Chapter Five: Normal and Pathologic Gait Flashcards
1
Q
What are self-contained passengers riding on the limb’s locomotor system?
A
Head
Neck
Trunk
Pelvis
2
Q
What are the four basic functions of a normative gait?
A
Weight-bearing stability
Progression
Shock absorption
Energy conservation
3
Q
Which muscles maintain the limb’s ability to support body weight?
A
The extensor muscles.
This begins with the hamstrings and quadriceps preparing the swinging limb for stance.
4
Q
Which muscles provide weight-bearing stability when the body weight is rapidly dropped onto the foot?
A
the hip extensors and quadriceps stabilize the flexed hip and knee, while the hip abductors support the pelvis.
5
Q
As body weight progresses over the foot, what muscles are activated and what do they do?
A
the ankle plantar flexors restrain the tibia and provide indirect extensor stabilityof the hip and knee.
6
Q
The change in muscle control in regards to weight-bearing stability is dictated by what
A
The changing alignment of the body weight line with the individual joints. As the vector moves away from the joint center, a rotational moment devleops that must be controlled by opposing muscles to preserve postural stability.
7
Q
What are the three rocker actions used to advance the weight-bearing limb over the supporting foot during progression?
A
Heel rocker
Ankle Rocker
Forefoot rocker.
8
Q
What does the fourth rocker do in progression and what is it called?
A
Toe rocker
It initiates swing limb advancement.
9
Q
What is the heel rocker?
A
Following floor contact, the descent of body weight through the tibia plantar flexes the ankle while the pretibial muscles slow the rate of foot drop. This creates an unstable period of heel-only support, which rolls the limb forward on the rounded calcaneus.
10
Q
What is the ankle rocker?
A
As momentum advances the body vector, ankle dorsiflexion allows the stance limb to roll forward over the stationary foot. Stance stability depends on graded restraint by the ankle plantar flexor muscles.
11
Q
What is forefoot rocker?
A
Heel rise moves body weight across the forefoot. Both the foot and the limb roll forward over the unstable area of support provided by the rounded metatarsal heads.
12
Q
What is toe rocker?
A
Advancement of the body weight vector to the metatarsophalangeal (MP) joint allows the foot to dorsiflex rapidly about the base of the toes. The knee is unlocked and swing limb advancement is initiated. Dorsiflexion availability at the ankle and MP joints is the critical factor.
13
Q
What are the two forces that stimulate progression?
A
Forward fall of body weight and momentum created by the swinging limb.
14
Q
From a quiet stance, how is fall initiated?
A
Flexion of the swing limb and calf muscle relaxation, which allows the weight-bearing tibia to advance.
15
Q
What is shock absorption?
A
The impact of rapid body weight transfer onto the limb is dissipated by knee flexion redirecting the force to the quadriceps.
16
Q
Shock absorption is initiated by what rocker?
A
Heel rocker.
17
Q
What is energy conservation?
A
Selective relaxation of muscle action by substitution of momentum or passive positioning can conserve energy.
18
Q
Is cocontraction of antagonists rare?
A
Yes
19
Q
When does cocontraction occur?
A
Hamstrings and quadriceps are cocontracted during the limb loading
Anterior and posterior tibialis are cocontracted during medial foot control.
20
Q
What are the intervals called when at the beginning and end of stance, there is an interval when both limbs are in contact with the floor for weight transfer?
A
Initial and terminal double stance.
21
Q
What is the term, when one leg is providing all the support while the other is in midair?
A
Single-limb support.
22
Q
What are the three tasks of gait?
A
Task 1: Weight acceptance
Task 2: Stance limb progression (single-limb support)
Task 3: Swing limb advancement.
23
Q
Which phases of gait are divided into each task?
A
Task 1: Initial contact, Loading response
Task 2: Midstance, Terminal stance
Task 3: Preswing, Initial swing, midswing, Terminal swing.
24
Q
What is a short description of initial contact?
A
The way the foot contacts the floor is the first influence on the pattern of limb loading.
25
What is a short description of loading response?
Three major functions are shock absorption to blunt the floor impact force, limb stability to accept body weight, and preservation of progression.
26
What is a short description of midstance?
The ankle serves as a rocker that allows the limb to advance over the stationary foot.
