Neurology Physiotherapy Wk7-11

Difference between Walking & Gait

Walking: means of locomotion involving the use of two legs, where one foot is always in contact with the ground, and each leg alternately provides support with propulsion (the action)

Gait: a person’s manner of locomotion (the pattern)

What are some common neurological Presentations of Gait?

• Ataxic gait (lurching from side to side)

• Parkinsonian gait (shuffling)

• Spastic gait (hemiplegic, diplegic) (affected leg swoops)

• Myopathic gait (waddling)

• Neuropathic gait (high-stepping to compensate foot drop)

3 Essential Components of Walking

1. Propulsion → generation of power to propel body in intended direction

2. Postural control → maintain dynamic stability though movement

3. Adaptation → modulation of pattern to achieve goals

What is Postural Control? and the 2 aims?

Control of posture and movement in attaining balance

• Motor output that occurs following integration of sensory, perceptual, cognitive and motor processes

Aims:

1. Postural equilibrium/stability: maintain upright position and COM

2. Postural orientation: gravity, vertical, internal references, environment

Sensorimotor Control of Balance

1. Sensory Input (vestibular, visual, proprioceptive)

2. Integration of Input (coordination of posture, movement and balance)

3. Motor output (VOR, motor impulses)

4. Balance

3 Essential Components of Sensation

• Somatosensory System (proprioception)

• Vision (perception of verticality)

• Vestibular system (head position relative to gravity)

Sensory feedforward for anticipatory postural adjustments

Components of Sensory Integration and Weighting of Perception

1. Brain receives visual, vestibular and somatosensory input to guide motor control

2. Signals are effectively integrated and weighted (upweighted-downweighed)

3. Minimal cognitive processing by the cortex for postural control

Movement Plan Selection and Coordination

Optimal motor plans developed with:

• Knowledge of individual, task and environment

Motor plan generated in cerebral cortex → refined in BG → transmitted to peripheral motor system → motor plan acted upon

BG and cerebellum use sensory feedback to detect errors

Execution of Balance Motor Responses

• Motor response by which balance recovering determines whether the displacement is COM causes a fall

• Appropriate motor responses require

  • Muscle strength, power, endurance, ROM

  • Fine grading of agonists, antagonists, synergists and appropriate co-contraction

  • High level of reciprocal innervation

  • Attention, cognition, judgement and memory

3 Reflexes of Balance in Motor

1. VOR → stabilization of the gaze when the head moves

2. VSR → controls body when head moves

3. Righting reactions → head righting, trunk righting and limb movement

What are APRs?

APR → Automatic Postural Responses

• Operate to keep center of gravity of base of support

• Occur in response to unexpected stimulus

• If a balance disturbance is predicted, the body responds in advance by developing a “postural set” to counteract the coming forces

• Failure to produce appropriately calibrated APAs → risk of sudden balance loss

• 4 stereotypical APRs

APR: Ankle Strategy

• Anteroposterior perturbations

• Ankle movement to restore COM

  • Forward loss of balance: gastrocs → hammys → paraspinals

  • Backward loss of balance: tib ant → quads → abdominals

• Head movement occurs in-phase with hips

APR: Hip strategy

• Anteroposterior and medial-lateral perturbations

• Rapid hip flexion and extension to maintain

  • Forward loss of balance: abdominals → quads → tib ant

  • Backward loss of balance: paraspinals → hammys → gastrocs

• Head movements occur out of phase with hips

APR: Suspension Strategy

• Lowering of COG toward BOS

• lower extremity flexion

• easier to control COG

APR: Stepping and Reaching Strategies

• Large forces displace COM beyond stability limits

• Step/reach enlarges BOS

• Perturbations are rapid and large amplitude

Motor Components of Balance: Volitional Postural Movements

• Consciously controlled movements

• Range from simple weight shifts to complex balance skills

• disturbances COG disturbances to reach a goal

• Strongly modified by experience and instruction

3 Key Steps in Functional Assessment of Balance

1. Observe the Task

2. Identify movement components (postural alignment, quality, patterns)

3. Identify impairments interfering with movement

Physical Examination of Balance: Examine & Establish

Examine:

