspinatus (suprascapular nerve injury).
• Swelling or asymmetry: Joint effusion, bursitis, trauma.
• Scars or skin changes: Prior surgeries, infections, bruising.

✔ Clinical Importance:

• Wasting of infraspinatus: Suggests suprascapular nerve injury (entrapment in the spinoglenoid notch).
• Winging of scapula: Indicates serratus anterior weakness (long thoracic nerve injury).
• Step-off deformity: Acromioclavicular joint dislocation.

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4. Palpation

✔ Palpate systematically:

• Sternoclavicular joint – Tenderness suggests arthritis, infection, or dislocation.
• Clavicle – Fractures common in falls.
• Acromioclavicular joint – Pain suggests AC joint dislocation or arthritis.
• Coracoid process – Tender in bicipital tendinitis, fractures.
• Greater & lesser tuberosities of humerus – Tenderness may indicate rotator cuff tears or tendinopathy.
• Bicipital groove – Tenderness suggests biceps tendinitis.
• Scapula & spine of scapula – Pain suggests fractures, winging, muscle atrophy.

✔ Clinical Importance:

• Pain over the supraspinatus tendon → Rotator cuff pathology.
• Localized AC joint pain → AC joint arthritis or separation.
• Bicipital groove tenderness → Biceps tendinitis or rupture.

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5. Range of Motion (ROM) Testing

✔ Active ROM: The patient moves the joint.
✔ Passive ROM: Examiner moves the joint.
✔ Compare both sides and note any restrictions, pain, or crepitus.

✔ Movements & Normal Ranges:

• Flexion: 180° (deltoid, biceps, pectoralis major, coracobrachialis).
• Extension: 50° (posterior deltoid, latissimus dorsi).
• Abduction: 180° (supraspinatus initiates, deltoid continues).
• Adduction: 50° (pectoralis major, latissimus dorsi).
• Internal rotation: 90° (subscapularis, pectoralis major).
• External rotation: 90° (infraspinatus, teres minor).

✔ Clinical Importance:

• Painful Arc Test (60–120° abduction) → Subacromial impingement syndrome.
• Frozen Shoulder (Adhesive Capsulitis): Restricted active & passive ROM, especially external rotation.
• Rotator Cuff Tears: Weakness in abduction with painful or limited movement.

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6. Strength Testing (Resisted Movements)

✔ Test each movement against resistance and check for pain, weakness, or asymmetry.
✔ Movements & Their Clinical Correlation:

• Abduction (Deltoid, Supraspinatus) → Weakness suggests rotator cuff pathology or axillary nerve injury.
• External Rotation (Infraspinatus, Teres Minor) → Weakness suggests suprascapular nerve injury.
• Internal Rotation (Subscapularis) → Weakness suggests subscapularis tear.

✔ Clinical Importance:

• Drop Arm Test: Inability to hold arm at 90° abduction → Supraspinatus tear.
• Weak external rotation: Rotator cuff or suprascapular nerve injury.

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7. Special Tests for Shoulder Pathologies

✔ Rotator Cuff Tears & Impingement:

• Neer’s Test: Pain with passive forward flexion → Impingement syndrome.
• Hawkins-Kennedy Test: Pain with passive internal rotation → Subacromial impingement.
• Drop Arm Test: Sudden arm drop → Supraspinatus tear.

✔ Biceps Tendon Injury:

• Speed’s Test: Pain over bicipital groove on resisted forward flexion → Biceps tendinitis.
• Yergason’s Test: Pain with resisted supination → Biceps tendinitis or SLAP tear.

✔ Glenohumeral Instability:

• Apprehension Test: Patient feels shoulder instability in abduction and external rotation → Anterior instability.
• Sulcus Sign: Visible depression below acromion → Inferior instability.

✔ Acromioclavicular Joint Pathology:

• Cross-Body Adduction Test: Pain when arm is brought across chest → AC joint arthritis.

✔ Labral Tears:

• O’Brien’s Test: Pain with resisted flexion in pronation → SLAP (Superior Labral Anterior-Posterior) tear.

✔ Nerve Injuries:

• Spinal Accessory Nerve: Weak trapezius, shoulder shrug difficulty.
• Axillary Nerve: Deltoid atrophy, sensory loss over lateral shoulder.

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8. Neurological Examination

✔ Dermatomes:

• C4: Shoulder pad area.
• C5: Lateral arm.
• C6: Lateral forearm, thumb.
• C7: Middle finger.
• C8: Medial hand.

