Exam III Flashcards
(272 cards)
1
Q
where is COM located in the human body?
A
S2
2
Q
what is HAT?
A
(1) head, arm, trunk weight
(2) weight of the upper body acting on the LE
3
Q
what is considered a full HAT? half HAT?
A
(1) full HAT: the full weight of the HAT on ONE LEG
half HAT: HAT distributed between TWO legs on the ground
4
Q
what kind of force can the COM and HAT create?
A
rotation torque
5
Q
where is the femur weakest or most susceptible to fracture? why is this area prone to fracture?
A
ward’s triangle (near mid neck); doesn’t have sufficient trabecular bone in the area
6
Q
what is the closed pack position of the hip?
A
extension, IR, and abduction
7
Q
what makes the closed pack position of the hip different than other joints?
A
although the ligaments of the hip are taut in closed pack, there is poor surface contact between the head and acetabulum
8
Q
how much of the head of the hip does the acetabulum cover? what does this help provide?
A
half; provides stability
9
Q
what is the open pack position of the hip?
A
30 degrees flexion, 30 degrees abduction, slight ER
10
Q
which way does the femoral head project to articulate with the acetabulum?
A
anterior/medial
11
Q
why are the muscles of the hip less likely to be impinged when compared to the shoulder?
A
the muscles attach further from the head of the hip, unlike in the shoulder where muscles attach very close to the head
12
Q
what directions does the acetabulum face?
A
anterior, lateral, and inferior
13
Q
what ligament of the hip doesn’t undergo much stress at all?
A
ligamentum teres; this ligament is primarily there to provide passage for blood supply for femoral head
14
Q
what can happen with a tear of the ligamentum teres?
A
a-vascular necrosis of the head of the femur
15
Q
what is the purpose of the transverse acetabular ligament?
A
protects vessels from being pinched
16
Q
what are the functions of the acetabular labrum? (4)
A
(1) deepens socket (increases concavity)
(2) provides negative pressure
(3) provides proprioception and pain sensation
(4) enhance lubrication
17
Q
what prevents superior dislocation of the hip?
A
center-edge angle
18
Q
what complication could arise from having an increased acetabular anteversion angle?
A
more prone to anterior dislocation of the hip
19
Q
why does the posterior side of the hip have less ligament support than the anterior side of the hip?
A
the posterior hip has a large rim of the acetabulum preventing a posterior dislocation, therefore it doesn’t need as strong ligaments to secure hip posteriorly
20
Q
does the labrum of the hip bare weight?
A
no, it shouldn’t; not in healthy populations
21
Q
what different mechanisms add stability to the hip joint? (4)
A
(1) ligaments and capsule
(2) muscles (provide dynamic stability)
(3) body weight compressive forces
(4) intra-articular (negative) pressure and labrum
22
Q
what happens to the moment arm with coxa vara? what can this cause?
A
(1) the moment arm is larger
(2) increased compressive forces medially, which could increase risk for OA or stress fracture of neck
23
Q
what happens to the moment arm with coxa valga? what can this cause?
A
(1) the moment arm is smaller
(2) weaker abductors, which increases stress superiorly
24
Q
what is commonly associated with coxa varum?
A
(1) hip adduction
(2) genu valgum
(3) foot pronation
25
what is commonly associated with coxa valgum?
(1) hip abduction
(2) genu varum
(3) foot supination
26
what is the normal angle of inclination?
125 degrees
27
what is the angle of inclination for coxa varum?
105 degrees (or less)
28
what is the angle of inclination for coxa valgum?
140 degrees (or more)
29
excessive anteversion of the hip can lead to what compensation? why does this occur?
toes pointed inward; internal rotation of the hip improves joint congruity
30
how much hip anteversion does an infant usually have?
40 degrees
31
***what is considered "normal" hip anteversion by the age of about 16?***
15 degrees
32
excessive anteversion of the hip that persists into adulthood can lead to what problems?
(1) increased risk of hip dislocation
(2) articular incongruence
(3) increased joint contact stress
(4) increased wear on cartilage or labrum
33
what are the two main ligaments of the anterior hip? which is the strongest of the hip?
(1) iliofemoral ligament (strongest)
| (2) pubofemoral
34
what ligament runs posterior to the hip?