27
What is a short description of terminal stance?
The forefoot provides a rocker that allows both the foot and the limb to roll forward.
28
What is a short description of preswing?
Actions at the ankle and hip of the unloaded limb initiate knee flexion in preparation for swing.
29
What is a short description of initial swing/
Muscle action at the hip, knee and ankle lift the foot and advance the limb.
30
What is a short description of midswing?
the limb is advanced by continued hip flexion and early knee extension. With the tibia vertical, active foot support is required.
31
What is a short description of terminal swing?
Limb advancement is completed by knee extension, while further hip flexion is inhibited in preparation for stance.
32
How does eccentric muscle contraction work?
The tendon lengthens and stretches while the muscle exerted an isometric contraction to stabilize the joint, muscles only shorten or maintain neutral length.
33
What occurs at the ankle during each stride?
At the onset of stance, the ankle is in neutral dorsiflexion, and floor contact is by the heel. Rapid loading of the heel causes the ankle to quickly plantarflex and then return to neutral before forefoot contact. This motion was the result of tibialis anterior tendon stretch. Release of the stretch force occurs as the heel lever shortens with the advancement of the vector across the heel. Following forefoot contact with the ground, ankle motion reverses to 10 degrees dorsiflexion as the tibia advances over the stationary foot for stance limb progression. Then the ankle plantarflexes 20 degrees during the final phase of stance (preswing). As the toe-off starts swing, the foot again dorsiflexes under control of the pretibial muscles. Full elevation of the foot to neutral does not occur until midswing.
34
What does the subtalar joint do during gait?
It moves into eversion following initial floor contact by the heel. This unlocks the midtarsal joint.
35
What does the midtarsal joint do during gait?
The midtarsal joint dorsiflexes slightly (the arch is flattened) following forefoot impact with the floor. Then the subtalar joint progressively inverts and locks the midtarsal joint through late midstance and terminal stance.
36
What does the MP joint do during gait?
It dorsiflexes and is essential for heel rise. The foot rols up over the base of the toes, particularly the great toe, as the trailing limb advances.
37
Dorsiflexion is controlled by what during gait?
The pretibial muscles during the loading response and swing. (tibialis anterior, extensor hallucis longus, and extensor digitorum).
38
The soleus and gastrocnemius control what during gait?
They control the tibia during stance limb progression. During terminal stance, the gastrosoleus muscles increase in muscle mass rapidly in response to the dorsiflexion moment generated by the advancement of the body mass over the forefoot rocker. This same moment also stretches the tendon and gains 5 degrees of dorsiflexion at the ankle. In preswing the the tension of the achilles tendon is abruptly released by the rapid transfer of body weight to the other limb. This creates a large power burst of plantar flexion by elastic recoil. The muscle is inactive as the push off power generated is sufficient to initiate swing.
39
What does the anterior tibialis, posterior tibialis, and soleus do during gait?
Control subtalar inversion
40
What do the peroneus brevis and peroneus longer muscles do?
Restrain inversion as they produce an eversion force on the lateral side of the foot.
41
What do the intrinsic flexor muscles, subtalar muscles, and long toe flexors do?
Midtarsal restraint of the dorsiflexing forces created by body weight advancement.
42
What is the role of the flexor hallucis longus and flexor digitorum longus?
To stabilize the MP joint during heel rise.
43
What occurs at the knee during gait?
It is fully extended at initial contact. The knee then rapidly flex 18 degrees during weight acceptance. This is the result of patellar tendon stretch while the quadriceps muscle is undergoing an isometric contraction. This is followed by progressive extension throughout the period of single stance, reaching a final position of 5 degrees flexion. The knee then rapidly flexes to 40 degrees during preswing and goes to 60 degrees at initial swing. Then it extends to neutral.
44
What do the quadriceps do during gait?
Restrain the knee flexion in stance and assists extension. All the vasti respond simultaneously.
45
What does the gluteus maximus do during gait?
Through its iliotibial band insertion, it contributes to knee extensor stability.
46
What does the rectus femoris do during gait?
Along with the vastus intermedius, restrains excessive preswing flexion.
47
What does the short head of the biceps femoris do during gait?
It aids in knee flexion in swing
48
What does the hamstring muscle group do during gait?
It limits knee extension during terminal swing.
