20. Walking and Gait Flashcards Preview

Semester 2 - MSK > 20. Walking and Gait > Flashcards

Flashcards in 20. Walking and Gait Deck (41)
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1
Q

What is gait?

A
  • Mechanism by which the body is transported using co-ordinated movements of the major lower limb joints
  • requires an energy- efficient interaction between the MSK and neurological systems
2
Q

What two phases does gait consist of?

A

1) Stance phase: 60% of cycle - time in which the foot is in contact with the ground and is bearing weight
2) Swing phase: 40% of cycle - time during which the foot is not in contact with the ground

3
Q

What is the gait cycle?

A

Describes the period of time from initial contact to next initial contact on the same side of the body

4
Q

What five important attributes are needed for normal gait?

A

1) stability in stance - must be able to transfer weight from one foot to another so must be able to stand on one leg. This requires adequate neuromuscular and proprioceptive (joint position sense) function
2) foot clearance during the swing phase - need to be able to raise the foot as we bring it forward
3) pre-positioning for initial contact - be able to prepare the position of the foot for the next stance phase
4) adequate step length - lower limb should be brought forward a suitable distance during the swing phase before making contact with the ground for the next stance phase
5) energy conservation - need to make our movements as energy-efficient as possible

5
Q

What part of the foot makes the initial contact with the ground?

A

Heel

6
Q

In diplegic gait and other pathological gaits, what part of the foot makes initial contact with the ground?

A

Toes

7
Q

What are periods of double support?

A

Where both feet are in contact with the ground

for most of the cycle when one leg is in swing phase the other is in stance phase

8
Q

What happens to the period of double support when the speed of gait increases?

A

Decreases

9
Q

when does running commence in the gait cycle?

A

as soon as there is a time in the gait cycle in which neither foot is in contact with the ground. This is called double float. The faster you run, the longer the period of double float within each gait cycle

10
Q

What happens to the length of the stance and swing phases in sprinting?

A

Reverse so that stance constitutes only

40% of the gait cycle, and swing 60%

11
Q

What is the stance phase subdivided into?

A

1) initial contact - heel strike
2) loading response - period of deceleration where the shock of the impact is absorbed by the knee and ankle joints. Person rocks forwards on their heel to prepare to bring the rest of the foot into contact with the ground
3) mid-stance - foot is flat on ground and the centre of gravity of the body is shifted from behind the foot to in front of it, ready for forward propulsion
4) terminal stance - ankle is plantarflexed and the heel of the supporting leg raises from ground
5) pre-swing - the metatarsophalangeal joints flex to give a push off by the toes

during normal walking, pre-swing occurs in one limb at the same time as the loading response in the other limb

12
Q

What is the swing phase further divided into?

A

1) initial swing - knee flexes to let foot clear the ground
2) mid-swing - hip flexes and pelvis swings forward to enable forward progression. Dorsiflexion of ankle to the neutral position
3) terminal swing - knee extends, and foot is brought close to the ground to prepare for heel strike/initial contact

13
Q

What is forward progression generated by?

A

partly by:

  • push off of toes
  • powerful plantarflexion of ankle
  • flexion of hips and swinging movements of pelvis
14
Q

What prevents tilting of the pelvis to the unsupported side when one foot is off the ground?

A

Hip abductors (gluteus medius and minimus)

15
Q

Define stride?

A

Distance from initial contact with one leg to the next initial contact with the same leg

16
Q

Define step?

A

Distance from initial contact with one leg to initial contact with the opposite leg

two steps to every stride

17
Q

Define cadence?

A

Number of steps per minute

18
Q

How is gait analysed?

A

1) kinematic season - describes motions e.g. joint angles, displacements, velocities and accelerations
2) kinetics - describes forces and moments that cause motions

19
Q

Why do muscles produce force for gait?

A
  • to provide stability and oppose gravity

- to propel body segments forward through controlled movements of joints

20
Q

How do muscles work during the stance phase of gait?

A
  • during heel strike the tibialis anterior works eccentrically (contracting whilst lengthening gently) to prevent the foot slapping the ground
  • during mid-stance it can relax
  • during terminal stance, gastrocnemius and soleus take over to generate power needed for propulsion by powerfully plantarflexing the ankle
21
Q

What are the 3 ways in which muscles work?

A

 Concentric contraction (shortening) - acceleration and power generation
 Eccentric contraction (lengthening) - deceleration and shock absorption
 Isometric contraction (same length) - stability

22
Q

How is energy conserved during normal gait?

A
  • minimising the excursion of the centre of gravity of the body
  • controlling momentum e.g. by eccentric muscle contraction
  • transferring energy passively between body segments by using some elasticity from tendons/ ligaments
  • phasic muscle action
23
Q

What is phasic muscle action?

A

Using muscles intermittently e.g. tibialis anterior switches on for mid-swing and off for mid-stance

If a muscle contracts continuously during the gait cycle, it will fatigue much more rapidly than if it is used intermittently.