(1) ischiofemoral
35
which motion makes all 3 hip ligaments taut?
full hip extension (think closed pack)
36
which ligaments of the hip are the strongest?
anterior ligaments (iliofemoral & pubofemoral)
37
what structures become taught at end-range hip flexion with knee EXTENDED (1)
(1) hamstrings
38
what structures become taught at end-range hip flexion with knee FLEXED? (2)
(1) posterior/inferior capsule
| (2) glute max
39
what structures become taught at end-range hip extension with knee EXTENDED? (5)
```
PRIMARY
(1) iliofemoral ligament
(2) anterior capsule
SECONDARY
(3) pubofemoral ligament
(4) ischiofemoral ligament
(5) iliopsoas
```
40
what structures become taught at end-range hip extension with knee FLEXED? (1)
(1) rectus femoris
41
what structures become taught at end-range hip abduction? (2)
(1) pubofemoral ligament
| (2) adductors
42
what structures become taught at end-range hip adduction? (2)
(1) IT band
| 2) abductors (TFL, glute med
43
what structures become taught at end-range IR? (2)
(1) ischiofemoral ligament
| 2) external rotators (piriformis, glute max
44
what structures become taught at end-range hip ER? (3)
(1) iliofemoral ligament
(2) pubofemoral ligament
(3) internal rotators (TFL, glute minimus)
45
what is a normal center edge angle?
35 degrees
46
what is the most vulnerable position for the hip to be in for a dislocation to occur? why?
flexion, adduction, slight IR; ligaments are relaxed and trauma can cause posterior dislocation
47
what is considered excessive anteversion of the hip?
35+ degrees
48
in an OPEN CHAIN, what motions occur when the hip is flexed?
(1) posterior pelvic tilt
| (2) flexion of the lumbar spine
49
in an OPEN CHAIN, what motions occur when the hip is extended?
(1) anterior pelvic tilt
| (2) extension of the lumbar spine
50
in an OPEN CHAIN, what motions occur when the hip is abducted?
(1) ipsilateral side flexion of lumbar spine
51
in an OPEN CHAIN, what motions occur when the hip is adducted?
(1) contralateral side flexion of lumbar spine
52
in an OPEN CHAIN, what motions occur when the hip is internally rotated?
(1) inflare of the pelvis
| (2) contralateral rotation of the lumbar spine
53
in an OPEN CHAIN, what motions occur when the hip is externally rotated?
(1) outflare of the pelvis
| (2) ipsilateral rotation of the lumbar spine
54
what is an ipsidirectional lumbopelvic rhythm?
when the lumbar spine and pelvis rotate in the same direction (ex. when bending over to pick up a box)
55
what is a contradirectional lumbopelvic rhythm?
when the lumbar spine and pelvis rotate in opposite directions
56
what are two causes of a contradirectional lumbopelvic rhythm?
(1) anterior pelvic tilt
| (2) posterior pelvic tilt
57
***when you have an anterior pelvic tilt, what happens at the lumbar spine?***
the spine extends to compensate for the anterior tilt
58
***when you have a posterior pelvic tilt, what happens at the lumbar spine?***
the spine flexes to compensate for the posterior tilt
59
when the hip flexes in an open kinematic chain, which way does the pelvis rotate?
posteriorly
60
how is hip flexion accomplished in a closed kinematic chain?
by the pelvis tilting anteriorly
61
how is hip extension accomplished in a closed kinematic chain?
by the pelvis tilting posteriorly
62
how is the hip abducted in a closed kinematic chain?
by hiking the iliac crest on the contralateral (non-support) side
63
how is the hip adducted in a closed kinematic chain?
by lowering the iliac crest on the contralateral (non-support) side
64
when in the gait cycle does the hip adduct? when does it abduct?
(1) adducts: 20-30%
| (2) abducts: 60%
65
in a closed kinetic chain, what happens when the hip is internally rotated?
contralateral forward rotation of the pelvis
66
in a closed kinetic chain, what happens when the hip is externally rotated?
contralateral backwards rotation of the pelvis
67
when the hip is flexed, which direction is the glide of the femoral head?
posterior glide
68
when the hip is extended, which direction is the glide of the femoral head?
anterior glide
69
when the hip is abducted, which direction is the glide of the femoral head?
inferior glide
70
when the hip is internally rotated, which direction is the glide of the femoral head?
posterior glide
71
when the hip is externally rotated, which direction is the glide of the femoral head?
anterior glide
72
what muscles assist with performing an anterior pelvic tilt?
(1) force-couple between hip flexors and low back extensors
| (2) iliopsoas, sartorious, erector spinae
73
weakness of what muscles can lead to an increased anterior pelvic tilt? why does this occur?
(1) weak abdominals; the hip flexors have a strong inferior pull on the pelvis, and the abs stabilize the pelvis by pulling the pelvis superiorly
(2) when the abs are weak, the hip flexors over power the abdominals and pull the pelvis anteriorly
74
how does an increased anterior pelvic tilt affect the spine?
increased lumbar lordosis
75
how does a hip flexor contracture cause metabolically inefficiency?
the extensors are expend more energy to prevent further hip flexion
76
what can hip flexor contractures lead to? (3)
(1) increased lumbar lordosis
(2) spine pain
(3) knee OA
77
what muscles assist with performing an posterior pelvic tilt?
