Neurological and Physiological Basis of Movement

• Neurological and physiological basis involves both reflexive and voluntary movements

Reflexive Movements

• Involuntary and stereotyped responses
• They are elicited in response to a sensory stimulus
• Represent the simplest form of interaction with the world
• Control protection and posture

Voluntary Movements

• Performed under conscious control
• Purposeful and goal-directed
• Flexible and modifiable
• Most occupations require a combination of both voluntary and reflexive movements
• Motor control is the ability to regulate or direct the mechanics essential to movement
• Motor control emerges from multiple body systems, including cognitive and motor aspects
• Important CNS regions include the spinal cord, brainstem, cerebellum, basal ganglia, and sensorimotor areas of the cerebral cortex

Nervous System - Upper Motor Neurons (UMN)

• UMNs transmit signals from higher to lower centers in the nervous system
• Cell bodies are generally contained in the gray matter of the cerebral cortex motor area
• Axons are contained in the white matter and travel in descending motor tracks

Signs/Symptoms of UMN Lesions

• Common after CVA, TBI, SCI or MS, primary lateral sclerosis
• Damage to either somas or axons of UMNs proximal to anterior horn cells will produce UMN signs such as:
  • Weakness (paresis) or paralysis (plegia)
  • Disuse atrophy (muscle wasting)
  • Spasticity
  • Hypertonicity
  • Hyperreflexia
  • Positive Babinski and Hoffman sign

Lower Motor Neurons (LMN)

• Transmit signals from UMN to muscles
• Cell bodies are contained in the gray matter of the spinal cord and brainstem motor nuclei of cranial nerves
• Axons are contained in spinal and some cranial nerves

Signs/Symptoms of LMN Lesions

• Common after peripheral nerve injuries or diseases like Guillain-Barre, SMA
  • Flaccid paralysis followed by atrophy
  • Fibrillation or fasciculations
  • Hypotonia
  • Hyporeflexia or areflexia

Key CNS Functions - Cerebral Cortex

• Sensorimotor areas identify locations of targets, choosing actions, programming movements
• The primary motor cortex contains UMNs and conveys signals to modulate lower levels

Spinal Cord

• Contains LMNs that send commands to muscles for reflexes and voluntary movement
• Receives and integrates somatosensory input

Brainstem

• Regulates posture and movement via various nuclei
• Integrates somatosensory information from cranial nerve nuclei
• Controls motor output to neck, head, and face muscles via cranial nerves

Cerebellum

• Compares information from the cerebral cortex about intended motor plans with sensory information received from the spinal cord and brainstem
• Modulates UMN activity via communication with cerebral cortex motor areas and brainstem
• Important for updating motor plans, motor learning, motor response modulation

Signs of Damage to the Cerebellum

• Poor balance and coordination
• Dysmetria, intention tremors

Basal Ganglia

• Receives information from the cerebral cortex and modulates UMN activity
• Important for motor strategy planning, appropriate motor plan selection, movement initiation/termination

Motor Dysfunctions by CNS Lesions - Cortical Lesions

• Impaired ability to plan and produce effective/efficient movement
• Signs are often contralateral
• Hypo- or hypertonia
• Spasticity, often accompanied by clonus and/or clasp-knife reflex
• Clonus
• Weakness
• Loss of fractionation
• Apraxia
• Lead pipe rigidity (common in PD): Not velocity dependent
• Cold environment (outside) increases tone
• Cold gym (while doing intentional movements) helps decrease tone

Motor Dysfunctions by CNS Lesions - Cerebellar Lesions

• Impairments generally affect coordination (accuracy, smoothness, control)
• Intention tremor
• Dysmetria
• Dyssynergia
• Dysdiadochokinesia
• Adiadochokinesia
• Ataxia
• Ataxic gait