✔ Reflexes:

• Biceps Reflex (C5-C6): Weak in C5-C6 radiculopathy.

✔ Clinical Importance:

• Weak deltoid & sensory loss over lateral arm → Axillary nerve injury.
• Weak elbow flexion & decreased biceps reflex → Musculocutaneous nerve injury.

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Conclusion

A comprehensive shoulder examination helps diagnose rotator cuff injuries, nerve entrapments, impingement syndromes, and instability. Early detection ensures timely treatment, rehabilitation, and prevention of long-term disability.

Clinical Examination of the Low Back Region

1. Introduction

The low back region (lumbar spine, sacrum, and pelvis) is a common site of pain and disability, often due to degenerative, traumatic, inflammatory, or mechanical causes. A structured clinical examination is essential to differentiate between musculoskeletal, neurological, and systemic causes of low back pain.

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2. Steps of Low Back Examination

✔ Inspection
✔ Palpation
✔ Range of Motion (ROM) Testing
✔ Neurological Examination (Motor, Sensory, Reflexes)
✔ Special Tests for Low Back Pain
✔ Provocative Tests for Radiculopathy & Sciatica

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3. Inspection

✔ Patient Position: Standing, sitting, and lying down.
✔ Look for:

• Postural abnormalities: Scoliosis, kyphosis, excessive lumbar lordosis.
• Pelvic tilt or leg length discrepancy: Can cause altered gait and low back pain.
• Muscle wasting: Seen in chronic nerve compression, polio, muscular dystrophies.
• Asymmetry of spine or ribs: Possible scoliosis, vertebral fractures, or tumors.
• Skin changes: Café-au-lait spots (neurofibromatosis), midline dimples (spina bifida), surgical scars.

✔ Clinical Importance:

• Loss of lumbar lordosis → Suggests muscle spasm, ankylosing spondylitis.
• Exaggerated lordosis → Suggests spondylolisthesis, weak abdominal muscles.
• Lateral deviation (scoliosis) → May indicate spinal deformities or disc herniation.

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4. Palpation

✔ Palpate systematically from the sacrum to thoracic spine for:

• Tenderness: Suggests fractures, disc herniation, infections (osteomyelitis, TB spine).
• Muscle spasm: Associated with lumbar strain, spondylolisthesis.
• Step-off deformity: Suggests spondylolisthesis (one vertebra slipping over another).
• Paraspinal muscle tightness: Indicates protective muscle guarding due to spinal pathology.
• Sacroiliac joint tenderness: Seen in sacroiliitis (Ankylosing Spondylitis, Reactive Arthritis).

✔ Clinical Importance:

• Midline tenderness → Suggests vertebral pathology (fractures, infections, malignancy).
• Paraspinal muscle tenderness → Suggests muscle strain, ligament injury.
• Sacroiliac joint tenderness → Suggests sacroiliitis, ankylosing spondylitis.

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5. Range of Motion (ROM) Testing

✔ Movements to Assess:

• Flexion (Normal: 60°-90°): Tests lumbar spine mobility.
• Extension (Normal: 20°-30°): Limited in degenerative and inflammatory conditions.
• Lateral Flexion (Normal: 25°-30°): Assesses symmetrical movement on both sides.
• Rotation (Normal: 30°-45°): Limited in lumbar spine pathology.

✔ Clinical Importance:

• Pain on forward flexion → Suggests disc herniation, muscle strain.
• Pain on extension → Indicates facet joint arthritis, spondylolisthesis.
• Restricted movements → Seen in ankylosing spondylitis (Schober’s Test positive).

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6. Neurological Examination

6.1 Motor Testing (Myotomes)

✔ Assess strength in lower limbs using the MRC scale (0-5):

• Hip Flexion (L2-L3): Weak in lumbar plexus compression, upper motor neuron lesions.
• Knee Extension (L3-L4): Weak in femoral nerve injury, L3-L4 radiculopathy.
• Ankle Dorsiflexion (L4-L5): Weak in L4-L5 radiculopathy, foot drop.
• Great Toe Extension (L5): Weak in L5 nerve root compression.
• Ankle Plantarflexion (S1-S2): Weak in S1 radiculopathy.

✔ Clinical Importance:

• Foot drop (L4-L5 compression) → Seen in herniated discs, peroneal nerve palsy.
• Weak knee extension (L3-L4) → Seen in lumbar disc herniation.
• Weak plantarflexion (S1) → Suggests S1 radiculopathy.

