1
Q
Rolling: Momentum Strategy
A
- generates momentum by initiating motion by head, lead shoulder and trunk
- either simultaneous or immediately followed by lead UE reaching
- the lead leg may be lifted and rotated over the opposite leg
2
Q
First Common Form of Rolling
A
Arm pattern: lift and reach above shoulder level
HT pattern: shoulder girdle leads
Leg pattern: unilateral lift
3
Q
Third common form of rolling
A
Arm pattern: lift and reach above shoulder level
HT pattern: shoulder girdle leads
Leg pattern: bilateral lift
4
Q
Rolling: Force-control Strategy
A
- pt pushes with LE either in a flexed/semi-flexed position which propels the body to side lying
- flexion of the shoulder, head, trunk and lead UE assists in the motion
5
Q
Second common form of rolling
A
Arm pattern: lift and reach above shoulder level
HT pattern: shoulder girdle leads
Leg pattern: unilateral push with far side leg
6
Q
First common form of supine to standing
A
UE pattern: symmetrical push
Axial pattern: symmetrical
LE pattern: symmetrical squat
7
Q
Second common form of supine to standing
A
UE pattern: symmetrical push
Axial pattern: symmetrical
LE pattern: asymmetrical squat
8
Q
Third common form of supine to standing
A
UE pattern: asymmetrical push and reach
Axial pattern: partial rotation
LE pattern: half kneel -> stand
9
Q
Kids: First common form of supine to standing
A
UE pattern: asymmetrical push
Axial pattern: forward with rotation
LE pattern: asymmetrical wide-based squat
10
Q
Supine to Erect Stance
A
- Symmetrical form of rising seems to require the greatest control of direction and force production
- in older adults and young children, transitional points (points for attaining balance) are more common
- those with less balance, partition movement into discrete components
11
Q
Sit to stand: task
A
- task - moving the COM from BOS defined by buttock to the BOS define by the feet
- Butt and feet -> feet
- Wide BOS -> narrow BOS
12
Q
Sit to stand – Variability
A
- Change ht of chair/table
- If they cannot start normal…raise the ht
- Refining the chair and pt’s knees/feet placement
- Armrests
- Novo experience -> try different ways to get up if they haven’t tried it before in therapy
13
Q
STS: Momentum Strategy
A
- requires at least a certain amount of speed and no breaks in the motion
- Accelerate then decelerate the COM
14
Q
STS: Force Strategy
A
- characterized by frequent stops
- trunk generates force to bring the COM over the BOS (trunk flexion so over knees)
- Stop or nearly stop
- Then LE forces lift the body to the vertical position
- Atypical movement strategy
15
Q
Momentum Strategy [ all one movement]: Phase 1
A
Flexion-Momentum Phase
- begins with movement initiation and ends just before buttock lift-off
- Balls of feet behind knees
- weight shift COM horizontal
- erector spinae – eccentric control of forward momentum
- -Flexors will still have to work
16
Q
Momentum Strategy [ all one movement]: Phase 2
A
Momentum-Transfer Phase
- begins as the buttock is lifted and ends with maximum ankle dorsiflexion
- transfer of momentum from upper body to total body (lift) (horizontal and vertical motion)
- co-activation of the hip and knee extensors
17
Q
Momentum Strategy [ all one movement]: Phase 3
A
Extension Phase
- Begins just after maximum DF and ends when the hips first cease to extend (including leg and trunk extension)
- lift or extension phase - extension of hips and knees
- moves body vertical
18
Q
Momentum Strategy [ all one movement]: Phase 4
A
Stabilization Phase
-Begins after hip extension is reached and ends when all motion associated with stabilization is completed
19
Q
Momentum Strategy requires (2 items)
A
- requires generation of concentric forces to propel the body
- requires generation of eccentric forces to control the motion of the body
20
Q
Momentum Strategy: Safety
A
- can result in a backward fall especially if the pt tries to transfer momentum from the trunk to the legs for the vertical lift before the COM is sufficiently forward over the feet
- -Rushing Stage 1and 2, not getting COM over BOS -> fall backwards
- -Could also be early extension bc increased extension tone
- can result in a forward fall especially if the pt is unable to control the horizontal forces at the end of the STS movement (continued forward acceleration is not stopped by eccentric posterior trunk, HS and GS muscles)
- -Accelerate too much and decelerate too late
21
Q
Momentum Strategy: not for what pt population?
A
May not be appropriate for patients with orthostatic hypotension, vestibular problems or dizziness since speed of movement may increase symptoms
22
Q
STS: Force-Control Strategy
A
- **zero-momentum strategy
- frequent stops
- ensures stability but requires greater forces (strength) for progression
23
Q
Force-Control Strategy: Phase 1
A
trunk flexion and anterior tilt of pelvis to bring COM over the feet
24
Q
Force-Control Strategy: Phase 2
A
extension of trunk, hips and knees with sufficient force to bring the body to the vertical position
25
Force-Control Strategy: Phase 3
stabilization
26
Force-Control Strategy: Strengthen
strengthening of trunk, hip and knee extensors may augment the ability to perform the force-control sit to stand strategy
27
STS: Both strategies (intervention)
- manually assist (prevent buckling) pt at the knee for stability but do not block the anterior translation of the knee
- progress from a higher seat height to the lower seat height
- pressure downward through the knee may increase the WB sensation of the foot on the contact surface
- pressure through the dorsum of the foot may facilitate WB through that LE
- Use quads to slow descent
28
STS: Rules
-Feet usually shoulder width apart
-Anterior view – symmetrical alignment
-With or without arms
-Sagittal view – aligned although feet can be staggered
-Prep = set up
Initiation
Perform
Stabilize/Transition
29
STS – Variability
- Intra-subject – significant variability even if start position controlled
- Intra-subject – much more variability if start position not controlled
- Sit to stand often different according to what activity is planned next
- Inter-subject variability – very high
30
STS: Forces
- eccentric control of body weight as lower from vertical stance to the sit position
- eccentric action of paraspinals, quadriceps and gastroc-soleus
- relies on some passive tension forces; therefore, it is mechanically easier?