Basal Ganglia Lesions

• Usually cause hypo and hyperkinetic signs
• Resting tremors (stop at initiation of voluntary movement, fatiguing)
• Cogwheel rigidity
• Hypokinesia
  • Akinesia: poor initiation of voluntary movement
  • Bradykinesia = SLOW
• Reflected in lack of facial expression, monotone speech, reduced eye movement, reduced arm sway, decreased balance and equilibrium responses
• Festinating gait
• Athetosis
• Dystonia
• Chorea
• Hemiballismus

Muscle Tone

• Involuntary resistance of a muscle to passive stretch
• Felt when passively moving the patient's body part
• Assessed by observing muscular response to passive stretch
• Hypotonia: less than normal resistance
• Hypertonia: more than normal resistance
• Rigidity as a severe form of hypertonia
  • Lead pipe
  • Cogwheel

Deep Tendon Reflexes

• Normal DTR: brisk tap of muscle tendon results in muscular contraction
• This response is modulated by cerebral cortex motor areas on brainstem
• Hyperreflexia: increase in DTR
• Hyporeflexia: decrease in DTR
• Areflexia: absence of DTR
• Assessed by palpating muscle tendon and tapping briskly with reflex hammer

Postural Control

• Controlling the body's position in space for stability and orientation is key
  • Righting reactions support vertical head positioning and trunk/limb alignment
  • Equilibrium responses are activated when posture is perturbed
  • Protective reactions prevent head and face injury from failed equilibrium

Paresis and selective motor control:

• Typically assess weakness and poor fractionation of movement through observation and ADL tasks
• Observe:
  • Abnormal limb posturing or trunk alignment
  • Compensatory motor strategies
  • Weakness to specific muscle groups
  • Inability to selectively control specific joints
  • Incorrect timing of movement components
  • Inability to appropriately coordinate movement at adjacent joints

Motor Planning

• The capacity to interact effectively, efficiently with the environment
• Task practice yields procedural memory storage
• Trauma can lead to ideomotor apraxia

Neuro Screening and Evaluation - Occupational Profile

• Includes the history of the current condition, medical history, and home information
• Also, caregiver support, PLOF, DME/AD/AE, history of falls, driving, and work
• Questionnaires include COPM, Stroke Impact Scale, and Patient-Specific Functional Scale

Observation

• Involves posture and symmetry, also synergistic patterns, and involuntary movements
• Also, muscle tone and/or atrophy with edema/skin integrity assessments
• Shoulder subluxation with metric scale measurement

Cognition

• Orientation x4
• Delayed recall (3 words to remember)
• Behavior/Language/Attention/Affect

Other

• Command-following
• Impulsivity/safety awareness

Modified Ashworth Scale

• 0: no increase in tone
• 1: slight increase in tone; catch/release at end ROM
• 1+: slight increase in tone, catch/release and resistance through rest ROM
• 2: more marked increase in tone through ROM, but the affected part moved easily
• 3: considerable increase in tone, passive movement difficult
• 4: affected part in rigid flexion and extension

Sensation

• Light touch, sharp/dull, proprioception, stereognosis, vibration, temperature should be tested
• Patient's vision should be occluded
• Move proximal to distal as per ASIA classification
• Compare side to side and look for patterns

Coordination

• Ability to produce accurate, smooth, and controlled movement
• Observed from first sight of patient, also in range of Motion, MMT, ADLs and/or simulated ADLS

Incoordination

• Difficulty initiating, controlling, terminating movement
• Slow, jerky movement
• Inaccuracy in movement path, also movement destination (dysmetria)

Visual Perception

• Acuity, smooth pursuits, saccades and fixation
• Visual field scores greater than 5 degrees off norms indicate field deficit
• Convergence
• Near point of convergence should be 3cm from nose
• Observe for diplopia and eye movement issues

Olfactory Nerve (CN I)

• Type: Sensory
• Function Testing: Smell
• Test: Identify a familiar smell (e.g., coffee, orange, vanilla, or cinnamon)
• Abnormal findings: Anosmia

Optic Nerve (CN II)

