Kinesiology Final Exam
What might be the significance of a hip dislocation on the health of the femoral head?
A hip dislocation may cause death of the femur bone of the hip due to avascular necrosis (not getting enough blood supply to the femoral head)
Describe the amount of load the healthy hip is able to withstand. What are the joint reaction forces at the hip with unilateral standing, ascending stairs, and running?
A normal healthy hip can tolerate 12 to 15 times body weight. Unilateral standing is 2 to 5 times body weight Ascending stairs is 3 times body weight Running is 5 times body weight
What ligament prevents anterior translation of the tibia on the femur?
ACL
Describe the role of the following ligaments: ACL, PCL, MCL, LCL
ACL: primarily resistant to anterior translation of the tibia on the femur PCL: resists posterior translation of the tibia on the femur MCL: resists valgus forces LCL: resists varus forces
When the hip is flexed at 90 degrees, the arthrokinematics change:
Abduction- anterior Adduction- posterior internal- inferior external- superior
What ligaments support the lateral ankle?
Answer: Anterior talofibular ligament, posterior talofibular, calcaneofibular
What are the actions of the muscles in the deep compartment of the lower leg on the ankle? A. Dorsiflex and evert the foot B. Dorsiflex and invert the foot C. Plantarflex and invert the foot D. Plantarflex and evert the foot
Answer: C Specific muscles: (flexor halicus longus, flexor digitorium longus, tibialis posterior)
Injury to the superficial peroneal nerve would result in what dysfunction? A. Inability to dorsiflex the ankle B. Inability to plantar the ankle C. Inability to invert the ankle D. Inability to evert the ankle
Answer: D Specific muscles: peroneus longus and brevis
The screw-home mechanism of the knee includes what motions at the knee?
Answer: Extension and external rotation
What effect does having an increased Q-angle have on the knee?
Answer: Knocked kneed appearance (valgus motion at the knee) Femoral adductors and internal rotation cause it; therefore, abductors and external rotators are weak
An athlete wearing cleats plants his foot to turn and change direction. While his foot remains planted, his femur moves into adduction and internal rotation. What structure(s) is/are being stressed in this scenario?
Answer: MCL, ACL, meniscus
Which ligament works to prevent posterior translation of the tibia on the femur?
Answer: PCL
Which muscle can cause internal rotation of the tibia while sitting at the edge of a table?
Answer: Popliteus (pops out of the locking out position [screw home mechanism]), semimembranosus, and semitendinosus
What muscles dynamically support the arch structure?
Answer: Posterior tibialis
Which ligament works to dynamically stabilize the knee by preventing anterior translation of the tibia on the femur/posterior translation of the femur on the tibia.
Answer: anterior cruciate ligament (ACL)
During the down phase of a back squat, what is the arthrokinematics of the hip joint?
Answer: concave (acetabulum) on convex (femur); closed chain movement; Rolls and glides in the same direction; anterior roll, anterior glide
the angle of inclination of the neck of the femur and its shaft: a value of ____ to ____ degrees is a normal angle for adults.
120 to 125
Normal angle of torsion ranges between __ and ___ degrees for the hip.
8 and 12
Limitation of what arthrokinematics motion at the talocrural joint would prevent someone from descending into a deep squat (hint: closed chain)
Answer: concave distal tibia and fibula moving on a convex talus; rolls and glides in opposite direction (anterior roll; posterior glide)
What malalignments at the foot may lead to excessive stress on the MCL?
Answer: foot pronation/collapsed arch
Weakness in which muscle could result in the patella riding laterally in the trochlear grove?
Answer: vastus medialis (tightness would be vastus lateralis)
What ligaments help form the deltoid ligament complex (anterior)?
Anterior talotibial, calcaneotibial, posterior talotibial, tibionavicular *prevents eversion/pronation of the foot
How might excessive femoral anteversion cause problems up and down the kinetic chain?
Anteversion looks like the feet are rotated inwards (pigeon toed); anteversion is when the angle of torsion at the femur is greater than the normal 8-12 degrees. People with an angle of torsion greater than 12 degrees will have an anteverted hip and will compensate in their stance with an inwardly rotated lower limb
What is the influence of the hip and foot/ankle on knee injury?
If the hip has a greater Q-angle it predisposes someone to an ACL tear
What is the significance of patellar malalignment?
If the patella is misaligned, it will not perform its function of protecting the knee ligaments and cause pain. It occurs when the patella is not centered within the trochlear grove due to outside forces
Describe the 3 main hip ligaments and what motions they prevent.
Iliofemoral ligament (wide ligament)—prevents hyperextension of the hip, helps stability in normal standing position Pubofemoral ligament—prevents excessive abduction of the hip Ischiofemoral ligament—prevents excessive extension of the hip
What is the role of the IT band? What are its proximal origins? What are its distal insertion sites? (there are several) How can we influence its mobility?
Iliotibial (IT) Band—thick band of fascia. Attaches proximally at the glutes and tensor fascia latae Attaches distally at Gerdy's tubercle, lateral retinaculum, and the patella Mobility is influenced by stretching the TFL and gluteus maximus
What are the actions of each muscle at the knee?