• variety of conditions, static/dynamic sitting, static/dynamic standing, running, skipping, bouncing, jumping etc

Establish:

• level of independence and support, endurance, alignment/symmetry, balance reactions, anxiety levels

Common Impairments in Neurological Patients Associated with Reduced Balance

Motor Dysfunction

Musculoskeletal: Muscle strength, trunk instability, ROM, altered muscle tone

Biomechanics: Stability limits, balance response, altered movement strategies

Sensory Dysfunction:

Altered sensation: proprioception, vestibular system damage, dizziness, visual deficits, somatosensation

Altered Sensory Integration: difficulty dividing attention between tasks, delayed response, altered stability limits

Gait Problems in Neurological Patients - Heel Strike to Midstance

• Impaired Trunk control (upper trunk over lower trunk)

• Lack of proper initiation pattern (lateral weight shift, forward trunk flexion)

• Insufficient ankle joint DF (muscle tightness, oedema, impaired muscle activation)

• Inappropriate foot contact

Gait Problems in Neurological Patients - Single & Double Limb Support

• Insufficient trunk control to maintain alignment over one leg (loss up upper trunk control, asymmetries during unilateral stance)

• Altered LL control (hip instability, loss of knee control, altered timing of LL muscles)

• Loss of ability to transfer weight through foot (inability to maintain leg on floor behind body)

Gait Problems in Neurological Patients - Early & Late Swing

• Atypical leg muscle firing patterns (lack of initiation, can’t control trunk and LL sequencing)

• Inability of body to continue to move forward as leg swings

• Aberrant foot movement

Functional Ambulation Assessment Considerations

• Clinical reasoning

• Consider use of walking aid

• Create a safe situation

• Incorporate various environmental contexts and tasks

• Challenge their behavior

Activity Measures (Balance, Mobility/Gait)

Balance

• Sitting Balance test

• Clinical Test of Sensory Interaction and Balance

• Functional reach test / lateral reach test

• Four square step test

Gait/Mobility

• 6-min walk test

• Timed up and go test

Considerations for Re-training Balance and Gait

• Impairments may be temporary and re-trained (neural adaptation)

• Consider principles of motor learning

• Follow a progression

• Target patient’s deficits/impairments

• Manage fear of falling and falls risk

Critical Factors to Optimize Motor Learning for Restoration of Function

• Establish concrete goals

• Modify tasks to achieve success

• Provide instructions as well as demonstrations

• Practice routines using same cues

• Monitor performance

• Give feedback

Benefits of Balance Training

• Encourages LL strength and endurance

• Optimize soft tissue extensibility and joint flexibility

• Maximize skill through progressive challenges

• Improve ADLs

Gait training often focusses on ___-___degrees hip _____ in _____ stance plantarflexion at end of stance for ____ __ flexion at the hip for pull off.

Gait training often focusses on 10-15hip extension in late stance plantarflexion at end of stance for push off flexion at the hip for pull off.

Parkinson Gait Characteristics

• Shuffling steps

• Bradykinesia

• Difficulty turning

• Reduced arm swing

• Muscle weakness

4 Components of Re-education in Balance

1. Restoration

2. Adaptation

3. Maintenace

4. Prevention

3 Types of Gait Training to maximize speed, skill and endurance

Overground walking → regular floor surface (whole task)

Speed-dependence & BW supported Treadmill → speed and duration gradually increased

Robot-assisted gait → walking with electromechanically controlled footplates that controls the legs.

Examples of Gait Training Interventions

• Improve gait velocity

• Improve swing motion and step length

• Address contributing impairments

• Improve gait symmetry

• Minimize impact of compensations

• Improve push-off