31
Sit to Stand: Typical & Atypical Movement -- Consists of 4 Phases
Phase 1: Flexion momentum
Phase 2: Momentum Transfer
Phase 3: Extension
Phase 4: Stabilization
32
Sit to Stand: Typical & Atypical Movement -- Common Maladjustments
- COG kept posterior and directed in an upward and backwards motion.
- Feet that are placed in front of the knees
- Hip extension prior to knee extension
- Use of the back of the legs to assist the movement of coming to stand
- Unequal weight distribution through the lower extremities
- Excessive amount of weight distributed through the upper extremities
33
Stand to Sit: Typical Movement
- Forward movement of the trunk
- Downward movement of the trunk
- Flexion of the knees
- Backward movement of the trunk
34
Stand to Sit: Typical & Atypical Movement -- Common Maladjustments
- Decreased eccentric control (patient plops into the chair)
- Hip flexion initiating movement
- COG displaced too far posterior
- Excessive use of upper extremities to lower self into chair
- Unequal weight distribution through the LE
35
Patients who typically have trouble with gait initiation...
Parkinson’s Disease
Multiple Sclerosis
Cerebral Vascular Accident
Traumatic Brain Injury
36
Gait Initiation Define
- Often the center of mass/gravity (COM/COG) is confused with the center of pressure (COP)
- COM – the net weighted average of the COM of each body segment
37
COP Definition
- COP – the location of the vertical ground reaction force (GRF) as measured by a force plate
- COP is equal and opposite to a weighted average of the location of all downward forces acting on the force plate
- COP is independent of the COM
38
COM movement
- right LE; weight shift to the left LE
| - Move COM from between feet over L LE and then anterior
39
Initiation of Gait- below is the COP excursion
1. COP moves posterior and to the right toward the step foot
2. COP/COM moves toward the stance foot as the COM (body) moves over the left foot
3. COM moves anterior over the stance foot as right foot steps/swings forward
40
1st 40% of gait initiation
- “ankle strategy”movement
- LE (L > R) pre-tibial muscles (dorsiflexors) move the tibia/COM anterior over the L foot
- --Draw your weight forward with Ant. Tib contraction
- --“Pull forward into my hands” – hands on anterior pelvis
- Quadriceps muscles are activated to decelerate L knee flexion so the leg rotates forward as an aligned unit
- After R toe-off, left GS & HS propel body forward
41
steady-state gait velocity is reached (healthy individuals)
In 1-3 steps
42
PD- difficulty in initiating gait
- Stooped posture, shuffling gait
- Smaller steps (decreased step length and speed)
- PD 33.6 m/min; age-matched controls 81.6 m/min
- Lack of heel strike (foot-flat or ball of foot)
- Inability to extend the knee and plantarflex the ankle in terminal stance > resulting in decreased propulsion
- Forward trunk flexion and decreased trunk motion
- Reduces or absent arm swing
43
Clearance
Move over and around objects [moving or stationary]
44
Speed-Accuracy Relationship
- Move fast over obstacle, increase minimum clearance
| - Move slow over obstacle, decreases minimum clearance
45
Clearance – Gait
- Older persons (with more movement variability) do not step over obstacles using higher clearances.
- Appear to value energy conservation or conservative balance strategies rather than use higher clearances
46
Stair Ascent/Descent: concentric and eccentric control
- pts with decreased concentric control will have more trouble with stair ascent
- pts with decreased eccentric control will have more trouble with stair descent
47
Stair Ascent: Stance
- 64%
- Weight Acceptance Phase (move over the anterior foot)
- Pull Up (hip, knee and ankle extension)
- Forward Continuance (primarily knee (some ankle) generation of forward progression forces)
48
Stair Ascent: Swing
- 36%
- Foot Clearance (hip, knee and ankle flexion)
- Foot Placement (eccentric control of hip, knee and ankle flexors)
49
The greatest point of instability during ascent is
at CL toe off when the ipsilateral leg accepts body weight and ipsilateral hip, knee and ankle are in flexion
50
Stair Descent: Stance
- weight acceptance (absorption of energy at the knee and ankle by triceps surae, rectus femoris, and vastus lateralis; activation of gastroc-soleus prior to stair contact is critical for cushioning (2 x body weight))
- forward continuance
- controlled lowering (eccentric action of quadriceps and soleus)
51
Stair Descent: Swing
- leg pull through (hip, knee and ankle flexion then extension)
- preparation for foot placement (on the lateral border of the foot in a supinated position)