Knee extensors are the four quadricep muscles: vastus lateralis, rectus femoris, vastus intermedius, vastus medialis Knee flexors are hamstring muscles: biceps femoris, semimembranosus, semitendinosus Gastrocnemius pulls on the femur to induce knee flexion
How does the shape of the femoral condyles and tibial plateaus influence motion at the tibiofemoral joint?
Lateral tibial is convex compared to the concave medial plateau with increased congruity with its femoral condyle, which leads to more translational motion at the lateral side of the knee.
What are the differences in shape of the medial and lateral meniscus?
Medial is more C shaped, Lateral is more O shaped
What is the keystone of the medial longitudinal arch? Lateral longitudinal arch?
Medial longitudinal arch: Navicular bone (landmark for measurement of arch height) Lateral longitudinal arch: Cuboid
How does Q-angle effect the anterior knee?
Q-angle is the lateral line of pull of the quads to the patella. A larger Q-angle is thought to create a larger lateral vector and potential lateral tracking. A normal Q-angle is 10-15 degrees. Women generally have higher Q-angles
Arthrokinematics (OPEN chain)- Hip:
Sagittal: flexion, extension Frontal: abduction, adduction Transverse: internal/external rotation
Describe the mechanical advantage the patella provides the knee extensors.
The patella increases the perpendicular moment arm of the quadriceps to give more of a mechanical advantage.
What soft tissue structures support the arch? (muscles, ligaments, and fascia)
The plantar fascia, short and long plantar ligaments, and spring ligament are the passive structures that support the medial longitudinal arch Muscles that dynamically support arch structure: tibialis posterior muscles, tibialis anterior
What is the significance of the trochlear groove/femoral sulcus in patellofemoral stability?
The trochlear grove and femoral sulcus provide a notch for the patella to rest in and the patella is then held in place by the patellar ligaments. If the trochlear grove or femoral sulcus is too shallow, then the person is at a higher risk for patellar dislocation.
What portion of the meniscus is vascular?
Three zones of the meniscus: red zone, very vascular; pink zone, very little vascular supply; white zone, avascular
What foot position increases knee valgus (knock kneed)?
Toe in position
The acetabulum faces what directions?
anterior, lateral, and inferior
Hip joint ______ femoral head and _____ femur
convex, concave
Joint Ftn. of the Hip: _____ femoral head on _____ acetabulum
convex, concave
angle of inclination of the neck of the femur and its shaft: a value > 125 degrees is termed ______ _______.
coxa valga
Angle of inclination o the neck of the femur and its shaft: a value < 120 degrees is termed _____ ____.
coxa vara
What bone is the keystone of the lateral longitudinal arch?
cuboid
Disc nutrition is achieved primarily via
diffusion
the proximal part of the femur is the _____ _____, which projects superiorly, medially, and anteriorly to the articulate of the acetabulum.
femoral head
The labrum of the hip is made of?
fibrocartilage
What artery provides nutrition to that portion of the meniscus?
genicular artery
What are considered the gluteal muscles? What primary nerve innervates the muscles? What action do these muscles perform?
gluteus minimus, medius, maximus and tensor fasciae latae superior and inferior gluteal nerves Abduct the hip
What are the muscles of the medial thigh? What primary nerve innervates the muscles? What action do these muscles perform?
gracilis, adductor longus, adductor brevis, adductor magnus obturator nerve Adduct the hip
When standing, an athlete presents with an excessive posterior tilt of the pelvis. Passive insufficiency (muscle tightness) in which of the following muscles could contribute to this?
hamstrings
The ligament teres can be injured by trauma to the hip such as ______. This type of injury can lead to what?
hip dislocation avascular necrosis of the femoral head
what three bones form the pelvis?
ilium, ischium, pubis
The fibrocartilage of the labrum allows for _______ in the articular surface of the acetabulum by 10%, allowing the acetabulum to hold more than 1/2 the head of the femur, thus providing stability to the joint.
increases
People with an angle of torsion greater than 12 degrees have an anteverted hip and will compensate in their stance with an
inwardly rotated lower limb
The ligament of the head of the femur is the _________.
ligamentum teres
the rim of the acetabulum makes a horseshoe and the gap at the bottom allows the artery in the ___________ ______ to pass through.
ligamentum teres
What is the keystone of the medial longitudinal arch?
navicular bone
When a convex surface moves on a concave surface, rolls and glides
occur in opposite directions
What are the muscles of the lateral thigh? What primary nerve innervates the muscles? What action do these muscles perform?
piriformis, superior gemellus, obturator inernus, inferior gemellus, obturator externus, quadratus femoris Sacral plexus Externally rotate the hip
What are the muscles of the anterior thigh? What primary nerve innervates the muscles? What action do these muscles perform?
psoas, iliacus, rectus femoris, sartorius, pectineus Femoral nerve Hip flexion
What are the muscles of the posterior thigh? What primary nerve innervates the muscles? What action do these muscles perform?
semimembranosus, semitendinosus, biceps femoris Sciatic nerve Extend the hip
Hip joint articulation
synovial, ball and socket joint
IT band proximal and distal attachment
thick band of fascia Attaches proximally at the flutes and TFLAttaches distally at Gerdy's tubercle, lateral retinaculum, and the patella
Joint Function of the Hip:
-3 degrees of freedom-tight fit socket to limit translation (significant)-axis in center of femoral head
Nerve supply to the hip
-Sciatic-Superior and Inferior Gluteal-Femoral-Obturator
What is the end feels with various hip motions?