49
What occurs at the hip during gait?
The hip has an arc of extension through stance, reaching 10 degrees hyperextension in terminal stance. An arc of flexion occurs from preswing through midswing. The 35 degree of flexion is maintained in terminal swing and loading response. In the other planes there are small (4-5 degree) arcs of postural accommodation which are described as pelvic motions.
50
Hip extension is due to which muscles and which phases of gait?
Hip extensor muscle action begins with the hamstrings in terminal swing and proceeds to the gluteus maximus and adductor magnus during the loading response.
51
What does the gluteus medius and minimus and tensor fascia lata do during gait?
Provide lateral stability of the hip in stance.
52
Hip flexion is a result of which muscles?
Adductor longus (plus rectus femoris), iliacus, sartorius, and gracilis.
53
What occurs at the pelvis during gait?
It moves through small (5 degree) arcs in each plane as it yields to body weight in stance and follows the advancing limb in swing. Stability is provided by the muscles of the weight-bearing hip.
54
What occurs at the head and trunk during gait?
It maintains an upright posture. The small, 5 degree, arcs of motion that occur reflect the uneven support provided by the reciprocal actions of the two limbs. Motion is greatest in the lumbar area and decreases at each higher segment.
55
What do the spinal muscles do during gait?
They preserve balance, absorb shock, and minimize head displacement.
56
What is the first determinant of the ability to walk?
Weight acceptance.
57
What are the two objectives of weight acceptance?
Establishment of a stable limb for weight bearing and minimization of the shock of floor impact.
58
Which phases of gait are dedicated to optimum weight acceptance?
The last phase of swing and the first two stance phases.
59
During phase 8, terminal swing, what must happen to prepare the swinging limb for stance?
Hip flexion is interrupted, the knee extends, and the ankle remains dorsiflexed.
60
What muscles stop hip flexion and terminate swing?
Semimembranosus, semitendinosus, biceps femoris (long head).
61
What muscles reduce intensity and what muscles gain intensity when trying to extend the knee in terminal swing?
Hamstrings lower intensity to allow the quadriceps to increase in intensity to extend the knee. The continuation of mild hamstring action prevents knee hyperextension from the residual tibial momentum.
62
What muscles support the dorsiflexed foot during terminal swing?
Pretibial muscles.
63
What is the purpose of the heel when it makes floor contact?
To initiate the heel rocker for progression and shock absorbtion.
64
What are the significant postures during initial contact?
Ankle dorsiflexion and full knee extension.
65
How does initial floor contact by the heel begin?
With 1 cm of free fall between the foot and the ground. The event registers 50%-125% body weight during the first 10-20ms of stance. only 1%-2% of the gait cycle.
66
How does the heel react to contact to the ground?
It initiates small arcs of anklle plantar flexion and subtalar inversion.
67
Which muscle determines heel rocker effectiveness?
Anterior tibialis
68
During loading response, what occurs at the ankle?
The pretibial muscles preserve the heel rocker by intense isometric actiity, while stretch of the anterior tibialis tendon allows a small arc of plantar flexion for shock absorption. This reverses the early plantar flexion arc to neutral by the end of loading response.
69
The limb is _________ by the heel rocker and then supported by what?
Destabilized by the heel rocker and supported by strong extensor musclar response.
70
During loading response, what does the pretibial muscles do?
Decelerate the dropping foot and pulls the tibia forward. This leads to rapid knee flexion for shock absorption.
71
What do the quadriceps do during loading response?
Oppose the knee flexor moment to preserve knee stability and absorb the sock of initial floor impact.
72
Knee extensor stability during loading response is aided by what?
the femoral stability gained from the adductor magnus and gluteus maximus.
73
What do the hamstrings do during loading response?
Relax to avoid unnecessary flexor force.
74
What occurs at the hip during loading response?
Rapid response by the abductor muscle group to stabilize the pelvis, which lost its contralateral support with the transfer of body weight to the forward limb.
75
What is the second determinant of the ability of a person to walk?
Ability to advance the limb over the supporting foot.
76
What are the two phases that are involved in stance limb progression?
Midstance
| Terminal stance.
77
What is the critical event during midstance?
Ankle dorsiflexion. The soleus, assisted by the gastrocnemius, modulates the tibial advancement so the lower leg proceeds less rapidly than the femur. This causes passive extension of the hip and knee for weight bearing stability.