(1) force-couple between hip extensors and low back flexors (core muscles)
(2) glute max, hamstrings, external obliques, rectus abdominis
78
***when going from a completely erect standing position to bent over, what muscles are initially more active? what muscles become more active the more you flex the hips?***
(1) initially, the glutes are more active
| (2) the more the hip is flexed, glute activation decreases and hamstring and adductor activation increases
79
what muscles are required for stabilization of the spine when climbing uphill?
low back extensors (the multifidi)
80
during a single leg stance, how much force is required of the abductors to stabilize the pelvis?
twice the body weight
81
what happens when the abductors are weak and can't provide the the required stability to the pelvis?
the pelvis drops on the contralateral side during gait (trendelenburg gait)
82
at what angle are the hip abductors the strongest? what angle are they the weakest?
(1) strongest near 0 degrees abduction (neutral)
| (2) weakest near 40 degrees abduction
83
***adduction usually occurs in combination of movement in other planes; which plane?***
sagittal; adduction usually occurs with flexion or extension
84
when the hip is adducted, what muscle helps to eccentrically control the velocity and drop of the adducting hip?
glute medius
85
how does the adductor longus act as both a hip flexor and hip extensor?
(1) when the hip is extended, the adductor longus acts as a hip flexor
(2) when the hip is flexed, the adductor longus acts as a hip extensor
86
when does the piriformis act as an internal rotator?
when the hip is flexed to 90 degrees
87
when does the glute med act as an external rotator?
near neutral (0 degrees)
88
when is the glute med strongest as an internal rotator?
near 90 degrees of hip flexion
89
what group of muscles can act secondarily as internal rotators?
the adductors (specifically, the adductor longus)
90
when are the internal rotators most active during gait?
the first 30% of the gait cycle
91
during what athletic manuever are the external rotators very active? how does this occur?
cutting motions; with one leg planted, the external rotators contract causing the contralateral pelvis to move posteriorly
92
what muscles assist the external rotators with external rotation of the hip? (think closed chain)
back extensor muscles
93
what are the strongest muscles of the hip? what are the weakest?
(1) extensors (strongest)
(2) flexors
(3) adductors
(4) abductors
(5) internal rotators
(6) external rotators (weakest)
94
why is the cane placed on the unaffected side when ambulating? (2)
(1) moves the COP and LOG away from the injured side
(2) the lever arm is 4x longer; the UE muscles are in a much better advantage to produce force (triceps and shoulder extensors)
95
when does developmental hip dysplasia typically manisfest?
at birth or within the first few years of life
96
what are the causes of developmental hip dysplasia? (3)
(1) joint laxity
(2) abnormal intra-uterine positioning
(3) post natal positioning
97
what is Legg-Calve-Perthes disease? what age does this usually occur?
(1) avascular necrosis of the femoral head
| (2) children aged 4-10 years
98
during what activity do the adductors act as hip flexors and extensors? what activity do the adductors act as internal rotators?
(1) flexors and extensors during running
| (2) internal rotators during walking
99
what is a normal femoral-tibial angle?
170-175 degrees
100
what is the femoral-tibial angle with genu valgum and genu varum?
(1) genu valgum: <= 165 degrees
| (2) genu varum: >= 180 degrees
101
how are forces redistributed at the knee with genu valgum?
(1) medial structures under tension
| (2) lateral structures shorten and lateral condyles are compressed
102
how are forces redistributed at the knee with genu varum?
(1) lateral structures under tension
| (2) medial structures shorten and medial condyles are compressed
103
where can injury occur due to genu valgum? what about genu varum?
genu valgum
(1) medial knee pain: ligaments and capsule
(2) lateral knee pain: meniscus and cartilage
genu varum
(1) medial knee pain: meniscus and cartilage
(2) lateral knee pain: ligaments and capsule
104
what condition at the knee makes a person more prone to ACL and MCL tears?
genu valgum
105
what condition at the knee makes a person more prone to medial condyle OA?
genu varum
106
what condition at the knee makes a person more prone to PF syndrome, subluxation, and lateral dislocations of the patella?
genu valgum
107
what are two deformities associated with genu varum?
(1) osteitis deformans
| (2) osteomalacia
108
what patient populations may be associated with genu valgum?
(1) obese patients
| (2) patients with weak quads and hip abductors
109
what is considered a normal Q angle?
10-15 degrees
110
what is considered an abnormal Q angle?
>20 degrees
111
how does a larger Q angle affect forces at the knee?
increases the forces that pull the patella laterally
112
what are some different factors that increase the Q angle? (7)
(1) genu valgus
(2) femoral anteversion
(3) external tibial torsion
(4) lateral displacement of tibial tuberosity
(5) weak VMO
(6) foot overpronation
(7) tight lateral retinaculum
113
what is the Insall-Salvati ratio?
ratio of patellar tendon length to length of the patella
114
what is patella alta? what is it associated with?