24
Q

What can gait abnormalities be caused by?

A
  • nerve lesions
  • joint instability
  • immmobility of joints
  • pain
25
Q

How are gait abnormalities observed and diagnosed?

A

observe phases of walking, lower limb joint movement, stride length, arm swing and lateral movements of the shoulders and head

26
Q

What is antalgic gait?

A
  • Limping due to pain e.g. OA
  • shortening stance phase of painful limb to minimise time spend weight- bearing on it
  • automatically must shorten the swing phase of the unaffected limb to spend more time walking on unaffected limb
  • uneven gait
27
Q

What do people with antalgic gait often use?

A

often use a walking stick to reduce the load through the painful limb. The walking stick should be used in the hand opposite the painful limb. The patient can then lean
towards the walking stick, shift their centre of gravity away from the painful limb and therefore reduce the load through it during the stance phase

28
Q

What is trendelenburg gait?

A
  • hip adductors fail to prevent the pelvis dropping on the unsupported side during stance phase
  • patient tries to compenate for this by swinging their torso over towards the affected side - waddling
  • patient demonstrates a positive trendelenburg sign whilst standing on one leg
29
Q

What can cause trendelenburg gait?

A
  • superior gluteal nerve lesions (and consequent muscle paralysis) e.g. as a complication of hip surgery or injections to the buttock
  • muscle pain/ inhibition of function e.g. OA
  • trauma e.g. fracture of the greater trochanter where gluteus medius inserts or dislocation of hip joint
  • biomechanical hip instability e.g. developmental dysplasia of the hip
30
Q

What is hemiplegic gait?

A
  • spasticity (continuous contraction) of affected side - most severe in flexor muscles of upper limb and extensor muscles of lower limb
  • typically have a flexed upper limb and an extended lower limb
  • cannot flex their hip, knee or ankle so in order to step they must lean towards the unaffected side of the body and then circumduct the paralysed leg
  • short stance phase on affected limb - cant bear much weight on the paralysed leg
  • gait comprises short step with unaffected leg followed by circumduction of affected leg
31
Q

What causes hemiplegic gait?

A

due to paralysis of one side of the body e.g. stroke, cerebral palsy trauma to CNS

32
Q

With what condition does diplegic gait often occur?

A

Cerebral palsy

33
Q

What is diplegic gait?

A
  • spasticity affects both lower limbs
  • patients walks very narrow-based gait (feet close together), dragging both legs and scraping their toes on the ground
  • scissoring - legs cross midline due to spasticity in hip adductors
  • spasticity in hamstrings means knees are slightly flexed and spasticity in the gastrocnemius and soleus results in plantar flexion of the ankles
  • forefoot commonly makes initial contact
34
Q

What is high-steppage gait?

A
  • weakness of ankle dorsiflexion = foot drop
  • when the foot is raised in the swing phase, the absence of active dorsiflexion means it plantarflexes under gravity
  • patient must flex hip more to lift foot and stop toes dragging on the floor
  • during initial contact, the normal eccentric contraction of the tibialis anterior muscle is absent so foot tends to slap on the ground
35
Q

What are causes of high-steppage gait?

A
  • common peroneal nerve palsy e.g. trauma following fracture of fibula neck, compression against fibular neck by tightly applied plaster, peripheral neuropathy e.g. poorly controlled diabetes
  • sciatica (L4 myotome dorsiflexes ankle)
  • neuromuscular disease e.g. Charcot-Marie-tooth —> hereditarily motor and sensory neuropathy
36
Q

What happens in the deep peroneal nerve is damaged but the superficial peroneal nerve is intact?

A

instead of a classical high-steppage gait, Patient may compensate for lack of dorsiflexion in swing phase by everting food in a sudden motion - eversion flick

37
Q

What is parkinsonian gait?

A
  • difficult to initiate movement due to reduced dopamine
  • to counteract this patient flexes neck and trunk forwards to move their centre of gravity in front of lower limbs
  • very short steps - shuffling gait
  • festinant giant - accelerating steps
  • loss of arm swing
38
Q

What is an ataxic gait?

A
  • clumsy, staggering movements
  • broad-base (feet wide apart)
  • hold out arms for balance
  • whilst standing still may sway back and forth and side to side - titubation
  • cant walk heel to toe or in a straight line
39
Q

What causes ataxia?

A
  • proprioceptive - loss of awareness of position of joints
  • cerebellar dysfunction - inherited, acquired e.g. stroke, acute alcohol intoxication
  • vestibular damage - damage to organs of balance in inner ear
40
Q

What does the cerebellum coordinate?

A

Elements of movement e.g posture, balance, co-ordination, speech , resulting in smooth and balanced muscular activity

41
Q

What could be the causes of . Cerebellar dysfunction?

A

 Inherited – some degenerative conditions specifically affect the cerebellum
 Acquired e.g. a stroke affecting the cerebellum
 Due to acute alcohol intoxication (being ‘drunk’)