Proprioception and balance Flashcards
What is proprioception
Sensory function for detecting and identifying the relative position of body parts
What are the key components of proprioception
Muscle spindles
Golgi tendon organ
Describe the Golgi tendon organ
Located in the junction of a tendon and a muscle
Has a thin capsule of connective tissue that encloses tendon fascicles
Sensory nerve endings entwined within the collagen fibres
Monitor excessive tension
Results in the tendon reflex
Describe the muscle spindles
Proprioceptors detected in the muscle belly
More plentiful in muscles that produce fine and controlled movements
Made of intrafusal fibres - sensory nerve endings that wrap around 3-10 specialised muscle fibres, wrapped in connective tissue capsule anchored to endo and perimysium
Monitor changes in muscle length
Influence muscle tone
Results in a stretch reflex
Where is the primary motor cortex found
Found in the frontal lobe
Where is the somatosensory cortex found
Found in the parietal lobe
What are the motor areas and their functions
Premotor cortex - preparation, planning and controlling movements
Supplementary motor area - plans single movements, sequenced movements and coordinates bilateral movements
Primary motor cortex - gives conscious commands to muscles to perform movements
Describe the cerebellum
Does not initiate motor output
Modifies motor commands to make movements more adaptive and accurate
Maintains posture and balance
Coordination of voluntary movements
Motor learning
Cognitive functions
Damage = cerebellar ataxia
Describe the basal ganglia
Does not initiate motor output
Receives intended motor output from the motor cortex, weighs the signals and determines the actions to inhibit or disinhibit
Helps initiate and terminate movement
Suppresses unwanted movement
Regulates tone
Damaged in Parkinson’s disease
What are the roles of descending tracts
Motor info/signals
Descend from brain to spinal cord
Main role is to transmit motor signals to the effectors
Describe a 2 neuron reflex arc
Cannot be influenced by consciousness
No neuron between the afferent and efferent
Protective as it prevents excessive stretch to the muscle
E.g. Patella
Describe a 3 neuron reflex arc
Can be influenced by conscious thought
E.g. taking hold of a hot plate but dont want to lose the food
What do reflexes assess
Allow us to assess the integrity of the nervous system
A normal response means its intact
No response or abnormal response shows the neural pathway has been affected
What are the reflex gradings
0 means no response
1+ means diminished, low normal
2+ means average, normal
3+ means brisker than average
4+ very brisk, hyperactive
What are the reflex responses
Absent - lower motor neuron
Present - normal
Brisk - upper motor neuron?
Hyper-reflexive - upper motor neuron
What is reflex testing
Biceps - C5/6
Brachioradialis - C6/7
Triceps - C7/8
Patellar - L3/4
Ankle - S1/2
What is the Babinski reflex
Plantar response
Patient supine, well supported and comfortable to ensure they are fully relaxed
- use the end of the reflex hammer
- using a continuous movement at quick speed, draw the end upwards along the lateral border of the foot
- at the end of the 5th toe, move medially across the ball of the foot
- note toe movement
What are the 5 reflex tests
Babinski
Stereognosis (UL)
Mirroring
Joint position sense
Co-ordination (ataxia)
What is stereognosis and how is it carried out
Ability to recognise an object through touch alone
Model in sitting
Introduce/consent/procedure
Model closes eyes
Place an object in one of their hands
Ask them to feel it and tell you what it is
Repeat 2/3 times with different objects
Repeat in other hand
How is mirroring carried out
Model sitting or supine
Introduce/consent/procedure
Model closes eyes
Place an upper or lower limb in a position
Ask model to place opposite limb in the same position
How is joint position sense carried out
Model in long sitting
Introduce/consent/procedure
Demonstrate with thumb or big toe
Passively move limb into more flexion or extension
Ask model if its more bent or straight
Model closes eyes
Repeat on both sides
How is upper limb co-ordination testing carried out
Finger to nose test
Patient supine of sitting in a chair
Therapist faces them
Therapist holds finger in front of patient at eye level
Eyes open, patient touches own nose then the therapists finger
Repeat faster if accurate
Change position of finger and repeat the test
How is lower limb co-ordination testing carried out
Heel-shin test
Patient supine or sitting
Patient asked to place heel of one limb on opposite limb
Patient should run heel down shin towards ankle
Can be repeated and with increasing speed
Can also be repeated with eyes closed
What is static balance
Ability to maintain the body in some fixed posture with COG over the BOS and body at rest
What is dynamic balance
Ability to transfer the vertical projection of the COG around the supporting BOS whilst the body is in motion
What is anticipatory/preparatory postural adjustment
Activation of postural muscles before a self initiated/expected movement begins
Involves motor planning feedforward to adapt motor and sensory systems on the basis of previous experience
Influenced by cortex but regulated by brainstem
What are reactive postural adjustments
Response to external perturbation, identified movement strategies
Basis of ongoing visual, vestibular and somatosensory info
What are muscle synergies
Pre-programmed muscle activation patterns of groups of muscles so they are constraint to act together as a unit
Ensures forces generated at one joint for balance does not produce instability elsewhere in the body
What are the muscle synergies
Ankle strategy
Hip strategy
Stepping strategy
Grasping
UL extension/abduction
Trunk flexion
Causes of problems with balance
Motor control problems
Sensory problems
Muscle length and strength
Joint ROM/posture
Perceptual
Environment
Pain
Adaptive/habitual
Learnt non-use
What are the balance tests
Rombergs test
Berg balance score
Tinetti
Force plates
Clinical test for sensory interaction on balance
Brunel balance assessment
Timed get up and go
Motor assessment scale
Timed unsupported steady stand
How is the Romberg test carried out
Model in standing, feet shoulder-width apart, arms by side or crossed over chest
Eyes open, stand for 30s
Repeat with eyes closed
Repeat with one foot in front of the other
How is the berg balance test carried out
14-point test with a maximum score of 14 for each point
Max score of 56
Score below 45 indicates risk of falls
Stroke patients adjusted to below 49