(1) high patella
| (2) excessive lateral tracking of the patella making it more prone to subluxation; PF syndrome
115
what is patella baja? what is the most common cause of this condition?
(1) low patella
| (2) rare side effect of surgery; can limit ROM and cause pain
116
where is the synovial fluid of the knee forced during full extension?
anteriorly
117
where is the synovial fluid of the knee forced during full flexion?
posteriorly
118
what position is the capsule under the least tension and most comfortable when joint effusion is present?
a semi-flexed position
119
what passive (2) and active (1) structures reinforce the capsule of the knee anteriorly?
PASSIVE
(1) patellar tendon and patellar retinacular fibers
ACTIVE
(1) quads
120
what passive (3) and active (3) structures reinforce the capsule of the knee laterally?
```
PASSIVE
(1) LCL
(2) lateral patellar retinaculum
(3) IT band
ACTIVE
(1) biceps femoris, popliteal tendon, lateral head of gastroc
```
121
what passive (2) and active (3) structures reinforce the capsule of the knee posteriorly?
```
PASSIVE
(1) oblique popliteal ligament
(2) arcuate popliteal ligament
ACTIVE
(1) popliteus, gastroc, hamstrings
```
122
what passive (3) and active (1) structures reinforce the capsule of the knee posterior-laterally?
```
PASSIVE
(1) arcuate popliteal ligament
(2) LCL
(3) popliteofibular ligament
ACTIVE
(1) tendon of popliteus
```
123
what passive (3) and active (3) structures reinforce the capsule of the knee medially?
```
PASSIVE
(1) MCL
(2) medial patellar retinaculum
(3) posterior oblique ligament
ACTIVE
(1) tendons of the medial hamstrings, sartorious, gracilis
```
124
the knee has how many bursae?
14
125
which meniscus of the knee is larger?
medial meniscus
126
what are some of the functions of the menisci? (6)
(1) increase concavity of tibial condyle (stability)
(2) weight distribution
(3) reduce friction
(4) lubricates articular cartilage
(5) provides proprioception
(6) helps absorb shock (muscles are main shock absorbers)
127
what muscle attaches to the medial meniscus? what attaches to the lateral meniscus?
(1) medial: semimembranosus
| (2) lateral: popliteus
128
when the meniscus is injured and stress distribution becomes abnormal, what can this cause?
increased risk of OA
129
what is considered normal ROM at the knee joint for flexion and extension?
(1) flexion: 140 degrees
| (2) extension: 0 - 10 degrees hyperextension are WNL
130
what is genu recurvatum?
hyperextension of the knee >10 degrees
131
how much tibial rotation occurs at the knee when it's fully extended?
0 degrees; the knee is locked
132
at what degree of knee flexion is tibial rotation the greatest? how much tibial rotation occurs?
(1) 90 degrees of knee flexion
| (2) 40-45 degrees of total rotation
133
what is the ratio of ER to IR at the knee?
2:1 (twice as much ER than IR)
134
how much total abduction and adduction occurs at the knee?
6 degrees (passively)
135
in an open chain, which direction does the rotation of the knee occur?
SAME DIRECTION
| femur is stationary and the rotation occurs in the same direction of the tibia
136
in a closed chain, which direction does the rotation of the knee occur?
OPPOSITE DIRECTIONS
the tibia is fixed, and the femur is moving on the tibia
(1) ER of the knee occurs with IR of the femur
(1) IR of the knee occurs with ER of the femur
137
***how much extension at the knee is required for normal gait, stair climbing, and running?***
0 degrees (full extension)
138
how much knee flexion is required for normal gait?
60 degrees
139
how much knee flexion is required for stair climbing?
80 degrees
140
how much knee flexion is required for sitting and rising from most chairs?
90 degrees
141
how much knee flexion is required for sitting and rising from a toilet seat?
115 degrees
142
how much knee flexion is required for "advanced function?"
> 115 degrees
143
which way does the tibia glide with knee extension in an OPEN CHAIN?
(1) concave tibia moving on convex femur; SAME DIRECTION
| (2) anterior glide
144
which way does the tibia glide with knee flexion in an OPEN CHAIN?
(1) concave tibia moving on convex femur; SAME DIRECTION
| (2) posterior glide
145
which way does the femur glide with knee extension in a CLOSED CHAIN?
(1) convex femur moving on concave tibia; OPPOSITE DIRECTION
| (2) posterior glide
146
which way does the femur glide with knee flexion in a CLOSED CHAIN?