78
What do the hip extensor and quadriceps do during midstance?
Rapidly relax
79
What do the plantar flexor muscles do during midstance?
Stabilize the hip and knee
80
During midstance, what occurs at the hip involving the swinging limb?
A major adducting moment as lifting the other limb for swing removes the support for that side of the pelvis. This creates a large medial vector, which is restrained by the luteus medius.
81
What is the critical event during terminal stance?
Heel rise to continue progression. Free dorsiflexion mobility of the MP joints is also essential. Both the foot and limb roll forward over the forefoot rocker.
82
What do the gastrocsoleus muscles do during terminal stance?
Lock the flightly dorsiflexed ankle, so the forefoot is the site of limb rotation.
83
What is created during terminal stance?
A lever (anle to met heads) which enlarges the arc of limb rotation. Heel height is preserved while greater advancement of the center of mass adds to step length.
84
What is heel rise on the contralateral limb at initial contact while this limb is at initial contact?
3.5cm
85
What is the third determinant of walking ability?
Ability to lift the foot.
86
What is the critical event during preswing?
Passive knee flexion to 40 degrees because it is the primary contributor to foot clearance of the floor in swing.
87
Which muscles provide the initial force during preswing?
Plantar flexiors.
88
What is the plantar flexor power caused by during preswing?
Elastic energy generated by the abrupt release of the previously tense soleus and gastrocnemius muscles.
89
The forward roll of the foot and leg is accelerated by what during preswing?
The rapid ankle plantar flexion stimulated by the release of the the tension stored in the eccentrically stretched soleus and gastroc.
90
What occurs at the knee during preswing?
Passive knee flexion
91
Unloading the limb during preswing release the tension of what? And combined with ______ initiates early what?
Releases the tension in the hip flexors. Combined with the adductor longus action initiates early hip flexion and assists knee flexion.
92
What is the critical event of initial swing?
Knee flexion sufficient for the toe to clear the floor as the thigh advances.
93
Total limb ______ is involved in initial swing?
Flexion.
94
Hip flexion may be due to what during initial swing?
Passive continuation of the preswing events or direct action by the iliacus, sartorius, and gracilis.
95
Full knee flexion during initial swing is due to what?
The imbalance between the forward momentum of the femur generated by hip flexion and inertia of the tibia.
Active assistance is provided by the biceps femoris (short head).
96
Ankle dorsiflexion during initial swing is due to what?
Pretibial muscles, but the arc is incomplete in initial swing.
97
What is the critical event of midswing?
Ankle dorsiflexion to neutral for floor clearance.
98
What occurs at the hip and knee during midswing?
Hip flexion and partial knee extension to advance the limb.
99
What position is the lower leg in during midswing, and what causes it?
A vertical posture, which is caused by the pretibial muscle support of the ankle.
100
What is the critical event of terminal swing?
Forward swing of the limb for step length.
101
How is forward swing of the limb accomplished during terminal swing?
Knee extension.
102
What are the most common problems that lead to gait abnormailities?
Restricted passive motion and malalignment.
103
What are the pathologies that contribute to restricted passive motion and malalignment?
Contractures, skeletal deformity, and musculoskeletal pain.
104
What is a contracture?
Fibrous connective tissue stiffness.
105
What are the major causes of contractures?
Inactivity during the acute phase of illness, rigid immobilization for early healing, and stretch inhibition by spasticity.
106
What is stiffness?
The inability of the strong, relatively inelastic collagen fibers to alter their alignment.
107
Normally, the collagen fibers move within what?
The gel-like proteoglycan matrix that provides both support and lubrication.
108
With inactivity, what can occur to the proteoglycan ground substance?
It suffers chemical deterioration and loss of water, which can be measured within 2 weeks of inactivity.
109
What are the two levels of contracture?
Elastic and rigid.
110
Both contracture levels resist what?
Manual testing.
111
What is an elastic contracture?
It yields under body weight to allow near-normal function.
112
What is rigid contracture?
Obstructs motion in both stance and swing.
113
What are the most significant contractures?
Plantar flexion, knee flexion, and hip flexion contractures.
114
Plantar flexion contractures of 15 degrees can significantly impair what?
