Neuromuscular Biomechanics - Pathological Gait

Question 1

Key characteristics of Hemiplegic cerebral palsy effects on gait

Answer 1

• arm bent; hand spastic or floppy, often of little use
• other side completely or almost normal
• walk on tiptoe or outside of foot on affected side

Question 2

Key characteristics of Quadriplegic cerebral palsy effects on gait

Answer 2

• both arms & legs
• arms, head & even mouth may twist strangely
• if all 4 limbs affected, often have such severe brain damage that they never are able to walk
• knees press together
• legs & feet turned inward

Question 3

Key characteristics of Paraplegic or Diplegic cerebral palsy effects on gait

Answer 3

• Paraplegic = both legs only, Diplegic = slight involvement elsewhere
• upper body usually normal or with very minor signs
• may develop contractures of ankles & feet

Question 4

Most common form of Cerebral Palsy and key characteristics

Answer 4

• Spastic CP
• muscles continually receive messages to contract
• results in stiff & tight muscles interfere with muscle tone & movements such as gait & speech

Question 5

What is Multiple Sclerosis

Answer 5

where the body attacks its own immune system by depleting myelin

Question 6

How does Multiple Sclerosis affect gait & potential rehab methods

Answer 6

• gait/postural problems due to sensory & motor dysfunction
• appropriate resistance training may increase gait functioning
• strength/weaknesses of the hamstrings is a critical factor in how well MS sufferers can walk (quads not as important)
• rehab of MS should focus on strengthening knee flexors

Question 7

What is Motor Neuron Disease

Answer 7

• MND causes motor nerves to become damaged and as a result the muscles they supply lose strength (sensory nerves are not affected).
• affects peripheries initially, also swallowing and speech

Question 8

Difference between Parkinson’s and Huntington’s

Answer 8

Parkinson’s
- causes muscular rigidity & lack of movement (failure in initiation of movement)
Huntington’s
- a degenerative illness with symptoms of contorted body movements (excessive initiation of movement)
Both
- caused by damage to basal ganglia

Question 9

How do Parkinson’s and Huntington’s affect gait

Answer 9

Parkinson’s
- struggle with turning or crossing obstacles (similar tot toddlers)
- decreased ability to walk due to a loss of flexibility & adaptability in their locomotor responses that in turn is due to neurotransmitter imbalances in the brain
Huntington’s
- have much more variable gait than non-sufferers

Question 10

Limitations with gait assessment in CP

Answer 10

• main issue is VARIABILITY
• (White et al., 1999) most GRF parameters too variable, not possible to distinguish if results due to intervention or CP gait variability
• (Damiano et al., 2010) conditioning regimens varied in effectiveness depending on participant requires individualized approach

Question 11

Role of the cerebellum and what can damage to the cerebellum cause

Answer 11

• (Role) stores skilled sequences and adds fine tuning and timing to movements
• (damage) loss of ability to learn new movements
• disruption of posture
• jerkiness of movements
• inability to make rhythmic movements
• impaired sequencing of movements

Question 12

Potential treatment/aid for Cerebral Palsy

Answer 12

• Foot Orthoses
• Pathological gait feature assessed, then the Orthoses is designed to aid in walking
• mainly work in an attempt to restore normal mechanism of knee extension
• Personalised for each sufferer as condition affects each individual differently

Question 13

What is muscular dystrophy and its effects on gait

Answer 13

• is a muscle wasting disease of which symptoms worsen as time goes by, and becomes life threatening when it affects muscle of CV system
• affects gait both during both stance & swing phases
• (stance)increase in pelvis tilt anteriorly & knee undergoes abnormal loading
• (swing) plantarflexion of the ankle results in increased need for larger hip abduction & flexion
• these result from the body attempting to cope with muscle weakness

Question 14

How does gait & motor performance alter when ageing occurs

Answer 14

• decreased stride lengths, walking velocity & lift of feet
• changes occur to maintain stability, which can decrease due to declines in vision and mental well being

Question 15

Reasons to hypothesise that strengthening the hip & knee extensors can improve the condition of gait kinematics in CP patients (x2)

Answer 15

• helps aid in hip rotation

- been shown to produce positive effects on gross motor functional abilities (e.g max walking speed0

Question 16

Reasons as to why improvements in gait may not occur

Answer 16

• neurological factors, such as primary agonist insufficiency that was not amenable to training
• pre-existing muscle adaptations that may have limited the capacity of some muscles to change in response to loading

Question 17

5 parameters used to establish normal gait that are missing from typical gait patterns of CP patients

Answer 17

1) stance phase stability
2) swing phase clearance
3) foot preposition in terminal swing
4) adequate step length
5) energy conservation

Question 18

how can energy costs be reduced in a CP sufferers

Answer 18

1) restoration of stance stability of the hip & knee via the GRFs
2) elimination of foot drag
- therefore restoration of normal mechanism of knee extension during the last half of stance is a primary goal of CP treatment

Question 19

example of primary and secondary anomalies with CP gait abnormalities and how best to treat them

Answer 19

• (Primary) stiff knee resulting from rectus femoris & hamstring cospasticity (muscles continually contracted)
• (Secondary) the coping response, in this case is the circumduction (contorted movements)
• this leads to inefficient gait, therefore to optimise the efficiency of gait, need to correct primary abnormality & not interfere with the coping responses, which will naturally disappear when no longer required

Question 20

(Lam et al., 2005) ways of which Ankle foot orthoses (AFO) and dynamic ankle foot orthoses (DAFO) aid CP sufferers

Answer 20

• both provide better foot positioning for initial foot contact & control of equinus during stance and swing
• both limit plantar flexion at push-off (less in DAFO) to ‘normal’ values, therefore the calf muscles move to slight dorsiflexed position, gaining a biomechanical advantage
• position of the hip may be altered by changes in knee & ankle position
• increase in hip flexion

Question 21

3 advantages of orthoses

Answer 21

• they’re effective on controlling for equinus (horsefoot)
• less restriction of ankle movement, thus preventing muscle weaknesses
• DAFO are lighter & less bulky than AFO

Question 22

Power generating characteristics of CP sufferers

Answer 22

• low average power generation by the ankle plantar flexors
• positive and negative work around the ankle joint are nearly the same (excessive removal of energy by the knee extensors), which is a serious waste of energy
• reduced level of ankle work results in increased amount of work being done by muscle groups of the hip