This document discusses the pathophysiology of stroke and traumatic brain injury (TBI), as well as ergonomic principles for orthotic design. It defines different types of acquired brain injuries, including traumatic injuries from external forces and non-traumatic injuries from internal factors like lack of oxygen. It describes the pathophysiology of ischemic and hemorrhagic strokes, focusing on how narrowed or blocked arteries can lead to reduced blood flow and oxygen to the brain. Finally, it outlines several ergonomic principles for orthotic design, such as using simple, durable, and cost-effective materials, properly distributing forces across contact points, and allowing natural joint movement while providing control and comfort.

1. Stroke & TBI : Pathophysiology
and Ergonomical Principles of
Orthotic Designe
Praveen Kumar Shukla, MPO 2ND Year,(Batch-5) PDUNIPPD, New Delhi

2. BASICS

3. Brain Injury
Acquired : occurred after birth. It is not hereditary, congenital,
degenerative, induced by birth trauma. The injury results in a change to the
brain’s neuronal activity, which affects the physical integrity, metabolic
activity, or functional ability of nerve cells in the brain. It is of two types :
Traumatic and Non-traumatic

4. Traumatic Brain Injury (TBI)
It results in alteration of brain function due to an external force. It
is either open (penetrating) or closed (non-penetrating)
Non Traumatic Brain Injury (NTBI)
Causes damage to the brain by internal factors such as lack of
oxygen, exposure to toxins, pressure from a tumour etc.

9. Stroke
also known as transient ischemic attack or cerebrovascular accident, happens
when blood flow to the brain is blocked. This prevents the brain from getting
oxygen and nutrients from the blood. Without oxygen and nutrients, brain cells
begin to die within minutes.

10. Pathophysiology of Stroke
A stroke occurs when the blood flow to an area of the brain is interrupted,
resulting in some degree of permanent neurological damage. The two major
categories of stroke are ischaemic (lack of blood and hence oxygen to an
area of the brain) and haemorrhagic (bleeding from a burst or leaking blood
vessel in the brain)

11. Pathophysiology of Ischaemic Stroke
• Ischaemic stroke occurs due to lack of sufficient blood flow to perfuse cerebral
tissue due to narrowed or blocked arteries leading to or within the brain.
It is of 2 types:
Thrombotic Stroke: Narrowing is commonly the result of atherosclerosis- the
occurrence of fatty plaques lining the blood vessel. As the plaques grow in size,
the blood vessel becomes narrowed and the blood flow to the area beyond is
reduced. Damaged areas of an atherosclerotic plaque can cause a blood clot to
form, which blocks the blood vessel.
Embolic Strokes : blood clots or debris from elsewhere in the body, typically the
heart valves, travel through the circulatory system and block narrower blood
vessels.

12. Pathophysiology of Haemorrhagic Stroke
• Due to the rupture of a blood vessels leading to compression of brain tissue from
an expanding haematoma which create pressure that may lead to a loss of blood
supply to affected tissue with resulting infarction, and the blood released by brain
haemorrhage appears to have direct toxic effects on brain tissue and vasculature.
It is of 2 types :
Intracerebral Haemorrhage: caused by rupture of a blood vessel and accumulation
of blood within the brain. This is commonly the result of blood vessel damage from
chronic hypertension, vascular malformation, or the use of medication associated
with increased bleeding rates, such as anticoagulants, thrombolytics, and
antiplatelet agents.
Subarachnoid Haemorrhage : It is the gradual collection of blood in the
subarachnoid space of the brain dura, typically caused by trauma to the head or
rupture of a cerebral aneurysm.

16. Treatment Options
• Medication : Anticoagulants
• Procedures: Angioplasty and stent placement
• Rehabilitation: Speech Therapy, Cognitive Therapy, Sensory and
Motor skills, Physiotherapy, Orthotics
• Nutritional Therapy: low fat, cholesterol, salt and sugar diet, avoid
alcohol. Increased fibre and green vegetables ,fruits etc.

17. Ergonomical Principles of
Orthotic Design
•SIMPLE AND RELIABLE ORTHOTIC DESIGN
•EASY TO CONSTRUCT AND REPAIR BY AN OTHOTIST
•DURABILTY
•COST EFFECTIVE
•MINIMUM POWER CONSUMPTION
•SAFE AND SECURE DESIGN
•EASE OF OPERATION

18. EROGONOMICAL PRINCIPLES
• EASILY AVAILABLE MATERIAL AND
COMPONENTS SHOULD BE USED
• SKIN ALLERGY TO ANY PARTICULAR
MATERIAL SHOULD BE CONSIDERED
• WELL PADDED AND VENTILATED AS
NECESSARY
• 3- POINT FORCE SYSTEM SHOULD BE
CORRECTLY APPLIED
• ROUTINE MAINTAINECE/ALIGNMENT
CHECK IS MUST

19. ERGONOMICAL PRINCIPLES
• CORNER SURFACES SHOULD BE
ROUND AND BELVELLED.
• CIRCULAR BANDS SHOULD BE OF
PROPER WIDTHT.
• THERE SHOULD N’T BE EXCESSIVE
FRICTION IN JOINTS-high energy cost.

20. ERGONOMICAL PRINCIPLES
• COMFORTABLE AND USEFUL DESIGN AS
PER PATIENT REQUIREMENT
• SHOULD NOT RESTRICT THE
MOVEMENTS OF NORMAL JOINTS
• LESSS CUMBERSOME
• PROPERLY ALIGNED AND
PROPRIOCEPTIVE

21. ERGONOMICAL PRINCIPLES
• PROPER WORKMANSHIP SHOULD BE DONE (NO
SHARP EDGES, BLUNT CORNERS, LOOSE SCREWS,
UNSHAPED RIVET HEADS, PROPER LOCATION AND
TYPES OF FASTENERS ETC.)
• SELECTION OF MATERIAL AS PER THE AVAILABILITY
AND FUNCTIONAL REQUIREMENT OF PATIENT(BODY
WEIGHT AND ACTIVITY LEVEL)
• EASE OF DONNING AND DOFFING. SPECIAL
CONSIDERATIONS TO VISUALLY IMPAIRED. ACCESSIBLE
AND SMOOTH JOINT LOCKS AND FASTENERS.
• COSMETICALLY APPEALING

22. ERGONOMICAL PRINCIPLES
• TRIM LINES AND LENGTH OF THE
ORTHOSIS CORRESPONDS DEGREE OF
CONTROL AND COMFORT.
• JOINT ALIGNMENT IN SPACE-
PARALLEL TO THE SAGITTAL PLANE
AND PERPENDICULAR TO THE
CORRESPONDING AXIS OF ROTATION
• BANDS AND MOLDED SHELLS
SHOULD BE BROAD ENOUGH AND IN
PROPER CONTACT WITH THE
BODY(P=F/A)

23. ERGONOMICAL PRINCIPAL
• LIGHT WIEGHTED AS WELL AS STRESS
BEARING.
• AVOID HIGH SHEAR FOCES
• CONTOURED OVER THE BONY
PROMINENCES
• PATIENT MUST BE SAFE AND SECURE

24. ERGONOMICAL PRINCIPLES
• EXISTING MOTIONS MUST NOT BE
RESTRICTED MORE THAN IS NECESSARY
• ORTHOTIC JOINTS AXES SHOULD COINCIDE
WITH THE ANATOMICAL AXES- REDUCED
SHEAR FORCES.
• SHOE MUST BE STABLE ON THE FLOOR
WITH PROPER BALANCE AND CONTACT
• THERE MUST BE PROPER CLEARANCE OVER
THE BONY LANDMARKS

25. Thank You