• Type: Sensory
• Function Testing: Vision/visual acuity, pupillary reflex
• Test: visual acuity with a Snellen or pocket card, and screen visual field one eye at a time
• Abnormal findings: myopia, hyperopia, or cataracts, and
• Impaired direct or consensual light reflex
• Homonomous hemianopsia: Loss of the side (half) of the visual field, opposite from the neurological injury
• Bitemporal hemianopsia: Loss of the lateral visual field from each eye, often related to pituitary tumor

Oculomotor Nerve (CN III)

• Type: Motor
• Function Testing: Most eye movements (adducts, elevates, and depresses the eye, opens the eyelid.
• Test: Check resting eye position by observing the reflection of room light in the pupil
• Test: Test for conjugate eye movements with an "H" pattern of eye movement and convergence

Trochlear Nerve (CN IV)

• Type: Motor
• Function Testing: Eye movements up/down, back/forth. Depresses the adducted eye

Trigeminal Nerve (CN V)

• Type: Both
• Function Testing: Facial sensation and jaw motor/mastication, taste
• Test: Jaw strength, face sensation and test corneal reflex
• Abnormal findings: Anesthesia or ipsilateral sensation decrease

Abducens Nerve (CN VI)

• Type: Motor
• Function Testing: abduct the eyeballs -
• See CN III & IV for testing

Facial Nerve (CN VII)

• Type: Both
• Function Testing: facial expressions, symmetry of face as a whole, taste from the front of the tongue
• Test:Test all muscles of facial sensation
• Abnormal findings: paralysis of the upper & lower face , decreased appetite and taste

Vestibulocochlear Nerve (CN VIII)

• Type: Sensory
• Function Testing: screen hearing with whisper or rubbing fingers and weber test for sensorineural loss

Glossopharyngeal Nerve (CN IX)

• Type: Both
• Function Testing: Swallowing and taste
• Test: Ask patient if having issues swallowing
• Test motor phayrnx and palate- test gag reflex

Vagus Nerve (CN X)

• Type: both
• Function Testing: gag, swallow, cardiorespiratory regulation
• Test motor palate/pharynx
• Observe soft palate rise

Accessory Nerve (CN XI)

• Type: Motor
• Function Testing: MMT upper trap and SCM function

Hypoglossal Nerve (CN XII)

• Type: Motor
• Function Testing: movement of the tongue - asking the patient to stick out their tongue

Postural Analysis

- Notes: - should be done sitting

Check and monitor inferior and superior angle of scapula, be sure patient is at the end of the seat

UE Screen- BUE AROM

• Includes testing both L & R sides for:
  • Shoulder Flexion & Abduction
  • Functional IR and ER
  • Elbow Flexion & Extension
  • Forearm Pronation & Supination
• Wrist Extension and Flexion :
  • Composite digit flexion, and extension -

UE Screen- BUE MMT:

• Includes testing both L & R sides for:
  • Shoulder Flex & Abd (C5 nerve root and deltoids)
  • Shoulder IR & ER
  • Elbow Flex (C5 nerve root with biceps) & Ext (C7 nerve root with triceps)

BUE MMT:

• Includes both L & R sides for:
  • Forearm Pronation
  • Forearm Supination
  • Wrist Extension C6 (ECRL/B)
  • Wrist Flexion C7
  • Composite digit flex C8 (FDS), and digit ext C7
  • D1 extension (C7 & C8??)(Posterior Interosseous n.)
  • DAB abduction root T1 (dorsal interossei)

Postural Control and Balance

• Functional Ambulation
• Transfers
• TUG
• FRT

Functional Activity-

• Used to help increase body parts affected
• Includes: - Doffing/donning socks/shirts - Any transfer
  • Ambulation
  • Brushing teeth

Neuroplasticity

• use it or lose it
• Intensity/ repetition matters.
  • Age, interest/saliance also matters. *The Panunmbra= weakened/atrophied regions by injury is susceptible to death