Lecture 5: Mvmt System & Balance Diagnosis

During INITIAL POSTURE, what constructs should you assess?

Postural control

• Verticality

• Stability

You're looking at the patient before they initiate movement: Are they upright/aligned relative to vertical? Can they maintain the starting position?

During PREPARATION, what should you assess?

Whether the patient appropriately sets up/adjusts for the task and understands the movement instructions.

Consider:

• Stimulus identification

• Response selection

Think: Do they understand what they're supposed to do, and can they prepare the appropriate response?

During INITIATION, what construct should you assess?

Coordination, specifically:

• Smoothness

• Sequencing

• Timing

(Did the movement begin with the appropriate timing and direction?)

During EXECUTION, what constructs should you assess?

• Coordination → smoothness, sequencing, timing

• Alignment → appropriate body/segment alignment

• Amplitude → appropriate amount/size of movement for the task

During TERMINATION, what constructs should you assess?

• Alignment

• Coordination

• Postural control → verticality + stability

• Symptom provocation

  • What does the patient look like when they finish the movement, and did finishing it provoke symptoms?

During OVERALL TASK PERFORMANCE, what should you assess?

• Speed → Was the overall speed appropriate for the task?

• Repetition → Did performance change with repetition?

  • If yes, consider all constructs. 

A patient performs sit-to-stand with inadequate forward trunk movement while rising. What phase and construct describe the problem?

Execution → Amplitude

A patient completes sit-to-stand but is unstable once they reach standing. What phase and construct describe the problem?

Termination → Postural control → Stability

What is sequencing & timing constructs?

The spatial organization and temporal structure of different body segments needed to complete a task, including initiation, execution, and termination.
Example: Delayed initiation, delayed stepping strategy, or freezing during a 180° turn.

• these describe coordination

What is smoothness construct?

The ability to complete a task in a continuous fashion without interruptions in velocity or trajectory.
Example: Hesitancy during reaching, jerky limb advancement during swing, or intention tremor. 

• this describes coordination

What is verticality construct?

The ability to orient the body in relation to the line of gravity.
Example: Lateral trunk lean or head tilt. 

• this describes postural control

What is stability construct?

The ability to control the body’s center of mass in relation to the base of support.
Example: Increased sway or loss of balance during reaching.

• this describe postural control

What is alignment construct?

The biomechanical relationship of body segments to one another and to the base of support in order to achieve the task.
Example: Elevated shoulder, genu varus/valgus, rotated pelvis, or scoliosis.

What is amplitude construct?

The extent or range of movement, either of the whole body or body segments, used to complete a task.
Example: Low amplitude of arm swing or asymmetric step length after stroke.

What is speed construct?

The rate of change or velocity of a body segment or body displacement during task execution.
Example: Time to walk 10 meters and back, or time to complete a reaching task.

What is symptom provocation?

An observation or patient report of symptoms caused by movement.
Example: Change in O₂ saturation or heart rate, or reported pressure, pain, dizziness, or fear.

Six core tasks are used for every patient, emphasizing….

• Controlled initial conditions → standardized environment + scripted instructions

• Analysis across all aspects of the movement continuum

• Progressions → add complexity to better understand movement capacity

• Regressions → reduce task demands so independent movement can still be observed

  • sitting, STS, standing, walking, step up/down, reach/grasp/manipulate

What aspects of a core task can be adapted to fully evaluate movement constructs? AKA what can we change to make a task harder or easier?

• Instructions

• Environmental setup

• Number of repetitions

What factors should be considered when changing a core task?

• Speed

• Vision

• Cognitive demand

• Surface type/height

• Response to internal & external perturbations

What is the order for providing assistance during core task movement analysis?

Verbal cue → Tactile cue → Physical assistance

What is balance (postural control)?

The ability to control the body’s position in space with respect to gravity, support surfaces, visual surroundings, and internal references for two purposes:

• Stability

• Orientation

What is Steady-State Postural Control?

The ability to control the body’s COM within the BOS under predictable, relatively stable conditions.
Example: Maintaining standing without excessive sway or LOB.

What is Anticipatory Postural Control?

The ability to generate postural adjustments BEFORE voluntary movement to prepare for the expected disturbance or reposition the COM before changing the BOS.
Example: Shifting weight onto one leg before taking a step.

What is Reactive Postural Control?

The ability to respond to sensory input signaling a disturbance and make an appropriate response to maintain/regain postural control.
Example: Taking a step after an unexpected push to prevent a fall.

What is a Postural Control Strategy?

The use of muscle synergies for postural control during postures, voluntary movements, and internal/external perturbations.
Examples: Sway, anticipatory postural adjustments, ankle/hip strategies, and protective stepping responses.

What is Sensory Processing?

The CNS’s ability to select, weight, and integrate sensory information to develop an accurate perception of the body and environment.

• input fom visual, vestibular, somatosensory

What is Balance Confidence?

The degree of certainty a person has in their ability to maintain balance and stability while performing tasks.

What is Perception of Verticality?

The perception of the body’s orientation relative to gravity, based on information about the body and environment.

What is Multi-Task Ability?

The attentional ability to maintain postural control during goal-directed activity while simultaneously performing another motor/cognitive task or dealing with concurrent sensory input

Which core tasks primarily assess Steady-State Postural Control?

Sitting and standing

Which core tasks primarily assess Anticipatory Postural Control?

• Sit-to-stand

• Walking

• Step up/down

• Reach/grasp/manipulate
  Sitting and standing can also assess it with task or environmental variations.

