Upper Limb Considerations in Neurologic Conditions – Comprehensive Study Notes

Upper Limb Considerations in Neurologic Conditions — Study Notes

• Objectives (Page 2)

  • Introduce components of functional upper extremity use

  • Discuss impact of neurologic dysfunction on UE performance

  • Apply a conceptual framework to guide a hypothesis-driven decision-making process for UE dysfunction post-stroke

  • Describe Outcome Measure Assessment of UE dysfunction

• Upper Limb Dysfunction Post-Stroke (Page 3)

  • Prevalence: approx. $50{-}80 ext{ extpercent}$ of individuals have some level of UE dysfunction after stroke

  • Presentation varies with size/location of stroke; extend and presentation differ

  • UE function is critical for many daily activities

  • Limitations in UE function profoundly impact independence and can increase healthcare costs and other disease-related expenses

  • Question: Embolic stroke impacting which artery will result in UE impairment? Answer: Middle Cerebral Artery (MCA)

• Evaluation/Diagnosis and Framework (Pages 4)

  • HOAC: Hypothesis-Oriented Algorithm for Clinicians (framework used in PT)

  • Examination, Prognosis, Plan of Care, Health Condition, Movement System, Movement Science, and Shared Decision Making

  • Framework supports a shared clinical decision-making approach

  • Systematic review referenced: Deutsch JE, Gill Body K, Schenkman M. Physical Therapy, 2022;102:1–17

  • Key elements: History, Outcome, Movement, Environment, and Plan of Care inside the HOAC framework

• Case-Based Health Condition and Patient-Centered Context (Pages 5–6)

  • Health Condition: Stroke (CVA)

  • Why patient is seeking care: difficulties with dressing and cooking; sitting balance ok, standing balance more challenging; has not attempted cooking or light housework; previously independent without AD or assistance

  • Patient goals: (1) dress without help and in less time; (2) be able to make simple meals for herself and spouse

  • Patient’s role in society: married with adult children and grandchildren; retired; prior leisure activities (bridge, book club)

  • Resources and constraints: single-story home with 5 steps to enter with a rail; spouse works full time; previously sedentary; some help from children and home health aide (6 hrs/day for ADLs, cooking, cleaning)

  • Patient preferences: visual demonstrations and simple written instructions; expressive aphasia makes verbal communication hard; desires independence but appreciates help

  • Implications: environment and preferences shape plan and goal-setting; cognitive/communication considerations influence instruction delivery

• Health Condition, Activity, Participation (Page 6)

  • Components (Health Condition → Activity → Participation):

  • Self-care, Activities of Daily Living (ADLs): meal preparation, dressing, etc.

  • Role as spouse/partner; recreational and social participation; standing balance; environmental factors (sedentary lifestyle, home layout)

  • Personal factors: single-story home with stairs, expressed aphasia, spouse support, and prior social activities

• Upper Extremity Functions (Page 7)

  • Core UE functions: Reach, Grasp, and Release

  • Object manipulation

  • Fine motor movements: ADLs, handwriting/typing

  • Crawling/weight bearing

  • Postural control

• Key Phases of UE Movement and Skill (Page 8)

  • Target location/Visual regard: coordination of eye and head movements to guide hand control

  • Reach: postural support and transfer of arm/hand in space

  • Grasp: grip formation, grasp, and release of an object

  • In-Hand Manipulation: object location within the hand

• Key Neurologic Elements of UE Control (Page 9)

  • Sensory processing: visual, vestibular, somatosensory inputs

  • Internal representations for mapping sensation to action

  • Motor control to complete eye, head, trunk, and arm movements

  • Higher-level processing for adaptive and anticipatory aspects of manipulation

• Physiology of "Typical" Movement Control (Synergy) (Page 10)

  • Components include: premotor neurons, spinal motor nuclei, neuromuscular synapses, descending inputs, cortical and subcortical areas, corticospinal tract, ventromedial brainstem tracts, dorsolateral brainstem tracts, spinal cord, muscles, and somatosensory feedback

• Feedback vs. Feedforward Control of Movement (Pages 11–12)

  • Feedback: sensory inputs inform initial limb positions; compare to reference signal; error signal drives motor output adjustment

  • Feedforward: internal models anticipate target path and best response based on prior experience and environment

  • Sequence example: eye, head, trunk orientation toward target in peripheral vision, then arm movement

• Task–Environment–Individual Framework (Page 13)

  • Upper Extremity Control is a function of three interacting factors: Task, Individual, Environment

• Visual Regard, Reach, Grasp, Manipulation Details (Page 16)

  • Reach involves goal-directed discrete motor plans and muscle synergies; synergies are building blocks that flexibly combine for tasks by modulating timing/amplitude of muscles

  • Visual feedback triggers discrete updates in synergy recruitment, enabling flexible movement

  • Reference: Santello M. Frontiers in Computational Neuroscience. 2013/2015

  • Sensory feedback supports accuracy during reaching; grasp requires precise visual inputs