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6.2 Sensory Testing (Dermatomes)

✔ Assess for sensory loss, paresthesia, or hyperesthesia:

• L1: Groin area.
• L2: Upper thigh.
• L3: Medial thigh.
• L4: Medial leg & great toe.
• L5: Dorsum of foot.
• S1: Lateral foot & heel.
• S2-S4: Perianal region (important in cauda equina syndrome).

✔ Clinical Importance:

• Saddle anesthesia (S2-S4 loss) → Urgent sign of cauda equina syndrome.
• Loss of L5 sensation → Indicates L5 radiculopathy.

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6.3 Reflex Testing

✔ Deep Tendon Reflexes (DTRs) and their clinical significance:

• Knee Reflex (L3-L4, Patellar Reflex): Absent in L4 radiculopathy.
• Ankle Reflex (S1-S2, Achilles Reflex): Absent in S1 radiculopathy.
• Babinski’s Sign (Plantar Reflex): Positive in upper motor neuron lesion (spinal cord pathology).

✔ Clinical Importance:

• Hyperreflexia: Suggests upper motor neuron lesion (spinal cord compression, stroke).
• Absent reflexes: Seen in radiculopathy, peripheral nerve injury.

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7. Special Tests for Low Back Pain

✔ Straight Leg Raise (SLR) Test:

• Pain at <40° hip flexion → Suggests sciatica due to L5-S1 disc herniation.

✔ Crossed SLR Test:

• Pain in contralateral leg → Suggests large disc herniation compressing nerve roots.

✔ Schober’s Test:

• Reduced lumbar flexion (<5 cm increase) → Suggests ankylosing spondylitis.

✔ ✔ Femoral Nerve Stretch Test:

• Patient Position: Prone (lying face down).
• Procedure: The examiner flexes the knee while extending the hip.
• Positive Test: Pain radiating down the anterior thigh suggests L2-L4 nerve root compression (e.g., upper lumbar disc herniation).

✔ Prone Instability Test:

• Used for detecting lumbar instability.
• Procedure: The patient lies prone with their legs hanging off the edge of the table. They lift their legs while pressure is applied to the lumbar spine.
• Positive Test: If pain is relieved when the legs are lifted, lumbar instability is suspected.

✔ Quadrant Test:

• Tests for lumbar facet joint pathology.
• Procedure: The patient extends and rotates their spine while pressure is applied.
• Positive Test: Pain indicates facet joint dysfunction or lumbar spondylosis.

✔ Sign of the Buttock:

• Differentiate lumbar pathology from hip pathology.
• Procedure: Perform SLR, then flex the knee and try hip flexion again.
• Positive Test: If hip flexion remains limited, it suggests hip pathology, not lumbar pathology.

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8. Provocative Tests for Radiculopathy & Sciatica

✔ SLR (Straight Leg Raise) Test:

• Procedure: Raise the patient’s straight leg while they are supine.
• Positive Test: Pain in the posterior thigh, calf, or foot suggests lumbar radiculopathy (L5-S1 disc herniation).

✔ Bragard’s Test:

• Procedure: Perform SLR, then dorsiflex the ankle.
• Positive Test: Increased pain suggests sciatica.

✔ Bowstring Test (Popliteal Compression Test):

• Procedure: After a positive SLR, flex the knee slightly and apply pressure to the popliteal fossa.
• Positive Test: Reproduction of sciatic pain suggests nerve root irritation.

✔ Slump Test:

• Procedure: The patient sits, flexes their neck, extends their knee, and dorsiflexes their ankle.
• Positive Test: Sciatic pain suggests lumbar disc herniation.

✔ Piriformis Syndrome Test:

• Procedure: The patient lies supine while the hip is flexed, adducted, and internally rotated.
• Positive Test: Pain in the buttocks suggests piriformis syndrome (sciatic nerve compression by the piriformis muscle).

✔ Valsalva Maneuver:

• Procedure: The patient performs a forceful exhalation against a closed glottis (like straining during defecation).
• Positive Test: Increased pain suggests space-occupying lesions (disc herniation, tumor, spinal stenosis).

✔ Femoral Nerve Stretch Test:

• Procedure: The patient lies prone, and the examiner extends the hip while flexing the knee.
• Positive Test: Pain in the anterior thigh suggests L2-L4 radiculopathy.