Limb progression. The body weight cannot move over the foot without substitutive posturing.
115
When there is a plantar flexion contracture, what is the common substitution to create limb progresion?
Premature heel rise to roll on the forefoot. You might also see knee hyperextension or forward trunk lean to advance the body vector over the stationary foot.
116
With a plantar flexion contracture, and with the common substitutions, what will still occur?
a shortened stride length.
117
Knee flexion contractures threaten what? Why?
Stance stability. With the trunk erect, the body vector is behind the knee joint, leading to greater demand on the guadriceps.
118
Having a 15 degree knee flexion contracture, puts how much more percent of effort on the quadriceps? How about 30 degree contracture?
20%
| 50%
119
If a patient has a knee flexion contracture and week quadriceps, what happens?
The patient loses their ability to walk.
120
Extra work of the quadricepes, also does what?
Creates an equal compressive load on the joint, which causes increased pain in arthritic patients.
121
A knee flexion contracture also requires increased what?
Ankle dorsiflexion.
122
Hip contractures threaten what? Why?
Stance stability and progression. The body vector becomes anterior to the supporting foot.
123
To stand erect with a hip contracture, what are the substitutions?
Excessive lordosis or knee flexion.
Lordosis is usually seen in kids because they are more flexible
Knee flexion is seen in adults and they will need crutches.
124
What can be further impaired by weight bearing?
Deformed join surfaces and supporting shafts.
125
Who are more susceptible to skeletal malalignment?
Children.
126
Why are children more susceptible to skeletal malalignment?
Their growing tissue accommodates the abnormal stress. Asymmetrical forces discourage new growth on the compressed side while inducing overgrowth contralaterally.
127
What happens to adults with skeletal malalignment?
Degenerative changes that lead to pain and loss of function.
128
During walking, skeletal malalignments are seen as what?
Motion errors.
129
Musculoskeletal pain is a common reaction to what?
Joint trauma or inflammation and swelling.
130
What happens at the joint with increased inflammation and fluid?
Makes the joint capsule tense and painful.
131
When the joint is painful what position will it assme?
A resting position with minimal intraarticular pressure.
132
What is the resting position of the ankle?
15 degrees plantar flexion.
133
What is the resting position of the hip and knee?
Approximately 30 degrees of flexion.
134
Swelling within a joint inhibits what?
Muscle action to avoid their compressive forces.
135
What are the four major components of a motor unit?
Anterior horn cell, axon, myoneural junction, and muscle fibers.
136
The anterior horn cell sits where?
in the spinal cord.
137
An axon extends to what?
The muscle, then divides into multiple branches.
138
Each axonal branch connects to what, through what?
A muscle fiber through a myoneural junction.
139
The myoneural junction does what?
Chemically transmits the activating signals from nerve to muscle.
140
In the lower limb, the muscles contain about how many motor units which contain about how many muscle fibers?
500 motor units
| 200-1000 muscle fibers.
141
What is poliomyelitis?
An acute viral invasion of the anterior horn cells that causes a random pattern of paralysis.
142
What percent of anterior horn cells recover in poliomyelitis?
47%
143
What may occur to provide addition function to a person with poliomyelitis?
Axons sprouting to adopt orphaned muscle fibers. This may allow patients to resume a normal lifestyle.
144
What is postpolio syndrome?
Overuse of the subnormal neuromuscluar system for at least 30 years, which can lead to loss of function.
145
Adults affected by postpolio syndrome usually experience what?
New muscle weakness, fatigue and pain.
146
What substitution are often the only signs of disability in patient's with postpolio syndrome?
Postural substitutions.
147
What is guillain-Barre syndrome?
A self-limiting inflammatory disease of unknown origin that strikes the roots of te axons as they exit the spinal cord.
148
Guillain-Barre patients are clinically similar to what?
Polio patients, except the involvement is symmetrical and recovery is more rapid.
149
What is Myasthenia gravis?
An autoimmune disease that involves the neuromuscular junction.
150
How is myasthenia gravis treated?
Medically and not with an orthosis.
151
What is muscular dystrophy?
A bilaterally symmetrical, progressive degeneration of the muscle fibers.
152
What is the most common form of muscular dystrophy?
Duchenne pseudohypertrophic.