• Visual Pathways for Motor Control (Page 17)

  • Dorsal Stream (Where and How): Primary visual cortex to posterior parietal cortex; informs spatial awareness and visual guidance for reach/grasp; action-relevant information

  • Ventral Stream (What): Primary visual cortex to inferior temporal lobe; object identification (shapes, colors) and visual perception

• Visual Regard and Eye Movement Control (Page 18)

  • Eye movements to locate/focus on targets; multisensory integration for planning/executing eye/head/body movements

  • Visual feedback is particularly critical for reaching accuracy (crucial for final accuracy in UE tasks)

  • Visual processing complexity increases when reaching across the body

• Reach Patterns (Page 19–20)

  • Movement patterns during reach depend on UE task: reach/point; reach/grasp; reach/grasp/throw (release); reach/grasp/manipulate

  • Reach patterns typically follow a bell-shaped curve; task constraints and goal influence speed and duration

• Grasp Mechanics (Page 21–23)

  • Hand has many degrees of freedom; reaching requires transporting the hand while orienting/pre-shaping and maintaining body COM within base of support

  • Grasp patterns depend on object size, shape, and location; categorized as either precision or power

  • Successful grasping requires: (1) pregrasp hand shaping with object adaptation during reach; use of visual inputs for accuracy; object properties affect grasp; (2) timing of finger movements must be accurate

  • Impaired grasping characteristics: slower movements, exaggerated grip, greater variability in hand postures, and increased need for visual guidance

• In-Hand Manipulation / Fine Motor Control (Page 24)

  • Definition: ability to move an object within one hand using thumb and fingers, without assistance from the other hand

  • Primary motor cortex: ~20% dedicated to hand function

  • Stereognosis: integration of tactile and proprioceptive signals while holding/manipulating an object to sense 3D structure

  • Manipulation components: Translation (moving object from fingers to palm or vice versa), Shift (linear movement with fingers), Rotation (turning object)

• Bilateral Coordination (BiManual Tasks) (Page 25)

  • Task-specific control of spatial/temporal characteristics of movements of both hands

  • Two limbs performing simultaneously in synergy

  • Single object with both hands (coupled bimanual tasks) or multiple objects

• Neurologic Dysfunction in the Upper Extremity (Page 26)

  • Recap of motor system components involved in UE control: premotor neurons, spinal motor nuclei, neuromuscular synapses, descending inputs, cortical/subcortical areas, corticospinal tract, ventromedial/dorsolateral brainstem tracts, spinal cord, muscles, somatosensory feedback

• Visual Deficits Post-Stroke (Page 27)

  • Prevalence: ~20% have a primary visual deficit (visual field loss); ~2% have visual perceptual deficits; ~70% have some level of ocular mobility/control issues (cranial nerve function, smooth pursuit, saccades, nystagmus, convergence disorders)

  • Impacts: target localization, reach/grasp speed and accuracy, planning/executing tasks, object identification

  • References: Singh T. Neurorehabilitation and Neural Repair. 2018;32(8):724-734

• Motor Dysfunction Post-Stroke (Page 28–29)

  • Neurological impact: neuronal death in motor cortex reduces motor drive via corticospinal tract; impaired descending control and integration with ascending somatosensory input

  • Pathologic synergies may develop: loss of coordinated muscle patterns, fixed/coordinated pattern constraints, reduced number of usable synergies, degraded accuracy/trajectory/variability of movement, impaired adaptability to task demands

  • Shoulder/elbow activation may lose direction-specificity; fingers may lose individuated control; impaired isolation of muscle activation; results in less focal force with abnormal coupling

• Somatosensory Deficits (Page 30)

  • Up to $50 ext{ extpercent}$ of individuals post-stroke have deficits in one or more somatosensory domains (touch, position sense, pain, temperature)

  • Proprioception updates internal limb dynamics; cutaneous inputs modulate grip forces

  • Effects: delayed motor learning, decreased accuracy of feedforward/feedback adaptive control, impaired timing/accuracy of movements, increased reliance on vision; deficits are more pronounced when visual input is altered

  • Reference: Hoh JEE. Curr Neurol Neurosci Rep. 2025

• Secondary Upper Limb Impairments (Pages 32–33)

  • Hemiparetic shoulder subluxation/glenohumeral subluxation: common post-stroke due to altered motor function and proprioceptive impairment; subacute phase (2–3 weeks) with weak hypotonic muscles; poor upright support increases risk

  • Interventions: slings, proper positioning in sitting/standing, and taping methods may improve alignment and decrease pain

  • Hemiparetic shoulder pain (HPS): prevalence $5{-}84 ext{ extpercent}$; typically develops in first $2{-}3 ext{ months}$; associated with higher readmission; risk factors include female gender, greater motor/sensory impairment, hypertonicity (MAS III/IV), neglect, prior shoulder pain; underlying pathology often includes supraspinatus/long head of biceps tendinitis, bursitis, and subluxation