(1) convex femur moving on concave tibia; OPPOSITE DIRECTION
| (2) anterior glide
147
how does the screw home mechanism occur in an OPEN CHAIN?
when the knee extends, the tibia externally rotates
148
how does the screw home mechanism occur in a CLOSED CHAIN?
when the knee extends, the femur internally rotates
149
what factors guide the screw home mechanism? (3)
(1) shape of medial femoral condyle
(2) tension in ACL
(3) lateral pull of quads
150
how does the popliteus "unlock" the knee in regards to the screw home mechanism? (open chain and closed chain)
OPEN CHAIN
(1) when the popliteus contracts, it internally rotates the tibia during knee flexion
CLOSED CHAIN
(1) when the popliteus contracts, it externally rotates the femur during knee flexion
151
what motion does the MCL restrict? (3)
(1) valgus
(2) extension
(3) ER of the knee
152
does the MCL prevent valgus more when the knee is flexed or extended?
during knee flexion
| 78% restraint during flexion vs. 57% during extension
153
what motion does the LCL restrict? (3)
(1) varus
(2) extension
(3) rotational forces of tibia
154
does the LCL prevent varus more when the knee is flexed or extended?
during knee flexion
| 69% restraint during flexion vs. 55% during extension
155
what motions does the ACL restrict? (3)
(1) anterior translation of the tibia (posterior glide of femur)
(2) varus AND valgus
(3) rotational forces of tibia (IR and ER)
156
what motions does the ACL restrict?
(1) posterior translation of the tibia (anterior glide of femur)
(2) varus AND valgus
(3) rotational forces of tibia (IR and ER)
157
what position are the ligaments of the knee most taut?
full extension
158
what structure does the IT band protect during knee flexion? how is this accomplished?
(1) protects the PCL
| (2) IT band slides posterior to the condyles, controlling anterior translation of the femur
159
what structure does the IT band protect during knee extension? how is this accomplished?
(1) protects the ACL
| (2) IT band slides anterior to the condyles, controlling posterior translation of the femur
160
what are the most commonly injured knee ligaments? (2)
ACL and MCL
161
at what angle of knee flexion is contact between the patella and femur greatest? what does this mean?
90 degrees; patella in the best position to resist stress at 90 degrees
162
what part of the patella is in contact with the femur at 20, 90, and 135 degrees of knee flexion?
(1) 20 degrees: inferior pole (not stable)
(2) 90 degrees: medial and lateral patellar facets (most stable)
(3) 135 degrees: odd facet and edge of lateral facet (not stable)
163
as the external force on the PF joint increases, what happens to the contact area and why?
(1) the contact area increases to disperse large compression forces
(2) this occurs up to 90 degrees of flexion and then beyond 90 degrees the contact area decreases again
164
what position is the torque on the patellofemoral joint the largest?
full extension in an open kinematic chain (ex. leg extension machine)
165
what position is STRESS on the patellofemoral joint the highest?
despite having the best contact, 90 degrees of knee flexion in a CKC puts the most stress on the PF joint (the knee is also in best position to be stressed)
166
what causes abnormal tracking of the patella often seen in PFS? (7)
```
FUNCTIONAL
(1) IT band adhering to VL
(2) tight quads (VMO specifically)
(3) weak hip abductors and ERs
STRUCTURAL
(1) genu valgus/varus
(2) femoral ante/retroversion
(3) external tibial torsion
(4) pronated foot
```
167
in what position does the tibiofemoral joint have the greatest surface contact and is in the best position to resist stress?
full knee extension (0 degrees)
168
what movement might hurt patients with OA of the tibiofemoral joint?
squatting (smaller surface area as the knee flexes)
169
which muscle group at the knee is stronger, knee flexors or extensors? how much stronger?
knee extensors; 2-3x stronger
170
what is the function of the quads during isometric, eccentric, and concentric muscle contractions?
(1) isometric: stabilizes the knee
(2) eccentric: shock absorption
(3) concentric: knee extension (ex. stand from sitting)
171
in an OPEN chain, when is the external torque imposed on the quadriceps highest?
full extension (0 degrees) (think leg extension)
172
in a CLOSED chain, when is the external torque imposed on the quadriceps highest?
90 degrees of knee flexion; (think the bottom of a squat)
173
when are the quads strongest? when are they weakest?
(1) strongest: mid range (45 degrees)
| 2) weakest: full extension (0 degrees
174
what are two main functions of the knee flexors during gait?
(1) eccentrically decelerate the leg during the terminal swing phase
(2) flex the knee during swing phase so the toes don't hit the ground and you trip
175
how does the short head of the biceps femoris and the pes anserinus muscle group control knee rotation in a closed kinematic chain?
(1) biceps femoris: accelerates femur internally (the knee joint moves into ER)
(2) pes anserinus: decelerate and limit ER at the knee
(these muscle groups work to accelerate and decelerate rotation at the knee)
176
when are the knee flexors strongest? when are they weakest?
