Lecture 21: Age-Related changes to gait Flashcards
Four Locomotor functions of gait
1) Shock absorption
2) Stance stability
3) Propulsion
4) Energy conservation
Muscle activity when loading the stance extremity. What absorbs shock when loading the joint
Shock absorption
Determined by ground reaction force vectors (GRFVs), ligament and joint support, and muscle activity
Stance stability
Forward, push off, momentum from swing
Propulsion
* mainly comes from the momentum from swing phase
Thought to be maximized by selective muscle recruitment and the determinants of gait
Energy conservation
Beginning of stance when heel or some other portion of foot contacts ground. Component of initial double limb stance
Inital contact
Body weight rapidly loads onto lead limb from trailing limb. Hip remains stable, knee flexes to absorb shockm and forefoot lowers to ground. Immediately follows inital contact and is final component of intital double limb stance. Ends when opposite limb lifts from ground for swing
Loading response
Turnk progresses from behind to in front of ankle over single stable limb. First half of single limb support. Starts when contrlatearl foot lifts from ground for swing
Mid stance
Trunk continues forward progression relative to foot. Heel rises from ground and limb achives trailing limb posture. Second half of single limb support. Ends with contraltaeral intital contarct
Terminal stance
Body weight rapidly unloads from reference limb and reference limb prepares for swing during this terminal double limb stance period. Starts with contralatearl inital contact and ends at ipsilatearl limb toe off
Pre swing
Starts when reference foot lifts from ground. Hip knee and ankle rapidly flex for clearance and advancement during this itital 1/3 of swing
Itital swing
Thigh continues advancing, knee begins to extend, and ankle achieves neutral posture during this middle 1/3 of swing
mid swing
During this final 1/3 of swing, knee achieves max extension and ankle remains at neutral in preparation for heel first intital contact. Ends when foot contacts ground
Terminal swing
What two times does weight acceptance happen during a noraml gait cycle?
Inital contact
Loading response
Single limb support happens during what two times in gait
Mid and terminal stance
Stance phase is made up of what two thigns
Weight acceptance
Single limb support
Swing phase is limb advancement made up of what 4 things
1) Preswing
2) Initial swing
3) Mid swing
4) Terminal swing
Stance phase is what % of the gait cycle?
60
Swing phase is what percent of gait cycle?
40%
The moment when the foot contacts the ground
* stance phase or swing phase
Initial contact
* Stance phase
When weight is rapidly transferred onto the stance limb. This is the first period of double support
* stance or swing phase
Loading repsonse
Stance
When body progresses over a single, stable limb
* stance phase or swing phase?
Mid stance
* stance phase
Progression over the stance limb continues. The bod moves ahead of the limb, and weight is transferred onto the forefoot
* stance or swing phase
Terminal stance
* stance
A praid unloading of the stance limb occurs as weight is transgerred onto the contralateral limb
* stance or swing
Pre swing
swing
this is the second period of double limb support
The thigh begins to advance as the foot comes up off the floor
* stance or swing
Initial swing
* swing
The thigh continues to advance as the knee begins to extend and the foot clears the ground in forward progression
* stance or swing
Mid swing
swing
The knee extends; the limb prepares to contact the ground for initial contact
* stance or swing
Terminal swing
* swing
PT’s
* Clear an older adult for safe discharge
* Assess mobiltiy concerns
Safe ambulation requires:
* The ability to appropriately and sometimes quickly accelerate and decelerate
* engage proactive and reactive balance control mechanisms
* Address myriad different environment and specific task demands
Criteria for frality
1) Unintentional weight loss of 10 lbs or more in the last year
2) Self reported exhaustion (3 ot more days)
3) Grip strength in lowest 20% (<23 lbs women, <32 men)
4) walking speed <0.8 m/s
5) Low level activity
* 270 kcal/wk women
* 383 kcal/wk men
* equivalent to sitting quitelt or lying down for majority of the day
need 3/5 = frail
Prefrality is presence of one or two of these characteristics
Reactive balance:
* think tripping and having to react
Proactive:
* inticipatory
* see something thats going to be in way and alter your path - proactively adjust
NOTE: You really need both to ambulate sucessfully
gait speed has ben termed a functional vital sign
* usually a 20m pathway with a central 10m marked (because it takes time to speed up and slwo down)
standard goal for gait used to be 150 meters
* not used anymore
* medicare issues
* if they can walk this far they wont get them in kind of assitive device
what gait speed is needed to cross interactions?
0.21 - 0.89 m/s
mean = 0.49 m/s
what is the goal when presciribing an assitive device?
Least assitive restrictive device
* dont get them a wheel chair when all they need is a cain
PT is responsible for prescription of assistive devices
* Instruction and practice
* energy consumption
* Some individuals may need some convincing
Typical changes with aging
Sensory:
* Visual and auditory changes
* Diminished input from somatosensory, proprioceptive, and vestibular systems
Motor:
* decreased motor neuron conduction velocity
* Decreased motor fibers
* Connective tissue stiffness - think about myofibirils decreasing
Central NS:
* Decreased reaction time
* Motor learning deficits
Typical gait changes
1) increased stance time, wider BOS
Decreased forward prpulsion, because we have decreased step length
decreases ROM and the sagittal plane except hip flexion - due to froward lean / you lose hip strategy so need more hip flexion
NOTE: Decreased gait speed jas preceded cognitive decline and dementia
Depressive symptoms decrease gait speed
Neural plasticity and activity based interventions
typical gait in older adults
decreased step length = increased cardience
more steps you take = more ability to fall
increased variability of gait - will be fast and slow
* need to make sure older adults can sustain speeds (think 6 minute walk test)
decreased excursion of movement at lower extremity joints EXCEPT HIP FLEXION WHICH IS INCREASED
decreased ankle startaegy
community mobility requirements
gait speed 0.8+