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9. Examination for Red Flags in Low Back Pain

✔ Cauda Equina Syndrome (Medical Emergency):

• Symptoms: Saddle anesthesia, bowel/bladder dysfunction, severe bilateral leg pain/weakness.
• Significance: Requires urgent MRI and surgical decompression.

✔ Spinal Infection (Osteomyelitis, Discitis):

• Symptoms: Fever, night pain, localized tenderness.
• Tests: ESR, CRP, MRI for confirmation.

✔ Spinal Malignancy:

• Symptoms: Weight loss, night pain, unrelieved by rest.
• Tests: MRI, X-ray, Bone scan.

✔ Aortic Aneurysm:

• Symptoms: Pulsatile abdominal mass, sudden severe back pain.
• Tests: Abdominal ultrasound, CT angiography.

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10. Clinical Correlation and Summary

✔ Mechanical Low Back Pain:

• Commonly due to muscle strain, ligament injury, or facet joint arthritis.
• Improves with rest and physiotherapy.

✔ Radiculopathy (Sciatica):

• Disc herniation compressing L5-S1 nerve roots.
• Positive SLR, Bragard’s, Slump tests.

✔ Spondylolisthesis:

• Vertebral slippage, causing back pain, stiffness, and radicular symptoms.
• Positive Step-off deformity on palpation.

✔ Spinal Stenosis:

• Narrowing of spinal canal, leading to neurogenic claudication (pain worsens with walking, relieved by sitting).
• Positive Shopping Cart Sign (pain relief on forward bending).

✔ Inflammatory Back Pain (e.g., Ankylosing Spondylitis):

• Morning stiffness, improves with exercise.
• Positive Schober’s Test, SI joint tenderness.

✔ Red Flag Symptoms:

• Cauda equina syndrome, spinal tumors, infections need urgent referral.

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Conclusion

A detailed examination of the low back region helps in differentiating mechanical, neurological, inflammatory, and systemic causes of back pain. Inspection, palpation, ROM testing, neurological assessment, and special tests guide accurate diagnosis and management. Identifying red flag symptoms is crucial to prevent delays in treating serious spinal conditions.

Knee Joint Examination – Detailed Guide

1. Introduction & Importance

The knee joint is the largest and most complex synovial joint, comprising the femur, tibia, and patella. It is prone to trauma, degenerative diseases, ligament injuries, and inflammatory conditions. A systematic knee examination helps in diagnosing conditions like ligament tears, meniscal injuries, osteoarthritis, inflammatory arthritis, and patellar disorders.

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2. Steps in Knee Joint Examination

✔ General Inspection
✔ Palpation
✔ Range of Motion (ROM) Assessment
✔ Ligament Stability Tests
✔ Meniscus Tests
✔ Patellar Examination
✔ Special Tests for Specific Knee Pathologies

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3. General Inspection

✔ Position & Posture

• Observe the patient's standing and supine positions.
• Look for valgus (knock-knee) or varus (bow-leg) deformity.
• Check for asymmetry or malalignment of the knees.

✔ Skin Changes

• Redness, swelling, warmth → Suggests inflammation, infection, or arthritis.
• Scars, sinuses, bruising → History of trauma or surgery.

✔ Swelling & Effusion

• Generalized swelling suggests joint effusion.
• Localized swelling over the patella suggests prepatellar bursitis.

✔ Muscle Wasting

• Quadriceps wasting → Common in chronic knee pathology (e.g., osteoarthritis, prolonged immobilization).

✔ Gait Analysis

• Antalgic gait → Painful knee pathology.
• Stiff-knee gait → Meniscal pathology.
• Instability while walking → Ligamentous injury.

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4. Palpation

✔ Temperature

• Increased warmth → Infection, inflammatory arthritis, acute trauma.

✔ Joint Line Tenderness

• Medial or lateral tenderness → Suggests meniscal tear.

✔ Patellar Tap Test (Ballottement Test) – For Large Effusions

• Procedure: Push the patella downward against the femur and release it.
• Positive Test: Patella floats and rebounds → Knee joint effusion.

✔ Bulge Test – For Small Effusions

• Procedure: Stroke the medial side of the knee and look for fluid bulging laterally.
• Positive Test: Fluid shift seen → Small effusion.

✔ Quadriceps Muscle Bulk

• Reduced size → Suggests chronic knee pathology (e.g., osteoarthritis, post-injury immobilization).

✔ Tenderness Over Ligaments

• Medial Joint Line Tenderness → Suggests medial meniscus or MCL injury.
• Lateral Joint Line Tenderness → Suggests lateral meniscus or LCL injury.