(1) strongest: near full extension (20 degrees of flexion)
| (2) weakest: 90 degrees of flexion
177
how do the knee flexors and extensors work synergistically during running?
(1) quads contract to maintain the knee extended
| 2) with the knee extended, the hamstrings contract and cause hip extension (assist the glutes
178
when the hip is flexed and knee is extended simultaneously, what occurs to the quads and hamstring muscles?
(1) active insufficiency of the quads
(2) passive insufficiency of the hamstrings
(efficiency is decreased)
179
when the hip is extended and knee is flexed simultaneously, what occurs to the quads and hamstring muscles?
(1) active insufficiency of the hamstrings
(2) passive insufficiency of the quads
(efficiency is decreased)
180
what percentage of ACL sport related injuries are non-contact? what position of the leg is the ACL most commonly injured?
(1) 70%
| (2) knee flexed with foot planted on the ground
181
what are 3 factors associated with non-contact ACL injuries?
(1) strong quad activation over a flexed or nearly extended knee
(2) valgus collapse of the
knee
(3) excessive
external rotation of the
knee (excessive IR of the femur or ER of the tibia)
182
are closed chain or open chain exercises better for the ACL when rehabbing? why?
closed chain; the tensile forces placed through the ACL are less when the hamstrings co-contract with the quads (closed chain) compared to the quads contracting alone (open chain)
183
what is an important factor in ACL injury prevention?
motor education; teaching athletes to land properly (among other movements) reduces the strain placed on the ACL
184
after recovery from an ACL injury, when can walking, jogging, and sports be resumed?
weeks 3-6: walking
weeks 7-12: jogging / strength training
months 4-7: sagittal plane sports
>8 months: slow introduction to cutting sports
185
what motions tend to worsen pain in patients with PFS? (3) what is one possible cause of PFS?
(1) squatting
(2) stair ascension
(3) sitting with knees flexed for extended periods of time
Possible Cause
-stress intolerance of articular cartilage
186
what is the relationship between Q angle and PFS?
increased Q angle contributes to PFS
187
where may OA occur in patients with genu varum?
medial side of the knee
188
what is the most common cause of genu recurvatum? how is this condition usually managed?
(1) weak quads (poliomyelitis and spinal cord injury also causes)
(2) brace or heel insole
189
what is involved with the PT management of PFS? (4)
(1) strengthen hip abductors and ERs
(2) strengthen VMO
(3) insole to improve foot pronation
(4) taping and bracing to guide tracking
190
what bones make up the hind foot, midfoot, and forefoot?
(1) hind foot: talus and calcaneus
(2) navicular, cuboid, 3 cuneifrom
(3) forefoot: metatarsals and phalanges
191
how does the ankle function to provide stability? (2) how does it provide mobility? (2)
Stability
(1) provide BOS with minimal energy expenditure
(2) act as rigid lever for push-off during gait
Mobility
(1) dampens torsional forces
(2) absorbs shock and allow foot to conform to uneven terrain
192
what are the triplanar movements that make up pronation?
(1) dorsiflexion
(2) eversion
(3) abduction
193
what are the triplanar movements that make up supination?
(1) plantarflexion
(2) inversion
(3) adduction
194
what direction is valgus at the ankle?
eversion
195
what direction is varus at the ankle?
inversion
196
what is the concave / convex rule at the PROXIMAL tibiofibular joint?
concave fibular head facet moving on a convex tibial facet
197
what is the concave / convex rule at the DISTAL tibiofibular joint?
convex fibular facet moving on a concave tibial facet
198
what type of joint is the distal tibiofibular joint?
syndesmosis joint (no synovial cavity)
199
are the ligaments at the distal tibiofibular joint weak or strong? what ligaments passive structures support this joint?
very strong
(1) anterior tibiofibular ligament
(2) posterior tibiofibular ligament
(3) interosseous membrane
200
what accessory motion occurs at the proximal tibiofibular joint?
superior fibular glide with dorsiflexion (crural) and pronation (subtalar)
201
what accessory motion occurs at the distal tibiofibular joint?
gapping between the distal tibia and fibula with dorsiflexion
202
how many planes of motion does the talocrural joint move in? what is the main degree of freedom the talocrural joint is responsible for?
(1) 3 (triplanar joint)
| (2) sagittal plane: dorsiflexion / plantarflexion
203
when is the congruency (stability) of the talus greatest? why?
(1) dorsiflexion
| (2) talus fits into ankle mortise
204
what accessory movement occurs at the talocrural joint with dorsiflexion in an OPEN CHAIN?
(1) CONVEX talus moving on CONCAVE tibia
| (2) posterior glide
205
what accessory movement occurs at the talocrural joint with plantarflexion in OPEN CHAIN?