End feel: flexion/adduction is soft, other motions is firm
According to the convex-concave rules, a convex surface will roll and glide in the same direction
FALSE
What is the significance of the shape of the intercondylar notch and injury rates to the knee?
Femoral condyles: A-shaped (triangular) intercondylar notch possibly predisposes athlete to higher rates of ACL disruption; Normal is inverted U-shaped Tibial plateaus: a flatter or convex lateral tibial plateau increases poorer recovery when an injury occurs at the medial meniscus. Because of the convexity of the lateral tibial plateau, any loss of meniscal tissue will substantially increase the compressive forces on the lateral side.
Arthrokinematics (CLOSED chain)- Hip
Flexion- pelvis glides anterior Extension- posterior abduction- superior adduction- inferior IR- anterior ER- posterior
Joint Ftn. of the Hip: Osteokinematic motions?
Flexion/Extension Abduction/Adduction Internal/External Rotation
What is the acetabular labrum? How does it affect hip stability? What happens when it is damaged?
Function of the labrum: provides a suction seal for the hip joint adding stability to the joint. If the labrum is damaged, it influences the hips ROM, alignment, and synovial fluid.
Describe the difference between genu valgum and genu varum. Which side of the joint would have greater amounts of pressure with each of these anatomical positions?
Genu valgum: excessive lateral loading; knock kneed position. Increased pressure on the lateral side of the joint Genu varum: excessive medial loading; bowlegs. Increased pressure on the medial side of the joint
If an athlete is standing with an anterior tilt of the hip, what muscles might be passively insufficient?
Hip flexors
What is the role of the meniscus of the knee?
Menisci are cartilaginous wedge-shaped discs, and their function is to provide stability, distribute the load, absorb shock, and provide lubrication and nutrition to the knee joint.
Where do most of the stresses occur on the acetabulum?
On the labrum
What is the open and closed pack position of the hip?
Open packed: 30 degrees of flexion, 30 degrees of abduction, slight external rotation. Most slack position allowing for more joint movement Closed packed positions: 20 degrees of hip extension with slight internal rotation and abduction. Most capsular tension, ligamentous tension, and bony contact
The inability to flex the knee past 120 degrees because of tight quads is an example of ________.
Passive insufficiency
What nerves innervate the following lower leg compartments: Posterior deep, posterior superficial, anterior, and lateral?
Posterior deep: deep fibular nerve, tibial nerve Posterior superficial: posterior tibial, sural nerve Anterior: anterior tibial, superficial peroneal nerve, deep peroneal nerve, saphenous Lateral: small saphenous
What three extrinsic muscles support the arch?
Posterior tibialis Hallucis longus Flexor digatorium longus
What are the lateral ankle ligaments?
Posterior tibiofibular, posterior talofibular, calcaneofibular, anterior talofibular, anterior tibiofibular *prevents inversion/supination of the foot
What motions make up open and closed chain pronation (ankle turning inward) and supination (ankle turning outward)?
Pronation: calcaneus everts, talus plantarflexes and adducts, tibia rotates internally, knee flexes Supination: calcaneus inverts, talus dorsiflexes and abducts, tibia rotates externally, knee extends Open chain: The talus is fixed so that the mobile forefoot dorsiflexes and abducts. Closed chain: The talus is mobile while the forefoot is fixed by its contact with the ground. The mobile talus plantar flexes and adducts (its anterior part tips inferiorly and medially)
Describe the screw home mechanism of the knee in open and closed chain.
Screw home mechanism is when your knee is fully extended or locked out and your foot externally rotates. This is due to the femoral condyle shapes where the lateral side stops moving while the medial side keeps moving. Open Chain: with knee extension, lateral rotation occurs. With knee flexion, unlocking occurs via medial rotation. Done by the tibia Closed chain: Done by the femur
The range of external and internal rotation at the hip is largely determined by the angle of torsion.
TRUE
What are the open and closed chain arthrokinematics at the talocrural joint?
Talar bone is convex. Tibiofibular complex is concave. Open chain: Convex on concave; rolls and glides opposite During plantar flexion, talus rolls posteriorly and glides anteriorly on tibiofibular surface. During dorsiflexion, talus rolls anteriorly and glides posteriorly on tibiofibular surface. Closed chain: Concave on convex; rolls and glides same direction During plantar flexion, tibiofibular surface rolls and glides posteriorly During dorsiflexion, tibiofibular surface rolls and glides anteriorly
The tendons of what muscles insert at the pes anserine area?
The insertion of the sartorius, gracilis, and semitendinosus muscles; they are located superficial to the MCL of the knee
The concavity formed by the three pelvic bones is called the _____ and is crucial for _____ _____.
acetabulum weight bearing