153
What occurs within the lower limbs of muscular dystrophy?
Progressive weakness begins in the pelvic girdle and extends distally.
Contractures usually occur due to fatty connective tissue replacement of the lost muscle fibers.
154
What reduces the patient's ability to substitute?
The addition of sensory loss to muscle paralysis.
155
What is a common cause of sensory loss?
Equina spinal cord injury.
156
What might cause equina spinal cord injury?
Spina bifida
| Acute trauma.
157
Impaired sensation occurs first where? What does this do?
Occurs on the soles of the feet.
| This delays awareness of floor contact.
158
Sacral lesion (S1 and S2) of spinal injury primarily impair what?
The posterior calf muscles, and early weakening of the hip extensor and abductor muscles.
159
Low lumbar lesions (L5, L4) of spinal injury primarily impair what?
The hamstrings, and most of the foot muscles.
160
What is the primary posture at midstance of a low lumbar lesion?
Excessive ankle dorsiflexion and knee flexion.
| Heel contact persists through stance.
161
Upper lumbar lesions (L3) of spinal injury primarily impair what?
The quadriceps.
162
Upper lumbar lesion (L2) of spinal injury primarily impairs what?
Hip flexion, and the ability to initiate a step.
163
Walking potential of each neurologic level is reduced by what/
Hip flexion contractures and bilateral involvement.
164
What are the common causes of central control dysfunction?
Brain lesions: stroke, acute head trauma, and cerebral palsy.
Spinal cord injuries in the cervical and thoracic areas.
165
What is a universal characteristic of central control function?
Spasticity.
166
What is selective control?
Independent movement of one joint or muscle relative to the direction, intensity, and duration of action.
167
Walking relies on _________ control?
Selective control.
168
Impaired selective control by itself results in what?
Muscle weakness.
169
What is primitive control?
Activates the muscles through basic synergies and reflex responses.
170
What happens to primative control when the supressive pathways are damaged?
They become dominant.
171
What are the three basic levels of primitive control?
Locomotor synergies, postural reflexes, and stretch reflexes.
172
What do locomotor synergies provide?
To mass patterns of muscle action. An extensor pattern activates the hip and knee extensors and the ankle plantar flexors.
A flexion pattern which activvates the ankle dorsiflexors in concert with the hip and knee flexor muscles.
173
What are Postural reflexes
Reflexes that are based on a patient's posture. Example: a patient is standing, or lying supine.
174
During standing, what are the postural reflexes?
An increase in extensor tone.
175
In stretch reflexes, what is the common response of a quick stretch?
Clonus.
176
How is gait typified for a patient with a upper motor neuron lesion?
Stiffness of the action and only midrange mobility.
177
What are gait deviations at the ankle?
Excessive dorsiflexion
| Excessive plantarflexion.
178
Excessive dorsiflexion is primarily only a problem in what ?
Stance.
179
What are the two distinct pattern of excessive dorsiflexion?
Prolonged heel rocker in weight acceptance
| Excessive tibial advancement during midstance and terminal stance.
180
Why is there a long heel rocker due to excessive ankle dorsiflexion?
Following heel contact, forefoot drop to the floor is delayed until the tibia rolls forward to a vertical position. This results in excessive knee flexion and prolonged quad. activity.
181
What might by the orthotic cause of excessive ankle dorsiflexion?
Solid shell AFO, prosthetic foot, or fusion of the ankle and subtalar joints in neutral.
182
Why is there excessive tibial advancement during midstance and terminal stance from excessive ankle dosriflexion?
Weakness of the gastrocsoleus is the most common cause. This results in excessive knee flexion
183
What are the two basic patterns of excessive ankle plantarflexion?
Passive drop foot
| Plantar flexor rigidity.
184
What gait tasks are involved with passive foot drop?
Swing limb advancement.
| Weight acceptance.
185
When is foot drop most easily to see?
Midswing. The foot will prematurely contact the floor with no substitutive effort.
186
What happens in weight acceptance with foot drop?
initial contact is made with the forefoot, and the heel rocker is lost. The loading response is usually a passive drop of the limb.
187
What does the lack of a heel rocker effect with foot drop?
It creates excessive knee extension.
188
What are the common causes of drop foot gait?
Inadequate function of the tibialis anterior and long to eextensor muscles.
