Examination of the Somatic Motor System

Body Asymmetry

Uneven body parts indicating potential neurological issues.

Joint Alignment

Positioning of joints affecting movement and posture.

Postures

Body positions reflecting muscle tone and balance.

Gait

Manner of walking assessed for abnormalities.

Rostrocaudal Sequence

Inspection order from head to toes.

Muscle Characteristics

Assessment of muscle bulk, tone, and strength.

Coordination

Ability to use different body parts together.

Station Assessment

Evaluation of standing posture and balance.

Gait Testing

Observing walking patterns for abnormalities.

Tandem Walking

Heel-to-toe walking to assess balance.

Deep Knee Bend

Test for lower limb strength and stability.

Somatotype

Classification of body build compared to standards.

Gait Analysis

Critical component of neurological examinations.

Heel Displacement

Deviation of heel from midline indicating gait issues.

Length-Strength Principle

Muscles strongest when shortest, weakest when longest.

Clinical Significance

Importance of findings in diagnosing conditions.

Involuntary Movements

Uncontrolled movements indicating neurological dysfunction.

Fasciculations

Small, local muscle contractions visible under skin.

Tremors

Rhythmic shaking movements often linked to disorders.

Steadiness

Ability to maintain balance during movement.

Unobtrusive Observation

Discreetly watching spontaneous activity for assessment.

Abnormal Findings

Unexpected results indicating potential health issues.

Lateropulsion

Side-to-side movement often seen in cerebellar dysfunction.

Neck Flexors

Strongest when neck is flexed, shortest position.

Neck Extensors

Strongest when neck is extended, prevents head drop.

Broad-based gait

Compensates for cerebellar unsteadiness during walking.

Tandem walking

Critical for detecting subtle ataxia in patients.

Quadriceps

Strongest with knee extended, shortest position.

Hamstrings

Strongest with knee flexed, shortest position.

Starling's Law

Cardiac muscle strength increases with fiber length.

Testing Adjustments

Inspect symmetry and adjust testing positions accordingly.

Involuntary movements

Includes tremors, tics, chorea, and fasciculations.

Antigravity Muscle Principle

Postural muscles are stronger than their antagonists.

Neck extensors vs. flexors

Extensors prevent head drop, stronger than flexors.

Triceps vs. Quadriceps

Both lock limbs against gravity during testing.

Plantar flexors vs. dorsiflexors

Plantar flexors are stronger for propulsion and posture.

Matching principle

Select movements matching examiner's strength for testing.

Rostrocaudal Sequence

Testing order: Head to toe for muscle strength.

Active ROM

Patient voluntarily moves joint during range of motion.

Passive ROM

Examiner moves joint when patient cannot do so.

Decerebrate Rigidity

Overactivity of gamma efferent fibers causes rigidity.

Scapular winging

Observed when patient leans against wall with arms.

Hip Adductors vs. Abductors

Adductors prevent limb splaying, stronger in quadrupeds.

Key Muscle Pairs

Stronger actions defined by joint movement pairs.

Latissimus Dorsi

Large back muscle aiding shoulder adduction.

Arm Elevation Test

Assesses shoulder flexor strength during elevation.

Decorticate Rigidity

Flexor reflex responses with diminished extensor tone.

Beevor Sign

Umbilicus shifts upward if lower abs are weak.

Scapular Winging

Indicates serratus anterior paralysis affecting scapula.

Hip Flexion Test

Patient lifts knee against resistance from examiner.

Thigh Adduction Test

Evaluates strength of adductor muscles in thighs.

Biceps Testing

Patient flexes forearm against examiner's extension force.

Triceps Testing

Assesses extension strength in flexed elbow position.

Wrist Flexors Test

Patient makes fist; examiner resists wrist extension.

Wrist Extensors Test

Examiner applies pressure on dorsiflexed wrist.

Dorsiflexion Test

Manual resistance during foot dorsiflexion assessment.

Plantar Flexion Test

Gait assessment by walking on toes.

Finger Muscle Inspection

Check for atrophy in hand muscles.

Arm Adduction Downward Test

Assesses strength of latissimus dorsi and teres major.

Scapular Adduction Test

Evaluates rhomboids and trapezius strength.

Supine Tests

Includes sit-ups or leg raises for abdominal strength.

Critical Technique

Motivate patient for maximal effort during tests.

Symptom-Driven Tests

Reproduce triggers to assess exertion weakness.

Engagement Principle

Frame tests as challenges to increase effort.

Forearm Testing

Includes wrist flexors and extensors strength evaluation.

Abduction

Movement away from the body's midline.

Adduction

Movement towards the body's midline.

Dynamometers

Tools for measuring muscle strength objectively.

Finger Extension

Hyperextension of fingers against resistance.

Finger Flexion

Grip strength measured with wrist in dorsiflexion.

Myotonia

Delayed muscle relaxation after contraction.

Percussion Irritability

Transient dimple forms upon muscle percussion.

Myotonic Dystrophy

Genetic disorder with CTG/CCTG repeats.

Myoedema

Palpable hump at percussion site.

Muscle Contraction

Shortening of muscle fibers during activity.

Antigravity Muscles

Muscles strongest in shortened positions.

Fist Test

Test for delayed finger/wrist relaxation.

Eyelid Test

Sustained eyelid closure indicates myotonia.

Cannon's Law

Increased irritability in denervated muscles.

Neuropathies

Disorders affecting nerve function.

Hyperexcitability

Increased responsiveness of nerve fibers.

Myopathies

Muscle disorders affecting strength and function.

Limb-Girdle Dystrophy

Type of myopathy affecting shoulder and pelvic muscles.

Rippling Muscle Disease

Self-propagating muscle rippling due to mutation.

Hypertonia

Increased muscle tone, seen in spasticity.

Functional Positioning

Optimizing muscle testing positions for accuracy.

Engagement

Motivating patients for maximal effort during tests.

Lesions

Damage to peripheral nerves affecting muscle function.

Muscle Wasting

Reduction in muscle mass within 2-3 weeks post-injury.

Hypokinetic

Reduced movement, often seen in Parkinson's Disease.

Bradykinesia

Slowness of movement characteristic of Parkinson's.

Hyperkinetic

Excessive movement disorders, including tremors.

Muscular Fasciculation

Twitching of muscle fibers, often in chronic diseases.

Muscular Contracture

Permanent shortening of muscles opposing paralyzed muscles.

Muscle Tone

State of muscle tension; absence results in flaccidity.

Hypotonia

Diminished muscle tone, leading to flaccid muscles.

Athetosis

Slow, writhing movements, primarily in distal limbs.

Chorea

Rapid, jerky movements, often nonsuppressible.

Tonic Spasm

Sustained contraction of muscles, seen in seizures.

Tremor

Rhythmic involuntary movements from muscle contractions.