✔ Popliteal Fossa Examination

• Swelling here may indicate a Baker’s cyst (common in rheumatoid arthritis and OA).

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5. Range of Motion (ROM) Assessment

✔ Active Movements (Patient Moves the Knee)

• Flexion: Normal range 0° to 135°.
• Extension: Normal range 0° to -10°.
• Restricted or painful ROM suggests arthritis, ligament injury, or meniscal pathology.

✔ Passive Movements (Examiner Moves the Knee)

• Compare passive vs. active movement restrictions.
• Painful end-range movements → Suspect meniscal or intra-articular pathology.

✔ Hyperextension Test

• If knee hyperextends >10°, it suggests ligamentous laxity.

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6. Ligament Stability Tests

6.1 Anterior Cruciate Ligament (ACL) Tests

✔ Lachman Test (Most Sensitive ACL Test)

• Procedure: Knee at 20-30° flexion, stabilize femur, and pull tibia forward.
• Positive Test: Increased anterior translation → ACL tear.

✔ Anterior Drawer Test

• Procedure: Knee at 90° flexion, pull tibia anteriorly.
• Positive Test: Excessive anterior movement → ACL tear.

✔ Pivot Shift Test

• Procedure: Apply valgus stress while flexing the knee.
• Positive Test: Clunk or shifting → ACL tear.

6.2 Posterior Cruciate Ligament (PCL) Tests

✔ Posterior Drawer Test

• Procedure: Push tibia posteriorly at 90° knee flexion.
• Positive Test: Excess posterior movement → PCL tear.

✔ Sag Sign

• Procedure: Compare tibial tuberosity height in both knees.
• Positive Test: Tibia appears sunken → PCL tear.

6.3 Medial & Lateral Collateral Ligament Tests

✔ Valgus Stress Test (MCL Test)

• Procedure: Apply valgus force at 30° knee flexion.
• Positive Test: Increased medial opening → MCL injury.

✔ Varus Stress Test (LCL Test)

• Procedure: Apply varus force at 30° knee flexion.
• Positive Test: Increased lateral opening → LCL injury.

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7. Meniscus Tests

✔ McMurray Test (Most Common Meniscus Test)

• Procedure: Flex knee fully, rotate tibia internally/externally, and extend.
• Positive Test: Clicking or pain → Meniscal tear.

✔ Apley’s Grind Test

• Procedure: Patient prone, knee flexed to 90°, apply downward pressure while rotating.
• Positive Test: Pain → Meniscal injury.

✔ Thessaly Test

• Procedure: Patient stands on one leg and twists.
• Positive Test: Pain → Meniscal pathology.

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8. Patellar Examination

✔ Patellar Apprehension Test

• Procedure: Push patella laterally.
• Positive Test: Patient shows fear → Patellar instability.

✔ Clarke’s Test (Patellofemoral Pain Syndrome)

• Procedure: Press superior patella while patient contracts quadriceps.
• Positive Test: Pain → Patellofemoral dysfunction.

✔ Q-Angle Measurement

• Increased Q-angle >20° suggests patellar maltracking.

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9. Special Tests for Specific Conditions

✔ Noble’s Test (Iliotibial Band Syndrome)

• Procedure: Apply pressure to the lateral femoral condyle while flexing the knee.
• Positive Test: Pain at 30° flexion → IT band friction syndrome.

✔ Ege’s Test (Meniscus Injury)

• Procedure: Patient squats with feet turned outward (medial meniscus) or inward (lateral meniscus).
• Positive Test: Clicking or pain → Meniscal tear.

✔ Wilson’s Test (Osteochondritis Dissecans)

• Procedure: Internally rotate the tibia while extending the knee.
• Positive Test: Pain relieved on external rotation → Osteochondritis Dissecans.

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10. Clinical Correlation & Summary

✔ Osteoarthritis → Reduced ROM, crepitus, effusion.
✔ ACL/PCL Tear → Positive Lachman/Drawer tests.
✔ Meniscus Tear → Positive McMurray/Apley’s/Thessaly tests.
✔ Patellar Instability → Positive Apprehension Test.
✔ Inflammatory Arthritis → Warm, swollen joint, morning stiffness >1 hour.

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A systematic knee joint examination using inspection, palpation, ROM, special tests, and correlation with symptoms ensures accurate diagnosis and management of knee disorders.