189
What gait tasks are effected by plantar flexor rigidity?
Weight acceptance.
Stance limb progression.
Swing limb advancement.
190
What are the gait patterns that occurs with plantar flexor rigidity?
Initial contact with an extended knee and only 15 degrees plantar flexion allows minimal heel strike.
Loading response includes a rapid forefoot drop and lack of knee flexion.
Loss of dorsiflexion at midstance.
191
if at initial contact, there is excessive ankle plantar flexion and a flexed knee, what joint is being overused?
THe forefoot.
192
A person with a slow gait and rigid plantar flexor will exhibit what?
Heel drop to the flor and knee extends. Tibial advancement is delayed or obstructed.
193
A person with a fast gait and rigid plantar flexor will exhibit what?
Heel-off, and forefoot support posture throughout gait.
194
During stance limb progression, a person with a rigid plantar flexor will show what?
Ankle rocker is curtailed or lost. Tibial advancement is inhibited unless with a premature heel rise. This results in metatarsal loading prolonged and excessive. And hurts the plantar support. This results in a short step.
195
What are the common causes of planta flexor rigidity?
Gastrocnemius-soleus contracture or spasticity.
| Weak quads, voluntarily mimic this pattern.
196
What is seen during swing limb advancement with a plantar flexor rigidity?
Midswing and terminal swing display excessive plantar flexion
197
What are gait deviations at the foot?
```
Excessive inversion (varus)
Excessive eversion (valgus)
```
198
What occurs during excessive inversion?
Displaces floor contact to the lateral side of the foot.
Continued inversion following heel rise leads to persistent forefoot weight bearing on the 5 metatarsal head. 1st met contact is delayed or absent.
199
What is the result of excessive inversion?
unstable weight bearing.
200
What are the common causes of excessive inversion?
Soleus contracture.
Overactivity of the anterior tibialis, posterior tibialis and soleus muscles.
Club foot.
201
What occurs with excessive eversion of the foot?
Medial heel weight bearing, a flat arch, and premature first met. loading
202
What are the causes of excessive eversion?
Invertor muscle weakness.
| Peroneal muscle overactivity
203
What are the knee gait deviation?
```
Excessive knee flexion
Inadequate knee flexion
Excessive knee extension
Knee varus
Knee valgus
```
204
What is the most common dysfunction at the knee?
Excessive knee flexion.
205
What gait tasks are effected by excessive knee flexion/
Weight acceptance
Stance limb progression
Swing limb advancement.
206
How is weight acceptance effected by excessive knee flexion?
There is added quad. demand.
207
What are the common causes of excessive knee flexion during weight acceptance?
Contractures
Overy intense hamstring muscles activity in spastic patients
Lack of ankle plantar flexion.
208
How is stance limb progression affeccted by excessive knee Flexion?
Inability to extend the knee progressively from initial flexed position prolongs quad demand. The flexed knee may obligate forefoot support and excessive anle dorsiflexion creating weight bearing instability.
Progression of the body of the foot is inhibited by lack of femoral advancement on the tibia.
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How is swing limb advancement affected by excessive knee flexion?
Tibial advancement may be restricted, which results in persistent knee flexion in terminal swing with inadequate knee posturing for stance.
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What gait tasks are affected by inadequate knee flexion?
Weight acceptance
| Swing limb advancement
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How is weight acceptance affected by inadequate knee flexion?
Without knee flexion, the shock-absorbing mechanism is absent, leading to greater join impact.
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What is the most common cause of inadequate knee flexion in weight acceptance?
Excessive ankle plantar flexion.
| Weak quads.
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How is swing limb advancement affected by inadequate knee flexion?
In preswing, flexion less than 40 egrees inadequately prepares the limb for swing.
During initial swing, inadequate knee flexion causes toe drag unless the patient usues substitue motions.
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What are the common causes of inadequate knee flexion during swing?
Continued action of the vasti as part of a spastic extensor pattern or inadequate terminal stance rocker because of persistent heel contact and absent dorsiflexion.
inadequate preswing flexion
Hip flexor weakness
Premature hamstring action.
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Excessive knee extension will be _________ or _________.
Hyperextension
| Extenor thrust.
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What is extensor thrust?
The limb is rapidly driven backwards but the knee lacks a passive range of hyperextension.