How can Reactive Postural Control deficits be observed during the core tasks?

Through a spontaneous LOB or by perturbing the patient/task/environment

What key movement observations suggest SSPC: Postural Movement Strategies?

• Stability: unable to maintain position/falls, needs UE support, atypical BOS, or atypical postural sway

• Alignment: impaired orientation of axial body segments, UEs held close to body, high guard/reaching/counterbalancing with UEs

What key Body Structure/Function findings support SSPC: Postural Movement Strategies?

• Insufficient trunk/LE muscle performance against gravity

• Impaired reflex integrity/tone → hypotonia or hypertonia

• Difficulty isolating body segment/limb movements through available ROM

• May have impaired interlimb or intralimb coordination

What outcome measures can be used for Deficit in Steady-State Postural Control: Postural Movement Strategies?

• Movement Assessment Scale → Balance Sitting item

• Berg Balance Scale (BBS) → items 2, 6, 7, 13, 14

• Function in Sitting Test (FIST) → static sitting item

• Postural Assessment Scale for Stroke (PASS) → items 1–4

• BESTest → items 11, 19A

• Mini-BESTest → items 3, 7

How are deficits in SSPC: Sensory Processing revealed during movement analysis?

Task/environmental variations are required, such as eyes closed or compliant surfaces, to reveal the sensory-processing deficit

What movement observations suggest SSPC: Sensory Processing during sitting or standing with altered sensory conditions?

• Stability: atypical postural sway

• Alignment: impaired orientation of axial body segments relative to the plumbline or each other

What Body Structure/Function (BSF) findings support SSPC: Sensory Processing?

• Impaired mCTSIB performance → unable to maintain each position for 30 sec

• Impaired sensory integrity → light touch, vibration, proprioception in LE

• Impaired visual acuity

• Impaired gaze stability → Head Impulse Test, Dynamic Visual Acuity

What outcome measures can be used for SSPC: Sensory Processing?

• FIST → Sitting Eyes Closed

• BESTest → items 19B–D

• Mini-BESTest → item 8

What key movement observations suggest SSPC: Verticality?

During sitting or standing:

• Lateral, posterior, or anterior trunk lean away from midline

• Pushes away from midline with an extremity

• Resists return to midline

What Body Structure/Function tests and outcome measures support SSPC: Verticality?

• Scale for Contraversive Pushing

• Burke Lateropulsion Scale

• BESTest → item 20

• Mini-BESTest → item 9

What key movement observations suggest SSPC: Balance Confidence?

During sitting or standing:

• Stability: Performance varies depending on availability of nearby support surfaces

• Symptom provocation: Task may evoke pain, anxiety, fatigue, fear, lightheadedness, or dizziness

What Body Structure/Function findings may support SSPC: Balance Confidence?

Changes in vital signs, including increased:

• Respiratory rate

• Heart rate

• Blood pressure

What activity-level findings support SSPC: Balance Confidence?

• Supportive environment/physical support → decreased fear or anxiety

• Open environment → increased fear or anxiety

What movement observations during Sit-to-Stand suggest APC: Postural Movement Strategies?

• Initiation

  • Timing → delayed

  • Sequencing → altered initial direction, no posterior shift of feet behind knees

• Execution

  • Amplitude → inadequate forward trunk flexion or tibial translation

  • Sequencing → knee extension before hip extension

• Termination

  • Stability → needs UE support, atypical BOS, or atypical sway

• Whole task

  • Stability → LOB with recovery, high guard/reaching/counterbalancing

How are APC: Postural Movement Strategy deficits revealed during sitting and standing?

Task/environmental variations are required. With these variations, you may see LOB with recovery, UE support, atypical BOS/sway, or high guard/counterbalancing.

What Body Structure/Function findings support APC: Postural Movement Strategies?

• No trunk/LE muscle-performance deficits limiting ability to support body weight against gravity

• May have interlimb or intralimb coordination deficits

• Impaired ability to isolate body segment/limb movement through available ROM

What outcome measures can be used for APC: Postural Movement Strategies?

• FGA

• DGI

• Berg Balance Scale

• BESTest

• Mini-BESTest

• Five Times Sit-to-Stand

• Functional Reach Test

What movement observations during Step Up/Down suggest APC: Postural Movement Strategies?

• Initiation: delayed timing, multiple starts/stops, LE lifts before weight shift

• Execution: atypical weight-shift amplitude, decreased leg-lift height, impaired sequencing/timing of weight shift + leg lift, non-continuous movement, impaired foot placement

• Termination: needs UE support, atypical BOS, or atypical sway

• Whole task: LOB with recovery or high guard/reaching/counterbalancing

What movement observations during Walk & Turn suggest APC: Postural Movement Strategies?

• Initiation: delayed, multiple starts/stops, LE lift before weight shift

• Execution: decreased speed during turn, variable foot placement/non-continuous swing, atypical step height, hesitation/stopping during turn, wide turn or multiple steps to turn

• Termination: UE support, atypical BOS, or atypical sway

• Whole task: LOB with recovery or high guard/reaching/counterbalancing

What movement observations during Reach & Grasp suggest APC: Postural Movement Strategies?

• Initiation: delayed, multiple starts/stops, UE lifts before weight shift

• Execution: inadequate forward translation of trunk/reaching UE; atypically slow or fast

• Termination: moving arm used for support

• Whole task: LOB with recovery, high guard/counterbalancing, or requires UE support to complete task