(1) CONVEX talus moving on CONCAVE tibia
| (2) anterior glide
206
what active and passive structures limit dorsiflexion? (3)
```
Knee Extended
(1) triceps surae
Knee Flexed
(1) soleus
(2) posterior capsule and ligaments
```
207
what active and passive structures limit plantarflexion? (2)
(1) dorsiflexors
| (2) anterior capsule and ligaments
208
what structural and functional problems may limit dorsiflexion?
(1) osteophytes on the dorsal talus or anterior distal tibia
| (2) tight intrinsic muscles of foot or tight plantar fascia
209
what side of the ankle has stronger passive structures? which has weaker?
(1) lateral side of the ankle has weaker ligaments
| (2) medial side has stronger ligaments
210
what are the most commonly injured ligaments of the ankle?
(1) ATFL (most commonly injured)
(2) calcaneofibular (2nd most most commonly injured)
(3) PTFL
211
what are the two main functions of the retinacula of the foot and ankle?
(1) pulley system for muscles
| (2) proprioception for joint protection
212
what motion is the subtalar joint primarily responsible for providing?
pronation and supination (triplanar motion occurs at this joint)
213
what direction are the roll and glide with pronation and supination of the subtalar joint in an OPEN chain?
talus and calcaneus move in the SAME direction with pronation and supination
214
what direction are the roll and glide with pronation and supination of the subtalar joint in a CLOSED chain?
OPPOSITE directions
(1) pronation: talus moves medially, while calcaneus glides laterally
(2) supination: talus moves laterally, while calcaneus glides medially
215
***internal rotation of a weight bearing leg causes what at the subtalar joint?***
pronation (pronation at subtalar joint also causes IR of the leg)
216
***external rotation of a weight bearing leg causes what at the subtalar joint?***
supination (supination at subtalar joint also causes ER of the leg)
217
in a closed chain, where does frontal and transverse plane movement come from at the subtalar joint?
(1) frontal: movement of calcaneus
| (2) transverse: movement of talus
218
what motions occur with pronation in a CLOSED chain? (4)
(1) eversion of the calcaneus
(2) plantarflexion of the talus
(3) adduction of the talus
(4) IR of the leg
219
going up the kinetic chain, what does over pronation cause?
(1) internal rotation of the leg (and adduction at the knee)
(2) causing an anterior pelvic tilt
(3) causing extension of the ipsilateral lumbar spine
220
what motions occur with supination in a CLOSED chain? (4)
(1) inversion of the calcaneus
(2) dorsiflexion of the talus
(3) abduction of the talus
(4) ER of the leg
221
what motions occur with pronation in an OPEN chain? (5)
(1) eversion of the calcaneus
(2) dorsiflexion of the calcaneus
(3) abduction of the calcaneus
(4) abduction of the talus
(5) dorsiflexion of the talus
222
what motions occur with supination in an OPEN chain? (5)
(1) inversion of the calcaneus
(2) plantarflexion of the calcaneus
(3) adduction of the calcaneus
(4) adduction of the talus
(5) plantarflexion of the talus
223
what two joints make up the midtarsal joint?
(1) talonavicular
| (2) calcaneocuboid
224
which joint of the two midtarsal joint allows more motion?
talonavicular joint
225
what causes cuboid syndrome? what are symptoms of this syndrome?
(1) forceful eversion of the cuboid while the calcaneus is inverted
(2) pain during push-off of gait
226
what ligaments protect the talonavicular joint? (4)
(1) inferior: spring ligament
(2) medial: deltoid
(3) superior: bifurcate ligament
(4) superior: talonavicular ligament
227
which bone is concave and which bone is convex at the talonavicular joint?
(1) convex: talus
| (2) concave: navicular
228
what are the 2 main functions of the midtarsal joint?
(1) add to the ROM at the subtalar joint (OKC)
| 2) compensate the forefoot for hindfoot positioning in a CKC (pronate or supinate
229
***when pronation occurs at the subtalar joint, how can the midtarsal joint compensate?***
it can either pronate OR supinate
230
***when supination occurs at the subtalar joint, how can the midtarsal joint compensate?***
supination, NOT pronation (limited ability for midtarsal joint to pronate when subtalar joint supinates)
231
what is a Lisfranc injury?
(1) fracture to base of the 2nd metatarsal
| (2) ligament between 1st cuniform and 2nd metatarsal
232
what ligament provides stability and prevents excessive splaying of the metatarsal heads?
deep transverse metatarsal ligament
233
which rays of the foot does triplanar motion occur?
1st and 5th (more motion on the medial and lateral sides of the foot)
234
which ray of the foot has the least amount of motion?
2nd
235
what are some main functions of the tarsometatarsal joint?