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What are the causes of excessive knee extension?
Rigid ankle plantar flexors
spastic overactivity of the vasti
Voluntary premature soleus action to stabilize a knee with insufficient quads.
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Knee varus and valgus are related to what?
The alignment of the join surfaces or bony shafts.
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What ar ethe gait deformity at the hip?
Inadequate hip flexion
| inadequate hip extension
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What gait tasks are affected by inadequate hip flexion?
Swing limb advancement
| Wieght acceptance.
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How is swing limb advancement affected by inadequate hip flexion?
Initial swing is affected.
| A grade of 2+ is flaccid paralysis.
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The most common cause of inadequate hip flexion during swing limb advancement in spastic patients is what?
Premature hamstrings.
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How is weight acceptance affected by inadequate hip flexion?
Inadequate hip flexion that continues into terminal swing and limits the limb's forward reach for stance.
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What gait task is impaired with inadequate hip extension?
Stance limb progression.
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How is stance limb progression affected by inadequate hip extension/
The patient is denied a trailing limb position in late midstance and terminal stance. Stride length is shortened.
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What are the common direct causes of inadequate hip extension? how about indirect?
Avoidance of stretching a painful joint capsule, hip flexion contracture, spasticity.
Postural adaptations for balance over a plantar flexed anke or flexed knee.
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What is hip past-retract?
A voluntary substitution to gain knee extension when the guads are paralyzed. It involves rapid excessive hip flexion advancing both thigh and tibia. Then, rapid hip extension retracts the thigh while inertia sustains the forward tibia.
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What are the gait deviation of the pelvis?
Contralateral pelvic drop
Pelvic hike
Excessive roation
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What gait task is affected by contralateral pelvic drop?
Weight acceptance
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How is weight acceptance affected by contralateral pelvic drop?
The transfer of body weight to the stance limb in prepraration for swing removes the support of the opposite side. Hip abductor muscle wekaness allows the unsupported pelvis to drop.
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What protects the abductors with contralateral pelvic drop?
A tight iliotibial band or prepositioning into adduction by a short leg.
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What gait task is affected by pelvic hike?
Swing limb advancement.
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What occurs during swing limb advancement pelvic hike?
Elevation of the ipsilateral side of the pelvis is used for foot clearance when hip and/or knee flexion is inadequate.
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What gait task is effected by excessive roation of the pelvis?
Swing limb advancement
| Stance limb progresion
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Why does excessive anterior rotation of the pelvis occur?
Anterior pelvic motion substitutes the trunk muscles for weak hip flexors to assist limb advancement.
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Why does excessive postierior rotation of the pelvis occur?
Posterior rotation and drop in terminal stance provide mild leg lengthening to accommodate persistent heel contact.
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What are the gait deviation at the trunk?
Forward trunk lean
Backward trunk lean
Lateral trunk lean.
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What gait tasks are affected by forward trunk lean?
Weight acceptance
| Stance progression.
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Why does forward trunk lean occur during weight acceptance?
To reduce quad demand by moving the vector anterior to the knee.
Muscle weakness is an indication.
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Why does forward trunk lean occur during stance progression?
Anterior displacement of the body vector is used to restore standing balance over a plantar flexed anklle or flexed knee.
Excessive hip flexion that lacks compensatory lordosis also create a forward trunk lean.
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What are the gait tasks affected by backward trunk lean?
Weight acceptance
Stance progression
Swing limb advancement.
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Why does backward trunk lean occur during weight acceptance and stance progression?
It reduces the demand on weak hip extensor muscles. This posture begins with floor contact.
Hip flexion contracture increases the amount of backward lean required to preserve standing balance.
Bilateral posterior arm position adds further balance.
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Why does backward trunk lean occur during swing limb advancement?
It is accompanied by anterior pelvic tilt which assists limb advancement when the hip flexors are weak.
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What gait tasks are affected by lateral trunk lean?
Weight acceptance through stance progression
| Swing limb advancment
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Why does lateral trunk lean occur during weight acceptance through stance progression?
It is used to reduce the demand on the hip abductor muscles.
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Why does lateral trunk lean occur during swing limb advancement?
Combined conttralateral lean of the trunk and ipsilateral pelvic hike is another subtitution to assist limb advancment.
