Knee joint Flashcards
joint structure and motions
- flexion and extension with accessory rotation
- screw-home mechanism
- allows for locking of the knee joint - open-chain knee extension
- tibia rotates laterally on the femur - closed-chain knee extension
- femur rotates medially on the tibia
- screw-home mechanism
open chain
knee flexion while standing
closed chain
squat
ligaments and other structures
- anterior and posterior cruciate ligaments
- medial and lateral collateral ligaments
- medial and lateral meniscus
- bursae of the knee
- popliteal space
- pes anserine muscle group
Anterior muscles of the knee
rectus femoris
vastus lateralis
vastus medialis
vastus intermedialis
Rectus Femoris
O-AIIS
I-tibial tuberosity via patellar tendon
A- hip flexion, knee extension
N-femoral nerve (L2,3,4)
Vastus Lateralis muscle
O-linea aspera
I- tibial tuberosity via patellar tendon
A- Knee extension
N-Femoral nerve (L2,3,4)
Vastus Medialis muscle
O-linea aspera
I-tibial tuberosity via patellar tendon
A-knee extension
N-femoral nerve (L2,3,4)
Vastus intermedialis muscle
O- anterior femur
I-tibial tuberosity
A-knee extension
N-femoral nerve (L2,3,4)
Posterior muscles of the knee
Semimembranosus Semitendinosus Biceps Femoris Popliteus Gastrocnemius Tensor fascia latae Gracilis Sartorius
Semimembranosus Muscle
O- ischial tuberosity
I-posterior surface of medial condyle of tibia
A- extend hip and flex knee
N-sciatic nerve (L5,S1,S2)
Semitendinosus muscle
O-ischial tuberosity
I-anteromedial surface of proximal tibia
A-extend hip and flex knee
N-sciatic nerve (L5,S1,S2)
Biceps femoris muscle
O- Long head: ischial tuberosity short head: lateral lip of linea aspera I- fibular head A- long head: extend hip and flex knee Short head: flex knee N- long head: sciatic nerve (S1,2,3) Short head: common perineal nerve (L5,S1,S2)
Popliteus muscle
O-lateral condyle of femur
I-posterior medial condyle of tibia
A-initiates knee flexion
N-tibial nerve (L4,L5,S1)
Gastrocnemius muscle
O-medial and lateral condyles of femur
I- posterior calcaneus
A-knee flexion, ankle plantar flexion
N-tibial nerve (S1,2)
Common knee pathologies
Genu valgum- knock knees
Genu varum- bow legged
Genu recurvatum- “back knees” (knees hyperextend posteriorly)
Patellar tendonitis- jumper’s knee, tenderness at the patellar tendon and results from overuse stress or sudden impact overloading associated with jumping
Osgood-Schlatter disease-common overuse injury among growing adolescents
Baker’s cyst- popliteal cyst, refers to any synovial hernia or bursitis involving the posterior aspect of the knee
More common knee pathologies
Patellofemoral pain syndrome
Chondromalacia patella- softening and degeneration of the cartilage on the posterior aspect of the patella, causing anterior knee pain
Prepatellar bursitis- housemaid’s knee, occurs when there is constant pressure between the skin and the patella
Terrible triad- knee injury caused by a single blow to the knee and involves tears to the anterior cruciate ligament, medial collateral ligament, and the medial meniscus
Miserable malalignment syndrome
SGT
sartorius (most anterior), gracillis, semitendinosus (most posterior)
the hamstrings ar innervated by what nerve
sciatic
the hamstrings ar innervated by what nerve
sciatic
which ligament prevents the tibia from sliding too far forward (prevents anterior translation, PCL prevents posterior translation)
anterior cruciate ligament (ACL)
a painful fluid filled mass on posterior knee is most likely what condition?
Baker’s cyst
what is the distal attachment of the patellar tendon
tibial tuberosity
femoral trochlea is also known as
patellar surface