(1) hollow and flatten the foot
(2) augments midtarsal joint function
(3) provides pronation and supination when hindfoot and midfoot are at end range
236
how do you lock the foot?
with the toes in full extension
237
***when the foot is locked (toes fully extended), all ankle joints are locked except which one?***
the talocrural joint
238
with extreme subtalar pronation, what occurs at the forefoot?
supination at the forefoot
239
with extreme subtalar supination, what occurs at the forefoot?
pronation at the forefoot
240
what is a high longitudinal foot arch associated with?
supination
241
what is a low longitudinal foot arch associated with?
pronation
242
what is the concave/convex rule at metatarsophalangeal joint in an OPEN chain?
concave phalange moving on a convex metatarsal (roll and glide the same)
243
what is the concave/convex rule at metatarsophalangeal joint in a CLOSED chain?
convex metatarsal moving on a concave phalange
| roll and glide opposite
244
what are 2 functions of the two sesamoid bones on the bottom of the 1st metatrasophalange?
(1) serve as pulley for the flexor hallucis brevis
| (2) protect the tendons of the flexor hallucis longus
245
what is turf toe and how is it caused?
(1) sprain of the ligaments of the big toe
| (2) caused by forced hyperextension of the big toe
246
what is the keystone of the longitudinal arches of the foot?
talus
247
what is the keystone of the transverse arch of the foot?
intermediate cuneiform
248
when do the arches of the foot start to develop?
when a child starts weight bearing (walking)
249
what are 3 structures that provide passive support to the arches of the feet? (3)
(1) spring ligament
(2) interosseous talocalcaneal ligament
(3) plantar aponeurosis
250
what are the two main functions of the arches of the foot? how are these functions accomplished?
(1) mobility
(a) dampen impact forces
(b) dampen rotational forces
(c) adapt to changes of ground surfaces
(2) stability
(a) distribute weight through the foot
(b) convert flexible foot to rigid level during gait
251
what motion causes the plantar aponeurosis to tighten?
MTP extension
252
what percentage of the weight of the body passes through the talus in standing?
(1) 50% through each each talus in bilateral standing
| (2) 100% in unilateral standing
253
how is weight distributed through the joints of the foot in standing?
(1) 50% of the weight falls posterior to subtalar joint to calcaneus
(2) 50% falls anterior through the talonavicular and calcaneocuboid joints
254
what structure helps with shock absorption at the heel during gait and running?
heel fat pad
255
why does wearing open heel shoes reduce the ability of the heel pad to absorb shock?
open heel shoes allow the fat pad to spread out more to the sides of the heel
256
***what can said be about the intrinsic muscle support of the arches of the foot during walking and running?***
intrinsic foot muscles aren't very active during walking or standing; they're much more active during running
257
what muscles support the medial arch of the foot? (3)
(1) tibialis posterior
(2) flexor digitorum longus
(3) flexor hallucis longus
258
what muscles support the lateral and transverse arches of the foot? (1)
(1) peroneus longus
259
muscles passing medial to the subtalar joint cause what motion at the ankle? what about muscles passing lateral to the subtalar joint?
(1) medial: supination
| (2) lateral: pronation
260
what muscles of the ankle control pronation at the foot?
supinators (tibialis posterior); medial muscles eccentrically control pronation
261
what are the strongest muscles of the foot and ankle? which are the weakest?
(1) plantarflexors (strongest)
(2) dorsiflexors
(3) supinators
(4) pronators (weakest)
262
how does the triceps surae help lock the foot into a rigid lever?
the Achilles tendon passes medial to the subtalar joint, supinating the foot and locking it during weight bearing activities
263
what percentage of plantarflexion is the triceps surae responsible for?
95%
264
what muscles are important for balance and eccentrically controlling MTP extension? (2)
(1) flexor hallucis longus
| (2) flexor digitorum longus
265
***what arches does the peroneus longus tendon support?***
(1) lateral arch
| (2) transverse arch
266
what is the key supinator of the foot?
anterior tibialis
267
what type of lever is the gastroc?
type 2 (resistance in the middle)
268
what muscles stabilize the MTP joints and extend the IP joints?
(1) lumbricals
(2) dorsal interossei
(3) plantar interossei
269
what is pes cavus? how is the shock absorption with pes cavus?
(1) foot is more supinated (subtalar and transverse tarsal joints)
(2) poor shock absorption; foot is locked and inflexible
270
what is pes planus? how is the shock absorption with pes cavus?
(1) foot is more pronated (subtalar and transverse tarsal joints)
(2) better shock absorption than pes cavus; foot is overly mobile
271
can insoles help correct pes cavus or pes planus?
pes planus; it does so by increasing supination of the foot
272
generally speaking, what structures are the main stabilizers of the arches of the foot?
passive structures (bones and ligaments); muscles play a smaller role