• Outcome Assessment Overview (Page 34)

  • Canadian Occupational Performance Measure (COPM)

  • Goal Attainment Scale (GAS)

  • Stroke Impact Scale (SIS)

  • Motor Activity Log (MAL)

  • Action Research Arm Test (ARAT)

  • Box and Block Test (BBT)

  • Purpose: capture participation, self-care, activities, and specific UE function across daily tasks and quality of movement

• Motor Activity Log (MAL) Details (Page 35)

  • Type: semi-structured self-assessment of real-life arm function (gross motor activities and object manipulation)

  • Measures: Amount of Use (AOU) and Quality of Movement (QOM)

  • Scoring: AOU items scored from $0$ (never) to $5$ (same as before stroke); QOM items scored from $0$ (Never) to $5$ (normal)

  • Availability: available in $5$ languages; several versions by item count: MAL-14, MAL-26, MAL-28, MAL-12

  • 19-item observational assessment of UE function

  • Standardized setup: equipment, patient positioning, and instructions

  • Four subscales: grasp, grip, pinch, gross movement

  • Scoring: $0$ to $3$ per item; higher is better

  • Items arranged in order of difficulty

  • Predictive thresholds for recovery: <10 points = poor potential for recovery; $10{-}56$ points = moderate potential; $57$ points = good potential

  • ARAT Gross Movements examples: place hand behind head; place hand on top of head; hand to mouth (examples in Page 38)

  • Box and Block Test (BBT):

  • Unimanual gross dexterity assessment

  • Equipment: box, partition, and $150$ blocks (1-inch cubes)

  • Procedure: move blocks with the affected arm from one side to the other for $1$ minute

  • Validation: used in stroke, MS, SCI, neuromuscular disorders, PD

• Revisit of Patient-Centered Context for Clinical Application (Pages 4–6)

  • Health condition, patient goals, participation constraints, resources, and preferences must be integrated into decision-making

  • Emphasizes shared decision making and HOAC approach to tailor goals and interventions

• Quick References and Key Takeaways

  • UE dysfunction after stroke is common but heterogeneous; tailor evaluation to task demands and environment

  • Movement control involves integrated sensory, motor, and cognitive processes with feedforward/feedback loops and internal models

  • Visual processing, somatosensory feedback, and proprioception significantly influence reaching, grasping, and manipulation

  • Secondary impairments (subluxation, HPS) frequently accompany UE dysfunction and require targeted management

  • Outcome measures (ARAT, MAL, Box and Block, SIS, COPM, GAS) provide complementary views of impairment, function, participation, and patient-perceived outcomes

  • Use a hypothesis-driven HOAC framework to guide assessment, plan, and shared decision making in post-stroke UE rehabilitation

• Equations and Notable Numbers (LaTeX-formatted)

  • Prevalence ranges and proportions: $50{-}80 ext{ extpercent}$ UE dysfunction post-stroke; visual deficits: $20 ext{ extpercent}$ primary; somatosensory deficits: up to $50 ext{ extpercent}$; HPS prevalence: $5{-}84 ext{ extpercent}$

  • ARAT scoring thresholds: <10 points = poor recovery potential; $10{-}56$ points = moderate; $57$ points = good potential

  • MAL scales: $0{-}5$ per item for Amount of Use (AOU) and Quality of Movement (QOM)

  • Box and Block Test: $150$ blocks; 1 minute duration

  • Shoulder subluxation timing: subacute phase approx. $2{-}3 ext{ weeks}$ post-stroke

• Abbreviations and Concepts

  • UE: Upper Extremity

  • HOAC: Hypothesis-Oriented Algorithm for Clinicians

  • ARAT: Action Research Arm Test

  • MAL: Motor Activity Log; subtypes MAL-14, MAL-26, MAL-28, MAL-12 and MAL-30

  • SIS: Stroke Impact Scale

  • COPM: Canadian Occupational Performance Measure

  • GAS: Goal Attainment Scale

  • MAS: Modified Ashworth Scale

  • BBT: Box and Block Test

  • CN: Cranial Nerve (visually referenced in ocular movement concerns)

• Practical Implications for Clinicians

  • Begin with patient-centered assessment using HOAC framework; integrate task analysis (What is the task? Under what conditions?), movement strategies, and environment

  • Assess both impairment-level measures (ARAT, BBT) and activity/participation measures (MAL, COPM, SIS, GAS)

  • Consider visual and somatosensory contributions to motor performance; compensate with vision when proprioception or somatosensory feedback is impaired

  • Be vigilant for secondary impairments (subluxation, HPS) and address pain and alignment to facilitate function

  • Use case-derived goals aligned with patient resources, constraints, and preferences to drive therapy planning

  • Employ a combination of unimanual and bimanual tasks to promote functional hand use in daily activities